Source Level Debugging with LLVM¶
Introduction¶
This document is the central repository for all information pertaining to debug information in LLVM. It describes the actual format that the LLVM debug information takes, which is useful for those interested in creating front-ends or dealing directly with the information. Further, this document provides specific examples of what debug information for C/C++ looks like.
Philosophy behind LLVM debugging information¶
The idea of the LLVM debugging information is to capture how the important pieces of the source-language’s Abstract Syntax Tree map onto LLVM code. Several design aspects have shaped the solution that appears here. The important ones are:
- Debugging information should have very little impact on the rest of the compiler. No transformations, analyses, or code generators should need to be modified because of debugging information.
- LLVM optimizations should interact in well-defined and easily described ways with the debugging information.
- Because LLVM is designed to support arbitrary programming languages, LLVM-to-LLVM tools should not need to know anything about the semantics of the source-level-language.
- Source-level languages are often widely different from one another. LLVM should not put any restrictions of the flavor of the source-language, and the debugging information should work with any language.
- With code generator support, it should be possible to use an LLVM compiler to compile a program to native machine code and standard debugging formats. This allows compatibility with traditional machine-code level debuggers, like GDB or DBX.
The approach used by the LLVM implementation is to use a small set of intrinsic functions to define a mapping between LLVM program objects and the source-level objects. The description of the source-level program is maintained in LLVM metadata in an implementation-defined format (the C/C++ front-end currently uses working draft 7 of the DWARF 3 standard).
When a program is being debugged, a debugger interacts with the user and turns the stored debug information into source-language specific information. As such, a debugger must be aware of the source-language, and is thus tied to a specific language or family of languages.
Debug information consumers¶
The role of debug information is to provide meta information normally stripped away during the compilation process. This meta information provides an LLVM user a relationship between generated code and the original program source code.
Currently, there are two backend consumers of debug info: DwarfDebug and CodeViewDebug. DwarfDebug produces DWARF suitable for use with GDB, LLDB, and other DWARF-based debuggers. CodeViewDebug produces CodeView, the Microsoft debug info format, which is usable with Microsoft debuggers such as Visual Studio and WinDBG. LLVM’s debug information format is mostly derived from and inspired by DWARF, but it is feasible to translate into other target debug info formats such as STABS.
It would also be reasonable to use debug information to feed profiling tools for analysis of generated code, or, tools for reconstructing the original source from generated code.
Debugging optimized code¶
An extremely high priority of LLVM debugging information is to make it interact well with optimizations and analysis. In particular, the LLVM debug information provides the following guarantees:
- LLVM debug information always provides information to accurately read the source-level state of the program, regardless of which LLVM optimizations have been run, and without any modification to the optimizations themselves. However, some optimizations may impact the ability to modify the current state of the program with a debugger, such as setting program variables, or calling functions that have been deleted.
- As desired, LLVM optimizations can be upgraded to be aware of debugging information, allowing them to update the debugging information as they perform aggressive optimizations. This means that, with effort, the LLVM optimizers could optimize debug code just as well as non-debug code.
- LLVM debug information does not prevent optimizations from happening (for example inlining, basic block reordering/merging/cleanup, tail duplication, etc).
- LLVM debug information is automatically optimized along with the rest of the program, using existing facilities. For example, duplicate information is automatically merged by the linker, and unused information is automatically removed.
Basically, the debug information allows you to compile a program with
“-O0 -g
” and get full debug information, allowing you to arbitrarily modify
the program as it executes from a debugger. Compiling a program with
“-O3 -g
” gives you full debug information that is always available and
accurate for reading (e.g., you get accurate stack traces despite tail call
elimination and inlining), but you might lose the ability to modify the program
and call functions which were optimized out of the program, or inlined away
completely.
The LLVM test suite provides a framework to test optimizer’s handling of debugging information. It can be run like this:
% cd llvm/projects/test-suite/MultiSource/Benchmarks # or some other level
% make TEST=dbgopt
This will test impact of debugging information on optimization passes. If debugging information influences optimization passes then it will be reported as a failure. See LLVM Testing Infrastructure Guide for more information on LLVM test infrastructure and how to run various tests.
Debugging information format¶
LLVM debugging information has been carefully designed to make it possible for the optimizer to optimize the program and debugging information without necessarily having to know anything about debugging information. In particular, the use of metadata avoids duplicated debugging information from the beginning, and the global dead code elimination pass automatically deletes debugging information for a function if it decides to delete the function.
To do this, most of the debugging information (descriptors for types, variables, functions, source files, etc) is inserted by the language front-end in the form of LLVM metadata.
Debug information is designed to be agnostic about the target debugger and debugging information representation (e.g. DWARF/Stabs/etc). It uses a generic pass to decode the information that represents variables, types, functions, namespaces, etc: this allows for arbitrary source-language semantics and type-systems to be used, as long as there is a module written for the target debugger to interpret the information.
To provide basic functionality, the LLVM debugger does have to make some assumptions about the source-level language being debugged, though it keeps these to a minimum. The only common features that the LLVM debugger assumes exist are source files, and program objects. These abstract objects are used by a debugger to form stack traces, show information about local variables, etc.
This section of the documentation first describes the representation aspects common to any source-language. C/C++ front-end specific debug information describes the data layout conventions used by the C and C++ front-ends.
Debug information descriptors are specialized metadata nodes, first-class subclasses of Metadata
.
Debugger intrinsic functions¶
LLVM uses several intrinsic functions (name prefixed with “llvm.dbg
”) to
track source local variables through optimization and code generation.
llvm.dbg.addr
¶
void @llvm.dbg.addr(metadata, metadata, metadata)
This intrinsic provides information about a local element (e.g., variable). The first argument is metadata holding the address of variable, typically a static alloca in the function entry block. The second argument is a local variable containing a description of the variable. The third argument is a complex expression. An llvm.dbg.addr intrinsic describes the address of a source variable.
%i.addr = alloca i32, align 4
call void @llvm.dbg.addr(metadata i32* %i.addr, metadata !1,
metadata !DIExpression()), !dbg !2
!1 = !DILocalVariable(name: "i", ...) ; int i
!2 = !DILocation(...)
...
%buffer = alloca [256 x i8], align 8
; The address of i is buffer+64.
call void @llvm.dbg.addr(metadata [256 x i8]* %buffer, metadata !3,
metadata !DIExpression(DW_OP_plus, 64)), !dbg !4
!3 = !DILocalVariable(name: "i", ...) ; int i
!4 = !DILocation(...)
A frontend should generate exactly one call to llvm.dbg.addr
at the point
of declaration of a source variable. Optimization passes that fully promote the
variable from memory to SSA values will replace this call with possibly
multiple calls to llvm.dbg.value. Passes that delete stores are effectively
partial promotion, and they will insert a mix of calls to llvm.dbg.value
and llvm.dbg.addr
to track the source variable value when it is available.
After optimization, there may be multiple calls to llvm.dbg.addr
describing
the program points where the variables lives in memory. All calls for the same
concrete source variable must agree on the memory location.
llvm.dbg.declare
¶
void @llvm.dbg.declare(metadata, metadata, metadata)
This intrinsic is identical to llvm.dbg.addr, except that there can only be
one call to llvm.dbg.declare for a given concrete local variable. It is not control-dependent, meaning that if
a call to llvm.dbg.declare exists and has a valid location argument, that
address is considered to be the true home of the variable across its entire
lifetime. This makes it hard for optimizations to preserve accurate debug info
in the presence of llvm.dbg.declare
, so we are transitioning away from it,
and we plan to deprecate it in future LLVM releases.
llvm.dbg.value
¶
void @llvm.dbg.value(metadata, metadata, metadata)
This intrinsic provides information when a user source variable is set to a new value. The first argument is the new value (wrapped as metadata). The second argument is a local variable containing a description of the variable. The third argument is a complex expression.
Object lifetimes and scoping¶
In many languages, the local variables in functions can have their lifetimes or scopes limited to a subset of a function. In the C family of languages, for example, variables are only live (readable and writable) within the source block that they are defined in. In functional languages, values are only readable after they have been defined. Though this is a very obvious concept, it is non-trivial to model in LLVM, because it has no notion of scoping in this sense, and does not want to be tied to a language’s scoping rules.
In order to handle this, the LLVM debug format uses the metadata attached to llvm instructions to encode line number and scoping information. Consider the following C fragment, for example:
1. void foo() {
2. int X = 21;
3. int Y = 22;
4. {
5. int Z = 23;
6. Z = X;
7. }
8. X = Y;
9. }
Compiled to LLVM, this function would be represented like this:
; Function Attrs: nounwind ssp uwtable
define void @foo() #0 !dbg !4 {
entry:
%X = alloca i32, align 4
%Y = alloca i32, align 4
%Z = alloca i32, align 4
call void @llvm.dbg.declare(metadata i32* %X, metadata !11, metadata !13), !dbg !14
store i32 21, i32* %X, align 4, !dbg !14
call void @llvm.dbg.declare(metadata i32* %Y, metadata !15, metadata !13), !dbg !16
store i32 22, i32* %Y, align 4, !dbg !16
call void @llvm.dbg.declare(metadata i32* %Z, metadata !17, metadata !13), !dbg !19
store i32 23, i32* %Z, align 4, !dbg !19
%0 = load i32, i32* %X, align 4, !dbg !20
store i32 %0, i32* %Z, align 4, !dbg !21
%1 = load i32, i32* %Y, align 4, !dbg !22
store i32 %1, i32* %X, align 4, !dbg !23
ret void, !dbg !24
}
; Function Attrs: nounwind readnone
declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
attributes #0 = { nounwind ssp uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { nounwind readnone }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!7, !8, !9}
!llvm.ident = !{!10}
!0 = !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.7.0 (trunk 231150) (llvm/trunk 231154)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
!1 = !DIFile(filename: "/dev/stdin", directory: "/Users/dexonsmith/data/llvm/debug-info")
!2 = !{}
!3 = !{!4}
!4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, variables: !2)
!5 = !DISubroutineType(types: !6)
!6 = !{null}
!7 = !{i32 2, !"Dwarf Version", i32 2}
!8 = !{i32 2, !"Debug Info Version", i32 3}
!9 = !{i32 1, !"PIC Level", i32 2}
!10 = !{!"clang version 3.7.0 (trunk 231150) (llvm/trunk 231154)"}
!11 = !DILocalVariable(name: "X", scope: !4, file: !1, line: 2, type: !12)
!12 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
!13 = !DIExpression()
!14 = !DILocation(line: 2, column: 9, scope: !4)
!15 = !DILocalVariable(name: "Y", scope: !4, file: !1, line: 3, type: !12)
!16 = !DILocation(line: 3, column: 9, scope: !4)
!17 = !DILocalVariable(name: "Z", scope: !18, file: !1, line: 5, type: !12)
!18 = distinct !DILexicalBlock(scope: !4, file: !1, line: 4, column: 5)
!19 = !DILocation(line: 5, column: 11, scope: !18)
!20 = !DILocation(line: 6, column: 11, scope: !18)
!21 = !DILocation(line: 6, column: 9, scope: !18)
!22 = !DILocation(line: 8, column: 9, scope: !4)
!23 = !DILocation(line: 8, column: 7, scope: !4)
!24 = !DILocation(line: 9, column: 3, scope: !4)
This example illustrates a few important details about LLVM debugging
information. In particular, it shows how the llvm.dbg.declare
intrinsic and
location information, which are attached to an instruction, are applied
together to allow a debugger to analyze the relationship between statements,
variable definitions, and the code used to implement the function.
call void @llvm.dbg.declare(metadata i32* %X, metadata !11, metadata !13), !dbg !14
; [debug line = 2:7] [debug variable = X]
The first intrinsic %llvm.dbg.declare
encodes debugging information for the
variable X
. The metadata !dbg !14
attached to the intrinsic provides
scope information for the variable X
.
!14 = !DILocation(line: 2, column: 9, scope: !4)
!4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !5,
isLocal: false, isDefinition: true, scopeLine: 1,
isOptimized: false, variables: !2)
Here !14
is metadata providing location information. In this example, scope is encoded by !4
, a
subprogram descriptor. This way the location
information attached to the intrinsics indicates that the variable X
is
declared at line number 2 at a function level scope in function foo
.
Now lets take another example.
call void @llvm.dbg.declare(metadata i32* %Z, metadata !17, metadata !13), !dbg !19
; [debug line = 5:9] [debug variable = Z]
The third intrinsic %llvm.dbg.declare
encodes debugging information for
variable Z
. The metadata !dbg !19
attached to the intrinsic provides
scope information for the variable Z
.
!18 = distinct !DILexicalBlock(scope: !4, file: !1, line: 4, column: 5)
!19 = !DILocation(line: 5, column: 11, scope: !18)
Here !19
indicates that Z
is declared at line number 5 and column
number 0 inside of lexical scope !18
. The lexical scope itself resides
inside of subprogram !4
described above.
The scope information attached with each instruction provides a straightforward way to find instructions covered by a scope.
C/C++ front-end specific debug information¶
The C and C++ front-ends represent information about the program in a format that is effectively identical to DWARF 3.0 in terms of information content. This allows code generators to trivially support native debuggers by generating standard dwarf information, and contains enough information for non-dwarf targets to translate it as needed.
This section describes the forms used to represent C and C++ programs. Other languages could pattern themselves after this (which itself is tuned to representing programs in the same way that DWARF 3 does), or they could choose to provide completely different forms if they don’t fit into the DWARF model. As support for debugging information gets added to the various LLVM source-language front-ends, the information used should be documented here.
The following sections provide examples of a few C/C++ constructs and the debug
information that would best describe those constructs. The canonical
references are the DIDescriptor
classes defined in
include/llvm/IR/DebugInfo.h
and the implementations of the helper functions
in lib/IR/DIBuilder.cpp
.
C/C++ source file information¶
llvm::Instruction
provides easy access to metadata attached with an
instruction. One can extract line number information encoded in LLVM IR using
Instruction::getDebugLoc()
and DILocation::getLine()
.
if (DILocation *Loc = I->getDebugLoc()) { // Here I is an LLVM instruction
unsigned Line = Loc->getLine();
StringRef File = Loc->getFilename();
StringRef Dir = Loc->getDirectory();
}
C/C++ global variable information¶
Given an integer global variable declared as follows:
_Alignas(8) int MyGlobal = 100;
a C/C++ front-end would generate the following descriptors:
;;
;; Define the global itself.
;;
@MyGlobal = global i32 100, align 8, !dbg !0
;;
;; List of debug info of globals
;;
!llvm.dbg.cu = !{!1}
;; Some unrelated metadata.
!llvm.module.flags = !{!6, !7}
!llvm.ident = !{!8}
;; Define the global variable itself
!0 = distinct !DIGlobalVariable(name: "MyGlobal", scope: !1, file: !2, line: 1, type: !5, isLocal: false, isDefinition: true, align: 64)
;; Define the compile unit.
!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2,
producer: "clang version 4.0.0 (http://llvm.org/git/clang.git ae4deadbea242e8ea517eef662c30443f75bd086) (http://llvm.org/git/llvm.git 818b4c1539df3e51dc7e62c89ead4abfd348827d)",
isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug,
enums: !3, globals: !4)
;;
;; Define the file
;;
!2 = !DIFile(filename: "/dev/stdin",
directory: "/Users/dexonsmith/data/llvm/debug-info")
;; An empty array.
!3 = !{}
;; The Array of Global Variables
!4 = !{!0}
;;
;; Define the type
;;
!5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
;; Dwarf version to output.
!6 = !{i32 2, !"Dwarf Version", i32 4}
;; Debug info schema version.
!7 = !{i32 2, !"Debug Info Version", i32 3}
;; Compiler identification
!8 = !{!"clang version 4.0.0 (http://llvm.org/git/clang.git ae4deadbea242e8ea517eef662c30443f75bd086) (http://llvm.org/git/llvm.git 818b4c1539df3e51dc7e62c89ead4abfd348827d)"}
The align value in DIGlobalVariable description specifies variable alignment in case it was forced by C11 _Alignas(), C++11 alignas() keywords or compiler attribute __attribute__((aligned ())). In other case (when this field is missing) alignment is considered default. This is used when producing DWARF output for DW_AT_alignment value.
C/C++ function information¶
Given a function declared as follows:
int main(int argc, char *argv[]) {
return 0;
}
a C/C++ front-end would generate the following descriptors:
;;
;; Define the anchor for subprograms.
;;
!4 = !DISubprogram(name: "main", scope: !1, file: !1, line: 1, type: !5,
isLocal: false, isDefinition: true, scopeLine: 1,
flags: DIFlagPrototyped, isOptimized: false,
variables: !2)
;;
;; Define the subprogram itself.
;;
define i32 @main(i32 %argc, i8** %argv) !dbg !4 {
...
}
Debugging information format¶
Debugging Information Extension for Objective C Properties¶
Introduction¶
Objective C provides a simpler way to declare and define accessor methods using declared properties. The language provides features to declare a property and to let compiler synthesize accessor methods.
The debugger lets developer inspect Objective C interfaces and their instance variables and class variables. However, the debugger does not know anything about the properties defined in Objective C interfaces. The debugger consumes information generated by compiler in DWARF format. The format does not support encoding of Objective C properties. This proposal describes DWARF extensions to encode Objective C properties, which the debugger can use to let developers inspect Objective C properties.
Proposal¶
Objective C properties exist separately from class members. A property can be
defined only by “setter” and “getter” selectors, and be calculated anew on each
access. Or a property can just be a direct access to some declared ivar.
Finally it can have an ivar “automatically synthesized” for it by the compiler,
in which case the property can be referred to in user code directly using the
standard C dereference syntax as well as through the property “dot” syntax, but
there is no entry in the @interface
declaration corresponding to this ivar.
To facilitate debugging, these properties we will add a new DWARF TAG into the
DW_TAG_structure_type
definition for the class to hold the description of a
given property, and a set of DWARF attributes that provide said description.
The property tag will also contain the name and declared type of the property.
If there is a related ivar, there will also be a DWARF property attribute placed
in the DW_TAG_member
DIE for that ivar referring back to the property TAG
for that property. And in the case where the compiler synthesizes the ivar
directly, the compiler is expected to generate a DW_TAG_member
for that
ivar (with the DW_AT_artificial
set to 1), whose name will be the name used
to access this ivar directly in code, and with the property attribute pointing
back to the property it is backing.
The following examples will serve as illustration for our discussion:
@interface I1 {
int n2;
}
@property int p1;
@property int p2;
@end
@implementation I1
@synthesize p1;
@synthesize p2 = n2;
@end
This produces the following DWARF (this is a “pseudo dwarfdump” output):
0x00000100: TAG_structure_type [7] *
AT_APPLE_runtime_class( 0x10 )
AT_name( "I1" )
AT_decl_file( "Objc_Property.m" )
AT_decl_line( 3 )
0x00000110 TAG_APPLE_property
AT_name ( "p1" )
AT_type ( {0x00000150} ( int ) )
0x00000120: TAG_APPLE_property
AT_name ( "p2" )
AT_type ( {0x00000150} ( int ) )
0x00000130: TAG_member [8]
AT_name( "_p1" )
AT_APPLE_property ( {0x00000110} "p1" )
AT_type( {0x00000150} ( int ) )
AT_artificial ( 0x1 )
0x00000140: TAG_member [8]
AT_name( "n2" )
AT_APPLE_property ( {0x00000120} "p2" )
AT_type( {0x00000150} ( int ) )
0x00000150: AT_type( ( int ) )
Note, the current convention is that the name of the ivar for an auto-synthesized property is the name of the property from which it derives with an underscore prepended, as is shown in the example. But we actually don’t need to know this convention, since we are given the name of the ivar directly.
Also, it is common practice in ObjC to have different property declarations in the @interface and @implementation - e.g. to provide a read-only property in the interface,and a read-write interface in the implementation. In that case, the compiler should emit whichever property declaration will be in force in the current translation unit.
Developers can decorate a property with attributes which are encoded using
DW_AT_APPLE_property_attribute
.
@property (readonly, nonatomic) int pr;
TAG_APPLE_property [8]
AT_name( "pr" )
AT_type ( {0x00000147} (int) )
AT_APPLE_property_attribute (DW_APPLE_PROPERTY_readonly, DW_APPLE_PROPERTY_nonatomic)
The setter and getter method names are attached to the property using
DW_AT_APPLE_property_setter
and DW_AT_APPLE_property_getter
attributes.
@interface I1
@property (setter=myOwnP3Setter:) int p3;
-(void)myOwnP3Setter:(int)a;
@end
@implementation I1
@synthesize p3;
-(void)myOwnP3Setter:(int)a{ }
@end
The DWARF for this would be:
0x000003bd: TAG_structure_type [7] *
AT_APPLE_runtime_class( 0x10 )
AT_name( "I1" )
AT_decl_file( "Objc_Property.m" )
AT_decl_line( 3 )
0x000003cd TAG_APPLE_property
AT_name ( "p3" )
AT_APPLE_property_setter ( "myOwnP3Setter:" )
AT_type( {0x00000147} ( int ) )
0x000003f3: TAG_member [8]
AT_name( "_p3" )
AT_type ( {0x00000147} ( int ) )
AT_APPLE_property ( {0x000003cd} )
AT_artificial ( 0x1 )
New DWARF Tags¶
| TAG | Value |
|---|---|
| DW_TAG_APPLE_property | 0x4200 |
New DWARF Attributes¶
| Attribute | Value | Classes |
|---|---|---|
| DW_AT_APPLE_property | 0x3fed | Reference |
| DW_AT_APPLE_property_getter | 0x3fe9 | String |
| DW_AT_APPLE_property_setter | 0x3fea | String |
| DW_AT_APPLE_property_attribute | 0x3feb | Constant |
New DWARF Constants¶
| Name | Value |
|---|---|
| DW_APPLE_PROPERTY_readonly | 0x01 |
| DW_APPLE_PROPERTY_getter | 0x02 |
| DW_APPLE_PROPERTY_assign | 0x04 |
| DW_APPLE_PROPERTY_readwrite | 0x08 |
| DW_APPLE_PROPERTY_retain | 0x10 |
| DW_APPLE_PROPERTY_copy | 0x20 |
| DW_APPLE_PROPERTY_nonatomic | 0x40 |
| DW_APPLE_PROPERTY_setter | 0x80 |
| DW_APPLE_PROPERTY_atomic | 0x100 |
| DW_APPLE_PROPERTY_weak | 0x200 |
| DW_APPLE_PROPERTY_strong | 0x400 |
| DW_APPLE_PROPERTY_unsafe_unretained | 0x800 |
| DW_APPLE_PROPERTY_nullability | 0x1000 |
| DW_APPLE_PROPERTY_null_resettable | 0x2000 |
| DW_APPLE_PROPERTY_class | 0x4000 |
Name Accelerator Tables¶
Introduction¶
The “.debug_pubnames
” and “.debug_pubtypes
” formats are not what a
debugger needs. The “pub
” in the section name indicates that the entries
in the table are publicly visible names only. This means no static or hidden
functions show up in the “.debug_pubnames
”. No static variables or private
class variables are in the “.debug_pubtypes
”. Many compilers add different
things to these tables, so we can’t rely upon the contents between gcc, icc, or
clang.
The typical query given by users tends not to match up with the contents of
these tables. For example, the DWARF spec states that “In the case of the name
of a function member or static data member of a C++ structure, class or union,
the name presented in the “.debug_pubnames
” section is not the simple name
given by the DW_AT_name attribute
of the referenced debugging information
entry, but rather the fully qualified name of the data or function member.”
So the only names in these tables for complex C++ entries is a fully
qualified name. Debugger users tend not to enter their search strings as
“a::b::c(int,const Foo&) const
”, but rather as “c
”, “b::c
” , or
“a::b::c
”. So the name entered in the name table must be demangled in
order to chop it up appropriately and additional names must be manually entered
into the table to make it effective as a name lookup table for debuggers to
use.
All debuggers currently ignore the “.debug_pubnames
” table as a result of
its inconsistent and useless public-only name content making it a waste of
space in the object file. These tables, when they are written to disk, are not
sorted in any way, leaving every debugger to do its own parsing and sorting.
These tables also include an inlined copy of the string values in the table
itself making the tables much larger than they need to be on disk, especially
for large C++ programs.
Can’t we just fix the sections by adding all of the names we need to this table? No, because that is not what the tables are defined to contain and we won’t know the difference between the old bad tables and the new good tables. At best we could make our own renamed sections that contain all of the data we need.
These tables are also insufficient for what a debugger like LLDB needs. LLDB
uses clang for its expression parsing where LLDB acts as a PCH. LLDB is then
often asked to look for type “foo
” or namespace “bar
”, or list items in
namespace “baz
”. Namespaces are not included in the pubnames or pubtypes
tables. Since clang asks a lot of questions when it is parsing an expression,
we need to be very fast when looking up names, as it happens a lot. Having new
accelerator tables that are optimized for very quick lookups will benefit this
type of debugging experience greatly.
We would like to generate name lookup tables that can be mapped into memory from disk, and used as is, with little or no up-front parsing. We would also be able to control the exact content of these different tables so they contain exactly what we need. The Name Accelerator Tables were designed to fix these issues. In order to solve these issues we need to:
- Have a format that can be mapped into memory from disk and used as is
- Lookups should be very fast
- Extensible table format so these tables can be made by many producers
- Contain all of the names needed for typical lookups out of the box
- Strict rules for the contents of tables
Table size is important and the accelerator table format should allow the reuse of strings from common string tables so the strings for the names are not duplicated. We also want to make sure the table is ready to be used as-is by simply mapping the table into memory with minimal header parsing.
The name lookups need to be fast and optimized for the kinds of lookups that debuggers tend to do. Optimally we would like to touch as few parts of the mapped table as possible when doing a name lookup and be able to quickly find the name entry we are looking for, or discover there are no matches. In the case of debuggers we optimized for lookups that fail most of the time.
Each table that is defined should have strict rules on exactly what is in the accelerator tables and documented so clients can rely on the content.
Hash Tables¶
Standard Hash Tables¶
Typical hash tables have a header, buckets, and each bucket points to the bucket contents:
.------------.
| HEADER |
|------------|
| BUCKETS |
|------------|
| DATA |
`------------'
The BUCKETS are an array of offsets to DATA for each hash:
.------------.
| 0x00001000 | BUCKETS[0]
| 0x00002000 | BUCKETS[1]
| 0x00002200 | BUCKETS[2]
| 0x000034f0 | BUCKETS[3]
| | ...
| 0xXXXXXXXX | BUCKETS[n_buckets]
'------------'
So for bucket[3]
in the example above, we have an offset into the table
0x000034f0 which points to a chain of entries for the bucket. Each bucket must
contain a next pointer, full 32 bit hash value, the string itself, and the data
for the current string value.
.------------.
0x000034f0: | 0x00003500 | next pointer
| 0x12345678 | 32 bit hash
| "erase" | string value
| data[n] | HashData for this bucket
|------------|
0x00003500: | 0x00003550 | next pointer
| 0x29273623 | 32 bit hash
| "dump" | string value
| data[n] | HashData for this bucket
|------------|
0x00003550: | 0x00000000 | next pointer
| 0x82638293 | 32 bit hash
| "main" | string value
| data[n] | HashData for this bucket
`------------'
The problem with this layout for debuggers is that we need to optimize for the
negative lookup case where the symbol we’re searching for is not present. So
if we were to lookup “printf
” in the table above, we would make a 32-bit
hash for “printf
”, it might match bucket[3]
. We would need to go to
the offset 0x000034f0 and start looking to see if our 32 bit hash matches. To
do so, we need to read the next pointer, then read the hash, compare it, and
skip to the next bucket. Each time we are skipping many bytes in memory and
touching new pages just to do the compare on the full 32 bit hash. All of
these accesses then tell us that we didn’t have a match.
Name Hash Tables¶
To solve the issues mentioned above we have structured the hash tables a bit differently: a header, buckets, an array of all unique 32 bit hash values, followed by an array of hash value data offsets, one for each hash value, then the data for all hash values:
.-------------.
| HEADER |
|-------------|
| BUCKETS |
|-------------|
| HASHES |
|-------------|
| OFFSETS |
|-------------|
| DATA |
`-------------'
The BUCKETS
in the name tables are an index into the HASHES
array. By
making all of the full 32 bit hash values contiguous in memory, we allow
ourselves to efficiently check for a match while touching as little memory as
possible. Most often checking the 32 bit hash values is as far as the lookup
goes. If it does match, it usually is a match with no collisions. So for a
table with “n_buckets
” buckets, and “n_hashes
” unique 32 bit hash
values, we can clarify the contents of the BUCKETS
, HASHES
and
OFFSETS
as:
.-------------------------.
| HEADER.magic | uint32_t
| HEADER.version | uint16_t
| HEADER.hash_function | uint16_t
| HEADER.bucket_count | uint32_t
| HEADER.hashes_count | uint32_t
| HEADER.header_data_len | uint32_t
| HEADER_DATA | HeaderData
|-------------------------|
| BUCKETS | uint32_t[n_buckets] // 32 bit hash indexes
|-------------------------|
| HASHES | uint32_t[n_hashes] // 32 bit hash values
|-------------------------|
| OFFSETS | uint32_t[n_hashes] // 32 bit offsets to hash value data
|-------------------------|
| ALL HASH DATA |
`-------------------------'
So taking the exact same data from the standard hash example above we end up with:
.------------.
| HEADER |
|------------|
| 0 | BUCKETS[0]
| 2 | BUCKETS[1]
| 5 | BUCKETS[2]
| 6 | BUCKETS[3]
| | ...
| ... | BUCKETS[n_buckets]
|------------|
| 0x........ | HASHES[0]
| 0x........ | HASHES[1]
| 0x........ | HASHES[2]
| 0x........ | HASHES[3]
| 0x........ | HASHES[4]
| 0x........ | HASHES[5]
| 0x12345678 | HASHES[6] hash for BUCKETS[3]
| 0x29273623 | HASHES[7] hash for BUCKETS[3]
| 0x82638293 | HASHES[8] hash for BUCKETS[3]
| 0x........ | HASHES[9]
| 0x........ | HASHES[10]
| 0x........ | HASHES[11]
| 0x........ | HASHES[12]
| 0x........ | HASHES[13]
| 0x........ | HASHES[n_hashes]
|------------|
| 0x........ | OFFSETS[0]
| 0x........ | OFFSETS[1]
| 0x........ | OFFSETS[2]
| 0x........ | OFFSETS[3]
| 0x........ | OFFSETS[4]
| 0x........ | OFFSETS[5]
| 0x000034f0 | OFFSETS[6] offset for BUCKETS[3]
| 0x00003500 | OFFSETS[7] offset for BUCKETS[3]
| 0x00003550 | OFFSETS[8] offset for BUCKETS[3]
| 0x........ | OFFSETS[9]
| 0x........ | OFFSETS[10]
| 0x........ | OFFSETS[11]
| 0x........ | OFFSETS[12]
| 0x........ | OFFSETS[13]
| 0x........ | OFFSETS[n_hashes]
|------------|
| |
| |
| |
| |
| |
|------------|
0x000034f0: | 0x00001203 | .debug_str ("erase")
| 0x00000004 | A 32 bit array count - number of HashData with name "erase"
| 0x........ | HashData[0]
| 0x........ | HashData[1]
| 0x........ | HashData[2]
| 0x........ | HashData[3]
| 0x00000000 | String offset into .debug_str (terminate data for hash)
|------------|
0x00003500: | 0x00001203 | String offset into .debug_str ("collision")
| 0x00000002 | A 32 bit array count - number of HashData with name "collision"
| 0x........ | HashData[0]
| 0x........ | HashData[1]
| 0x00001203 | String offset into .debug_str ("dump")
| 0x00000003 | A 32 bit array count - number of HashData with name "dump"
| 0x........ | HashData[0]
| 0x........ | HashData[1]
| 0x........ | HashData[2]
| 0x00000000 | String offset into .debug_str (terminate data for hash)
|------------|
0x00003550: | 0x00001203 | String offset into .debug_str ("main")
| 0x00000009 | A 32 bit array count - number of HashData with name "main"
| 0x........ | HashData[0]
| 0x........ | HashData[1]
| 0x........ | HashData[2]
| 0x........ | HashData[3]
| 0x........ | HashData[4]
| 0x........ | HashData[5]
| 0x........ | HashData[6]
| 0x........ | HashData[7]
| 0x........ | HashData[8]
| 0x00000000 | String offset into .debug_str (terminate data for hash)
`------------'
So we still have all of the same data, we just organize it more efficiently for
debugger lookup. If we repeat the same “printf
” lookup from above, we
would hash “printf
” and find it matches BUCKETS[3]
by taking the 32 bit
hash value and modulo it by n_buckets
. BUCKETS[3]
contains “6” which
is the index into the HASHES
table. We would then compare any consecutive
32 bit hashes values in the HASHES
array as long as the hashes would be in
BUCKETS[3]
. We do this by verifying that each subsequent hash value modulo
n_buckets
is still 3. In the case of a failed lookup we would access the
memory for BUCKETS[3]
, and then compare a few consecutive 32 bit hashes
before we know that we have no match. We don’t end up marching through
multiple words of memory and we really keep the number of processor data cache
lines being accessed as small as possible.
The string hash that is used for these lookup tables is the Daniel J.
Bernstein hash which is also used in the ELF GNU_HASH
sections. It is a
very good hash for all kinds of names in programs with very few hash
collisions.
Empty buckets are designated by using an invalid hash index of UINT32_MAX
.
Details¶
These name hash tables are designed to be generic where specializations of the
table get to define additional data that goes into the header (“HeaderData
”),
how the string value is stored (“KeyType
”) and the content of the data for each
hash value.
Header Layout¶
The header has a fixed part, and the specialized part. The exact format of the header is:
struct Header
{
uint32_t magic; // 'HASH' magic value to allow endian detection
uint16_t version; // Version number
uint16_t hash_function; // The hash function enumeration that was used
uint32_t bucket_count; // The number of buckets in this hash table
uint32_t hashes_count; // The total number of unique hash values and hash data offsets in this table
uint32_t header_data_len; // The bytes to skip to get to the hash indexes (buckets) for correct alignment
// Specifically the length of the following HeaderData field - this does not
// include the size of the preceding fields
HeaderData header_data; // Implementation specific header data
};
The header starts with a 32 bit “magic
” value which must be 'HASH'
encoded as an ASCII integer. This allows the detection of the start of the
hash table and also allows the table’s byte order to be determined so the table
can be correctly extracted. The “magic
” value is followed by a 16 bit
version
number which allows the table to be revised and modified in the
future. The current version number is 1. hash_function
is a uint16_t
enumeration that specifies which hash function was used to produce this table.
The current values for the hash function enumerations include:
enum HashFunctionType
{
eHashFunctionDJB = 0u, // Daniel J Bernstein hash function
};
bucket_count
is a 32 bit unsigned integer that represents how many buckets
are in the BUCKETS
array. hashes_count
is the number of unique 32 bit
hash values that are in the HASHES
array, and is the same number of offsets
are contained in the OFFSETS
array. header_data_len
specifies the size
in bytes of the HeaderData
that is filled in by specialized versions of
this table.
Fixed Lookup¶
The header is followed by the buckets, hashes, offsets, and hash value data.
struct FixedTable
{
uint32_t buckets[Header.bucket_count]; // An array of hash indexes into the "hashes[]" array below
uint32_t hashes [Header.hashes_count]; // Every unique 32 bit hash for the entire table is in this table
uint32_t offsets[Header.hashes_count]; // An offset that corresponds to each item in the "hashes[]" array above
};
buckets
is an array of 32 bit indexes into the hashes
array. The
hashes
array contains all of the 32 bit hash values for all names in the
hash table. Each hash in the hashes
table has an offset in the offsets
array that points to the data for the hash value.
This table setup makes it very easy to repurpose these tables to contain different data, while keeping the lookup mechanism the same for all tables. This layout also makes it possible to save the table to disk and map it in later and do very efficient name lookups with little or no parsing.
DWARF lookup tables can be implemented in a variety of ways and can store a lot of information for each name. We want to make the DWARF tables extensible and able to store the data efficiently so we have used some of the DWARF features that enable efficient data storage to define exactly what kind of data we store for each name.
The HeaderData
contains a definition of the contents of each HashData chunk.
We might want to store an offset to all of the debug information entries (DIEs)
for each name. To keep things extensible, we create a list of items, or
Atoms, that are contained in the data for each name. First comes the type of
the data in each atom:
enum AtomType
{
eAtomTypeNULL = 0u,
eAtomTypeDIEOffset = 1u, // DIE offset, check form for encoding
eAtomTypeCUOffset = 2u, // DIE offset of the compiler unit header that contains the item in question
eAtomTypeTag = 3u, // DW_TAG_xxx value, should be encoded as DW_FORM_data1 (if no tags exceed 255) or DW_FORM_data2
eAtomTypeNameFlags = 4u, // Flags from enum NameFlags
eAtomTypeTypeFlags = 5u, // Flags from enum TypeFlags
};
The enumeration values and their meanings are:
eAtomTypeNULL - a termination atom that specifies the end of the atom list
eAtomTypeDIEOffset - an offset into the .debug_info section for the DWARF DIE for this name
eAtomTypeCUOffset - an offset into the .debug_info section for the CU that contains the DIE
eAtomTypeDIETag - The DW_TAG_XXX enumeration value so you don't have to parse the DWARF to see what it is
eAtomTypeNameFlags - Flags for functions and global variables (isFunction, isInlined, isExternal...)
eAtomTypeTypeFlags - Flags for types (isCXXClass, isObjCClass, ...)
Then we allow each atom type to define the atom type and how the data for each atom type data is encoded:
struct Atom
{
uint16_t type; // AtomType enum value
uint16_t form; // DWARF DW_FORM_XXX defines
};
The form
type above is from the DWARF specification and defines the exact
encoding of the data for the Atom type. See the DWARF specification for the
DW_FORM_
definitions.
struct HeaderData
{
uint32_t die_offset_base;
uint32_t atom_count;
Atoms atoms[atom_count0];
};
HeaderData
defines the base DIE offset that should be added to any atoms
that are encoded using the DW_FORM_ref1
, DW_FORM_ref2
,
DW_FORM_ref4
, DW_FORM_ref8
or DW_FORM_ref_udata
. It also defines
what is contained in each HashData
object – Atom.form
tells us how large
each field will be in the HashData
and the Atom.type
tells us how this data
should be interpreted.
For the current implementations of the “.apple_names
” (all functions +
globals), the “.apple_types
” (names of all types that are defined), and
the “.apple_namespaces
” (all namespaces), we currently set the Atom
array to be:
HeaderData.atom_count = 1;
HeaderData.atoms[0].type = eAtomTypeDIEOffset;
HeaderData.atoms[0].form = DW_FORM_data4;
This defines the contents to be the DIE offset (eAtomTypeDIEOffset) that is encoded as a 32 bit value (DW_FORM_data4). This allows a single name to have multiple matching DIEs in a single file, which could come up with an inlined function for instance. Future tables could include more information about the DIE such as flags indicating if the DIE is a function, method, block, or inlined.
The KeyType for the DWARF table is a 32 bit string table offset into the “.debug_str” table. The “.debug_str” is the string table for the DWARF which may already contain copies of all of the strings. This helps make sure, with help from the compiler, that we reuse the strings between all of the DWARF sections and keeps the hash table size down. Another benefit to having the compiler generate all strings as DW_FORM_strp in the debug info, is that DWARF parsing can be made much faster.
After a lookup is made, we get an offset into the hash data. The hash data needs to be able to deal with 32 bit hash collisions, so the chunk of data at the offset in the hash data consists of a triple:
uint32_t str_offset
uint32_t hash_data_count
HashData[hash_data_count]
If “str_offset” is zero, then the bucket contents are done. 99.9% of the hash data chunks contain a single item (no 32 bit hash collision):
.------------.
| 0x00001023 | uint32_t KeyType (.debug_str[0x0001023] => "main")
| 0x00000004 | uint32_t HashData count
| 0x........ | uint32_t HashData[0] DIE offset
| 0x........ | uint32_t HashData[1] DIE offset
| 0x........ | uint32_t HashData[2] DIE offset
| 0x........ | uint32_t HashData[3] DIE offset
| 0x00000000 | uint32_t KeyType (end of hash chain)
`------------'
If there are collisions, you will have multiple valid string offsets:
.------------.
| 0x00001023 | uint32_t KeyType (.debug_str[0x0001023] => "main")
| 0x00000004 | uint32_t HashData count
| 0x........ | uint32_t HashData[0] DIE offset
| 0x........ | uint32_t HashData[1] DIE offset
| 0x........ | uint32_t HashData[2] DIE offset
| 0x........ | uint32_t HashData[3] DIE offset
| 0x00002023 | uint32_t KeyType (.debug_str[0x0002023] => "print")
| 0x00000002 | uint32_t HashData count
| 0x........ | uint32_t HashData[0] DIE offset
| 0x........ | uint32_t HashData[1] DIE offset
| 0x00000000 | uint32_t KeyType (end of hash chain)
`------------'
Current testing with real world C++ binaries has shown that there is around 1 32 bit hash collision per 100,000 name entries.
Contents¶
As we said, we want to strictly define exactly what is included in the
different tables. For DWARF, we have 3 tables: “.apple_names
”,
“.apple_types
”, and “.apple_namespaces
”.
“.apple_names
” sections should contain an entry for each DWARF DIE whose
DW_TAG
is a DW_TAG_label
, DW_TAG_inlined_subroutine
, or
DW_TAG_subprogram
that has address attributes: DW_AT_low_pc
,
DW_AT_high_pc
, DW_AT_ranges
or DW_AT_entry_pc
. It also contains
DW_TAG_variable
DIEs that have a DW_OP_addr
in the location (global and
static variables). All global and static variables should be included,
including those scoped within functions and classes. For example using the
following code:
static int var = 0;
void f ()
{
static int var = 0;
}
Both of the static var
variables would be included in the table. All
functions should emit both their full names and their basenames. For C or C++,
the full name is the mangled name (if available) which is usually in the
DW_AT_MIPS_linkage_name
attribute, and the DW_AT_name
contains the
function basename. If global or static variables have a mangled name in a
DW_AT_MIPS_linkage_name
attribute, this should be emitted along with the
simple name found in the DW_AT_name
attribute.
“.apple_types
” sections should contain an entry for each DWARF DIE whose
tag is one of:
- DW_TAG_array_type
- DW_TAG_class_type
- DW_TAG_enumeration_type
- DW_TAG_pointer_type
- DW_TAG_reference_type
- DW_TAG_string_type
- DW_TAG_structure_type
- DW_TAG_subroutine_type
- DW_TAG_typedef
- DW_TAG_union_type
- DW_TAG_ptr_to_member_type
- DW_TAG_set_type
- DW_TAG_subrange_type
- DW_TAG_base_type
- DW_TAG_const_type
- DW_TAG_file_type
- DW_TAG_namelist
- DW_TAG_packed_type
- DW_TAG_volatile_type
- DW_TAG_restrict_type
- DW_TAG_atomic_type
- DW_TAG_interface_type
- DW_TAG_unspecified_type
- DW_TAG_shared_type
Only entries with a DW_AT_name
attribute are included, and the entry must
not be a forward declaration (DW_AT_declaration
attribute with a non-zero
value). For example, using the following code:
int main ()
{
int *b = 0;
return *b;
}
We get a few type DIEs:
0x00000067: TAG_base_type [5]
AT_encoding( DW_ATE_signed )
AT_name( "int" )
AT_byte_size( 0x04 )
0x0000006e: TAG_pointer_type [6]
AT_type( {0x00000067} ( int ) )
AT_byte_size( 0x08 )
The DW_TAG_pointer_type is not included because it does not have a DW_AT_name
.
“.apple_namespaces
” section should contain all DW_TAG_namespace
DIEs.
If we run into a namespace that has no name this is an anonymous namespace, and
the name should be output as “(anonymous namespace)
” (without the quotes).
Why? This matches the output of the abi::cxa_demangle()
that is in the
standard C++ library that demangles mangled names.
Language Extensions and File Format Changes¶
Objective-C Extensions¶
“.apple_objc
” section should contain all DW_TAG_subprogram
DIEs for an
Objective-C class. The name used in the hash table is the name of the
Objective-C class itself. If the Objective-C class has a category, then an
entry is made for both the class name without the category, and for the class
name with the category. So if we have a DIE at offset 0x1234 with a name of
method “-[NSString(my_additions) stringWithSpecialString:]
”, we would add
an entry for “NSString
” that points to DIE 0x1234, and an entry for
“NSString(my_additions)
” that points to 0x1234. This allows us to quickly
track down all Objective-C methods for an Objective-C class when doing
expressions. It is needed because of the dynamic nature of Objective-C where
anyone can add methods to a class. The DWARF for Objective-C methods is also
emitted differently from C++ classes where the methods are not usually
contained in the class definition, they are scattered about across one or more
compile units. Categories can also be defined in different shared libraries.
So we need to be able to quickly find all of the methods and class functions
given the Objective-C class name, or quickly find all methods and class
functions for a class + category name. This table does not contain any
selector names, it just maps Objective-C class names (or class names +
category) to all of the methods and class functions. The selectors are added
as function basenames in the “.debug_names
” section.
In the “.apple_names
” section for Objective-C functions, the full name is
the entire function name with the brackets (“-[NSString
stringWithCString:]
”) and the basename is the selector only
(“stringWithCString:
”).
Mach-O Changes¶
The sections names for the apple hash tables are for non-mach-o files. For
mach-o files, the sections should be contained in the __DWARF
segment with
names as follows:
- “
.apple_names
” -> “__apple_names
” - “
.apple_types
” -> “__apple_types
” - “
.apple_namespaces
” -> “__apple_namespac
” (16 character limit) - “
.apple_objc
” -> “__apple_objc
”
CodeView Debug Info Format¶
LLVM supports emitting CodeView, the Microsoft debug info format, and this section describes the design and implementation of that support.
Format Background¶
CodeView as a format is clearly oriented around C++ debugging, and in C++, the majority of debug information tends to be type information. Therefore, the overriding design constraint of CodeView is the separation of type information from other “symbol” information so that type information can be efficiently merged across translation units. Both type information and symbol information is generally stored as a sequence of records, where each record begins with a 16-bit record size and a 16-bit record kind.
Type information is usually stored in the .debug$T
section of the object
file. All other debug info, such as line info, string table, symbol info, and
inlinee info, is stored in one or more .debug$S
sections. There may only be
one .debug$T
section per object file, since all other debug info refers to
it. If a PDB (enabled by the /Zi
MSVC option) was used during compilation,
the .debug$T
section will contain only an LF_TYPESERVER2
record pointing
to the PDB. When using PDBs, symbol information appears to remain in the object
file .debug$S
sections.
Type records are referred to by their index, which is the number of records in
the stream before a given record plus 0x1000
. Many common basic types, such
as the basic integral types and unqualified pointers to them, are represented
using type indices less than 0x1000
. Such basic types are built in to
CodeView consumers and do not require type records.
Each type record may only contain type indices that are less than its own type
index. This ensures that the graph of type stream references is acyclic. While
the source-level type graph may contain cycles through pointer types (consider a
linked list struct), these cycles are removed from the type stream by always
referring to the forward declaration record of user-defined record types. Only
“symbol” records in the .debug$S
streams may refer to complete,
non-forward-declaration type records.
Working with CodeView¶
These are instructions for some common tasks for developers working to improve
LLVM’s CodeView support. Most of them revolve around using the CodeView dumper
embedded in llvm-readobj
.
Testing MSVC’s output:
$ cl -c -Z7 foo.cpp # Use /Z7 to keep types in the object file $ llvm-readobj -codeview foo.obj
Getting LLVM IR debug info out of Clang:
$ clang -g -gcodeview --target=x86_64-windows-msvc foo.cpp -S -emit-llvm
Use this to generate LLVM IR for LLVM test cases.
Generate and dump CodeView from LLVM IR metadata:
$ llc foo.ll -filetype=obj -o foo.obj $ llvm-readobj -codeview foo.obj > foo.txt
Use this pattern in lit test cases and FileCheck the output of llvm-readobj
Improving LLVM’s CodeView support is a process of finding interesting type records, constructing a C++ test case that makes MSVC emit those records, dumping the records, understanding them, and then generating equivalent records in LLVM’s backend.


Coin Change
问题描述 :
Suppose there are 5 types of coins: 50-cent, 25-cent, 10-cent, 5-cent, and 1-cent. We want to make changes with these coins for a given amount of money.
For example, if we have 11 cents, then we can make changes with one 10-cent coin and one 1-cent coin, or two 5-cent coins and one 1-cent coin, or one 5-cent coin and six 1-cent coins, or eleven 1-cent coins. So there are four ways of making changes for 11 cents with the above coins. Note that we count that there is one way of making change for zero cent.
Write a program to find the total number of different ways of making changes for any amount of money in cents. Your program should be able to handle up to 100 coins.
输入:
The input file contains any number of lines, each one consisting of a number ( ≤250 ) for the amount of money in cents.
输出:
The input file contains any number of lines, each one consisting of a number ( ≤250 ) for the amount of money in cents.
样例输入:
11 26
样例输出:
4 13
// Time 0ms, Memory 404K
#include<stdio.h> int a[255][105],temp[255][105]; int val[6]={0,1,5,10,25,50}; int num[255]={0}; int main() { int i,j,k,t,n; a[0][0]=1; for(i=1;i<=5;i++) { for(j=0;j<=250;j++) for(k=0;j+k*val[i]<=250;k++) for(t=0;t+k<=100;t++) temp[j+k*val[i]][t+k]+=a[j][t]; for(j=0;j<=250;j++) for(t=0;t<=100;t++) { a[j][t]=temp[j][t]; temp[j][t]=0; } } for(i=0;i<=250;i++) for(j=0;j<=100;j++) num[i]+=a[i][j]; while(scanf("%d",&n)!=EOF) { printf("%d\n",num[n]); } return 0; }
解题转自：http://blog.csdn.net/qhc_20130731/article/details/9050955
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穷***组合
sha
为什么for循环找到的i一定是素数叻，而且约数定理说的是n=p1^a1*p2^a2*p3^a3*…*pk^ak，而你每次取余都用的是原来的m，也就是n
写的好····· Pollard Rh
&这是C语言？
上面的评论很起劲，为什么我看不懂啊
We do not harbor that I couldn’t remove other individuals’ problems whenever this arrived at.
有意思，有难度
为避免精度问题，PI值请使用arccos(-1)。应该是acos
This write-up presents the gentle in which we can notice the fact. this is extremely wonderful one and gives in depth info.
[…] 答案：http://www.acmerblog.com/interview-2-1549/ […]
第15行代码，/n/n，应该改为\n\n
因为是要把从字符串s的start位到当前位在hash中重置，修改提交后能accept，但是不修改居然也能accept
[…] 如果此题没有要求 相对位置不变，可以参考文章：http://www.acmerblog.com/interview-9-2427/ […]


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This is a tutorial on how to do your own mini-slider for GoPro or any other lightweight camera out there. It's not ment to be a step by step tutorial, because you are probably not going to have the exact same materials I used. Because of that, it's more an extended overview on how I did it, so you can get a good picture on what you really need to acomplish a good result. I have some experience on building sliders, mainly bigger motorized sliders for video and Timelapse. From that experience I've learned that with a DIY slider you are never going to achieve that professional smoothness that you get with bought sliders, but that, spending a lot less you get a pretty good result. For now, this tutorial will cover how to make an hand-powered slider. Maybe later on I will extend it to show how you can motorize it.
4mm.(diameter)
4mm.(diameter)
4mm.(diameter)
4mm.(inner diameter) 13mm.(outher diameter) 6mm.(thick)
10mm(long) 4mm.(diameter)
30mm.(long) 4mm.(diameter)
75mm.(long) 4mm.(diameter)
86mm.(long) 35.5mm.(wide) 3mm.(thick)
86mm.(long) 29.5mm.(wide) 2.4mm.(thick)
600mm.(long) 35.5(wide) 19.5mm.(height) 1.5mm.(thick)
To mount the slider on a tripod, you will need at least two of these.
for fixing the tripod adapter to the dolly
Before we start with the Tutorial, let's see some sample footage I took with the slider
Here I give you an overview of what you will achive if you follow the tutorial. It also shows again the materials needed
You might not find all the materials I used in your Hardware Store, like the Bearings and the tripod bolt and nut. I myself bought them on Ebay, so you might want to do the same. Just search with the title I used and maybe the diameter, making sure the specs are the same. If you can't find it, just contact me.
You also might find a similar material, but not totally the same as mine, then you have to adjust all the measurments to your materials.
Alright, now it's time to cut up the aluminium tube and plates, if you haven't done that already. You can choose another lenght for the dolly, in my case 86mm., if you take that measurment into account for the drilling.
For the drilling, I would recommend to follow my instructions and measurments, because there are more things that you have to consider so that all the bearings touch the rail. The holes for the bolts are all 4mm., the only one that is different is the one for the tripod mount, which is 6mm.
This plate will hold the two L plates together. It's also were the tripod mount is going to be fixated.
You will need to make two of these. They are going to hold the bearings so that the dolly can slide up and down. Because of that, you need to be as precise as possible with the drilling.  This is so that the bearings don't touch the L Plate. It's better if you just cut out just as much as you need so that that doesn't happen.
These are the exact measures for the drilling. All the measures are in mm. The holes have all 4mm in diameter except the the one at thee center of the Top plate, which has 6mm.
Now that you have everithing ready, lets assemble the dolly. There are some things that need to be done first:
To make sure that the dolly will slide properly, you have to make sure that you get this step right, beacuse otherwie, the bearings won't be aligned or will get loose. Getting this right is a matter patience and, if you don't make sure that the distances are right, you may spend a lot more time asembling the dolly, because you might undo some of your work.
PRO TIP: For the thread rod, you might find it difficult to srew in the Nylo Nuts, because you only have one point to apply force. Just set two nyloc nuts at the other end of the thread rod, and fix your tool to the second one. Now, you have two points to apply force to.
Now that everything is prepared, let's proceed to assemble the dolly. To further expalin the graphic below, there are some photos of the dolly fully assembled as well as a 3 view graphic below of that.
Now that the dolly is asssembled, you can try out if everything works by placing it on the rectangular tube. In my case, at first the side bearings weren't tight enought, so i just pressed the four bolts together with my hands, and that fixed it.
If you want to mount the slider on a tripod, I recommend you to buy at least two Tripod Nuts (just search "1/4 BSW x5/8" Whitworth Nuts" on Ebay), drill a hole trough the bottom of the aluminum rectangular pipe and glue the nut from inside with two-component glue.
On the dolly, you might want some sort of tripod head. What I use is the tripod adapter from GoPro fixed to the dolly with a tripod screw and a washer (just search "1/4 BSW x5/8" Whitworth Bolt" on Ebay). To rotate the GoPro, y just apply force.


User stories: 1) I can submit a FormData object that includes a file upload. 2) When I submit something, I will receive the file size in bytes within the JSON response
Submit a file to view its size


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Generated with the
Darkfish Rdoc Generator
2
.


An IRIS serial date number is just a plain number that represents a particular date. You can create serial date numbers using the following functions (depending on desired periodicity):
Furthermore, you can use the usual colon operator to produce a specific range, such as
rng = qq(1990,1):qq(2010,4);
Finally, you can use the following functions to convert dates to strings and vice versa:
You needn't, in fact, care about the serial date numbers themselves too much, but for you info: The integer part of the serial date number is based on the count of periods from (a hypothetical) year 0, say N, whereas its decimal part carries information on periodicity: annual (N + 0.01), semiannual (N + 0.02), quarterly (N + 0.04), bimonthly (N + 0.06), monthly (N + 0.12), or indeterminate (N + 0.00).
Hence, if you type
x = yy(2000)you get a serial number 2000.01, while
x = qq(2000,1)produces 8000.04, i.e. a total of 8000 quarters from year 0 plus 0.04 to specify the periodicity.


A set of custom functions that I use regularly in React and node applications.
npm install
👤 Jeremiah Tenbrink
Contributions, issues and feature requests are welcome!
Feel free to check issues page. You can also take a look at the contributing guide.
Give a ⭐ if this project helped you!
Copyright © 2020 Jeremiah Tenbrink.
This project is ISC licensed.
This README was generated with ❤ by readme-md-generator
Generated using TypeDoc


| Overview | Module | Use | Devguide | Index |
| Nested Modules | Services | Singletons | Interfaces | Structs | Exceptions | Enums | Typedefs | Constant Groups |
| module tree |
| Services | |
| MutableTreeDataModel | If you do not want to implement the XTreeDataModel yourself, use this service. This implementation uses MutableTreeNode for its nodes. |
| MutableTreeNode | Represents an editable tree node as used by the MutableTreeDataModel |
| TreeControl | A control that displays a set of hierarchical data as an outline. |
| TreeControlModel | specifies the standard model of a TreeControl. |
| Interfaces | |
| XMutableTreeDataModel | This is the editable version of the XTreeDataModel. |
| XMutableTreeNode | Represents a mutable tree node as used by the MutableTreeDataModel |
| XTreeControl | An interface to a control that displays a set of hierarchical data as an outline. |
| XTreeDataModel | An instance of this interface is used by the TreeControl to retrieve the hierarchical outline data that is displayed in the actual control. |
| XTreeDataModelListener | An instance of this interface is used by the TreeControl to get notifications about data model changes. |
| XTreeEditListener | You can implement this interface and register with |
| XTreeExpansionListener | An instance of this interface can get notifications from a TreeControl when nodes are expanded or collapsed. |
| XTreeNode | An instance implementing this interface represents the model data for an entry in a XTreeDataModel. |
| Structs | |
| TreeDataModelEvent | An event used by a XTreeDataModel to notify changes in the data model to the XTreeControl. You usually need to fill this event only if you implement the XTreeDataModel yourself. |
| TreeExpansionEvent | This event tells you what node is currently expanding or collapsing. |
| Exceptions | |
| ExpandVetoException | Exception used to stop an expand/collapse from happening. |
Copyright © 2013, The Apache Software Foundation, Licensed under the Apache License, Version 2.0. Apache, the Apache feather logo, Apache OpenOffice and OpenOffice.org are trademarks of The Apache Software Foundation. Other names may be trademarks of their respective owners.


Class VsReference
Data model that presents a visual studio reference that has been loaded.
Inherited Members
Namespace: CodeFactory.VisualStudio
Assembly: CodeFactory.VisualStudio.dll
Syntax
public abstract class VsReference : VsModel, IVsReference, IVsModel, IModel<VisualStudioModelType>
Constructors
| Improve this Doc View SourceVsReference(Boolean, Boolean, IReadOnlyList<ModelException<VisualStudioModelType>>, String, String, ProjectReferenceType, IReadOnlyList<String>)
Constructor for the base class VsModel
Declaration
protected VsReference(bool isLoaded, bool hasErrors, IReadOnlyList<ModelException<VisualStudioModelType>> modelErrors, string name, string filePath, ProjectReferenceType type, IReadOnlyList<string> aliases)
Parameters
| Type | Name | Description |
|---|---|---|
| Boolean | isLoaded | Flag that determines if the model is loaded. |
| Boolean | hasErrors | Flag that determines if errors occured while loading the model. |
| IReadOnlyList<ModelException<VisualStudioModelType>> | modelErrors | The list of errors that occured if any. |
| String | name | The name of the model. |
| String | filePath | The fully qualified file path to the reference |
| ProjectReferenceType | type | The type of reference that is set for the project. |
| IReadOnlyList<String> | aliases | Readonly list of the aliases assigned to this reference. |
Properties
| Improve this Doc View SourceAliases
Readonly list of the aliases assigned to this reference.
Declaration
public IReadOnlyList<string> Aliases { get; }
Property Value
| Type | Description |
|---|---|
| IReadOnlyList<String> |
FilePath
The fully qualified path to the source reference.
Declaration
public string FilePath { get; }
Property Value
| Type | Description |
|---|---|
| String |
HasAliases
Flag that determines if the reference has aliases.
Declaration
public bool HasAliases { get; }
Property Value
| Type | Description |
|---|---|
| Boolean |
Type
The type of the project reference.
Declaration
public ProjectReferenceType Type { get; }
Property Value
| Type | Description |
|---|---|
| ProjectReferenceType |
Methods
| Improve this Doc View SourceGetReferencedProjectAsync()
Gets the VsProject model for the project that represents this reference.
Declaration
public abstract Task<VsProject> GetReferencedProjectAsync()
Returns
| Type | Description |
|---|---|
| Task<VsProject> | The loaded project model or null if the reference does not support a project based reference. |


Installation¶
Overview¶
EnergyBoost is python-based and you can easily install all required library through pip install or conda install for conda users.
Pre-request: Python 3.4+.
Required Packages and versions¶
| A | B |
|---|---|
| pandas | 0.23.0 |
| numpy | 1.14.2 |
| pvlib | 0.5.2 |
| matplotlib | 2.1.2 |
| scikit-learn | 0.20.2 |
| tensorflow-gpu | 1.12.0 |
| cxvpy | 1.0.6 |
| gurobipy | 8.1.0 |
| gym | 0.10.5 |
Via Git or Download¶
If you want the latest version, you can clone our GitHub repository.
Install Git on your computer:
$ sudo apt-get install git
Check and clone the latest version of EnergyBoost:
$ git clone https://github.com/sustainable-computing/EnergyBoost.git
Install requirements:
$ cd ./EnergyBoost/Scripts $ ./installation.sh


object FirebaseHelper
Firebase helper utility functions for performing basic Firebase Realtime functions |
|
object SessionRepository
Session repository Singleton class to manage a connection to a room. |
|
object ShopRepository
Shop repository Handles various Shop functions such as downloading packs, Getting the items to display, getting the user's packs from the database and syncing with local packs. |
|
object UserRepository
User repository Handles the logic of all user operations |


Prophet's birth 'purified civilisation', says PM Imran in message on Eid-i-Miladun Nabi
by https://www.dawn.com/authors/4728/javed-hussain, Dawn.com | Javed HussainAs the country celebrated Eid-i-Miladun Nabi on Sunday, Prime Minister Imran Khan said that the birth of Prophet Muhammad (PBUH) marked the end of a history of inhumanity, oppression, tyranny, ignorance, injustice and deviation from the right path, Radio Pakistan reported.
In his message on the occasion, the premier added that Prophet Muhammad's birth "purified civilisation by inculcating characteristics like human dignity and forgiveness".
He said that the idea of a welfare state was first introduced by Islam.
Eid-i-Miladun Nabi is being celebrated today with religious enthusiasm across the country. The day began with a 31-gun salute in Islamabad and a 21-gun salute in all the provincial capitals.
Following Fajr prayers, special prayers for the unity of the Muslim ummah as well as for the progress and prosperity of Pakistan were offered in various mosques, Radio Pakistan reported.
Special conferences, events and Mehfil Milad are also being held to mark the occasion.
The 'International Rehmatul-lil-Alameen (SAW) Conference' was also held in Islamabad.
Addressing the conference Prime Minister Imran said: "If a person wants to become great, they should make the Prophet their role model. If a country wants to become great, it should follow the principles of the state of Madina."
He added that compassion is for the poor and downtrodden segments of society and not for powerful and corrupt people, Radio Pakistan reported.
In his message, President Dr Arif Alvi said the government is trying to develop Pakistan as a welfare state based on the principles of the state of Madina, Radio Pakistan reported.
The president urged citizens, particularly religious scholars, to play their role in making Pakistan a welfare state, adding that the government is making economic and social reforms in various sectors which could bring positive results "very soon".
In his message, Leader of the Opposition in the National Assembly Shehbaz Sharif said it is a day of salvation from restlessness and illiteracy for humanity.


title
The Life of a
Simple Man
date-main
Dec-05-2006
Everything started when Zebulon discovered that he had a
doppelgänger
who was a serious baseball
aficionado
.


Carmel by the Sea
Carmel by the Sea, California—
I went to the highly anticipated coastal town Carmel by the Sea, and drove the 17-mile scenic drive. It is well while it!
On my way back, I visited Walton Lighthouse in Santa Cruz.
Again, I saw rainbow during my weekend trip!


| < Day Day Up > |
8.7 Further InformationIn this chapter we showed you how to implement basic scripting that enables you to alter game AI outside the main game program. Such scripting can be very effective. Indeed, we successfully implemented these techniques in an MMORG to enable game masters to change the game AI and other game parameters in real time. Implementing a full-fledged scripting engine can be very challenging, and it involves additional concepts that we have not yet covered. These concepts include finite state machines and rule-based systems, which we'll get to in Chapters 9 and 11 of this book. If you decide to pursue scripting even further than we do in this book, you might find the following resources to be particularly helpful:
In the first reference, author Tim Jones shows how to implement a scripted rule-based system from scratch. His approach combines concepts we covered in this chapter and those we will cover in Chapter 11. The second reference includes seven articles written by game programming veterans focusing specifically on issues related to implementing scripting engines for games. |
| < Day Day Up > |


|
||||||||||
| PREV NEXT | FRAMES NO FRAMES |
| Packages that use DataObject | |
|---|---|
| com.extentech.ExtenBean | The ExtenBean package contains an Object Relational Data Object implementation used by ExtenXLS CellBinder data mapping and various data operations. |
| com.extentech.ExtenBean.swing | The ExtenBean swing package contains user interface components for the ExtenBean DataObjects. |
| com.extentech.ExtenXLS | The ExtenXLS package contains the primary classes for working with spreadsheets. |
| com.extentech.ExtenXLS.binder | The ExtenXLS binder package contains the CellBinder API which automates mapping of data to spreadsheets. |
| com.extentech.ExtenXLS.ui | The ExtenXLS UI package contains swing UI spreadsheet components. |
| com.extentech.ExtenXLS.ui.swing | The ExtenXLS UI package contains swing UI spreadsheet components. |
| Uses of DataObject in com.extentech.ExtenBean |
|---|
| Subinterfaces of DataObject in com.extentech.ExtenBean | |
|---|---|
interface |
PageableDataObject
An interface which extends the DataObject interface allowing for paging through result set data. |
| Classes in com.extentech.ExtenBean that implement DataObject | |
|---|---|
class |
DataObjectImpl
A concrete implementation of DataObject and RelationalObject |
class |
ExtenDataObject
The ExtenDataObject provides the functionality of a persistent entity bean. |
class |
GenericDataObject
A basic DataObject implementation. |
class |
XMLDataObject
A DataObject implementation which uses XML data. |
| Fields in com.extentech.ExtenBean declared as DataObject | |
|---|---|
DataObject |
DataObjectImpl.doparent
|
| Methods in com.extentech.ExtenBean that return DataObject | |
|---|---|
DataObject |
XMLDataObjectFactory.createNewDataObject(DataObject d)
creates a new Data Object |
DataObject |
PersistenceEngine.createNewDataObject(DataObject d)
Gets a new instance of a dataobject including empty fields. |
DataObject |
ExtenBeanFactory.createNewDataObject(DataObject d)
Gets a new instance of a dataobject including empty fields. |
DataObject |
PagedDataFactory.createNewDataObject(PageableDataObject d)
Initialize a new, empty dataobject. |
DataObject |
DataObjectImpl.getChildByName(String name)
Find a child DataObject |
DataObject |
DataObject.getChildByName(String name)
|
DataObject |
XMLDataObjectFactory.initDataObject(DataObject dobj)
initDataObject handles parsing an XML file and creating a data object off of it. |
DataObject |
PersistenceEngine.initDataObject(DataObject o)
Loads data into a DataObject according to the DataObject's SQL statement. |
DataObject |
ExtenBeanFactory.initDataObject(DataObject o)
Loads data into a DataObject according to the DataObject's SQL statement. |
DataObject |
PagedDataFactory.initDataObject(PageableDataObject o)
|
DataObject |
PagedDataFactory.initDataObject(PageableDataObject o,
int startRecord,
int count)
|
DataObject |
PagedDataFactory.initDataObjectByPage(PageableDataObject o,
int pageNum,
int count)
|
DataObject |
DataObjectQueryParser.parse(String str)
Read in a SQL string, parse it into a graph of Relational DataObjects -- not initialized with data. |
| Methods in com.extentech.ExtenBean with parameters of type DataObject | |
|---|---|
void |
Transaction.addObject(DataObject o)
|
DataObject |
XMLDataObjectFactory.createNewDataObject(DataObject d)
creates a new Data Object |
DataObject |
PersistenceEngine.createNewDataObject(DataObject d)
Gets a new instance of a dataobject including empty fields. |
DataObject |
ExtenBeanFactory.createNewDataObject(DataObject d)
Gets a new instance of a dataobject including empty fields. |
void |
DataObjectActionListener.dataChanged(DataObject dob)
|
void |
DataObjectImpl.fireDataObjectActionEvent(DataObject dob)
|
void |
DataObject.fireDataObjectActionEvent(DataObject dob)
fires a DataObjectAction event |
int |
ExtenBeanFactory.getHiID(DataObject d)
Get the current HI-ID for a numeric index field. |
String |
DataObjectQueryParser.getQuery(DataObject root)
Read in a DataObject, parse its graph of Relational DataObjects into a valid Query that, when run against the datasource, produces a denormalized resultset suitable for mapping. |
String[] |
DataObjectQueryParser.getQueryParts(DataObject dob)
Read in a DataObject, parse its Query parts |
DataObject |
XMLDataObjectFactory.initDataObject(DataObject dobj)
initDataObject handles parsing an XML file and creating a data object off of it. |
DataObject |
PersistenceEngine.initDataObject(DataObject o)
Loads data into a DataObject according to the DataObject's SQL statement. |
DataObject |
ExtenBeanFactory.initDataObject(DataObject o)
Loads data into a DataObject according to the DataObject's SQL statement. |
void |
DataObjectImpl.initFromDataObject(DataObject dobj)
init with an alternate DataObject type |
void |
GenericDataObject.initNode(int idx,
DataObject dobj)
more or less clone this node, except as a singleton |
void |
VariableConverter.processDataObject(DataObject dobj)
|
boolean |
XMLDataObjectFactory.removeDataObject(DataObject o)
removes the dataobject from the DOM and re-persists to the underlying datasource if possible. |
boolean |
PersistenceEngine.removeDataObject(DataObject o)
Delete a DataObject from its persistent store. |
boolean |
ExtenBeanFactory.removeDataObject(DataObject o)
Delete a DataObject from its persistent store. |
boolean |
XMLDataObjectFactory.storeDataObject(DataObject o)
stores the dataobject to the underlying datasource if possible. |
boolean |
PersistenceEngine.storeDataObject(DataObject o)
Insert a new DataObject into its persistent store. |
boolean |
ExtenBeanFactory.storeDataObject(DataObject o)
Insert a new DataObject into its persistent store. |
boolean |
XMLDataObjectFactory.updateDataObject(DataObject o)
udpates the values of a given node and its children and writes to the underlying data source if possible. |
boolean |
PersistenceEngine.updateDataObject(DataObject o)
Persist changes to a DataObject back to its datastore |
boolean |
ExtenBeanFactory.updateDataObject(DataObject o)
Persist changes to a DataObject back to its datastore |
| Uses of DataObject in com.extentech.ExtenBean.swing |
|---|
| Classes in com.extentech.ExtenBean.swing that implement DataObject | |
|---|---|
class |
ExtenBeanTreeNode
An ExtenDataObject which is also a MutableTreeNode |
class |
XMLBeanNode
TreeNode backed by an XML DataObject |
| Methods in com.extentech.ExtenBean.swing that return DataObject | |
|---|---|
DataObject |
ExtenBeanListModel.getDataObject()
|
DataObject[] |
ExtenBeanComboBoxModel.getDataObject()
|
| Methods in com.extentech.ExtenBean.swing with parameters of type DataObject | |
|---|---|
void |
ExtenBeanListModel.setDataObject(DataObject dobj)
|
| Constructors in com.extentech.ExtenBean.swing with parameters of type DataObject | |
|---|---|
ExtenBeanComboBoxModel(DataObject[] dobj)
|
|
ExtenBeanListModel(DataObject dobj)
|
|
ExtenBeanTreeNode(DataObject dobj)
init with an alternate DataObject type |
|
ExtenBeanTreeNode(DataObject dobj,
String nodetype)
init with an alternate DataObject type |
|
ExtenDataObjectTableModel(DataObject dob,
PersistenceEngine fact)
|
| Uses of DataObject in com.extentech.ExtenXLS |
|---|
| Methods in com.extentech.ExtenXLS that return DataObject | |
|---|---|
DataObject |
WorkBookBeanFactory.createNamedRangeDataObject(NameHandle n,
RelationalObject RDF)
creates a named range data object based off of a name handle |
DataObject |
WorkBookBeanFactory.getInfoBeansFromWorkBook(WorkBookHandle bk,
ExtenXLSReportFactory rptFactory)
This method retrieves values from WorkBookHandles and instantiates an DataObject from the Cell contents. |
| Uses of DataObject in com.extentech.ExtenXLS.binder |
|---|
| Classes in com.extentech.ExtenXLS.binder that implement DataObject | |
|---|---|
class |
CellRangeDataObject
DataObject bound to a Cell Range. |
class |
NamedRangeDataObject
NamedRangeDataObject is an implementation of the DataObject that is intialized off of an ExtenXLS NamedRange |
| Methods in com.extentech.ExtenXLS.binder that return DataObject | |
|---|---|
DataObject |
ExtenXLSReportFactory.createNamedRangeDataObjectX(NameHandle n)
Create a namedRangeDataObject off of a NameHandle. |
DataObject |
CellBinder.getConnection()
Returns connection DataObject for this cellbinder |
DataObject |
ExtenXLSReportFactory.getParentDataObject()
|
| Methods in com.extentech.ExtenXLS.binder with parameters of type DataObject | |
|---|---|
String |
DataBoundCellRange.getHlink(DataObject dobj,
int t)
Get the Hyperlink for the DataBoundCellRange |
static String |
DataBoundCellRange.handleHlinkParams(String hl,
String params,
DataObject dobj,
int t)
|
void |
NamedRangeDataObject.init(DataObject d,
NameHandle n)
Initialize the NRDO with an XML collection DO and a NameHandle |
| Constructors in com.extentech.ExtenXLS.binder with parameters of type DataObject | |
|---|---|
CellBinder(WorkBook b,
DataObject cn,
com.extentech.toolkit.LogOutputter lgr)
The CellBinder is responsible for managing the data bindings of a single connection (JDBC) with the Cells of a single com.extentech.ExtenXLS.WorkBook. |
|
DataBoundCell(CellHandle c,
DataObject d,
String fieldname)
Create a DataBoundCell passing in the CellHandle that it represents, the DataObject to which it is bound, and the field/index in the DataObject containing its values. |
|
DataBoundCell(CellHandle c,
DataObject d,
String fieldname,
int i)
Create a DataBoundCell passing in the CellHandle that it represents, the DataObject to which it is bound, and the field/index in the DataObject containing its values. |
|
NamedRangeDataObject(DataObject d,
NameHandle n)
Constructor Created off of an XMLDataObject and NameHandle. |
| Uses of DataObject in com.extentech.ExtenXLS.ui |
|---|
| Methods in com.extentech.ExtenXLS.ui with parameters of type DataObject | |
|---|---|
void |
ExtenXLSCellRenderer.dataChanged(DataObject dob)
|
| Uses of DataObject in com.extentech.ExtenXLS.ui.swing |
|---|
| Methods in com.extentech.ExtenXLS.ui.swing that return DataObject | |
|---|---|
DataObject[] |
ExtenXLSMapPanel.getConnections()
|
DataObject |
DataObjectTableControllerPanel.getCurrentDataObject()
returns the active dataobject shown in the grid |
DataObject |
ExtenBeanComponentPanel.getDataObject()
|
DataObject |
DataObjectTablePanel.getDataObject()
|
| Methods in com.extentech.ExtenXLS.ui.swing with parameters of type DataObject | |
|---|---|
void |
ExtenXLSRowTable.addNewNode(DataObject cpobj)
set table and XML Mapping values from PropertiesPanel |
void |
ExtenDataObjectPanel.addParameter(DataObject p)
|
void |
ExtenXLSXMLEditorPanel.dataChanged(DataObject dob)
|
void |
ExtenDataObjectPanel.dataChanged(DataObject dob)
|
void |
DataObjectPanel.dataChanged(DataObject dob)
|
void |
ExtenDataObjectPanel.initConnectionNodes(DataObject[] conns)
|
void |
DataObjectPanel.initConnectionNodes(DataObject[] conns)
|
void |
ExtenBeanComponentPanel.initFromDataObject(DataObject o)
initialize the component panel from a DO |
void |
JDBConnectionDialogPanel.setDataObject(DataObject dobj)
|
void |
DataObjectTablePanel.setDataObject(DataObject dataObject)
|
| Constructors in com.extentech.ExtenXLS.ui.swing with parameters of type DataObject | |
|---|---|
DataObjectTablePanel(DataObject d,
PersistenceEngine f,
DataObject parentobj)
|
|
DataObjectTablePanel(String sql,
Connection conn,
DataObject parentobj)
|
|
PropertiesPanel(DataObject dbj)
Display properties panel using data from DataObject dbj Options include Edit-ability, set via a system property |
|
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| PREV NEXT | FRAMES NO FRAMES |


% include("/static/include/title.html"){} include("/static/include/css.html"){} include("/static/include/js.html"){} %>
${i.authorizerName}


Ocala events
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Deep Creek Lake Family Fishing Tours - Garrett County Chamber of ...
Deep Creek Lake Family Fishing Tours | Tours | Guide Services | Fly Fishing | Fishing | Family Activities.
http://garrett.chambermaster.com/list/member/deep-creek-lake-family-fishing-tours-mountain-lake-park-821Fishing Forecast for Deep Creek Lake - The Weather Channel
Find out when the fish are biting at Deep Creek Lake with our Deep Creek Lake fishing reports and fishing forecasts.
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Ocala's best venues
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Wisp Resort-Maryland's own 4-season ski and golf destination
Find skiing, snowboarding, golf, fishing and vacation real estate opportunities. . Wisp Resort and the Deep Creek Lake area have to offer: mountain coaster, .
http://www.wispresort.com/ -
Railey Realty - Deep Creek Lake Maryland Information & Facts
Serving Deep Creek Lake, Garrett County, and Surrounding Areas . Ice fishing is becoming increasingly popular when the lake freezes over in the winter. . Other than a few dead spots in the county, you should be able to get good signals .
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Deep Creek Lake State Park - Maryland Department of Natural ...
Maryland State Park Welcome Map · DNR HOME . DNR predicts great walleye fishing in Deep Creek Lake. . For more information check out our park map.
http://www.dnr.state.md.us/publiclands/western/deepcreek.asp -
Maryland Fishing Information: The Maryland Angler's Network ...
MdAngler.net features Tides, Weather, Fishing News, Articles, Message Board, . Take a look at this very cool interactive map made with Microsoft Virtual Earth . After several weeks of waiting and being hunkered down in deep channels and . Sunken wood, creek mouths and main points are all good places to look for .
http://www.mdangler.net/


We aim to build software that will be a model to serve municipalities across the globe. Each team adds their specific pieces to the puzzle and create software that many benefit from as they seek a reference or a guide to their respectieve municipalities.
The software engineering specialization provides software developers with advanced software methodology, design, and coding techniques. You’ll learn aspect-oriented programming, object-oriented programming, and the principles and techniques to lead a software development team.
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BY EDWIN JAHIEL
MEN OF HONOR (2000) **1/2 Directed by George Tillman. Written by Scott Marshall Smith, based on the life of Carl Brashear. Photography, Anthony B. Richmond. Editing, John Carter. Production design, Leslie Dilley. Music, Mark Isham. Producers, Robert Teitel , Bill Badalato. Cast: Robert De Niro (Billy Sunday), Cuba Gooding Jr. (Carl Brashear), Charlize Theron (Gwen), Aunjanue Ellis (Jo), Hal Holbrook (Mr. Pappy), Michael Rapaport (Snowhill), David Conrad (Hanks), Powers Boothe (Captain Pullman) ,David Keith (Captain Hartigan), et al. A Fox 2000 Pictures release. 128 minutes. Prudishly and illogically rated R (for Navymen's salty language)
Biopics (biographical picture) have been a staple genre since movies began. They--including Hollywood productions--are overwhelmingly "creative," readjust fancifully the lives of notable persons, invent, adapt, prettify... and make historians despair.
Yet many of those films have been major hits. For example, the movies directed by German-born actor and director William Dieterle who achieved fame and glory with a string of MGM pictures with great actors: "The Story of Louis Pasteur" (1936), "The Life of Emile Zola" (1937), "Juarez" (1939), "Dr. Ehrlich's Magic Bullet" (1940), "A Dispatch from Reuters" (1940), "Tennessee Johnson" (1942).
There have been movies about baseball greats like Lou Gehrig, "Pride of the Yankees" (1942); about a remarkable polio-treating nurse, "Sister Kenny" (1946); about the famous nurse Florence Nightingale in "White Angel" (1936) (by Dieterle) or in the British "Lady with a Lamp" (1951); about "Nurse Edith Cavell" (1939), that brave woman who, during World War I, helped Allied soldiers escape German-occupied Belgium and ended up before a firing squad. The list is enormous.
In the heyday of biopics (the 1930s and 1940s) the world was younger, the audiences more naive than now, the film critics fewer and less sophisticated, at least when dealing with history of the big screen. But flights of fancy and non-scholarship notwithstanding, those movies contributed a great deal to educating their spectators. The biopics were a wonderful introduction to facts and persons which only a small fraction of the masses knew anything about or even had ever heard of.
Today, in the area of films about real people and events, the more discriminating viewers and reviewers are more demanding than in the past, The case of "Men of Honor" is another litmus test.
It is "based on" (words that ring the alarm bell) the life of Carl Brashear who was the first black to be accepted (grudgingly) to the Navy's Salvage school. He became an ace deep-sea diver and later a role model hero.
In those days (late 1950s on) the Armed Forces were officially integrated, but there was still no lack of violent, rampant racism. It took superhuman will, tenacity, patience as well as talent to get to where Carl Brashear got. So what we have here is a feel-good movie and a feel-bad one rolled into one during two-plus hours of spectacle. But how many of the details are true and how many are Hollywood?
What rings truest is the feel-bad side. Carl was the son of a Kentucky sharecropper whose struggle to survive is realistically shown as pure horror. Sad and powerful too are most of the many episodes of Brashear's painful rise within a white and openly hostile military milieu. Without revealing the march of events, it is obvious to me that this huge and painful aspect of the movie is its best element.
The feel-good part is another story. Robert De Niro plays Billy Sunday, a super-talented Master Chief and Carl's immediate superior at diving school. Billy is a rebellious, authority-defying maverick, an alcoholic at some point, and while superior at his job, flawed in many other ways. Yet he will turn out to be a man with a conscience.
All this could be true, but is it? And all his is vitiated by bucketfuls of movie cliches, excessive colorfulness, improbable dialogue and speechmaking, paint by numbers progression, and much else that required a suspension of disbelief.
This story also echoes quantities of movies that feature tougher-than-hell D.I.s, movies about Marines shaping up on Parris Island, movies with typically Hollywoodian moments complete with Big Emotions made even bigger by a Too Big Musical Score.
De Niro, who at times is like a parody of Douglas MacArthur plus Popeye, has had better roles, though even here, his being De Niro does salvage some of the silliness.
Even so, in the footage of Sarl and Billy, the two leading characters, when their personal lives are depicted the film piles up unconvincing or phony or cute passages. A sampling, in no order of priority:
In the opening scenes in Kentucky, we glimpse the boy Carl's beautiful mother. She is oddly chic within a context of people who live in misery --at least I remember her as elegant. The romance between Carl and and a lady librarian plus medical student is touching, partly because Jo (Aunjanue Ellis) is good and appealing. But the war hero commandant of the diving school (Holbrook) is so totally gaga that his mega-racism is ludicrous and ineffectual, more a mental case than anything else. Worse yet, Gwen (Charlize Theron) who seems to be De Niro's child-wife, is a totally useless, unclear and unneeded character.
Where the guillotine's blade falls is in the last sequence, set in a military courtroom. It is so "inspirational," colorful, sentimental and fabricated that the audience should be provided with certificates of authenticity.
The film does keep you going, does perform a good service by acquainting us with the unusual and admirable Carl Brashear, but is also as untrustworthy as the near totality of biopics. One would think that in the second century of movies there must be ways to maximize veracity and minimize theatrics. Yet the picture does have a saving grace -- in that it deals clearly with the scourge of racism. This can make us forgive "Men of Honor" many of its sins.
Technically it's A-1 and, I suppose, true to deep-sea procedures in sequences that make the divers in heavy gear look like immigrants from Jules Verne and "20,000 Leagues under the Sea."
The review above was posted to the
rec.arts.movies.reviews newsgroup (de.rec.film.kritiken for German reviews).
The Internet Movie Database accepts no responsibility for the contents of the
review and has no editorial control. Unless stated otherwise, the copyright
belongs to the author.
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Related links: index of all rec.arts.movies.reviews reviews


| Modifier and Type | Field and Description |
|---|---|
protected static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.EMPTY
Default instance has no explicitly ignored fields, does not ignore unknowns,
does not explicitly allow getters/setters (that is, ignorals apply to both),
but does use merging for combining overrides with base settings
|
| Modifier and Type | Method and Description |
|---|---|
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.construct(Set<String> ignored,
boolean ignoreUnknown,
boolean allowGetters,
boolean allowSetters,
boolean merge)
Factory method that may be used (although is NOT the recommended way)
to construct an instance from a full set of properties.
|
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.empty()
Accessor for default instances which has "empty" settings; that is:
No explicitly defined fields to ignore
Does not ignore unknown fields
Does not "allow" getters if property ignored (that is, ignorals apply to both setter and getter)
Does not "allow" setters if property ignored (that is, ignorals apply to both setter and getter)
Does use merge when combining overrides to base settings, such that `true` settings
for any of the properties results in `true`, and names of fields are combined (union)
|
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.forIgnoredProperties(Set<String> propNames) |
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.forIgnoredProperties(String... propNames) |
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.forIgnoreUnknown(boolean state) |
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.from(JsonIgnoreProperties src) |
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.merge(JsonIgnoreProperties.Value base,
JsonIgnoreProperties.Value overrides)
Helper method that will try to combine values from two
JsonIgnoreProperties.Value
instances, using one as base settings, and the other as overrides
to use instead of base values when defined; base values are only
use if override does not specify a value (matching value is null
or logically missing). |
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.mergeAll(JsonIgnoreProperties.Value... values) |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withAllowGetters() |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withAllowSetters() |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withIgnored(Set<String> ignored) |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withIgnored(String... ignored) |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withIgnoreUnknown() |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withMerge() |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withoutAllowGetters() |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withoutAllowSetters() |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withoutIgnored() |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withoutIgnoreUnknown() |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withoutMerge() |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withOverrides(JsonIgnoreProperties.Value overrides)
Mutant factory method that merges values of this value with given override
values, so that any explicitly defined inclusion in overrides has precedence over
settings of this value instance.
|
| Modifier and Type | Method and Description |
|---|---|
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.merge(JsonIgnoreProperties.Value base,
JsonIgnoreProperties.Value overrides)
Helper method that will try to combine values from two
JsonIgnoreProperties.Value
instances, using one as base settings, and the other as overrides
to use instead of base values when defined; base values are only
use if override does not specify a value (matching value is null
or logically missing). |
static JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.mergeAll(JsonIgnoreProperties.Value... values) |
JsonIgnoreProperties.Value |
JsonIgnoreProperties.Value.withOverrides(JsonIgnoreProperties.Value overrides)
Mutant factory method that merges values of this value with given override
values, so that any explicitly defined inclusion in overrides has precedence over
settings of this value instance.
|
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