ChapterÂ 3.Â Using

Debug Versions of Library Binary Files

+ As described above, libstdc++ is built with debug symbols enabled by default, + but because it's also built with optimizations the code can be hard to + follow when stepping into the library in a debugger. +

+ If you would like to debug libstdc++.so itself, + there are two ways to build an unoptimized libstdc++ with debug flags. + The first is to create a separate debug build by running make from the + top-level of a tree freshly-configured with +

+     --enable-libstdcxx-debug
+

and perhaps

+     --enable-libstdcxx-debug-flags='...'
+

+ Both the normal build and the debug build will persist, without + having to specify CXXFLAGS, and the debug library will + be installed in a separate directory tree, in (prefix)/lib/debug. + For more information, look at the + configuration section. +

+ A second approach is to use the configuration flags +

+     make CXXFLAGS='-g3 -fno-inline -O0' all
+

The new version imposes a much smaller space overhead on the generated object file. The checks are also cleaner and easier to read and understand. -

They are off by default for all versions of GCC from 3.0 to 3.4 (the - latest release at the time of writing). +

They are off by default for all GCC 3.0 and all later versions. They can be enabled at configure time with --enable-concept-checks. You can enable them on a per-translation-unit basis with @@ -34,8 +33,15 @@ (or with #define _GLIBCPP_CONCEPT_CHECKS for versions 3.1, 3.2 and 3.3).

Please note that the concept checks only validate the requirements - of the old C++03 standard. C++11 was expected to have first-class - support for template parameter constraints based on concepts in the core - language. This would have obviated the need for the library-simulated concept - checking described above, but was not part of C++11. + of the old C++03 standard and reject some valid code that meets the relaxed + requirements of C++11 and later standards. + C++11 was expected to have first-class support for template parameter + constraints based on concepts in the core language. + This would have obviated the need for the library-simulated concept checking + described above, but was not part of C++11. + C++20 adds a different model of concepts, which is now used to constrain + some new parts of the C++20 library, e.g. the + <ranges> header and the new overloads in the + <algorithm> header for working with ranges. + The old library-simulated concept checks might be removed at a future date.

ChapterÂ 3.Â Using
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ChapterÂ 3.Â Using

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PartÂ I.Â Introduction -

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ChapterÂ 3.Â Using

Command Options

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ChapterÂ 3.Â Using

Command Options

The set of features available in the GNU C++ library is shaped by several GCC Command Options. Options that impact libstdc++ are diff --git a/libstdc++-v3/doc/html/manual/using_macros.html b/libstdc++-v3/doc/html/manual/using_macros.html index 62c66b7de4c2..ae5646926307 100644 --- a/libstdc++-v3/doc/html/manual/using_macros.html +++ b/libstdc++-v3/doc/html/manual/using_macros.html @@ -123,5 +123,5 @@ or malloc_allocator. The annotations must be present on all vector operations or none, so this macro must be defined to the same value for all translation units that create, - destroy or modify vectors. + destroy, or modify vectors.

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HeadersÂ	Home	Â Dual ABI

\ No newline at end of file diff --git a/libstdc++-v3/doc/xml/manual/debug.xml b/libstdc++-v3/doc/xml/manual/debug.xml index 7f6d0876fc61..23dbae5e5213 100644 --- a/libstdc++-v3/doc/xml/manual/debug.xml +++ b/libstdc++-v3/doc/xml/manual/debug.xml @@ -30,7 +30,7 @@ flags can be varied to change debugging characteristics. For instance, turning off all optimization via the

-g -O0
     -fno-inline

flags will disable inlining and optimizations, - and add debugging information, so that stepping through all functions, + and include debugging information, so that stepping through all functions, (including inlined constructors and destructors) is possible. In addition, -fno-eliminate-unused-debug-types can be used when additional debug information, such as nested class info, @@ -55,41 +55,30 @@ -

Debug Versions of Library Binary Files - +

Debug Mode - If you would like debug symbols in libstdc++, there are two ways to - build libstdc++ with debug flags. The first is to create a separate - debug build by running make from the top-level of a tree - freshly-configured with - - - --enable-libstdcxx-debug - -and perhaps - - --enable-libstdcxx-debug-flags='...' - - - Both the normal build and the debug build will persist, without - having to specify CXXFLAGS, and the debug library will - be installed in a separate directory tree, in (prefix)/lib/debug. - For more information, look at the - configuration section. + The Debug Mode + has compile and run-time checks for many containers. - A second approach is to use the configuration flags + There are also lightweight assertions for checking function preconditions, + such as checking for out-of-bounds indices when accessing a + std::vector. These can be enabled without using + the full Debug Mode, by using + (see ). - - make CXXFLAGS='-g3 -fno-inline -O0' all - + +

+ +

Tracking uncaught exceptions - This quick and dirty approach is often sufficient for quick - debugging tasks, when you cannot or don't want to recompile your - application to use the debug mode. + The verbose + termination handler gives information about uncaught + exceptions which kill the program. +

Memory Leak Hunting @@ -99,6 +88,13 @@ which is enabled by the option. + + The std::vector implementation has additional + instrumentation to work with AddressSanitizer, but this has to be enabled + explicitly by using + (see ). + + There are also various third party memory tracing and debug utilities that can be used to provide detailed memory allocation information @@ -331,22 +327,45 @@

Tracking uncaught exceptions +

Debug Versions of Library Binary Files - The verbose - termination handler gives information about uncaught - exceptions which kill the program. + As described above, libstdc++ is built with debug symbols enabled by default, + but because it's also built with optimizations the code can be hard to + follow when stepping into the library in a debugger. -

Debug Mode + + If you would like to debug libstdc++.so itself, + there are two ways to build an unoptimized libstdc++ with debug flags. + The first is to create a separate debug build by running make from the + top-level of a tree freshly-configured with + + + --enable-libstdcxx-debug + +and perhaps + + --enable-libstdcxx-debug-flags='...' + + + Both the normal build and the debug build will persist, without + having to specify CXXFLAGS, and the debug library will + be installed in a separate directory tree, in (prefix)/lib/debug. + For more information, look at the + configuration section. + + + + A second approach is to use the configuration flags + + + make CXXFLAGS='-g3 -fno-inline -O0' all + - The Debug Mode - has compile and run-time checks for many containers. -

Compile Time Checking The Compile-Time diff --git a/libstdc++-v3/doc/xml/manual/using.xml b/libstdc++-v3/doc/xml/manual/using.xml index b3b0c368e444..8ac7e74034c4 100644 --- a/libstdc++-v3/doc/xml/manual/using.xml +++ b/libstdc++-v3/doc/xml/manual/using.xml @@ -1341,7 +1341,7 @@ g++ -Winvalid-pch -I. -include stdc++.h -H -g -O2 hello.cc -o test.exe or malloc_allocator. The annotations must be present on all vector operations or none, so this macro must be defined to the same value for all translation units that create, - destroy or modify vectors. + destroy, or modify vectors.

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