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prog:gcc [2020/02/25 00:18] – [Information et taille des classes et tables virtuelles] : fix clang -fdump-record-layouts rootprog:gcc [2024/11/12 12:48] (Version actuelle) – Déplacement des sanitizer vers une page dédiée root
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 Nightly pour [[https://bitbucket.org/ejsvifq_mabmip/mingw-gcc/src/master/|Windows 64]] Nightly pour [[https://bitbucket.org/ejsvifq_mabmip/mingw-gcc/src/master/|Windows 64]]
 +
 +[[https://gcc.gnu.org/projects/cxx-status.html|C++ status]], [[https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html|libstdc++ status]]
 +
 +====Ubuntu====
 +
 +  * Installation en parallèle
 +
 +Ubuntu ne fournit pas de méthode 100% automatique. Il faut passer manuellement par ''update-alternatives''.
 +
 +<code bash>
 +sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 110 --slave /usr/bin/g++ g++ /usr/bin/g++-11
 +</code>
 +
 +Utiliser pour switcher entre les versions :
 +
 +<code bash>
 +sudo update-alternatives --config gcc
 +</code>
  
 =====Diagnostic===== =====Diagnostic=====
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 [[https://www.thegeekstuff.com/2012/08/gprof-tutorial/|GPROF Tutorial – How to use Linux GNU GCC Profiling Tool]] {{ :prog:gcc:gprof_tutorial_how_to_use_linux_gnu_gcc_profiling_tool_2020-02-24_3_24_57_pm_.html |Archive du 20/08/2012 le 24/02/2020}} [[https://www.thegeekstuff.com/2012/08/gprof-tutorial/|GPROF Tutorial – How to use Linux GNU GCC Profiling Tool]] {{ :prog:gcc:gprof_tutorial_how_to_use_linux_gnu_gcc_profiling_tool_2020-02-24_3_24_57_pm_.html |Archive du 20/08/2012 le 24/02/2020}}
-=====Commun avec clang===== 
-====Sanitizer==== 
-Il existe ''-fsanitize=address,thread,undefined'' mais ''address'' et ''thread'' ne sont pas compatible simultanément. 
-===address=== 
-Il détecte des erreurs de type global-buffer-overflow, heap-use-after-free. 
-[[https://www.youtube.com/watch?v=qTkYDA0En6U|CppCon 2015: Kostya Serebryany “Beyond Sanitizers, Fuzzing and Hardening your C++ apps for Security and Reliability”]] 
  
-  * global-buffer-overflow +====Couverture de code====
-<file c main.c> +
-int global_array[100] = {-1};+
  
-int main(int argc, char **argv) { +Options à ajouter à la compilation : ''-O0 %%--%%coverage''
-  return global_array[argc+100]; +
-} +
-</file>+
  
-  gcc main.c -g -fsanitize=address -o main && ./main+Options à ajouter au lieur : ''%%--%%coverage''
  
-  ================================================================= +Puis exécuter le ou les programmes. Attention, pas d'exécution en parallèle. Les fichiers ''.gcno'' ne le supportent pas.
-  ==2500==ERROR: AddressSanitizer: global-buffer-overflow on address 0x000000740cf4 at pc 0x00000050d9bf bp 0x7ffeabb89b70 sp 0x7ffeabb89b68 +
-  READ of size 4 at 0x000000740cf4 thread T0 +
-      #0 0x50d9be in main /tmp/main.c:4:10 +
-      #1 0x7f1208faa461 in __libc_start_main /home/legarrec/info/portage/sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 +
-      #2 0x419709 in _start (/tmp/main+0x419709) +
-   +
-  0x000000740cf4 is located 4 bytes to the right of global variable 'global_array' defined in 'main.c:1:5' (0x740b60) of size 400 +
-  SUMMARY: AddressSanitizer: global-buffer-overflow /tmp/main.c:4:10 in main +
-  Shadow bytes around the buggy address: +
-    0x0000800e0140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0000800e0150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0000800e0160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0000800e0170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0000800e0180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-  =>0x0000800e0190: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[f9]f9 +
-    0x0000800e01a0: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 +
-    0x0000800e01b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0000800e01c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0000800e01d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0000800e01e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-  Shadow byte legend (one shadow byte represents 8 application bytes): +
-    Addressable:           00 +
-    Partially addressable: 01 02 03 04 05 06 07  +
-    Heap left redzone:       fa +
-    Freed heap region:       fd +
-    Stack left redzone:      f1 +
-    Stack mid redzone:       f2 +
-    Stack right redzone:     f3 +
-    Stack after return:      f5 +
-    Stack use after scope:   f8 +
-    Global redzone:          f9 +
-    Global init order:       f6 +
-    Poisoned by user:        f7 +
-    Container overflow:      fc +
-    Array cookie:            ac +
-    Intra object redzone:    bb +
-    ASan internal:           fe +
-    Left alloca redzone:     ca +
-    Right alloca redzone:    cb +
-  ==2500==ABORTING+
  
-[[prog:valgrind|valgrind]] ne détecte pas l'erreur. +<code bash> 
- +lcov --capture --directory build --gcov-tool /usr/bin/gcov-10 --rc lcov_branch_coverage=1 --output-file build/coverage.info 
-  * heap-use-after-free +lcov --remove build/coverage.info "/usr/include/*" --rc lcov_branch_coverage=1 -o build/coverage2.info 
-<file c main2.cc> +genhtml --output-directory build/coverage --demangle-cpp --num-spaces 2 --sort --function-coverage --branch-coverage --legend build/coverage2.info 
-int main(int argc, char **argv) { +find build/coverage -name "*.html" -exec sed -i -r "s#headerValue""\>.*-.*-.* .*:.*:.*td#headerValue""></td#g" {} \; 
-  int *array = new int[100]; +</code>
-  delete [] array; +
-  return array[argc]; +
-} +
-</file> +
- +
-  g++ main2.c -g -fsanitize=address -o main2 && ./main2 +
- +
-  ================================================================= +
-  ==2765==ERROR: AddressSanitizer: heap-use-after-free on address 0x614000000044 at pc 0x000000512445 bp 0x7ffd51684f60 sp 0x7ffd51684f58 +
-  READ of size 4 at 0x614000000044 thread T0 +
-      #0 0x512444 in main /tmp/main2.c:4:10 +
-      #1 0x7fd8d0086461 in __libc_start_main /home/legarrec/info/portage/sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 +
-      #2 0x419d29 in _start (/tmp/main2+0x419d29) +
-   +
-  0x614000000044 is located 4 bytes inside of 400-byte region [0x614000000040,0x6140000001d0) +
-  freed by thread T0 here: +
-      #0 0x50ef30 in operator delete[](void*) /home/legarrec/info/portage/sys-libs/compiler-rt-sanitizers-5.0.0/work/compiler-rt-5.0.0.src/lib/asan/asan_new_delete.cc:141 +
-      #1 0x5123f6 in main /tmp/main2.c:3:3 +
-      #2 0x7fd8d0086461 in __libc_start_main /home/legarrec/info/portage/sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 +
-      #3 0x419d29 in _start (/tmp/main2+0x419d29) +
-     +
-  previously allocated by thread T0 here: +
-      #0 0x50e1c8 in operator new[](unsigned long) /home/legarrec/info/portage/sys-libs/compiler-rt-  sanitizers-5.0.0/work/compiler-rt-5.0.0.src/lib/asan/asan_new_delete.cc:95 +
-      #1 0x5123d4 in main /tmp/main2.c:2:16 +
-      #2 0x7fd8d0086461 in __libc_start_main /home/legarrec/info/portage/sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 +
-      #3 0x419d29 in _start (/tmp/main2+0x419d29) +
-   +
-  SUMMARY: AddressSanitizer: heap-use-after-free /tmp/main2.c:4:10 in main +
-  Shadow bytes around the buggy address: +
-    0x0c287fff7fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0c287fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0c287fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0c287fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0c287fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-  =>0x0c287fff8000: fa fa fa fa fa fa fa fa[fd]fd fd fd fd fd fd fd +
-    0x0c287fff8010: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd +
-    0x0c287fff8020: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd +
-    0x0c287fff8030: fd fd fd fd fd fd fd fd fd fd fa fa fa fa fa fa +
-    0x0c287fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa +
-    0x0c287fff8050: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa +
- +
-[[prog:valgrind|valgrind]] détecte l'erreur. +
- +
-  ==2787== Command: ./main2 +
-  ==2787==  +
-  ==2787== Invalid read of size 4 +
-  ==2787==    at 0x4005AF: main (main2.c:4) +
-  ==2787==  Address 0x5b25c84 is 4 bytes inside a block of size 400 free'd +
-  ==2787==    at 0x4C2CAA5: operator delete[](void*) (vg_replace_malloc.c:621) +
-  ==2787==    by 0x4005A6: main (main2.c:3) +
-  ==2787==  Block was alloc'd at +
-  ==2787==    at 0x4C2BAC8: operator new[](unsigned long) (vg_replace_malloc.c:423) +
-  ==2787==    by 0x400584: main (main2.c:2) +
- +
-  * stack-use-after-return +
-<file c main3.c> +
-int *g; +
- +
-void LeakLocal() { +
-  int local; +
-  g = &local; +
-} +
- +
-int main(){ +
-  LeakLocal(); +
-  return *g; +
-} +
-</file> +
- +
-  gcc main3.c -g -o main3 -fsanitize=address +
-  ASAN_OPTIONS=detect_stack_use_after_return=1 ./main3 +
- +
-L'utilisation de ''ASAN_OPTIONS=detect_stack_use_after_return=1'' est nécessaire car cette option peut créer des faux positifs. +
- +
-  ================================================================= +
-  ==2907==ERROR: AddressSanitizer: stack-use-after-return on address 0x7f57b2a00020 at pc 0x00000050db25 bp 0x7ffe8dfc7330 sp 0x7ffe8dfc7328 +
-  READ of size 4 at 0x7f57b2a00020 thread T0 +
-      #0 0x50db24 in main /tmp/main3.c:10:10 +
-      #1 0x7f57b604d461 in __libc_start_main /home/legarrec/info/portage/sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 +
-      #2 0x419709 in _start (/tmp/main3+0x419709) +
-   +
-  Address 0x7f57b2a00020 is located in stack of thread T0 at offset 32 in frame +
-      #0 0x50d95f in LeakLocal /tmp/main3.c:3 +
-   +
-    This frame has 1 object(s): +
-      [32, 36) 'local' (line 4) <== Memory access at offset 32 is inside this variable +
-  HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext +
-        (longjmp and C++ exceptions *are* supported) +
-  SUMMARY: AddressSanitizer: stack-use-after-return /tmp/main3.c:10:10 in main +
-  Shadow bytes around the buggy address: +
-    0x0feb76537fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0feb76537fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0feb76537fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0feb76537fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0feb76537ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-  =>0x0feb76538000: f5 f5 f5 f5[f5]f5 f5 f5 00 00 00 00 00 00 00 00 +
-    0x0feb76538010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0feb76538020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0feb76538030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0feb76538040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
-    0x0feb76538050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +
- +
-[[prog:valgrind|valgrind]] détecte l'erreur. +
- +
-  valgrind --track-origins=yes ./main3 +
- +
-  ==2961== Syscall param exit_group(status) contains uninitialised byte(s) +
-  ==2961==    at 0x4F002B8: _Exit (_exit.c:31) +
-  ==2961==    by 0x4E70423: __run_exit_handlers (exit.c:98) +
-  ==2961==    by 0x4E704DC: exit (exit.c:105) +
-  ==2961==    by 0x4E58468: (below main) (libc-start.c:329) +
-  ==2961==  Uninitialised value was created by a stack allocation +
-  ==2961==    at 0x4004A4: main (main3.c:10) +
- +
-===thread=== +
-<file cpp main4.cc> +
-#include <thread> +
- +
-int main() { +
-  int x; +
-  std::thread t([&]{x=42;}); +
-  x = 43; +
-  t.join(); +
- +
-  return 0; +
-} +
-</file> +
- +
-  g++ -std=c++11 main4.c -g -o main4 -fsanitize=thread +
- +
-<note important>Le plantage reste aléatoire et il est nécessaire de lancer l'application plusieurs fois. +
-</note> +
- +
-  ================== +
-  WARNING: ThreadSanitizer: data race (pid=3226) +
-    Write of size 4 at 0x7ffd04d5b144 by thread T1: +
-      #0 operator() /tmp/main4.c:5 (main4+0x000000400d0b) +
-      #1 __invoke_impl<void, main()::<lambda()> > /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/bits/invoke.h:60 (main4+0x000000401171) +
-      #2 __invoke<main()::<lambda()> > /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/bits/invoke.h:95 (main4+0x000000400e30) +
-      #3 _M_invoke<0> /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/thread:234 (main4+0x0000004014b5) +
-      #4 operator() /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/thread:243 (main4+0x000000401448) +
-      #5 _M_run /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/thread:186 (main4+0x0000004013ee) +
-      #6 <null> <null> (libstdc++.so.6+0x0000000e251e) +
-   +
-    Previous write of size 4 at 0x7ffd04d5b144 by main thread: +
-      #0 main /tmp/main4.c:6 (main4+0x000000400d75) +
-   +
-    Location is stack of main thread. +
-   +
-    Thread T1 (tid=3228, running) created by main thread at: +
-      #0 pthread_create <null> (libtsan.so.0+0x00000002917a) +
-      #1 std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)()) <null> (libstdc++.so.6+0x0000000e288c) +
-      #2 main /tmp/main4.c:5 (main4+0x000000400d69) +
-   +
-  SUMMARY: ThreadSanitizer: data race /tmp/main4.c:5 in operator() +
-  ================== +
-  ThreadSanitizer: reported 1 warnings +
- +
-[[prog:valgrind|valgrind]] ne détecte pas l'erreur. +
- +
-===undefined=== +
-<file c main5.c> +
-int main(int argc, char **argv) { +
-  int t = argc << 16; +
-  return t*t; +
-} +
-</file> +
- +
-  gcc -fsanitize=undefined main5.c -g -o main5+
  
-  main6.c:3:11: runtime error: signed integer overflow: 65536 * 65536 cannot be represented in type 'int'+Attention, la version de gcov doit correspondre à celle de gcc.
  
-[[prog:valgrind|valgrind]] ne détecte pas l'erreur.+En option, on supprime la date pour qu'un diff simple puisse se faire.
  
prog/gcc.1582586335.txt.gz · Dernière modification : 2020/02/25 00:18 de root