即使gccv7和v9.3.1-O0优化已关闭，GDB仍会显示变量<optimized out>

如何解决即使gccv7和v9.3.1-O0优化已关闭，GDB仍会显示变量<optimized out>

已修正！ 只有3个源代码模块，没有make文件。如图所示，一个gcc命令进行编译和链接。我看不到所有方式都无法编译的方式。

我尝试打印的矩阵指针是从较大的结构数组提取到自动变量的。当我在gdb中打印完整的结构路径时，它就起作用了。

当您明确关闭优化并在COLLECT_GCC_OPTIONS ='-O0'中显示详细的编译器输出进行验证时，“使调试产生预期的结果”以优化并隐藏变量似乎是矛盾的。

即使使用-0g，别名变量仍为

在Opensuse飞跃15.1上使用gcc 9.3.1 设置env var CFLAGS =“” 使用-O0关闭所有优化 我也尝试使用gcc 7.5.0 我正在隔离。当我尝试在gdb中打印变量时，它们显示

您的帖子似乎主要是代码；请添加更多详细信息。 更多详情 更多细节 修复了！！

user1@nova:~/bin> CFLAGS=""; gcc -v  -O0 -g -m64  -Wuninitialized -fopenmp -I/usr/local/mysql/include -O0 /home/user1/bin/align_ppm.c -lm  -lgd -lpng16 -lz            -o /home/user1/bin/align_ppm_d 

`/home/user1/bin/align_ppm_d' has changed; re-reading symbols.
Starting program: /home/user1/bin/align_ppm_d pf-2020.0805-291582.dt.ppm  pf-2020.0805-291583.dt.ppm  -d -d -s  -d  -f    > ap23c.dt.log

[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
[New Thread 0x7fff58627700 (LWP 5330)]
[New Thread 0x7fff57e26700 (LWP 5331)]
[New Thread 0x7fff57625700 (LWP 5332)]
[New Thread 0x7fff56e24700 (LWP 5333)]
[New Thread 0x7fff56623700 (LWP 5334)]
[New Thread 0x7fff55e22700 (LWP 5335)]
[New Thread 0x7fff55621700 (LWP 5336)]

Thread 1 "align_ppm_d" received signal SIGSEGV,Segmentation fault.
0x00000000004a5631 in graph_hit_mis (mgc=0x718d80 <MGC>,smcss=0x719c10 <smcss>,gfinal=1,maia=0x719b70 <MMIA>,tsa=0x71a440 <tsa>,debug=3) at /home/user1/bin/align_ppm.c:1240
     1240                                              if((fmat[fy][fintoff]) & bmask) hitidx += 2; } // FIN
(gdb) p fmat
$151 = <optimized out>
(gdb) p  fmat[fy][fintoff]
value has been optimized out

Using built-in specs.
COLLECT_GCC=/usr/bin/gcc-9
COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/9/lto-wrapper
OFFLOAD_TARGET_NAMES=hsa:nvptx-none
Target: x86_64-suse-linux
Configured with: ../configure --prefix=/usr --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64 --enable-languages=c,c++,fortran,ada,go --enable-offload-targets=hsa,nvptx-none=/usr/nvptx-none,--without-cuda-driver --disable-werror --with-gxx-include-dir=/usr/include/c++/9 --enable-ssp --disable-libssp --disable-libvtv --disable-cet --disable-libcc1 --disable-plugin --with-bugurl=https://bugs.opensuse.org/ --with-pkgversion='SUSE Linux' --with-slibdir=/lib64 --with-system-zlib --enable-libstdcxx-allocator=new --disable-libstdcxx-pch --enable-version-specific-runtime-libs --with-gcc-major-version-only --enable-linker-build-id --enable-linux-futex --enable-gnu-indirect-function --program-suffix=-9 --without-system-libunwind --enable-multilib --with-arch-32=x86-64 --with-tune=generic --build=x86_64-suse-linux --host=x86_64-suse-linux
Thread model: posix
gcc version 9.3.1 20200406 [revision 6db837a5288ee3ca5ec504fbd5a765817e556ac2] (SUSE Linux) 
COLLECT_GCC_OPTIONS='-v' '-O0' '-g' '-m64' '-Wuninitialized' '-fopenmp' '-I' '/usr/local/mysql/include' '-O0' '-o' '/home/user1/bin/align_ppm_d' '-mtune=generic' '-march=x86-64' '-pthread'
 /usr/lib64/gcc/x86_64-suse-linux/9/cc1 -quiet -v -I /usr/local/mysql/include -D_REENTRANT /home/user1/bin/align_ppm.c -quiet -dumpbase align_ppm.c -m64 -mtune=generic -march=x86-64 -auxbase align_ppm -g -O0 -O0 -Wuninitialized -version -fopenmp -o /home/user1/tmp/cchRAKiS.s
GNU C17 (SUSE Linux) version 9.3.1 20200406 [revision 6db837a5288ee3ca5ec504fbd5a765817e556ac2] (x86_64-suse-linux)
        compiled by GNU C version 9.3.1 20200406 [revision 6db837a5288ee3ca5ec504fbd5a765817e556ac2],GMP version 6.1.2,MPFR version 4.0.1,MPC version 1.1.0,isl version isl-0.18-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/mysql/include
 /usr/lib64/gcc/x86_64-suse-linux/9/include
 /usr/local/include
 /usr/lib64/gcc/x86_64-suse-linux/9/include-fixed
 /usr/lib64/gcc/x86_64-suse-linux/9/../../../../x86_64-suse-linux/include
 /usr/include
End of search list.
GNU C17 (SUSE Linux) version 9.3.1 20200406 [revision 6db837a5288ee3ca5ec504fbd5a765817e556ac2] (x86_64-suse-linux)
        compiled by GNU C version 9.3.1 20200406 [revision 6db837a5288ee3ca5ec504fbd5a765817e556ac2],isl version isl-0.18-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 00000000000000000000000000000000
COLLECT_GCC_OPTIONS='-v' '-O0' '-g' '-m64' '-Wuninitialized' '-fopenmp' '-I' '/usr/local/mysql/include' '-O0' '-o' '/home/user1/bin/align_ppm_d' '-mtune=generic' '-march=x86-64' '-pthread'
 /usr/lib64/gcc/x86_64-suse-linux/9/../../../../x86_64-suse-linux/bin/as -v -I /usr/local/mysql/include --64 -o /home/user1/tmp/ccCC3GjB.o /home/user1/tmp/cchRAKiS.s
GNU assembler version 2.32.0 (x86_64-suse-linux) using BFD version (GNU Binutils; openSUSE Leap 15.1) 2.32.0.20190909-lp151.3.6
COMPILER_PATH=/usr/lib64/gcc/x86_64-suse-linux/9/:/usr/lib64/gcc/x86_64-suse-linux/9/:/usr/lib64/gcc/x86_64-suse-linux/:/usr/lib64/gcc/x86_64-suse-linux/9/:/usr/lib64/gcc/x86_64-suse-linux/:/usr/lib64/gcc/x86_64-suse-linux/9/../../../../x86_64-suse-linux/bin/
LIBRARY_PATH=/usr/lib64/gcc/x86_64-suse-linux/9/:/usr/lib64/gcc/x86_64-suse-linux/9/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/usr/lib64/gcc/x86_64-suse-linux/9/../../../../x86_64-suse-linux/lib/:/usr/lib64/gcc/x86_64-suse-linux/9/../../../:/lib/:/usr/lib/
Reading specs from /usr/lib64/gcc/x86_64-suse-linux/9/libgomp.spec
COLLECT_GCC_OPTIONS='-v' '-O0' '-g' '-m64' '-Wuninitialized' '-fopenmp' '-I' '/usr/local/mysql/include' '-O0' '-o' '/home/user1/bin/align_ppm_d' '-mtune=generic' '-march=x86-64' '-pthread'
 /usr/lib64/gcc/x86_64-suse-linux/9/collect2 -plugin /usr/lib64/gcc/x86_64-suse-linux/9/liblto_plugin.so -plugin-opt=/usr/lib64/gcc/x86_64-suse-linux/9/lto-wrapper -plugin-opt=-fresolution=/home/user1/tmp/cc1z5Qzl.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lpthread -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s --build-id --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o /home/user1/bin/align_ppm_d /usr/lib64/gcc/x86_64-suse-linux/9/../../../../lib64/crt1.o /usr/lib64/gcc/x86_64-suse-linux/9/../../../../lib64/crti.o /usr/lib64/gcc/x86_64-suse-linux/9/crtbegin.o /usr/lib64/gcc/x86_64-suse-linux/9/crtoffloadbegin.o -L/usr/lib64/gcc/x86_64-suse-linux/9 -L/usr/lib64/gcc/x86_64-suse-linux/9/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/lib64/gcc/x86_64-suse-linux/9/../../../../x86_64-suse-linux/lib -L/usr/lib64/gcc/x86_64-suse-linux/9/../../.. /home/user1/tmp/ccCC3GjB.o -lm -lgd -lpng16 -lz -lgomp -lgcc --push-state --as-needed -lgcc_s --pop-state -lpthread -lc -lgcc --push-state --as-needed -lgcc_s --pop-state /usr/lib64/gcc/x86_64-suse-linux/9/crtend.o /usr/lib64/gcc/x86_64-suse-linux/9/../../../../lib64/crtn.o /usr/lib64/gcc/x86_64-suse-linux/9/crtoffloadend.o
COLLECT_GCC_OPTIONS='-v' '-O0' '-g' '-m64' '-Wuninitialized' '-fopenmp' '-I' '/usr/local/mysql/include' '-O0' '-o' '/home/user1/bin/align_ppm_d' '-mtune=generic' '-march=x86-64' '-pthread'

解决方法

gcc似乎可以优化别名变量 当我尝试打印别名版本时，gdb只会打印 从一组结构中打印深层嵌套的原始变量，然后按预期进行打印。 在此处发布的类似问题中，使用-O0进行编译可解决此问题。这不适用于我的代码。