GCC 命令
功能参数
-frename-registers: Attempt to avoid false dependencies in scheduled code by making use of registers left over after register allocation. This optimization will most benefit processors with lots of registers. It can, however, make debugging impossible, since variables will no longer stay in a “home register”.-fno-inline: 禁止inline函数
utils
-Wall -Wextra -Werror: 没有特殊理由建议编译任何程序都将这三个参数加上，提前暴露可能的诡异问题。比如C++里面定义除了main函数之外的函数如果定义了返回类型却没有return语句，则属于未定义行为。默认只是默默的给出一条warning，容易被忽略（问题描述参考这里）。-Wl,option: 给链接器传的参数，比如-Wl,-verbose会输出链接过程，包括所用的链接脚本，库文件等-H: 打印源文件依赖的头文件树-fno-common: 不把未初始化的全局变量放到COMMON块中处理-fdump-tree-all-all： all后面加上all可以dump更多的调试信息出来，方便理解pass的情况-fdump-tree-optimized-gimple: dump出来的格式可以通过-fgimple重新编译-fdump-rtl-all、-fdump-rtl-all-graph： 首先生成dump file，然后根据dump file生成对应的.dot文件，然后通过dot -O -Tpng xxx.dot生成png图片-save-temps： 将中间文件，比如编译可执行程序时，将预处理后的结果（.i）、汇编结果（.s）和目标文件（.o）保存起来-dumpdir dir/： 表示将生成的文件放到dir目录中，注意需要/在结尾，不过没有则是表示在生成的dump文件名前面加dir-前缀。比如上面三个参数生成的文件：-fdump-tree-all -fdump-rtl-all -save-temps -dumpdir dirfno-builtin：告诉编译器不要识别不带__builtin_前缀的builtin方法，也就是说把它当作普通方法对待-nostdlib：链接时不默认链接标准库，比如libc、libgcc等。-
-v： 打印GCC driver实际调用的各个阶段的程序。比如当需要调试编译器时，可以拷贝下面运行的cc1的命令，前面带上
gdb --args即可：gdb --args /path/to/gcc/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/cc1 -quiet -v -iprefix /path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/ hello.c -quiet -dumpdir a- -dumpbase hello.c -dumpbase-ext .c -mtune=generic -march=x86-64 -version -o /tmp/ccK38nl3.sUsing built-in specs. COLLECT_GCC=/path/to/gcc/bin/gcc COLLECT_LTO_WRAPPER=/path/to/gcc/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc/configure --prefix=/home/lding/apps/gcc --enable-languages=c,c++ --disable-multilib Thread model: posix Supported LTO compression algorithms: zlib gcc version 12.0.0 20210928 (experimental) (GCC) COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64' '-dumpdir' 'a-' /path/to/gcc/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/cc1 -quiet -v -iprefix /path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/ hello.c -quiet -dumpdir a- -dumpbase hello.c -dumpbase-ext .c -mtune=generic -march=x86-64 -version -o /tmp/ccK38nl3.s GNU C17 (GCC) version 12.0.0 20210928 (experimental) (x86_64-pc-linux-gnu) compiled by GNU C version 12.0.0 20210928 (experimental), GMP version 6.0.0, MPFR version 3.1.1, MPC version 1.0.1, isl version none GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096 ignoring nonexistent directory "/path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/../../../../x86_64-pc-linux-gnu/include" ignoring duplicate directory "/path/to/gcc/bin/../lib/gcc/../../lib/gcc/x86_64-pc-linux-gnu/12.0.0/include" ignoring duplicate directory "/path/to/gcc/bin/../lib/gcc/../../lib/gcc/x86_64-pc-linux-gnu/12.0.0/include-fixed" ignoring nonexistent directory "/path/to/gcc/bin/../lib/gcc/../../lib/gcc/x86_64-pc-linux-gnu/12.0.0/../../../../x86_64-pc-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/include /path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/include-fixed /usr/local/include /path/to/gcc/bin/../lib/gcc/../../include /usr/include End of search list. GNU C17 (GCC) version 12.0.0 20210928 (experimental) (x86_64-pc-linux-gnu) compiled by GNU C version 12.0.0 20210928 (experimental), GMP version 6.0.0, MPFR version 3.1.1, MPC version 1.0.1, isl version none GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096 Compiler executable checksum: 88cd59bf6ef807dbe47195c7b09fe0ee COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64' '-dumpdir' 'a-' as -v --64 -o /tmp/cce83hPF.o /tmp/ccK38nl3.s GNU assembler version 2.27 (x86_64-redhat-linux) using BFD version version 2.27-44.base.el7 COMPILER_PATH=/path/to/gcc/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/:/path/to/gcc/bin/../libexec/gcc/ LIBRARY_PATH=/path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/:/path/to/gcc/bin/../lib/gcc/:/path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64' '-dumpdir' 'a.' /path/to/gcc/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/collect2 -plugin /path/to/gcc/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/liblto_plugin.so -plugin-opt=/path/to/gcc/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper -plugin-opt=-fresolution=/tmp/ccKjbVli.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 /lib/../lib64/crt1.o /lib/../lib64/crti.o /path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/crtbegin.o -L/path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0 -L/path/to/gcc/bin/../lib/gcc -L/path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/../../.. /tmp/cce83hPF.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /path/to/gcc/bin/../lib/gcc/x86_64-pc-linux-gnu/12.0.0/crtend.o /lib/../lib64/crtn.o COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64' '-dumpdir' 'a.' -fdump-passes： 打印编译过程运行的pass# 比如-O3会运行的pass： *warn_unused_result : ON *diagnose_omp_blocks : OFF *diagnose_tm_blocks : OFF tree-omp_oacc_kernels_decompose : OFF tree-omplower : ON tree-lower : ON tree-tmlower : OFF tree-ehopt : OFF tree-eh : ON tree-coro-lower-builtins : OFF tree-cfg : ON *warn_function_return : ON tree-coro-early-expand-ifns : OFF tree-ompexp : ON tree-walloca1 : ON *build_cgraph_edges : ON *free_lang_data : ON ipa-visibility : ON ipa-build_ssa_passes : ON tree-fixup_cfg1 : ON tree-ssa : ON tree-warn-printf : OFF *nonnullcmp : OFF *early_warn_uninitialized : OFF tree-ubsan : OFF tree-nothrow : ON *rebuild_cgraph_edges : ON ipa-opt_local_passes : ON tree-fixup_cfg2 : ON *rebuild_cgraph_edges : ON tree-local-fnsummary1 : ON tree-einline : ON *infinite-recursion : OFF tree-early_optimizations : ON *remove_cgraph_callee_edges : ON tree-early_objsz : ON tree-ccp1 : ON tree-forwprop1 : ON tree-ethread : ON tree-esra : ON tree-ealias : ON tree-fre1 : ON tree-evrp : ON tree-mergephi1 : ON tree-dse1 : ON tree-cddce1 : ON tree-phiopt1 : ON tree-tailr1 : ON tree-iftoswitch : ON tree-switchconv : ON tree-ehcleanup1 : OFF tree-profile_estimate : ON tree-local-pure-const1 : ON tree-modref1 : ON tree-fnsplit : ON *strip_predict_hints : ON tree-release_ssa : ON *rebuild_cgraph_edges : ON tree-local-fnsummary2 : ON ipa-remove_symbols : ON ipa-ipa_oacc : OFF ipa-pta1 : OFF ipa-ipa_oacc_kernels : ON tree-oacc_kernels : OFF tree-ch1 : ON tree-fre2 : ON tree-lim1 : ON tree-dom1 : ON tree-dce1 : ON tree-parloops1 : OFF tree-ompexpssa1 : ON *rebuild_cgraph_edges : ON ipa-targetclone : ON ipa-afdo : OFF ipa-profile : OFF tree-feedback_fnsplit : OFF ipa-free-fnsummary1 : ON ipa-increase_alignment : ON ipa-tmipa : OFF ipa-emutls : OFF ipa-analyzer : OFF ipa-odr : OFF ipa-whole-program : ON ipa-profile_estimate : ON ipa-icf : ON ipa-devirt : ON ipa-cp : ON ipa-sra : ON ipa-cdtor : OFF ipa-fnsummary : ON ipa-inline : ON ipa-pure-const : ON ipa-modref : ON ipa-free-fnsummary2 : ON ipa-static-var : ON ipa-single-use : ON ipa-comdats : ON ipa-pta2 : OFF ipa-simdclone : OFF tree-fixup_cfg3 : ON tree-ehdisp : OFF tree-oaccloops : OFF tree-omp_oacc_neuter_broadcast : OFF tree-oaccdevlow : OFF tree-ompdevlow : ON tree-omptargetlink : OFF tree-adjust_alignment : ON *all_optimizations : ON *remove_cgraph_callee_edges : ON *strip_predict_hints : ON tree-ccp2 : ON tree-objsz1 : ON tree-post_ipa_warn1 : OFF tree-cunrolli : ON tree-backprop : ON tree-phiprop : ON tree-forwprop2 : ON tree-alias : ON tree-retslot : ON tree-fre3 : ON tree-mergephi2 : ON tree-threadfull1 : ON tree-vrp1 : ON tree-dse2 : ON tree-dce2 : ON tree-stdarg : ON tree-cdce : ON tree-cselim : ON tree-copyprop1 : ON tree-ifcombine : ON tree-mergephi3 : ON tree-phiopt2 : ON tree-tailr2 : ON tree-ch2 : ON tree-cplxlower1 : ON tree-sra : ON tree-thread1 : ON tree-dom2 : ON tree-copyprop2 : ON tree-isolate-paths : ON tree-reassoc1 : ON tree-dce3 : ON tree-forwprop3 : ON tree-phiopt3 : ON tree-ccp3 : ON tree-sincos : ON tree-bswap : ON tree-laddress : ON tree-lim2 : ON tree-walloca2 : ON tree-pre : ON tree-sink1 : ON tree-sancov1 : OFF tree-asan1 : OFF tree-tsan1 : OFF tree-dse3 : ON tree-dce4 : ON tree-fix_loops : ON tree-loop : ON tree-loopinit : ON tree-unswitch : ON tree-sccp : ON tree-lsplit : ON tree-lversion : ON tree-unrolljam : ON tree-cddce2 : ON tree-ivcanon : ON tree-ldist : ON tree-linterchange : ON tree-copyprop3 : ON tree-graphite0 : OFF tree-graphite : OFF tree-lim3 : ON tree-copyprop4 : ON tree-dce5 : ON tree-parloops2 : OFF tree-ompexpssa2 : ON tree-ch_vect : ON tree-ifcvt : ON tree-vect : ON tree-dce6 : ON tree-pcom : ON tree-cunroll : ON *pre_slp_scalar_cleanup : OFF tree-fre4 : ON tree-dse4 : ON tree-slp1 : ON tree-aprefetch : OFF tree-ivopts : ON tree-lim4 : ON tree-loopdone : ON tree-no_loop : OFF tree-slp2 : ON tree-simduid1 : OFF tree-veclower21 : ON tree-switchlower1 : ON tree-recip : OFF tree-reassoc2 : ON tree-slsr : ON tree-split-paths : ON tree-tracer : OFF tree-fre5 : ON tree-thread2 : ON tree-dom3 : ON tree-strlen1 : ON tree-threadfull2 : ON tree-vrp2 : ON tree-ccp4 : ON tree-wrestrict : ON tree-dse5 : ON tree-cddce3 : ON tree-forwprop4 : ON tree-phiopt4 : ON tree-fab1 : ON tree-widening_mul : ON tree-sink2 : ON tree-store-merging : ON tree-tailc : ON tree-dce7 : ON tree-crited1 : ON tree-uninit1 : OFF tree-local-pure-const2 : ON tree-modref2 : ON tree-uncprop1 : ON *all_optimizations_g : OFF *remove_cgraph_callee_edges : ON *strip_predict_hints : ON tree-cplxlower2 : ON tree-veclower22 : ON tree-switchlower2 : ON tree-ccp5 : ON tree-post_ipa_warn2 : OFF tree-objsz2 : ON tree-fab2 : ON tree-strlen2 : ON tree-copyprop5 : ON tree-dce8 : ON tree-sancov2 : OFF tree-asan2 : OFF tree-tsan2 : OFF tree-crited2 : ON tree-uninit2 : OFF tree-local-pure-const3 : ON tree-modref3 : ON tree-uncprop2 : ON *tminit : OFF tree-tmmark : ON tree-tmmemopt : OFF tree-tmedge : ON tree-simduid2 : OFF tree-vtable-verify : OFF tree-lower_vaarg : ON tree-veclower : ON tree-cplxlower0 : ON tree-sancov_O0 : OFF tree-switchlower_O0 : OFF tree-asan0 : OFF tree-tsan0 : OFF tree-sanopt : OFF tree-ehcleanup2 : OFF tree-resx : OFF tree-nrv : ON tree-isel : ON tree-hardcbr : OFF tree-hardcmp : OFF tree-optimized : ON *warn_function_noreturn : OFF tree-waccess : ON rtl-expand : ON *rest_of_compilation : ON rtl-vregs : ON rtl-into_cfglayout : ON rtl-jump : ON rtl-subreg1 : ON rtl-dfinit : ON rtl-cse1 : ON rtl-fwprop1 : ON rtl-cprop1 : ON rtl-rtl pre : ON rtl-hoist : OFF rtl-cprop2 : ON rtl-store_motion : OFF rtl-shorten_memrefs : ON rtl-cse_local : OFF rtl-ce1 : ON rtl-reginfo : ON rtl-loop2 : ON rtl-loop2_init : ON rtl-loop2_invariant : ON rtl-loop2_unroll : OFF rtl-loop2_doloop : OFF rtl-loop2_done : ON rtl-subreg2 : OFF rtl-web : OFF rtl-cprop3 : ON rtl-cse2 : ON rtl-dse1 : ON rtl-fwprop2 : ON rtl-auto_inc_dec : OFF rtl-init-regs : ON rtl-ud_dce : ON rtl-combine : ON rtl-insert_vsetvli : ON rtl-ce2 : ON rtl-jump_after_combine : ON rtl-bbpart : OFF rtl-outof_cfglayout : ON rtl-split1 : ON rtl-subreg3 : ON rtl-no-opt dfinit : OFF *stack_ptr_mod : ON rtl-mode_sw : OFF rtl-asmcons : ON rtl-sms : OFF rtl-lr_shrinkage : OFF rtl-sched1 : ON rtl-early_remat : ON rtl-ira : ON rtl-reload : ON *all-postreload : OFF rtl-postreload : OFF rtl-gcse2 : ON rtl-split2 : ON rtl-ree : ON rtl-cmpelim : OFF rtl-pro_and_epilogue : ON rtl-dse2 : ON rtl-csa : OFF rtl-jump2 : ON rtl-compgotos : ON rtl-sched_fusion : OFF rtl-peephole2 : ON rtl-ce3 : ON rtl-rnreg : OFF rtl-cprop_hardreg : ON rtl-rtl_dce : ON rtl-bbro : ON *leaf_regs : ON rtl-split3 : ON rtl-sched2 : ON *stack_regs : OFF rtl-split4 : OFF rtl-stack : ON *all-late_compilation : OFF rtl-zero_call_used_regs : ON rtl-alignments : ON rtl-vartrack : OFF *free_cfg : ON rtl-mach : ON rtl-barriers : ON rtl-dbr : OFF rtl-split5 : ON rtl-eh_ranges : OFF rtl-shorten : ON rtl-nothrow : ON rtl-dwarf2 : OFF rtl-final : ON rtl-dfinish : ON *clean_state : ON