http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54328
Bug #: 54328 Summary: capture pointer by value is not correct Classification: Unclassified Product: gcc Version: 4.8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: yaoyuan1...@gmail.com int a[1]; a[0] = 1; auto fun = [a]{cout<<a[0]<<endl;}; fun(); a[0] = 2; fun(); This will produce: 1 1 I think it shoud be: 1 2 g++ -std=c++0x -v -save-temps -Wall t.cpp outputs: 使用内建 specs。 COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/home/mww/.gcc/libexec/gcc/x86_64-unknown-linux-gnu/4.8.0/lto-wrapper 目标:x86_64-unknown-linux-gnu 配置为:../gcc-trunk/configure --disable-multilib --enable-checking=release --enable-languages=c,c++ --enable-threads=posix --prefix=/home/mww/.gcc 线程模型:posix gcc 版本 4.8.0 20120816 (experimental) (GCC) COLLECT_GCC_OPTIONS='-std=c++11' '-v' '-save-temps' '-Wall' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /home/mww/.gcc/libexec/gcc/x86_64-unknown-linux-gnu/4.8.0/cc1plus -E -quiet -v -D_GNU_SOURCE t.cpp -mtune=generic -march=x86-64 -std=c++11 -Wall -fpch-preprocess -o t.ii 忽略不存在的目录“/home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/../../../../x86_64-unknown-linux-gnu/include” #include "..." 搜索从这里开始: #include <...> 搜索从这里开始: /home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/../../../../include/c++/4.8.0 /home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/../../../../include/c++/4.8.0/x86_64-unknown-linux-gnu /home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/../../../../include/c++/4.8.0/backward /home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/include /usr/local/include /home/mww/.gcc/include /home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/include-fixed /usr/include 搜索列表结束。 COLLECT_GCC_OPTIONS='-std=c++11' '-v' '-save-temps' '-Wall' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /home/mww/.gcc/libexec/gcc/x86_64-unknown-linux-gnu/4.8.0/cc1plus -fpreprocessed t.ii -quiet -dumpbase t.cpp -mtune=generic -march=x86-64 -auxbase t -Wall -std=c++11 -version -o t.s GNU C++ (GCC) 版本 4.8.0 20120816 (experimental) (x86_64-unknown-linux-gnu) 由 GNU C 版本 4.8.0 20120816 (experimental) 编译, GMP version 5.0.5, MPFR version 3.1.1, MPC version 0.9 GGC 准则:--param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU C++ (GCC) 版本 4.8.0 20120816 (experimental) (x86_64-unknown-linux-gnu) 由 GNU C 版本 4.8.0 20120816 (experimental) 编译, GMP version 5.0.5, MPFR version 3.1.1, MPC version 0.9 GGC 准则:--param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 68a842c32ece7e9b3774793c3488162d t.cpp: 在函数‘int main(int, const char**)’中: t.cpp:7:6: 警告: variable ‘a’ set but not used [-Wunused-but-set-variable] int a[1]; ^ COLLECT_GCC_OPTIONS='-std=c++11' '-v' '-save-temps' '-Wall' '-shared-libgcc' '-mtune=generic' '-march=x86-64' as -v --64 -o t.o t.s GNU assembler version 2.20.1 (x86_64-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.20.1-system.20100303 COMPILER_PATH=/home/mww/.gcc/libexec/gcc/x86_64-unknown-linux-gnu/4.8.0/:/home/mww/.gcc/libexec/gcc/x86_64-unknown-linux-gnu/4.8.0/:/home/mww/.gcc/libexec/gcc/x86_64-unknown-linux-gnu/:/home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/:/home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/ LIBRARY_PATH=/home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/:/home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-std=c++11' '-v' '-save-temps' '-Wall' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /home/mww/.gcc/libexec/gcc/x86_64-unknown-linux-gnu/4.8.0/collect2 --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 /usr/lib/../lib64/crt1.o /usr/lib/../lib64/crti.o /home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/crtbegin.o -L/home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0 -L/home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/../../.. t.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /home/mww/.gcc/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/crtend.o /usr/lib/../lib64/crtn.o