https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68450
Bug ID: 68450 Summary: regex matching different from ECMAScript? Product: gcc Version: 4.9.2 Status: UNCONFIRMED Severity: minor Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: lcoquelle at gmail dot com Target Milestone: --- Created attachment 36777 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36777&action=edit Code sample Using a complex regex to remove comment in JSON file (...), the behaviour seems to differ from ECMAScript. FYI: boost::regex 1.59 seems to have the correct behaviour. Regex: ((['"])(?:(?!\2|\\).|\\.)*\2)|\/\/[^\n]*|\/\*(?:[^*]|\*(?!\/))*\*\/ (can be try here: https://regex101.com/r/vI2iW5/2#javascript) Input string: "Entry": "Value", // Skip "me" Expected output: "Entry": "Value", Real output: "Entry": "Value", // Skip "me" Attached a code sample. Compiling output as below: > /usr/local/gcc49/bin/g++ -v -save-temps -Wall -std=gnu++14 re.cc Using built-in specs. COLLECT_GCC=/usr/local/gcc49/bin/g++ COLLECT_LTO_WRAPPER=/usr/local/gcc49/libexec/gcc/x86_64-unknown-linux-gnu/4.9.2/lto-wrapper Target: x86_64-unknown-linux-gnu Configured with: /usr/local/src/gcc-4.9.2/configure --disable-multilib --enable-cloog-backend=isl --enable-gold=default --enable-languages=c,c++ --enable-lto --enable-libssp --enable-plugins --enable-plugin --with-build-config=bootstrap-lto --enable-stage1-checking=release --prefix=/usr/local/gcc49 Thread model: posix gcc version 4.9.2 (GCC) COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-std=gnu++1y' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/local/gcc49/libexec/gcc/x86_64-unknown-linux-gnu/4.9.2/cc1plus -E -quiet -v -D_GNU_SOURCE re.cc -mtune=generic -march=x86-64 -std=gnu++1y -Wall -fpch-preprocess -o re.ii ignoring nonexistent directory "/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../x86_64-unknown-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../include/c++/4.9.2 /usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../include/c++/4.9.2/x86_64-unknown-linux-gnu /usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../include/c++/4.9.2/backward /usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/include /usr/local/include /usr/local/gcc49/include /usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/include-fixed /usr/include End of search list. COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-std=gnu++1y' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/local/gcc49/libexec/gcc/x86_64-unknown-linux-gnu/4.9.2/cc1plus -fpreprocessed re.ii -quiet -dumpbase re.cc -mtune=generic -march=x86-64 -auxbase re -Wall -std=gnu++1y -version -o re.s GNU C++ (GCC) version 4.9.2 (x86_64-unknown-linux-gnu) compiled by GNU C version 4.9.2, GMP version 6.0.0, MPFR version 3.1.2, MPC version 1.0.2 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU C++ (GCC) version 4.9.2 (x86_64-unknown-linux-gnu) compiled by GNU C version 4.9.2, GMP version 6.0.0, MPFR version 3.1.2, MPC version 1.0.2 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 4c9e457b752b2d9171dda4de0a18535a COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-std=gnu++1y' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../x86_64-unknown-linux-gnu/bin/as -v --64 -o re.o re.s GNU assembler version 2.24 (x86_64-unknown-linux-gnu) using BFD version (GNU Binutils) 2.24 COMPILER_PATH=/usr/local/gcc49/libexec/gcc/x86_64-unknown-linux-gnu/4.9.2/:/usr/local/gcc49/libexec/gcc/x86_64-unknown-linux-gnu/4.9.2/:/usr/local/gcc49/libexec/gcc/x86_64-unknown-linux-gnu/:/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/:/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/:/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../x86_64-unknown-linux-gnu/bin/ LIBRARY_PATH=/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/:/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../x86_64-unknown-linux-gnu/lib/:/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-std=gnu++1y' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/local/gcc49/libexec/gcc/x86_64-unknown-linux-gnu/4.9.2/collect2 -plugin /usr/local/gcc49/libexec/gcc/x86_64-unknown-linux-gnu/4.9.2/liblto_plugin.so -plugin-opt=/usr/local/gcc49/libexec/gcc/x86_64-unknown-linux-gnu/4.9.2/lto-wrapper -plugin-opt=-fresolution=re.res -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 /lib/../lib64/crt1.o /lib/../lib64/crti.o /usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/crtbegin.o -L/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2 -L/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../../../x86_64-unknown-linux-gnu/lib -L/usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/../../.. re.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/local/gcc49/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/crtend.o /lib/../lib64/crtn.o Running output: > ./a.out "Field": "Value" "Field": "Value" // Skip "me"