https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63497
Bug ID: 63497 Summary: std::regex can't handle [^class] correctly and cause runtime crash Product: gcc Version: 4.9.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: moophy at foxmail dot com Created attachment 33671 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33671&action=edit preprocessed source files generated When using pattern : "([a-z]*)([^c])(e)(i)([a-z]*)", it incorrectly matched the input "cei" and caused runtime crash when iterating through the std::smatch container. Source: #include <string> #include <regex> #include <iostream> int main() { std::string pattern("([a-z]*)([^c])(e)(i)([a-z]*)"); std::regex r(pattern); std::smatch results; std::string test_str = "cei"; if (std::regex_search(test_str, results, r)) { std::cout << results.str() << std::endl; for (size_t i = 0; i < results.size(); ++i) std::cout << i << ": " << results[i].str() << '\n'; } } output: cei 0: cei 1: cei terminate called after throwing an instance of 'std::length_error' what(): basic_string::_S_create Aborted (core dumped) Command Line: g++-4.9 -v -save-temps -std=c++11 -Wall -Wextra main.cpp GCC Info: Using built-in specs. COLLECT_GCC=g++-4.9 COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-linux-gnu/4.9/lto-wrapper Target: i686-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.9.1-3ubuntu2~14.04.1' --with-bugurl=file:///usr/share/doc/gcc-4.9/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.9 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.9 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.9-i386/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.9-i386 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.9-i386 --with-arch-directory=i386 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-targets=all --enable-multiarch --disable-werror --with-arch-32=i686 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu Thread model: posix gcc version 4.9.1 (Ubuntu 4.9.1-3ubuntu2~14.04.1) COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++11' '-Wall' '-Wextra' '-shared-libgcc' '-mtune=generic' '-march=i686' /usr/lib/gcc/i686-linux-gnu/4.9/cc1plus -E -quiet -v -imultiarch i386-linux-gnu -D_GNU_SOURCE main.cpp -mtune=generic -march=i686 -std=c++11 -Wall -Wextra -fpch-preprocess -fstack-protector -Wformat-security -o main.ii ignoring duplicate directory "/usr/include/i386-linux-gnu/c++/4.9" ignoring nonexistent directory "/usr/local/include/i386-linux-gnu" ignoring nonexistent directory "/usr/lib/gcc/i686-linux-gnu/4.9/../../../../i686-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /usr/include/c++/4.9 /usr/include/i386-linux-gnu/c++/4.9 /usr/include/c++/4.9/backward /usr/lib/gcc/i686-linux-gnu/4.9/include /usr/local/include /usr/lib/gcc/i686-linux-gnu/4.9/include-fixed /usr/include/i386-linux-gnu /usr/include End of search list. COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++11' '-Wall' '-Wextra' '-shared-libgcc' '-mtune=generic' '-march=i686' /usr/lib/gcc/i686-linux-gnu/4.9/cc1plus -fpreprocessed main.ii -quiet -dumpbase main.cpp -mtune=generic -march=i686 -auxbase main -Wall -Wextra -std=c++11 -version -fstack-protector -Wformat-security -o main.s GNU C++ (Ubuntu 4.9.1-3ubuntu2~14.04.1) version 4.9.1 (i686-linux-gnu) compiled by GNU C version 4.9.1, GMP version 5.1.3, MPFR version 3.1.2-p3, MPC version 1.0.1 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU C++ (Ubuntu 4.9.1-3ubuntu2~14.04.1) version 4.9.1 (i686-linux-gnu) compiled by GNU C version 4.9.1, GMP version 5.1.3, MPFR version 3.1.2-p3, MPC version 1.0.1 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 55bd930871a1c0a5ebd28bf15548c7c2 COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++11' '-Wall' '-Wextra' '-shared-libgcc' '-mtune=generic' '-march=i686' as -v --32 -o main.o main.s GNU assembler version 2.24 (i686-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.24 COMPILER_PATH=/usr/lib/gcc/i686-linux-gnu/4.9/:/usr/lib/gcc/i686-linux-gnu/4.9/:/usr/lib/gcc/i686-linux-gnu/:/usr/lib/gcc/i686-linux-gnu/4.9/:/usr/lib/gcc/i686-linux-gnu/ LIBRARY_PATH=/usr/lib/gcc/i686-linux-gnu/4.9/:/usr/lib/gcc/i686-linux-gnu/4.9/../../../i386-linux-gnu/:/usr/lib/gcc/i686-linux-gnu/4.9/../../../../lib/:/lib/i386-linux-gnu/:/lib/../lib/:/usr/lib/i386-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/i686-linux-gnu/4.9/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++11' '-Wall' '-Wextra' '-shared-libgcc' '-mtune=generic' '-march=i686' /usr/lib/gcc/i686-linux-gnu/4.9/collect2 -plugin /usr/lib/gcc/i686-linux-gnu/4.9/liblto_plugin.so -plugin-opt=/usr/lib/gcc/i686-linux-gnu/4.9/lto-wrapper -plugin-opt=-fresolution=main.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 --sysroot=/ --build-id --eh-frame-hdr -m elf_i386 --hash-style=gnu --as-needed -dynamic-linker /lib/ld-linux.so.2 -z relro /usr/lib/gcc/i686-linux-gnu/4.9/../../../i386-linux-gnu/crt1.o /usr/lib/gcc/i686-linux-gnu/4.9/../../../i386-linux-gnu/crti.o /usr/lib/gcc/i686-linux-gnu/4.9/crtbegin.o -L/usr/lib/gcc/i686-linux-gnu/4.9 -L/usr/lib/gcc/i686-linux-gnu/4.9/../../../i386-linux-gnu -L/usr/lib/gcc/i686-linux-gnu/4.9/../../../../lib -L/lib/i386-linux-gnu -L/lib/../lib -L/usr/lib/i386-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/i686-linux-gnu/4.9/../../.. main.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/i686-linux-gnu/4.9/crtend.o /usr/lib/gcc/i686-linux-gnu/4.9/../../../i386-linux-gnu/crtn.o