I'm in the process of converting some older Boost regex code to C++11, and I stumbled upon an issue with one of my test cases. Here is a scenario which causes a stack overflow exception using std::regex, but worked fine with boost::regex. I have not changed the regular expression pattern, and have verified the pattern is what I want. It seems this particular string input fragment is causing the stack overflow. Using VS2012, x64 debug build:
std::regex regx( "(^|\\})(([^\\{:])+:)+([^\\{]*\\{)" );
const std::string testinput = " COLOR: #000; BACKGROUND-COLOR: #FFF; FONT-FAMILY: VERDANA, ARIAL, HELVETICA, SANS-SERIF; BACKGROUND:URL(URL(___FOO___)); BACKGROUND-2:URL(URL(___FOO___)); BORDER: 0 0 0 0; BORDER-2: 0 0 0; BORDER-3: 0 0; BORDER-4: 0PX; BORDER-5: 0.6; FILTER:PROGID:DXIMAGETRANSFORM.MICROSOFT.ALPHA(OPACITY=100); } ";
std::smatch what;
// this next line causes a stack overflow
std::regex_search( testinput.cbegin(), testinput.cend(), what, regx );
Looking at the call stack after the exception, there seems to be some type of infinite recursion going on in the regex implementation. I don't currently have GCC to test this with. What am I doing wrong?
Update: After the suggestions below, I pasted this code into a console app, VS 2012 x64 debug and I get the stack overflow. If I change it to x64 release, or Win32 debug or release it runs fine. Huh??? Do i need to reinstall VS and/or the platform SDK? I'm on Win7 x64.
Update #2: Somewhat related post: Why does std::regex_iterator cause a stack overflow with this data? I suppose if I rewrite my regex, it might help. I'm still not sure why the bitness matters though. And why it works for others, but not for me on my system. Sigh.
I've been reproduced this with x64 debug build, and I belive this is a real stack overflow.
When you change your stack size to 10MB or so (linker command line option /STACK:"10000000"
),
it will work fine.
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