C backend mishandles C++ struct return #2497
Description
| Bugzilla Link | 2125 |
| Resolution | DUPLICATE |
| Resolved on | Feb 07, 2009 16:26 |
| Version | trunk |
| OS | All |
| CC | @edwintorok |
Extended Description
Compiling the following C++ testcase:
#include
#include
using namespace std;
int main()
{
ostringstream oss(string(1162*9, 'x'));
oss.str();
return 0;
}
with llvm-g++ -emit-llvm and using llc -march=c to produce a C
source file, compiling that and executing it, gets a Segmentation
Fault, at least on x86 Darwin. The problem is the call to str(), which returns
a std::string by value. The generated C source has str() returning a
small struct by value, however the library is expecting it to be returned
by hidden-argument because std::string has a copy constructor.
This is causing bigfib and possibly other llvm-test tests to fail.