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Subject: [Bug target/47178] New: QtWebKit miscompiled for x86_64-*-mingw*
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47178

           Summary: QtWebKit miscompiled for x86_64-*-mingw*
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: vanboxem.ruben@gmail.com


The 64-bit runtime provided by the mingw-w64 project together with the GCC
toolchain can compile Qt completely (with no known issues as far as I know)
with GCC 4.4 (earlier versions don't have the necessary support for x64
Windows).

Only with GCC 4.5 and 4.6, issues arise in the form of runtime errors when
QtWebKit is compiled for x86_64-w64-mingw32.

I have created a WebKit bug report here:
https://bugs.webkit.org/show_bug.cgi?id=44052

The report has a stack backtrace of a Qt application (Assistant) showing the
crash. All binaries are compiled with "-g3" (highest debug level). Optimization
level (none or -O2) does not change the fact that the app crashes.

Looking at the backtrace, the problem is in WebKit somewhere, but as no other
platforms show this problem, the issue must be toolchain-side somewhere.

A correct binary is produced using patched (for Win64) 4.4 GCC toolchains.