Bug#521904: llvm-gcc-4.2: miscompiled code on amd64/sid

[brian m. carlson]

Package: llvm-gcc-4.2
Version: 2.5-1
Severity: normal

I have found a case where llvm-gcc-4.2 miscompiles code on amd64/sid.
The testcase is attached.  Unfortunately, the testcase requires Qt 4 (I
used 4.5.0 from experimental; I don't know if the version from sid will
work.)  I tried to remove the last dependency on QString from Token, but
when I did, the code no longer failed.  Thus, to compile it, you'll need
to use:

   /usr/lib/llvm/llvm/gcc-4.2/bin/x86_64-linux-gnu-llvm-g++ -O2 -D_REENTRANT -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I/usr/include/qt4/QtCore -I/usr/include/qt4 -o troff foo.cxx -lQtCore -lpthread

I apologize in advance for this problem.

The bug occurs in TroffReadxer::parseRequestName.  m_compat is set to 4
by the TroffReader constructor.  Therefore, m_compat.getMode() returns
4.  CompatibilityMode::AllowLongNames is 8.  Therefore, maxtoke should
be 2, since (4 & 8) is false.  Instead, maxtoke is set to (size_t)-1.  A
couple of lines down, the code checks for this case and calls abort(3).

If you need anything else, please let me know.

-- System Information:
Debian Release: squeeze/sid
   APT prefers unstable
   APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.29-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages llvm-gcc-4.2 depends on:
ii  libc6                         2.9-6      GNU C Library: Shared libraries
ii  libgcc1                       1:4.3.3-5  GCC support library
ii  libstdc++6                    4.3.3-5    The GNU Standard C++ Library v3
ii  llvm                          2.5-2      Low-Level Virtual Machine (LLVM) c
ii  llvm-dev                      2.5-2      common libraries and headers for L

llvm-gcc-4.2 recommends no packages.

Versions of packages llvm-gcc-4.2 suggests:
pn  gcc-4.2-doc                   <none>     (no description available)

-- no debconf information

-- 
brian m. carlson / brian with sandals: Houston, Texas, US
+1 713 440 7475 | http://crustytoothpaste.ath.cx/~bmc | My opinion only
troff on top of XML: http://crustytoothpaste.ath.cx/~bmc/code/thwack
OpenPGP: RSA v4 4096b 88AC E9B2 9196 305B A994 7552 F1BA 225C 0223 B187
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