CMake gcc version check is incorrect for SUSE linux

[martyngigg]

From mailing list:

I've successfully compiled and installed Mantid from source code on a OpenSUSE 12.3 Linux system after carefully selecting and installing the necessary libraries and software and doing the following necessary adjustment.

In fact, I've found that the Build/CMake/GNUSetup.cmake script incorrectly extracts the GCC compiler version string on Linux systems. The original script fragment is:

# Get the GCC version
EXEC_PROGRAM(${CMAKE_CXX_COMPILER} ARGS --version | cut -d \" \" -f 3 \
OUTPUT_VARIABLE _compiler_output)
STRING(REGEX REPLACE ".*([0-9]\\.[0-9]\\.[0-9]).*" "\\1" \
GCC_COMPILER_VERSION ${_compiler_output})
MESSAGE(STATUS "gcc version: ${GCC_COMPILER_VERSION}")

But the typical output of a 'gcc --version' command is a 4-row string, like the following:

gcc (SUSE Linux) 4.7.2 20130108 [gcc-4_7-branch revision 195012]
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

and by applying the 'cut -d " " -f 3' filter this ends up with a wrong-syntax CMakeCache.txt file, such as:

...
FIND_PACKAGE_MESSAGE_DETAILS_muparser:INTERNAL=[/usr/lib64/libmuparser.so][/usr/include][v()]
GCC_COMPILER_VERSION:INTERNAL=Linux)
2012
free
even
//ADVANCED property for variable: GIT_EXECUTABLE
GIT_EXECUTABLE-ADVANCED:INTERNAL=1
...

This causes errors in the compile/install process and, even when one corrects manually the error in the CMakeCache.txt file to bypass the problem, the error reappears after any cmake/make invocation.

Since we need to select the '4.7.2' string (or similar) on the first row, the following can be a good fix for the GNUSetup.cmake script:

# Get the GCC version
EXEC_PROGRAM(${CMAKE_CXX_COMPILER} ARGS --version | head -n 1 | cut -d \"\)\" -f 2 \
| cut -d \" \" -f 2 OUTPUT_VARIABLE _compiler_output)
STRING(REGEX REPLACE ".*([0-9]\\.[0-9]\\.[0-9]).*" "\\1" \
GCC_COMPILER_VERSION ${_compiler_output})
MESSAGE(STATUS "gcc version: ${GCC_COMPILER_VERSION}")

Best regards.

Gianluca Frustagli

[martyngigg]

This issue was originally trac ticket 10353