MantisBT - CMake
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ID	Project	Category	View Status	Date Submitted	Last Update
0008937	CMake	CTest	public	2009-04-28 05:29	2016-06-10 14:30

Reporter	Michael Haubenwallner
Assigned To	Bill Hoffman
Priority	normal	Severity	minor	Reproducibility	always
Status	closed	Resolution	moved
Platform		OS		OS Version
Product Version	CMake-2-6
Target Version		Fixed in Version

Summary	0008937: compiler error with Large File Support and pthread on AIX (gcc-4.4.0)
Description	On AIX, "cm_curl.h" does include system headers listening to _LARGE_FILES macro, which eventually is defined in <cmsys/Configure.h>, included via "cmCTest.h" lateron in "cmCTest.cxx". When using '-pthread' compiler flag with gcc-4.4.0, this results in: /usr/include/unistd.h:171: error: declaration of C function 'off64_t lseek64(int, off64_t, int)' conflicts with /usr/include/unistd.h:169: error: previous declaration 'off_t lseek64(int, off_t, int)' here What happens here: * When compiling C++, gcc defines _ALL_SOURCE, which implies _LARGE_FILE_API. * "cm_curl.h" includes <sys/types.h> somehow. * <sys/types.h> declares 'off64_t' due to _LARGE_FILE_API. * <sys/types.h> declares 'off_t' as 32bit, as _LARGE_FILES is not yet defined. * "cmsys/Configure.h" defines _LARGE_FILES. * Due to '-pthread', <pthread.h> gets included somehow. * <unistd.h> gets included by <pthread.h> due to _ALL_SOURCE. * <unistd.h> defines lseek to lseek64 with _LARGE_FILES defined, but still declares 'lseek(off_t)' and 'lseek64(off64_t)', resulting in 'lseek64(off_t)' and 'lseek64(off64_t)' due to redefinition of lseek. When _LARGE_FILES were defined early enough even for <sys/types.h>, off_t would be 64bit, and 'lseek(off_t)' would be the same as 'lseek64(off64_t)'. This does not depend on Bug#7933 - as it does happen either with or without that patch, when using gcc-4.4.0, or another gcc built with the patch from http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20366 [^] So in Source/cmCTest.cxx, "cm_curl.h" has to be included _after_ "cmCTest.h", to define _LARGE_FILES early enough for <sys/types.h> to correctly declare 'off_t' as 64bit, when Large File Support is available.
Steps To Reproduce
Additional Information	To reproduce this, install gcc-4.4.0, and bootstrap cmake-2.6.3 using these commands: $ CC=/gcc-prefix/bin/gcc \ CXX=/gcc-prefix/bin/g++ \ CFLAGS=-pthread \ CXXFLAGS=-pthread \ LIBPATH=/gcc-prefix/lib/pthread:/gcc-prefix/lib \ ./bootstrap $ gmake Why to use '-pthread': On AIX, '-pthread' is a gcc multilib criterion, and needs different runpath (hence the LIBPATH setting). So I do have a wrapper script around gcc/g++, always adding '-pthread' (or a gcc with multilib disabled, but patched to default to '-pthread'), as mixing libraries built with and without '-pthread' does not work, even when the final application itself does not use threads. So I always use '-pthread', as it is required by threading libraries, and does not hurt non-threading libraries.
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Issue History
Date Modified	Username	Field	Change
2009-04-28 05:29	Michael Haubenwallner	New Issue
2009-04-28 05:47	Michael Haubenwallner	Note Added: 0016210
2009-09-14 14:04	Bill Hoffman	Note Added: 0017455
2009-09-14 14:04	Bill Hoffman	Status	new => assigned
2009-09-14 14:04	Bill Hoffman	Assigned To	=> Bill Hoffman
2016-06-10 14:27	Kitware Robot	Note Added: 0041548
2016-06-10 14:27	Kitware Robot	Status	assigned => resolved
2016-06-10 14:27	Kitware Robot	Resolution	open => moved
2016-06-10 14:30	Kitware Robot	Status	resolved => closed

Notes