I'm attempting to cross-compile the LAPACK library (fortran) and the C API, LAPACKE for bare-metal embedded targets powerpc-eabi target, using the gcc cross compilers for this target. Compiling proceeds but eventually hits this error:
[ 44%] Building C object LAPACKE/CMakeFiles/lapacke.dir/src/lapacke_cbbcsd.c.obj
cd /home/rcrozier/build/powerpc-eabi/lapack/LAPACKE && /usr/local/powerpc-eabi/bin/powerpc-eabi-gcc -DADD_ -mcpu=750 -I/home/rcrozier/src/fast-v8-hg/cross-dependancies/lapack-3.6.0/LAPACKE/include -o CMakeFiles/lapacke.dir/src/lapacke_cbbcsd.c.obj -c /home/rcrozier/src/fast-v8-hg/cross-dependancies/lapack-3.6.0/LAPACKE/src/lapacke_cbbcsd.c
In file included from /home/rcrozier/src/fast-v8-hg/cross-dependancies/lapack-3.6.0/LAPACKE/include/lapacke_utils.h:37:0,
from /home/rcrozier/src/fast-v8-hg/cross-dependancies/lapack-3.6.0/LAPACKE/src/lapacke_cbbcsd.c:34:
/home/rcrozier/src/fast-v8-hg/cross-dependancies/lapack-3.6.0/LAPACKE/include/lapacke.h:145:22: error: ‘LAPACK_GLOBAL’ declared as function returning a function
#define LAPACK_lsame LAPACK_GLOBAL(lsame,LSAME)
^
This error occurs when building the C interface to LAPACK, LAPACKE.
A post on the LAPACK forums suggests this is a problem with Fortran name mangling, and to add the -DADD_ processor flag. Above I have attempted this, but it makes no difference.
The preprocessor define is used in a header file, copied below:
#ifndef LAPACK_HEADER_INCLUDED
#define LAPACK_HEADER_INCLUDED
#ifndef LAPACK_GLOBAL
#if defined(LAPACK_GLOBAL_PATTERN_LC) || defined(ADD_)
#define LAPACK_GLOBAL(lcname,UCNAME) lcname##_
#elif defined(LAPACK_GLOBAL_PATTERN_UC) || defined(UPPER)
#define LAPACK_GLOBAL(lcname,UCNAME) UCNAME
#elif defined(LAPACK_GLOBAL_PATTERN_MC) || defined(NOCHANGE)
#define LAPACK_GLOBAL(lcname,UCNAME) lcname
#else
#define LAPACK_GLOBAL(lcname,UCNAME) lcname##_
#endif
#endif
#endif
The error occurs in another header file which uses LAPACK_GLOBAL like so:
#include "lapacke_mangling.h"
#define LAPACK_lsame LAPACK_GLOBAL(lsame,LSAME)
lapack_logical LAPACK_lsame( char* ca, char* cb,
lapack_int lca, lapack_int lcb );
The lapacke_mangling.h file contents is shown below:
#ifndef LAPACK_HEADER_INCLUDED
#define LAPACK_HEADER_INCLUDED
#endif
The error does not occur when building natively, or when building for another linux target, powerpc-linux-gnu.
Can anyone explain the problem?
Actually the problem was that the preprocessor header file was not actually used with the cmake build system, instead a different header was supposed to be generated by cmake. Cmake did not generate the file corectly (probably because of cross-compilation). The patch below modifies the lapacke CMakeLists to add an option to force the use of this header file.
--- CMakeLists.txt 2017-11-30 12:07:46.007080017 +0000
+++ newCMakeLists.txt 2017-11-30 12:06:54.491078643 +0000
@@ -3,11 +3,18 @@
set(LAPACK_INSTALL_EXPORT_NAME lapacke-targets)
+option(FORCE_LAPACKE_MANGLING_WITH_FLAGS "Force the use of the lapack_mangling_with_flags.h header rather than automatic detection" OFF)
+
# Create a header file netlib.h for the routines called in my C programs
-include(FortranCInterface)
-FortranCInterface_HEADER( ${CMAKE_CURRENT_SOURCE_DIR}/include/lapacke_mangling.h
- MACRO_NAMESPACE "LAPACK_"
- SYMBOL_NAMESPACE "LAPACK_" )
+if (FORCE_LAPACKE_MANGLING_WITH_FLAGS)
+ # copy the lapacke_mangling_with_flags.h to lapacke_mangling.h
+ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/include/lapacke_mangling_with_flags.h ${CMAKE_CURRENT_SOURCE_DIR}/include/lapacke_mangling.h)
+else (FORCE_LAPACKE_MANGLING_WITH_FLAGS)
+ include(FortranCInterface)
+ FortranCInterface_HEADER( ${CMAKE_CURRENT_SOURCE_DIR}/include/lapacke_mangling.h
+ MACRO_NAMESPACE "LAPACK_"
+ SYMBOL_NAMESPACE "LAPACK_" )
+endif (FORCE_LAPACKE_MANGLING_WITH_FLAGS)
# Old way to detect mangling
#include(FortranMangling)
With this, my definitions were picked up and the appropriate mangling applied.