SPEX: Try to put MPFR and GMP include directories last.

[mmuetzel]

IIUC, CMake adds system include directories always after "normal" include directories. Try to add the include directories last in the order by making them system include directories and adding the keyword AFTER.

Tbh, it's not entirely clean why CMake decides to add some of the include directories as system include directories. But this change might help to work around #565.

[DrTimothyAldenDavis]

SPEX still fails, if SPEX is built with "cd SPEX/build ; cmake .." etc. It gets the stale headers for all 3 packages: SuiteSparse_config, AMD, and COLAMD.

In the root CMakeLists (cd SuiteSparse/build ; cmake .. ; " etc, SPEX finds the correct SuiteSparse_config, but not AMD or COLAMD. That was a parallel build and if I slow it down with "VERBOSE=1 ; make -j1" it fails on CHOLMOD first (getting the wrong headers for AMD, COLAMD, CAMD, and CCOLAMD).

[mmuetzel]

Could you please show the failing compiler command?

I guess the fact that SuiteSparse_config depends on OpenMP and most of the SuiteSparse libraries depend on SuiteSparse_config makes that the folder where OpenMP installed its headers is added quite early...

[mmuetzel]

Does the following change make a difference?

diff --git "a/SuiteSparse_config/CMakeLists.txt" "b/SuiteSparse_config/CMakeLists.txt"
index 1ff9b66f6..b2c31f91f 100644
--- "a/SuiteSparse_config/CMakeLists.txt"
+++ "b/SuiteSparse_config/CMakeLists.txt"
@@ -146,11 +146,13 @@ if ( OpenMP_C_FOUND )
     message ( STATUS "OpenMP C flags:          ${OpenMP_C_FLAGS} ")
     if ( BUILD_SHARED_LIBS )
         target_link_libraries ( SuiteSparseConfig PRIVATE OpenMP::OpenMP_C )
-        target_include_directories ( SuiteSparseConfig PUBLIC
+        target_include_directories ( SuiteSparseConfig SYSTEM AFTER PUBLIC
             "$<TARGET_PROPERTY:OpenMP::OpenMP_C,INTERFACE_INCLUDE_DIRECTORIES>" )
     endif ( )
     if ( BUILD_STATIC_LIBS )
-        target_link_libraries ( SuiteSparseConfig_static PUBLIC OpenMP::OpenMP_C )
+        target_link_libraries ( SuiteSparseConfig_static PRIVATE OpenMP::OpenMP_C )
+        target_include_directories ( SuiteSparseConfig_static SYSTEM AFTER PUBLIC
+            "$<TARGET_PROPERTY:OpenMP::OpenMP_C,INTERFACE_INCLUDE_DIRECTORIES>" )
     endif ( )
 endif ( )
 

[DrTimothyAldenDavis]

Here's the failed command when I remove my hack and revert to a clean copy of dev2, with added linebreaks for readability:

Consolidate compiler generated dependencies of target SPEX
/Library/Developer/CommandLineTools/usr/bin/make  -f CMakeFiles/SPEX.dir/build.make CMakeFiles/SPEX.dir/build
[  1%] Building C object CMakeFiles/SPEX.dir/SPEX_Left_LU/Source/SPEX_Left_LU_backslash.c.o

/Library/Developer/CommandLineTools/usr/bin/cc -DSPEX_EXPORTS
-I/Users/davis/dev2/SuiteSparse/SPEX/build 
-I/Users/davis/dev2/SuiteSparse/SPEX
-I/Users/davis/dev2/SuiteSparse/SPEX/SPEX_Left_LU/Source
-I/Users/davis/dev2/SuiteSparse/SPEX/SPEX_Util/Source
-I/Users/davis/dev2/SuiteSparse/SPEX/Include
-I/Users/davis/dev2/SuiteSparse/SPEX/SPEX_Left_LU/Demo 
-isystem /Users/davis/dev2/SuiteSparse/SuiteSparse_config 
-isystem /usr/local/include
-isystem /opt/homebrew/include 
-isystem /Users/davis/dev2/SuiteSparse/AMD/Include 
-isystem /Users/davis/dev2/SuiteSparse/COLAMD/Include
-O3 -DNDEBUG -std=gnu11 -arch arm64 
-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX14.0.sdk
-mmacosx-version-min=13.6 -fPIC -MD -MT
CMakeFiles/SPEX.dir/SPEX_Left_LU/Source/SPEX_Left_LU_backslash.c.o -MF
CMakeFiles/SPEX.dir/SPEX_Left_LU/Source/SPEX_Left_LU_backslash.c.o.d -o
CMakeFiles/SPEX.dir/SPEX_Left_LU/Source/SPEX_Left_LU_backslash.c.o -c
/Users/davis/dev2/SuiteSparse/SPEX/SPEX_Left_LU/Source/SPEX_Left_LU_backslash.c

In file included from /Users/davis/dev2/SuiteSparse/SPEX/SPEX_Left_LU/Source/SPEX_Left_LU_backslash.c:45:
In file included from /Users/davis/dev2/SuiteSparse/SPEX/SPEX_Left_LU/Source/spex_left_lu_internal.h:18:
/Users/davis/dev2/SuiteSparse/SPEX/SPEX_Util/Source/spex_util_internal.h:114:2: error: "SPEX requires AMD 3.3.0 or later"
#error "SPEX requires AMD 3.3.0 or later"
 ^
/Users/davis/dev2/SuiteSparse/SPEX/SPEX_Util/Source/spex_util_internal.h:118:2: error: "SPEX requires COLAMD 3.3.0 or later"
#error "SPEX requires COLAMD 3.3.0 or later"
 ^
2 errors generated.

[DrTimothyAldenDavis]

Does the following change make a difference?

trying it now.

[mmuetzel]

Which version of CMake do you use?
IIUC, starting with CMake 3.25, imported targets are treated as system includes by default:
https://cmake.org/cmake/help/latest/prop_tgt/SYSTEM.html

Maybe, we could change that?

[DrTimothyAldenDavis]

On my mac I'm using cmake 3.27.