Merge pull request #4846 from martin-frbg/lapack1025

Make the type used for the "hidden" string length argument configurable (adapted from Reference-LAPACK PR 1025)

CMakeLists.txt

@@ -22,6 +22,8 @@ option(BUILD_WITHOUT_LAPACK "Do not build LAPACK and LAPACKE (Only BLAS or CBLAS
 
 option(BUILD_LAPACK_DEPRECATED "When building LAPACK, include also some older, deprecated routines" ON)
 
+set(LAPACK_STRLEN "" CACHE STRING "When building LAPACK, use this type (e.g. \"int\") for character lengths (defaults to size_t)")
+
 option(BUILD_TESTING "Build LAPACK testsuite when building LAPACK" ON)
 
 option(BUILD_BENCHMARKS "Build the collection of BLAS/LAPACK benchmarks" OFF)

Makefile

@@ -45,6 +45,10 @@ else
 LAPACK_NOOPT := $(filter-out -O0 -O1 -O2 -O3 -Ofast -O -Og -Os,$(LAPACK_FFLAGS))
 endif
 
+ifdef LAPACK_STRLEN
+LAPACK_FFLAGS += -DLAPACK_STRLEN=$(LAPACK_STRLEN)
+endif
+
 SUBDIRS_ALL = $(SUBDIRS) test ctest utest exports benchmark ../laswp ../bench cpp_thread_test
 
 .PHONY : all libs netlib $(RELA) test ctest shared install

Makefile.rule

@@ -134,6 +134,12 @@ VERSION = 0.3.27.dev
 # Build LAPACK Deprecated functions since LAPACK 3.6.0
 BUILD_LAPACK_DEPRECATED = 1
 
+# The variable type assumed for the length of character arguments when passing
+# data between Fortran LAPACK and C BLAS (defaults to "size_t", but older GCC
+# versions used "int"). Mismatches will not cause runtime failures but may result
+# in build warnings or errors when building with link-time optimization (LTO)
+# LAPACK_STRLEN=int
+
 # Build RecursiveLAPACK on top of LAPACK
 # BUILD_RELAPACK = 1
 # Have RecursiveLAPACK actually replace standard LAPACK routines instead of 

cmake/system.cmake

@@ -621,7 +621,10 @@ set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} ${FCOMMON_OPT}")
 set(FPFLAGS "${FPFLAGS} ${FCOMMON_OPT} ${COMMON_PROF}")
 
 #For LAPACK Fortran codes.
-set(LAPACK_FFLAGS "${LAPACK_FFLAGS} ${CMAKE_Fortran_FLAGS}")
+set(LAPACK_FFLAGS "${LAPACK_FFLAGS} ${CMAKE_Fortran_FLAGS}" )
+if (LAPACK_STRLEN)
+	set (LAPACK_FFLAGS "${LAPACK_FFLAGS} -DLAPACK_STRLEN=${LAPACK_STRLEN}")
+endif()
 set(LAPACK_FPFLAGS "${LAPACK_FPFLAGS} ${FPFLAGS}")
 
 #Disable -fopenmp for LAPACK Fortran codes on Windows.