Select c compiler based on fortran compiler id

Author: LKedward

src/fpm.f90

@@ -9,7 +9,7 @@ module fpm
 use fpm_model, only: fpm_model_t, srcfile_t, show_model, &
                     FPM_SCOPE_UNKNOWN, FPM_SCOPE_LIB, FPM_SCOPE_DEP, &
                     FPM_SCOPE_APP, FPM_SCOPE_EXAMPLE, FPM_SCOPE_TEST
-use fpm_compiler, only: get_module_flags, is_unknown_compiler
+use fpm_compiler, only: get_module_flags, is_unknown_compiler, get_default_c_compiler
 
 
 use fpm_sources, only: add_executable_sources, add_sources_from_dir
@@ -62,6 +62,8 @@ subroutine build_model(model, settings, package, error)
         model%fortran_compiler = settings%compiler
     endif
 
+    call get_default_c_compiler(model%fortran_compiler, model%c_compiler)
+
     if (is_unknown_compiler(model%fortran_compiler)) then
         write(*, '(*(a:,1x))') &
             "<WARN>", "Unknown compiler", model%fortran_compiler, "requested!", &
@@ -178,6 +180,7 @@ subroutine build_model(model, settings, package, error)
     if (settings%verbose) then
         write(*,*)'<INFO> BUILD_NAME: ',settings%build_name
         write(*,*)'<INFO> COMPILER:  ',settings%compiler
+        write(*,*)'<INFO> C COMPILER:  ',model%c_compiler
         write(*,*)'<INFO> COMPILER OPTIONS:  ', model%fortran_compile_flags 
         write(*,*)'<INFO> INCLUDE DIRECTORIES:  [', string_cat(model%include_dirs,','),']' 
      end if

src/fpm_compiler.f90

@@ -336,6 +336,33 @@ subroutine get_module_flags(compiler, modpath, flags)
 
 end subroutine get_module_flags
 
+subroutine get_default_c_compiler(f_compiler, c_compiler)
+    character(len=*), intent(in) :: f_compiler
+    character(len=:), allocatable, intent(out) :: c_compiler
+    integer(compiler_enum) :: id
+
+    id = get_compiler_id(f_compiler)
+
+    select case(id)
+    case default
+        c_compiler = 'gcc'
+
+    case(id_intel_classic)
+        c_compiler = 'icc'
+
+    case(id_intel_llvm)
+        c_compiler = 'icx'
+
+    case(id_flang)
+        c_compiler='clang'
+
+    case(id_ibmxl)
+        c_compiler='xlc'
+
+    end select
+
+end subroutine get_default_c_compiler
+
 function get_compiler_id(compiler) result(id)
     character(len=*), intent(in) :: compiler
     integer(kind=compiler_enum) :: id

src/fpm_model.f90

@@ -117,6 +117,9 @@ module fpm_model
     !> Command line name to invoke fortran compiler
     character(:), allocatable :: fortran_compiler
 
+    !> Command line name to invoke c compiler
+    character(:), allocatable :: c_compiler
+
     !> Command line flags passed to fortran for compilation
     character(:), allocatable :: fortran_compile_flags