add_custom_target: Fix regression with Fortran sources

Since commit 74b1d6caf3 (cmComputeLinkInformation: compute link info for
module-using targets, 2023-09-05, v3.27.5~7^2) we accidentally try to
compute link information for custom targets if they have Fortran
sources.  For module dependencies, we only need to consider target types
that can compile.

Fixes: #25252

Source/cmComputeLinkInformation.cxx

@@ -539,8 +539,9 @@ bool cmComputeLinkInformation::Compute()
         this->Target->GetType() == cmStateEnums::SHARED_LIBRARY ||
         this->Target->GetType() == cmStateEnums::MODULE_LIBRARY ||
         this->Target->GetType() == cmStateEnums::STATIC_LIBRARY ||
-        this->Target->HaveCxx20ModuleSources() ||
-        this->Target->HaveFortranSources())) {
+        (this->Target->CanCompileSources() &&
+         (this->Target->HaveCxx20ModuleSources() ||
+          this->Target->HaveFortranSources())))) {
     return false;
   }
 

Tests/FortranModules/CMakeLists.txt

@@ -128,3 +128,7 @@ endif()
 
 add_subdirectory(Issue25112)
 add_subdirectory(Issue25223)
+if( # Intel Fortran VS Integration breaks on custom targets with Fortran sources
+    NOT CMAKE_GENERATOR MATCHES "Visual Studio")
+  add_subdirectory(Issue25252)
+endif()

Tests/FortranModules/Issue25252/CMakeLists.txt

@@ -0,0 +1,6 @@
+add_custom_target(custom_target_with_fortran
+  COMMAND "${CMAKE_COMMAND}" -E echo "custom target with fortran sources"
+  SOURCES custom_target.f90)
+
+add_library(lib25252 lib.f90)
+add_dependencies(lib25252 custom_target_with_fortran)

Tests/FortranModules/Issue25252/custom_target.f90

@@ -0,0 +1,5 @@
+program main
+
+implicit none
+
+end program

Tests/FortranModules/Issue25252/lib.f90

@@ -0,0 +1,11 @@
+module lib
+
+implicit none
+
+contains
+
+pure real function func()
+func = 1.0
+end function
+
+end module