Ninja: Add source location as include directory for preprocessed files

Fortran INCLUDE statements are not handled by the preprocessor.

Since the location of the preprocessed file is distinct from the
original source file explicitly add the source file's directory
as an include path in the actual compile step (not the preprocessing step)
so INCLUDE can find it.

Closes: #16332

Source/cmNinjaTargetGenerator.cxx

@@ -841,6 +841,18 @@ void cmNinjaTargetGenerator::WriteObjectBuildStatement(
     // directive.
     ppVars["INCLUDES"] = vars["INCLUDES"];
 
+    // Prepend source file's original directory as an include directory
+    // so e.g. Fortran INCLUDE statements can look for files in it.
+    std::vector<std::string> sourceDirectory;
+    sourceDirectory.push_back(
+      cmSystemTools::GetParentDirectory(source->GetFullPath()));
+
+    std::string sourceDirectoryFlag = this->LocalGenerator->GetIncludeFlags(
+      sourceDirectory, this->GeneratorTarget, language, false, false,
+      this->GetConfigName());
+
+    vars["INCLUDES"] = sourceDirectoryFlag + " " + vars["INCLUDES"];
+
     // Explicit preprocessing always uses a depfile.
     ppVars["DEP_FILE"] =
       cmGlobalNinjaGenerator::EncodeDepfileSpace(ppFileName + ".d");

Tests/FortranModules/CMakeLists.txt

@@ -52,6 +52,8 @@ add_definitions(-DFOO -DBAR=1)
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/include)
 add_executable(test_preprocess test_preprocess.F90 test_preprocess_module.F90)
 
+add_executable(test_non_pp_include test_non_pp_include_main.f90)
+
 # Build the external project separately using a custom target.
 # Make sure it uses the same build configuration as this test.
 if(CMAKE_CONFIGURATION_TYPES)

Tests/FortranModules/non_pp_include.f90

@@ -0,0 +1,3 @@
+SUBROUTINE NON_PP_INCLUDE_SUBROUTINE
+   PRINT *, "Hello World!"
+END SUBROUTINE NON_PP_INCLUDE_SUBROUTINE

Tests/FortranModules/test_non_pp_include_main.f90

@@ -0,0 +1,5 @@
+INCLUDE "non_pp_include.f90"
+
+PROGRAM MAINF90
+   CALL NON_PP_INCLUDE_SUBROUTINE
+END PROGRAM MAINF90