Fortran: Fix suprious dependencies with submodules

In commit 695f0d0d3a (cmFortranParser: Parse keywords as lexical tokens,
2016-09-05, v3.7.0-rc1~150^2) we created keyword-specific variants of
the original `USE WORD other EOSTMT` production, such as
`MODULE WORD other EOSTMT` and `INTERFACE WORD other EOSTMT`.  The same
pattern was used by more keyword-specific productions in commit b5ac8b8aa7
(Fortran: Add support for submodule syntax in dependency scanning,
2016-09-05, v3.7.0-rc1~73^2~1).

The postfix part (`other`) of several keyword-specific productions is
not needed to match Fortran syntax.  See the Fortran 2018 standard,
para.4.1.4/1 on p.28, para.14.2.1/2 on pp.293-294.  The postfix is
needed only for a case of operator 'use':

    use <module-name> [, only : <list-of-vars>]

The unnecessary postfix matching from the keyword-specific productions
such as module, submodule, and interface declarations can cause spurious
module dependencies to be detected, so remove it.

Extend the test suite with examples covering the previously-broken
cases.

Fixes: #18427

4 files changed, 40 insertions, 3 deletions

diff --git a/Tests/FortranModules/Submodules/CMakeLists.txt b/Tests/FortranModules/Submodules/CMakeLists.txt
index ab8e0f9..783af7e 100644
--- a/Tests/FortranModules/Submodules/CMakeLists.txt
+++ b/Tests/FortranModules/Submodules/CMakeLists.txt
@@ -16,6 +16,7 @@
 add_executable(submod
   main.f90
   parent.f90
+  obfuscated_parent.f90
   child.f90
   grandchild.f90
   greatgrandchild.f90
diff --git a/Tests/FortranModules/Submodules/main.f90 b/Tests/FortranModules/Submodules/main.f90
index 3cd2989..67ffba8 100644
--- a/Tests/FortranModules/Submodules/main.f90
+++ b/Tests/FortranModules/Submodules/main.f90
@@ -1,7 +1,10 @@
 program main
   use parent, only : child_function,grandchild_subroutine
   use parent, only : sibling_function,GreatGrandChild_subroutine
+  ! Using a module without postfix
+  use obfuscated_parent
   implicit none
-  if (child_function()) call grandchild_subroutine
-  if (sibling_function()) call GreatGrandChild_subroutine
+  if (child_function())     call grandchild_subroutine
+  if (sibling_function())   call GreatGrandChild_subroutine
+  if (child_function_obf()) call grandchild_subroutine_obf
 end program
diff --git a/Tests/FortranModules/Submodules/obfuscated_parent.f90 b/Tests/FortranModules/Submodules/obfuscated_parent.f90
new file mode 100644
index 0000000..f3e68be
--- /dev/null
+++ b/Tests/FortranModules/Submodules/obfuscated_parent.f90
@@ -0,0 +1,33 @@
+! This module has two procedures from the "parent" module
+! but it has different combinations 'module <word>' phrases
+! in breaked lines for test of modules dependencies detection
+
+! Module declaration on breaked line with reminder
+module &
+         obfuscated_parent;  implicit none
+
+  interface
+
+    ! Boolean module function
+    module logical &
+                     function child_function_obf() result(child_stuff)
+    end function
+
+    ! Module subroutine
+    module subroutine &
+                     grandchild_subroutine_obf()
+    end subroutine
+
+  end interface
+
+  contains
+
+    module logical function child_function_obf() result(child_stuff)
+      child_stuff=.true.
+    end function
+
+    module subroutine grandchild_subroutine_obf()
+      print *,"Test passed."
+    end subroutine
+
+end module obfuscated_parent
diff --git a/Tests/FortranModules/test_module_main.f90 b/Tests/FortranModules/test_module_main.f90
index 6ac97fa..958d0a2 100644
--- a/Tests/FortranModules/test_module_main.f90
+++ b/Tests/FortranModules/test_module_main.f90
@@ -1,4 +1,4 @@
 PROGRAM MAINF90
-  USE TEST_MODULE
+  USE TEST_MODULE, only : TEST_MODULE_FUNCTION
   PRINT *,'Sum is',TEST_MODULE_FUNCTION(1., 2.)
 END PROGRAM MAINF90