Fortran: Add support for submodule dependencies

Since commit v3.7.0-rc1~73^2~1 (Fortran: Add support for submodule
syntax in dependency scanning, 2016-09-05) we support parsing Fortran
sources that use submodule syntax, but it left addition of `.smod`
dependencies to future work.  Add it now.

The syntax

    submodule (module_name) submodule_name

means the current source requires `module_name.mod` and provides
`module_name@submodule_name.smod`.  The syntax

    submodule (module_name:submodule_name) nested_submodule_name

means the current source requires `module_name@submodule_name.smod`
provides `module_name@nested_submodule_name.smod`.

Fixes: #17017

6 files changed, 59 insertions, 58 deletions

diff --git a/Tests/FortranModules/Submodules/CMakeLists.txt b/Tests/FortranModules/Submodules/CMakeLists.txt
index bf0152f..da204d0 100644
--- a/Tests/FortranModules/Submodules/CMakeLists.txt
+++ b/Tests/FortranModules/Submodules/CMakeLists.txt
@@ -1 +1,20 @@
-add_executable(submod main.f90 provide.f90)
+# The program units in this file consist of a module/submodule
+# tree represented by the following graph:
+#
+#        parent
+#          |
+#         / \
+#        /   \
+#    child   sibling
+#      |
+#  grandchild
+#
+# where the parent node is a module and all other nodes are submodules.
+
+add_executable(submod
+  main.f90
+  parent.f90
+  child.f90
+  grandchild.f90
+  sibling.f90
+  )
diff --git a/Tests/FortranModules/Submodules/child.f90 b/Tests/FortranModules/Submodules/child.f90
new file mode 100644
index 0000000..838ab61
--- /dev/null
+++ b/Tests/FortranModules/Submodules/child.f90
@@ -0,0 +1,10 @@
+! Test the notation for a 1st-generation direct
+! descendant of a parent module
+submodule ( parent ) child
+  implicit none
+contains
+  module function child_function() result(child_stuff)
+    logical :: child_stuff
+    child_stuff=.true.
+  end function
+end submodule child
diff --git a/Tests/FortranModules/Submodules/grandchild.f90 b/Tests/FortranModules/Submodules/grandchild.f90
new file mode 100644
index 0000000..1aef63e
--- /dev/null
+++ b/Tests/FortranModules/Submodules/grandchild.f90
@@ -0,0 +1,8 @@
+! Test the notation for an Nth-generation descendant
+! for N>1, which necessitates the colon.
+submodule ( parent : child ) grandchild
+contains
+  module subroutine grandchild_subroutine()
+    print *,"Test passed."
+  end subroutine
+end submodule grandchild
diff --git a/Tests/FortranModules/Submodules/parent.f90 b/Tests/FortranModules/Submodules/parent.f90
new file mode 100644
index 0000000..7693a72
--- /dev/null
+++ b/Tests/FortranModules/Submodules/parent.f90
@@ -0,0 +1,17 @@
+module parent
+  implicit none
+
+  interface
+
+    ! Test Fortran 2008 "module function" syntax
+    module function child_function() result(child_stuff)
+      logical :: child_stuff
+    end function
+
+    ! Test Fortran 2008 "module subroutine" syntax
+    module subroutine grandchild_subroutine()
+    end subroutine
+
+  end interface
+
+end module parent
diff --git a/Tests/FortranModules/Submodules/provide.f90 b/Tests/FortranModules/Submodules/provide.f90
deleted file mode 100644
index 0ad216a..0000000
--- a/Tests/FortranModules/Submodules/provide.f90
+++ /dev/null
@@ -1,57 +0,0 @@
-! The program units in this file consist of a
-! module/submodule tree represented by the following
-! graph:
-!
-!        parent
-!          |
-!         / \
-!        /   \
-!    child   sibling
-!      |
-!  grandchild
-!
-! where the parent node is a module and all other
-! nodes are submodules.
-
-module parent
-  implicit none
-
-  interface
-
-    ! Test Fortran 2008 "module function" syntax
-    module function child_function() result(child_stuff)
-      logical :: child_stuff
-    end function
-
-    ! Test Fortran 2008 "module subroutine" syntax
-    module subroutine grandchild_subroutine()
-    end subroutine
-
-  end interface
-
-end module parent
-
-! Test the notation for a 1st-generation direct
-! descendant of a parent module
-submodule ( parent ) child
-  implicit none
-contains
-  module function child_function() result(child_stuff)
-    logical :: child_stuff
-    child_stuff=.true.
-  end function
-end submodule child
-
-! Empty submodule for checking disambiguation of
-! nodes at the same vertical level in the tree
-submodule ( parent ) sibling
-end submodule sibling
-
-! Test the notation for an Nth-generation descendant
-! for N>1, which necessitates the colon.
-submodule ( parent : child ) grandchild
-contains
-  module subroutine grandchild_subroutine()
-    print *,"Test passed."
-  end subroutine
-end submodule grandchild
diff --git a/Tests/FortranModules/Submodules/sibling.f90 b/Tests/FortranModules/Submodules/sibling.f90
new file mode 100644
index 0000000..bba5f92
--- /dev/null
+++ b/Tests/FortranModules/Submodules/sibling.f90
@@ -0,0 +1,4 @@
+! Empty submodule for checking disambiguation of
+! nodes at the same vertical level in the tree
+submodule ( parent ) sibling
+end submodule sibling