gdb/fortran: Nested subroutine support

This patch is a rebase and update of the following three patches:

   https://sourceware.org/ml/gdb-patches/2018-11/msg00298.html
   https://sourceware.org/ml/gdb-patches/2018-11/msg00302.html
   https://sourceware.org/ml/gdb-patches/2018-11/msg00301.html

I have merged these together into a single commit as the second patch,
adding scope support to nested subroutines, means that some of the
changes in the first patch are now no longer useful and would have to
be backed out.  The third patch is tightly coupled to the changes in
the second of these patches and I think deserves to live together with
it.

There is an extra change in cp-namespace.c that is new, this resolves
an issue with symbol lookup when placing breakpoints from within
nested subroutines.

There is also an extra test added to this commit 'nested-funcs-2.exp'
that was written by Richard Bunt from ARM, this offers some additional
testing of breakpoints on nested functions.

After this commit it is possible to place breakpoints on nested
Fortran subroutines and functions by using a fully scoped name, for
example, given this simple Fortran program:

    program greeting
      call message
    contains
      subroutine message
        print *, "Hello World"
      end subroutine message
    end program greeting

It is possible to place a breakpoint in 'message' with:

    (gdb) break greeting::message
    Breakpoint 1 at 0x4006c9: file basic.f90, line 5.

What doesn't work with this commit is placing a breakpoint like this:

    (gdb) break message
    Function "message" not defined.

Making this work will come in a later commit.

gdb/ChangeLog:

	* cp-namespace.c (cp_search_static_and_baseclasses): Only search
	for nested static variables when searchin VAR_DOMAIN.
	* dwarf2read.c (add_partial_symbol): Add nested subroutines to the
	global scope, update comment.
	(add_partial_subprogram): Call add_partial_subprogram recursively
	for nested subroutines when processinng Fortran.
	(load_partial_dies): Process the child entities of a subprogram
	when processing Fortran.
	(partial_die_parent_scope): Handle building scope
	for Fortran nested functions.
	(process_die): Record that nested functions have a scope.
	(new_symbol): Always record Fortran subprograms on the global
	symbol list.
	(determine_prefix): How to build the prefix for Fortran
	subprograms.

gdb/testsuite/ChangeLog:

	* gdb.fortran/nested-funcs.exp: Tests for placing breakpoints on
	nested functions.
	* gdb.fortran/nested-funcs.f90: Update expected results.
	* gdb.fortran/nested-funcs-2.exp: New file.
	* gdb.fortran/nested-funcs-2.f90: New file.

gdb/doc/ChangeLog:

	* doc/gdb.texinfo (Fortran Operators): Describe scope operator.

1 files changed, 60 insertions, 3 deletions

diff --git a/gdb/testsuite/gdb.fortran/nested-funcs.f90 b/gdb/testsuite/gdb.fortran/nested-funcs.f90
index 3431705..ce2f269 100755
--- a/gdb/testsuite/gdb.fortran/nested-funcs.f90
+++ b/gdb/testsuite/gdb.fortran/nested-funcs.f90
@@ -13,8 +13,62 @@
 ! You should have received a copy of the GNU General Public License

 ! along with this program.  If not, see <http://www.gnu.org/licenses/>.

 

-program TestNestedFuncs

+module mod1

+  integer :: var_i = 1

+  integer :: var_const

+  parameter (var_const = 20)

+

+CONTAINS

+

+  SUBROUTINE sub_nested_outer

+    integer :: local_int

+    character (len=20) :: name

+

+    name = 'sub_nested_outer_mod1'

+    local_int = 11

+

+  END SUBROUTINE sub_nested_outer

+end module mod1

+

+! Public sub_nested_outer

+SUBROUTINE sub_nested_outer

+  integer :: local_int

+  character (len=16) :: name

+

+  name = 'sub_nested_outer external'

+  local_int = 11

+END SUBROUTINE sub_nested_outer

+

+! Needed indirection to call public sub_nested_outer from main

+SUBROUTINE sub_nested_outer_ind

+  character (len=20) :: name

+

+  name = 'sub_nested_outer_ind'

+  CALL sub_nested_outer

+END SUBROUTINE sub_nested_outer_ind

+

+! public routine with internal subroutine

+SUBROUTINE sub_with_sub_nested_outer()

+  integer :: local_int

+  character (len=16) :: name

+

+  name = 'subroutine_with_int_sub'

+  local_int = 1

+

+  CALL sub_nested_outer  ! Should call the internal fct

+

+CONTAINS

 

+  SUBROUTINE sub_nested_outer

+    integer :: local_int

+    local_int = 11

+  END SUBROUTINE sub_nested_outer

+

+END SUBROUTINE sub_with_sub_nested_outer

+

+! Main

+program TestNestedFuncs

+  USE mod1, sub_nested_outer_use_mod1 => sub_nested_outer

   IMPLICIT NONE

 

   TYPE :: t_State

@@ -22,10 +76,13 @@ program TestNestedFuncs
   END TYPE t_State

 

   TYPE (t_State) :: v_state

-  integer index

+  integer index, local_int

 

   index = 13

-  CALL sub_nested_outer

+  CALL sub_nested_outer            ! Call internal sub_nested_outer

+  CALL sub_nested_outer_ind        ! Call external sub_nested_outer via sub_nested_outer_ind

+  CALL sub_with_sub_nested_outer   ! Call external routine with nested sub_nested_outer

+  CALL sub_nested_outer_use_mod1   ! Call sub_nested_outer imported via module

   index = 11              ! BP_main

   v_state%code = 27