[Patch, Fortran] PR 34153 - Allow setting a breakpoint in the END PROGRAM/SUBROUTE line

[Tobias Burnus <burnus at net-b dot de>]

Hello all,

debugging of code such as

   subroutine foo(x)
      external
      integer, intent(out) :: x
      x =  f()
      ! some comment
   end subroutine foo

had the problem that you could not set a break pointer after "x = f(x)".
And then a "step" would return into the calling procedure - thus one
could not "print x" after the assignment.

The problem became clear for the short program
    subroutine foo()
    end subroutine foo
using "readelf --debug-dump=decodedline". The result was:
  File name                            Line number    Starting address
  test.f90                                         1                   0
  test.f90                                         1                 0x4

while "ifort" had the line numbers "1" and "2". The problem is that the
input_line remained at "subroutine foo()" instead of jumping to "end
subroutine foo()". The simplest solution for me was too add the new
EXEC_END_PROCEDURE which is a NOOP but sets in trans.c the line number.

Bootstrapped and being regtested on x86-64-linux. OK for the trunk?

Tobias

PS: Please note that the compiler is to aggressive with -O0 and thus
printing "i" for the original example in the bugreport will not work as
the assignment is optimized away ... (Ditto for the analogous C program.)

2009-05-12  Tobias Burnus  <burnus@net-b.de>

	PR fortran/34153
	* gfortran.h (gfc_exec_op): Add EXEC_END_PROCEDURE.
	* dump-parse-tree.c (show_code_node): Use EXEC_END_PROCEDURE.
	* trans.c (gfc_trans_code): Ditto.
	* resolve.c (resolve_code): Ditto.
	* st.c (gfc_free_statement): Ditto.
	* parse.c (accept_statement): Ditto.

Index: gcc/fortran/dump-parse-tree.c
===================================================================
--- gcc/fortran/dump-parse-tree.c	(Revision 147445)
+++ gcc/fortran/dump-parse-tree.c	(Arbeitskopie)
@@ -1148,6 +1148,9 @@ show_code_node (int level, gfc_code *c)
 
   switch (c->op)
     {
+    case EXEC_END_PROCEDURE:
+      break;
+
     case EXEC_NOP:
       fputs ("NOP", dumpfile);
       break;
Index: gcc/fortran/gfortran.h
===================================================================
--- gcc/fortran/gfortran.h	(Revision 147445)
+++ gcc/fortran/gfortran.h	(Arbeitskopie)
@@ -1893,7 +1893,7 @@ typedef enum
   EXEC_ENTRY, EXEC_PAUSE, EXEC_STOP, EXEC_CONTINUE, EXEC_INIT_ASSIGN,
   EXEC_IF, EXEC_ARITHMETIC_IF, EXEC_DO, EXEC_DO_WHILE, EXEC_SELECT,
   EXEC_FORALL, EXEC_WHERE, EXEC_CYCLE, EXEC_EXIT, EXEC_CALL_PPC,
-  EXEC_ALLOCATE, EXEC_DEALLOCATE,
+  EXEC_ALLOCATE, EXEC_DEALLOCATE, EXEC_END_PROCEDURE,
   EXEC_OPEN, EXEC_CLOSE, EXEC_WAIT,
   EXEC_READ, EXEC_WRITE, EXEC_IOLENGTH, EXEC_TRANSFER, EXEC_DT_END,
   EXEC_BACKSPACE, EXEC_ENDFILE, EXEC_INQUIRE, EXEC_REWIND, EXEC_FLUSH,
Index: gcc/fortran/trans.c
===================================================================
--- gcc/fortran/trans.c	(Revision 147445)
+++ gcc/fortran/trans.c	(Arbeitskopie)
@@ -1056,6 +1056,7 @@ gfc_trans_code (gfc_code * code)
 	{
 	case EXEC_NOP:
 	case EXEC_END_BLOCK:
+	case EXEC_END_PROCEDURE:
 	  res = NULL_TREE;
 	  break;
 
Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c	(Revision 147445)
+++ gcc/fortran/resolve.c	(Arbeitskopie)
@@ -6938,6 +6938,7 @@ resolve_code (gfc_code *code, gfc_namesp
 	  break;
 
 	case EXEC_INIT_ASSIGN:
+	case EXEC_END_PROCEDURE:
 	  break;
 
 	case EXEC_ASSIGN:
Index: gcc/fortran/st.c
===================================================================
--- gcc/fortran/st.c	(Revision 147445)
+++ gcc/fortran/st.c	(Arbeitskopie)
@@ -94,6 +94,7 @@ gfc_free_statement (gfc_code *p)
     case EXEC_GOTO:
     case EXEC_CYCLE:
     case EXEC_RETURN:
+    case EXEC_END_PROCEDURE:
     case EXEC_IF:
     case EXEC_PAUSE:
     case EXEC_STOP:
Index: gcc/fortran/parse.c
===================================================================
--- gcc/fortran/parse.c	(Revision 147445)
+++ gcc/fortran/parse.c	(Arbeitskopie)
@@ -1496,6 +1496,11 @@ accept_statement (gfc_statement st)
 	  new_st.op = EXEC_RETURN;
 	  add_statement ();
 	}
+      else
+	{
+	  new_st.op = EXEC_END_PROCEDURE;
+	  add_statement ();
+	}
 
       break;