[gcc r13-2833] fortran: Move the clobber generation code

[Mikael Morin <mikael@gcc.gnu.org>]

https://gcc.gnu.org/g:2b393f6f83903cb836676bbd042c1b99a6e7e6f7

commit r13-2833-g2b393f6f83903cb836676bbd042c1b99a6e7e6f7
Author: Mikael Morin <mikael@gcc.gnu.org>
Date:   Wed Aug 31 11:00:45 2022 +0200

    fortran: Move the clobber generation code
    
    This change inlines the clobber generation code from
    gfc_conv_expr_reference to the single caller from where the add_clobber
    flag can be true, and removes the add_clobber argument.
    
    What motivates this is the standard making the procedure call a cause
    for a variable to become undefined, which translates to a clobber
    generation, so clobber generation should be closely related to procedure
    call generation, whereas it is rather orthogonal to variable reference
    generation.  Thus the generation of the clobber feels more appropriate
    in gfc_conv_procedure_call than in gfc_conv_expr_reference.
    
    Behaviour remains unchanged.
    
    gcc/fortran/ChangeLog:
    
            * trans.h (gfc_conv_expr_reference): Remove add_clobber
            argument.
            * trans-expr.cc (gfc_conv_expr_reference): Ditto. Inline code
            depending on add_clobber and conditions controlling it ...
            (gfc_conv_procedure_call): ... to here.

Diff:
---
 gcc/fortran/trans-expr.cc | 60 +++++++++++++++++++++++++----------------------
 gcc/fortran/trans.h       |  3 +--
 2 files changed, 33 insertions(+), 30 deletions(-)

diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index 7895d034610..7cdab1cc9b4 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -6395,7 +6395,7 @@ gfc_conv_procedure_call (gfc_se * se, gfc_symbol * sym,
 				&& e->symtree->n.sym->attr.pointer))
 			&& fsym && fsym->attr.target)
 		/* Make sure the function only gets called once.  */
-		gfc_conv_expr_reference (&parmse, e, false);
+		gfc_conv_expr_reference (&parmse, e);
 	      else if (e->expr_type == EXPR_FUNCTION
 		       && e->symtree->n.sym->result
 		       && e->symtree->n.sym->result != e->symtree->n.sym
@@ -6502,22 +6502,36 @@ gfc_conv_procedure_call (gfc_se * se, gfc_symbol * sym,
 		    }
 		  else
 		    {
-		      bool add_clobber;
-		      add_clobber = fsym && fsym->attr.intent == INTENT_OUT
-			&& !fsym->attr.allocatable && !fsym->attr.pointer
-			&& e->symtree && e->symtree->n.sym
-			&& !e->symtree->n.sym->attr.dimension
-			&& !e->symtree->n.sym->attr.pointer
-			&& !e->symtree->n.sym->attr.allocatable
-			/* See PR 41453.  */
-			&& !e->symtree->n.sym->attr.dummy
-			/* FIXME - PR 87395 and PR 41453  */
-			&& e->symtree->n.sym->attr.save == SAVE_NONE
-			&& !e->symtree->n.sym->attr.associate_var
-			&& e->ts.type != BT_CHARACTER && e->ts.type != BT_DERIVED
-			&& e->ts.type != BT_CLASS && !sym->attr.elemental;
-
-		      gfc_conv_expr_reference (&parmse, e, add_clobber);
+		      gfc_conv_expr_reference (&parmse, e);
+
+		      if (fsym
+			  && fsym->attr.intent == INTENT_OUT
+			  && !fsym->attr.allocatable
+			  && !fsym->attr.pointer
+			  && e->expr_type == EXPR_VARIABLE
+			  && e->ref == NULL
+			  && e->symtree
+			  && e->symtree->n.sym
+			  && !e->symtree->n.sym->attr.dimension
+			  && !e->symtree->n.sym->attr.pointer
+			  && !e->symtree->n.sym->attr.allocatable
+			  /* See PR 41453.  */
+			  && !e->symtree->n.sym->attr.dummy
+			  /* FIXME - PR 87395 and PR 41453  */
+			  && e->symtree->n.sym->attr.save == SAVE_NONE
+			  && !e->symtree->n.sym->attr.associate_var
+			  && e->ts.type != BT_CHARACTER
+			  && e->ts.type != BT_DERIVED
+			  && e->ts.type != BT_CLASS
+			  && !sym->attr.elemental)
+			{
+			  tree var;
+			  /* FIXME: This fails if var is passed by reference, see PR
+			     41453.  */
+			  var = e->symtree->n.sym->backend_decl;
+			  tree clobber = build_clobber (TREE_TYPE (var));
+			  gfc_add_modify (&se->pre, var, clobber);
+			}
 		    }
 		  /* Catch base objects that are not variables.  */
 		  if (e->ts.type == BT_CLASS
@@ -9484,7 +9498,7 @@ gfc_conv_expr_type (gfc_se * se, gfc_expr * expr, tree type)
    values only.  */
 
 void
-gfc_conv_expr_reference (gfc_se * se, gfc_expr * expr, bool add_clobber)
+gfc_conv_expr_reference (gfc_se * se, gfc_expr * expr)
 {
   gfc_ss *ss;
   tree var;
@@ -9524,16 +9538,6 @@ gfc_conv_expr_reference (gfc_se * se, gfc_expr * expr, bool add_clobber)
 	  gfc_add_block_to_block (&se->pre, &se->post);
 	  se->expr = var;
 	}
-      else if (add_clobber && expr->ref == NULL)
-	{
-	  tree clobber;
-	  tree var;
-	  /* FIXME: This fails if var is passed by reference, see PR
-	     41453.  */
-	  var = expr->symtree->n.sym->backend_decl;
-	  clobber = build_clobber (TREE_TYPE (var));
-	  gfc_add_modify (&se->pre, var, clobber);
-	}
       return;
     }
 
diff --git a/gcc/fortran/trans.h b/gcc/fortran/trans.h
index 03d5288aad2..bc9035c1717 100644
--- a/gcc/fortran/trans.h
+++ b/gcc/fortran/trans.h
@@ -499,8 +499,7 @@ tree gfc_build_compare_string (tree, tree, tree, tree, int, enum tree_code);
 void gfc_conv_expr (gfc_se * se, gfc_expr * expr);
 void gfc_conv_expr_val (gfc_se * se, gfc_expr * expr);
 void gfc_conv_expr_lhs (gfc_se * se, gfc_expr * expr);
-void gfc_conv_expr_reference (gfc_se * se, gfc_expr * expr,
-			      bool add_clobber = false);
+void gfc_conv_expr_reference (gfc_se * se, gfc_expr * expr);
 void gfc_conv_expr_type (gfc_se * se, gfc_expr *, tree);