re PR fortran/91443 (-Wargument-mismatch does not catch mismatch for global procedure)

2019-08-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/91443
	* frontend-passes.c (check_externals_expr): New function.
	(check_externals_code): New function.
	(gfc_check_externals): New function.
	* gfortran.h (debug): Add prototypes for gfc_symbol * and
	gfc_expr *.
	(gfc_check_externals): Add prototype.
	* interface.c (compare_actual_formal): Do not complain about
	alternate returns if the formal argument is optional.
	(gfc_procedure_use): Handle cases when an error has been issued
	previously.  Break long line.
	* parse.c (gfc_parse_file): Call gfc_check_externals for all
	external procedures.
	* resolve.c (resolve_global_procedure): Remove checking of
	argument list.

2019-08-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/91443
	* gfortran.dg/argument_checking_19.f90: New test.
	* gfortran.dg/altreturn_10.f90: Change dg-warning to dg-error.
	* gfortran.dg/dec_union_11.f90: Add -std=legacy.
	* gfortran.dg/hollerith8.f90: Likewise. Remove warning for
	Hollerith constant.
	* gfortran.dg/integer_exponentiation_2.f90: New subroutine gee_i8;
	use it to avoid type mismatches.
	* gfortran.dg/pr41011.f: Add -std=legacy.
	* gfortran.dg/whole_file_1.f90: Change warnings to errors.
	* gfortran.dg/whole_file_2.f90: Likewise.

From-SVN: r274551

6 files changed, 147 insertions, 20 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 42cf2f5..3ddb007 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,21 @@
+2019-08-15  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/91443
+	* frontend-passes.c (check_externals_expr): New function.
+	(check_externals_code): New function.
+	(gfc_check_externals): New function.
+	* gfortran.h (debug): Add prototypes for gfc_symbol * and
+	gfc_expr *.
+	(gfc_check_externals): Add prototype.
+	* interface.c (compare_actual_formal): Do not complain about
+	alternate returns if the formal argument is optional.
+	(gfc_procedure_use): Handle cases when an error has been issued
+	previously.  Break long line.
+	* parse.c (gfc_parse_file): Call gfc_check_externals for all
+	external procedures.
+	* resolve.c (resolve_global_procedure): Remove checking of
+	argument list.
+
 2019-08-13  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/87991
@@ -7,7 +25,7 @@
 2019-08-13  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/88072
-	* misc.c (gfc_typename): Do not point to something that ought not to 
+	* misc.c (gfc_typename): Do not point to something that ought not to
 	be pointed at.
 
 2013-08-13  Thomas Koenig  <tkoenig@gcc.gnu.org>
diff --git a/gcc/fortran/frontend-passes.c b/gcc/fortran/frontend-passes.c
index be99a06..dd82089 100644
--- a/gcc/fortran/frontend-passes.c
+++ b/gcc/fortran/frontend-passes.c
@@ -56,7 +56,6 @@ static gfc_expr* check_conjg_transpose_variable (gfc_expr *, bool *,
 static int call_external_blas (gfc_code **, int *, void *);
 static int matmul_temp_args (gfc_code **, int *,void *data);
 static int index_interchange (gfc_code **, int*, void *);
-
 static bool is_fe_temp (gfc_expr *e);
 
 #ifdef CHECKING_P
@@ -5364,3 +5363,100 @@ gfc_code_walker (gfc_code **c, walk_code_fn_t codefn, walk_expr_fn_t exprfn,
     }
   return 0;
 }
+
+/* As a post-resolution step, check that all global symbols which are
+   not declared in the source file match in their call signatures.
+   We do this by looping over the code (and expressions). The first call
+   we happen to find is assumed to be canonical.  */
+
+/* Callback for external functions.  */
+
+static int
+check_externals_expr (gfc_expr **ep, int *walk_subtrees ATTRIBUTE_UNUSED,
+		      void *data ATTRIBUTE_UNUSED)
+{
+  gfc_expr *e = *ep;
+  gfc_symbol *sym, *def_sym;
+  gfc_gsymbol *gsym;
+
+  if (e->expr_type != EXPR_FUNCTION)
+    return 0;
+
+  sym = e->value.function.esym;
+
+  if (sym == NULL || sym->attr.is_bind_c)
+    return 0;
+
+  if (sym->attr.proc != PROC_EXTERNAL && sym->attr.proc != PROC_UNKNOWN)
+    return 0;
+
+  gsym = gfc_find_gsymbol (gfc_gsym_root, sym->name);
+  if (gsym == NULL)
+    return 0;
+
+  gfc_find_symbol (sym->name, gsym->ns, 0, &def_sym);
+
+  if (sym && def_sym)
+    gfc_procedure_use (def_sym, &e->value.function.actual, &e->where);
+
+  return 0;
+}
+
+/* Callback for external code.  */
+
+static int
+check_externals_code (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED,
+		      void *data ATTRIBUTE_UNUSED)
+{
+  gfc_code *co = *c;
+  gfc_symbol *sym, *def_sym;
+  gfc_gsymbol *gsym;
+
+  if (co->op != EXEC_CALL)
+    return 0;
+
+  sym = co->resolved_sym;
+  if (sym == NULL || sym->attr.is_bind_c)
+    return 0;
+
+  if (sym->attr.proc != PROC_EXTERNAL && sym->attr.proc != PROC_UNKNOWN)
+    return 0;
+
+  if (sym->attr.if_source == IFSRC_IFBODY || sym->attr.if_source == IFSRC_DECL)
+    return 0;
+
+  gsym = gfc_find_gsymbol (gfc_gsym_root, sym->name);
+  if (gsym == NULL)
+    return 0;
+
+  gfc_find_symbol (sym->name, gsym->ns, 0, &def_sym);
+
+  if (sym && def_sym)
+    gfc_procedure_use (def_sym, &co->ext.actual, &co->loc);
+
+  return 0;
+}
+
+/* Called routine.  */
+
+void
+gfc_check_externals (gfc_namespace *ns)
+{
+
+  gfc_clear_error ();
+
+  /* Turn errors into warnings if -std=legacy is given by the user.  */
+
+  if (!pedantic && !(gfc_option.warn_std & GFC_STD_LEGACY))
+    gfc_errors_to_warnings (true);
+
+  gfc_code_walker (&ns->code, check_externals_code, check_externals_expr, NULL);
+
+  for (ns = ns->contained; ns; ns = ns->sibling)
+    {
+      if (ns->code == NULL || ns->code->op != EXEC_BLOCK)
+	gfc_check_externals (ns);
+    }
+
+  gfc_errors_to_warnings (false);
+}
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 75e5b2f..8a0e8b3 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -3477,6 +3477,8 @@ void gfc_dump_parse_tree (gfc_namespace *, FILE *);
 void gfc_dump_c_prototypes (gfc_namespace *, FILE *);
 void gfc_dump_external_c_prototypes (FILE *);
 void gfc_dump_global_symbols (FILE *);
+void debug (gfc_symbol *);
+void debug (gfc_expr *);
 
 /* parse.c */
 bool gfc_parse_file (void);
@@ -3551,6 +3553,7 @@ int gfc_dummy_code_callback (gfc_code **, int *, void *);
 int gfc_expr_walker (gfc_expr **, walk_expr_fn_t, void *);
 int gfc_code_walker (gfc_code **, walk_code_fn_t, walk_expr_fn_t, void *);
 bool gfc_has_dimen_vector_ref (gfc_expr *e);
+void gfc_check_externals (gfc_namespace *);
 
 /* simplify.c */
 
diff --git a/gcc/fortran/interface.c b/gcc/fortran/interface.c
index 1d14f83..d6f6cce 100644
--- a/gcc/fortran/interface.c
+++ b/gcc/fortran/interface.c
@@ -2979,10 +2979,15 @@ compare_actual_formal (gfc_actual_arglist **ap, gfc_formal_arglist *formal,
 
       if (a->expr == NULL)
 	{
-	  if (where)
-	    gfc_error_now ("Unexpected alternate return specifier in "
-			   "subroutine call at %L", where);
-	  return false;
+	  if (f->sym->attr.optional)
+	    continue;
+	  else
+	    {
+	      if (where)
+		gfc_error_now ("Unexpected alternate return specifier in "
+			       "subroutine call at %L", where);
+	      return false;
+	    }
 	}
 
       /* Make sure that intrinsic vtables exist for calls to unlimited
@@ -3723,6 +3728,9 @@ gfc_procedure_use (gfc_symbol *sym, gfc_actual_arglist **ap, locus *where)
 
       for (a = *ap; a; a = a->next)
 	{
+	  if (a->expr && a->expr->error)
+	    return false;
+
 	  /* Skip g77 keyword extensions like %VAL, %REF, %LOC.  */
 	  if (a->name != NULL && a->name[0] != '%')
 	    {
@@ -3738,6 +3746,7 @@ gfc_procedure_use (gfc_symbol *sym, gfc_actual_arglist **ap, locus *where)
 	      gfc_error ("Assumed-type argument %s at %L requires an explicit "
 			 "interface", a->expr->symtree->n.sym->name,
 			 &a->expr->where);
+	      a->expr->error = 1;
 	      break;
 	    }
 
@@ -3751,6 +3760,7 @@ gfc_procedure_use (gfc_symbol *sym, gfc_actual_arglist **ap, locus *where)
 	      gfc_error ("Actual argument of LOCK_TYPE or with LOCK_TYPE "
 			 "component at %L requires an explicit interface for "
 			 "procedure %qs", &a->expr->where, sym->name);
+	      a->expr->error = 1;
 	      break;
 	    }
 
@@ -3764,13 +3774,16 @@ gfc_procedure_use (gfc_symbol *sym, gfc_actual_arglist **ap, locus *where)
 	      gfc_error ("Actual argument of EVENT_TYPE or with EVENT_TYPE "
 			 "component at %L requires an explicit interface for "
 			 "procedure %qs", &a->expr->where, sym->name);
+	      a->expr->error = 1;
 	      break;
 	    }
 
 	  if (a->expr && a->expr->expr_type == EXPR_NULL
 	      && a->expr->ts.type == BT_UNKNOWN)
 	    {
-	      gfc_error ("MOLD argument to NULL required at %L", &a->expr->where);
+	      gfc_error ("MOLD argument to NULL required at %L",
+			 &a->expr->where);
+	      a->expr->error = 1;
 	      return false;
 	    }
 
@@ -3780,6 +3793,7 @@ gfc_procedure_use (gfc_symbol *sym, gfc_actual_arglist **ap, locus *where)
 	    {
 	      gfc_error ("Assumed-rank argument requires an explicit interface "
 			 "at %L", &a->expr->where);
+	      a->expr->error = 1;
 	      return false;
 	    }
 	}
diff --git a/gcc/fortran/parse.c b/gcc/fortran/parse.c
index 66d84b4..31466d2 100644
--- a/gcc/fortran/parse.c
+++ b/gcc/fortran/parse.c
@@ -6319,6 +6319,12 @@ done:
   /* Do the resolution.  */
   resolve_all_program_units (gfc_global_ns_list);
 
+
+  /* Fixup for external procedures.  */
+  for (gfc_current_ns = gfc_global_ns_list; gfc_current_ns;
+       gfc_current_ns = gfc_current_ns->sibling)
+    gfc_check_externals (gfc_current_ns);
+
   /* Do the parse tree dump.  */
   gfc_current_ns = flag_dump_fortran_original ? gfc_global_ns_list : NULL;
 
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index ac9192a..1f48045 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -2506,8 +2506,7 @@ gfc_explicit_interface_required (gfc_symbol *sym, char *errmsg, int err_len)
 
 
 static void
-resolve_global_procedure (gfc_symbol *sym, locus *where,
-			  gfc_actual_arglist **actual, int sub)
+resolve_global_procedure (gfc_symbol *sym, locus *where, int sub)
 {
   gfc_gsymbol * gsym;
   gfc_namespace *ns;
@@ -2615,14 +2614,6 @@ resolve_global_procedure (gfc_symbol *sym, locus *where,
 			 " %s", sym->name, &sym->declared_at, reason);
 	  goto done;
 	}
-
-      if (!pedantic
-	  || ((gfc_option.warn_std & GFC_STD_LEGACY)
-	      && !(gfc_option.warn_std & GFC_STD_GNU)))
-	gfc_errors_to_warnings (true);
-
-      if (sym->attr.if_source != IFSRC_IFBODY)
-	gfc_procedure_use (def_sym, actual, where);
     }
 
 done:
@@ -3198,8 +3189,7 @@ resolve_function (gfc_expr *expr)
 
   /* If the procedure is external, check for usage.  */
   if (sym && is_external_proc (sym))
-    resolve_global_procedure (sym, &expr->where,
-			      &expr->value.function.actual, 0);
+    resolve_global_procedure (sym, &expr->where, 0);
 
   if (sym && sym->ts.type == BT_CHARACTER
       && sym->ts.u.cl
@@ -3675,7 +3665,7 @@ resolve_call (gfc_code *c)
 
   /* If external, check for usage.  */
   if (csym && is_external_proc (csym))
-    resolve_global_procedure (csym, &c->loc, &c->ext.actual, 1);
+    resolve_global_procedure (csym, &c->loc, 1);
 
   t = true;
   if (c->resolved_sym == NULL)