Index: gcc/fortran/decl.c
===================================================================
--- gcc/fortran/decl.c	(revision 266718)
+++ gcc/fortran/decl.c	(working copy)
@@ -281,6 +281,14 @@ var_element (gfc_data_variable *new_var)
   if (m != MATCH_YES)
     return m;
 
+  if (new_var->expr->expr_type == EXPR_CONSTANT
+      && new_var->expr->symtree == NULL)
+    {
+      gfc_error ("Inquiry parameter cannot appear in a "
+		 "data-stmt-object-list at %C");
+      return MATCH_ERROR;
+    }
+
   sym = new_var->expr->symtree->n.sym;
 
   /* Symbol should already have an associated type.  */
@@ -391,6 +399,14 @@ match_data_constant (gfc_expr **result)
     }
   else if (m == MATCH_YES)
     {
+      /* If a parameter inquiry ends up here, symtree is NULL but **result
+	 contains the right constant expression.  Check here.  */
+      if ((*result)->symtree == NULL
+	  && (*result)->expr_type == EXPR_CONSTANT
+	  && ((*result)->ts.type == BT_INTEGER 
+	      || (*result)->ts.type == BT_REAL))
+	return m;
+
       /* F2018:R845 data-stmt-constant is initial-data-target.
 	 A data-stmt-constant shall be ... initial-data-target if and
 	 only if the corresponding data-stmt-object has the POINTER
Index: gcc/fortran/dump-parse-tree.c
===================================================================
--- gcc/fortran/dump-parse-tree.c	(revision 266718)
+++ gcc/fortran/dump-parse-tree.c	(working copy)
@@ -3259,6 +3259,14 @@ write_proc (gfc_symbol *sym)
     {
       gfc_symbol *s;
       s = f->sym;
+
+      if (!s)
+	{
+	  gfc_error_now ("Par %L, \"Nous sommes tous nes pour le mal\"",
+			 &sym->declared_at);
+	  return;
+	}
+
       rok = get_c_type_name (&(s->ts), NULL, &pre, &type_name, &asterisk,
 			     &post, false);
       if (rok == T_ERROR)
Index: gcc/fortran/expr.c
===================================================================
--- gcc/fortran/expr.c	(revision 266718)
+++ gcc/fortran/expr.c	(working copy)
@@ -2688,6 +2688,9 @@ check_transformational (gfc_expr *e)
 static match
 check_null (gfc_expr *e)
 {
+  if (flag_dec && e->expr_type == EXPR_CONSTANT)
+   return MATCH_NO;
+
   if (strcmp ("null", e->symtree->n.sym->name) != 0)
     return MATCH_NO;
 
@@ -2698,6 +2701,9 @@ check_null (gfc_expr *e)
 static match
 check_elemental (gfc_expr *e)
 {
+  if (flag_dec && e->expr_type == EXPR_CONSTANT)
+   return MATCH_NO;
+
   if (!e->value.function.isym
       || !e->value.function.isym->elemental)
     return MATCH_NO;
@@ -2793,10 +2799,15 @@ gfc_check_init_expr (gfc_expr *e)
 	    && (m = check_transformational (e)) == MATCH_NO
 	    && (m = check_elemental (e)) == MATCH_NO)
 	  {
-	    gfc_error ("Intrinsic function %qs at %L is not permitted "
-		       "in an initialization expression",
-		       e->symtree->n.sym->name, &e->where);
-	    m = MATCH_ERROR;
+	    if (flag_dec && e->expr_type == EXPR_CONSTANT)
+	      return true;
+	    else
+	      {
+		gfc_error ("Intrinsic function %qs at %L is not permitted "
+			   "in an initialization expression",
+			   e->symtree->n.sym->name, &e->where);
+		m = MATCH_ERROR;
+	      }
 	  }
 
 	if (m == MATCH_ERROR)
@@ -4485,12 +4496,10 @@ gfc_apply_init (gfc_typespec *ts, symbol_attribute *at
 {
   if (ts->type == BT_CHARACTER && !attr->pointer && init
       && ts->u.cl
-      && ts->u.cl->length && ts->u.cl->length->expr_type == EXPR_CONSTANT)
+      && ts->u.cl->length
+      && ts->u.cl->length->expr_type == EXPR_CONSTANT
+      && ts->u.cl->length->ts.type == BT_INTEGER)
     {
-      gcc_assert (ts->u.cl && ts->u.cl->length);
-      gcc_assert (ts->u.cl->length->expr_type == EXPR_CONSTANT);
-      gcc_assert (ts->u.cl->length->ts.type == BT_INTEGER);
-
       HOST_WIDE_INT len = gfc_mpz_get_hwi (ts->u.cl->length->value.integer);
 
       if (init->expr_type == EXPR_CONSTANT)
Index: gcc/fortran/gfortran.h
===================================================================
--- gcc/fortran/gfortran.h	(revision 266718)
+++ gcc/fortran/gfortran.h	(working copy)
@@ -3395,7 +3395,7 @@ bool gfc_resolve_open (gfc_open *);
 void gfc_free_close (gfc_close *);
 bool gfc_resolve_close (gfc_close *);
 void gfc_free_filepos (gfc_filepos *);
-bool gfc_resolve_filepos (gfc_filepos *);
+bool gfc_resolve_filepos (gfc_filepos *, locus *);
 void gfc_free_inquire (gfc_inquire *);
 bool gfc_resolve_inquire (gfc_inquire *);
 void gfc_free_dt (gfc_dt *);
Index: gcc/fortran/io.c
===================================================================
--- gcc/fortran/io.c	(revision 266718)
+++ gcc/fortran/io.c	(working copy)
@@ -1636,6 +1636,12 @@ resolve_tag_format (gfc_expr *e)
 	  gfc_expr *r;
 	  gfc_char_t *dest, *src;
 
+	  if (e->value.constructor == NULL)
+	    {
+	      gfc_error ("FORMAT tag at %C cannot be a zero-sized array");
+	      return false;
+	    }
+
 	  n = 0;
 	  c = gfc_constructor_first (e->value.constructor);
 	  len = c->expr->value.character.length;
@@ -2161,6 +2167,12 @@ gfc_match_open (void)
 
       if (!open->file && open->status)
         {
+	  if (open->status->ts.type != BT_CHARACTER)
+	    {
+	     gfc_error ("STATUS must be a default character type at %C");
+	     goto cleanup;
+	    }
+
 	  if (open->status->expr_type == EXPR_CONSTANT
 	     && gfc_wide_strncasecmp (open->status->value.character.string,
 				       "scratch", 7) != 0)
@@ -2232,6 +2244,21 @@ gfc_match_open (void)
       if (!is_char_type ("ASYNCHRONOUS", open->asynchronous))
 	goto cleanup;
 
+      if (open->asynchronous->ts.kind != 1)
+	{
+	  gfc_error ("ASYNCHRONOUS= specifier at %L must have default "
+		     "CHARACTER kind", &open->asynchronous->where);
+	  return MATCH_ERROR;
+	}
+
+      if (open->asynchronous->expr_type == EXPR_ARRAY
+	  || open->asynchronous->expr_type == EXPR_STRUCTURE)
+	{
+	  gfc_error ("ASYNCHRONOUS= specifier at %L must be scalar",
+		     &open->asynchronous->where);
+	  return MATCH_ERROR;
+	}
+
       if (open->asynchronous->expr_type == EXPR_CONSTANT)
 	{
 	  static const char * asynchronous[] = { "YES", "NO", NULL };
@@ -2834,22 +2861,21 @@ cleanup:
 
 
 bool
-gfc_resolve_filepos (gfc_filepos *fp)
+gfc_resolve_filepos (gfc_filepos *fp, locus *where)
 {
   RESOLVE_TAG (&tag_unit, fp->unit);
   RESOLVE_TAG (&tag_iostat, fp->iostat);
   RESOLVE_TAG (&tag_iomsg, fp->iomsg);
-  if (!gfc_reference_st_label (fp->err, ST_LABEL_TARGET))
-    return false;
 
-  if (!fp->unit && (fp->iostat || fp->iomsg))
+  if (!fp->unit && (fp->iostat || fp->iomsg || fp->err))
     {
-      locus where;
-      where = fp->iostat ? fp->iostat->where : fp->iomsg->where;
-      gfc_error ("UNIT number missing in statement at %L", &where);
+      gfc_error ("UNIT number missing in statement at %L", where);
       return false;
     }
 
+  if (!gfc_reference_st_label (fp->err, ST_LABEL_TARGET))
+    return false;
+
   if (fp->unit->expr_type == EXPR_CONSTANT
       && fp->unit->ts.type == BT_INTEGER
       && mpz_sgn (fp->unit->value.integer) < 0)
@@ -3231,12 +3257,21 @@ gfc_resolve_dt (gfc_dt *dt, locus *loc)
 {
   gfc_expr *e;
   io_kind k;
+  locus loc_tmp;
 
   /* This is set in any case.  */
   gcc_assert (dt->dt_io_kind);
   k = dt->dt_io_kind->value.iokind;
 
-  RESOLVE_TAG (&tag_format, dt->format_expr);
+  loc_tmp = gfc_current_locus;
+  gfc_current_locus = *loc;
+  if (!resolve_tag (&tag_format, dt->format_expr))
+    {
+      gfc_current_locus = loc_tmp;
+      return false;
+    }
+  gfc_current_locus = loc_tmp;
+
   RESOLVE_TAG (&tag_rec, dt->rec);
   RESOLVE_TAG (&tag_spos, dt->pos);
   RESOLVE_TAG (&tag_advance, dt->advance);
@@ -3681,7 +3716,10 @@ check_io_constraints (io_kind k, gfc_dt *dt, gfc_code 
 #define io_constraint(condition,msg,arg)\
 if (condition) \
   {\
-    gfc_error(msg,arg);\
+    if ((arg)->lb != NULL) \
+      gfc_error(msg,arg);\
+    else \
+      gfc_error(msg,&gfc_current_locus);\
     m = MATCH_ERROR;\
   }
 
@@ -3741,11 +3779,14 @@ if (condition) \
   if (expr && expr->ts.type != BT_CHARACTER)
     {
 
-      io_constraint (gfc_pure (NULL) && (k == M_READ || k == M_WRITE),
-		     "IO UNIT in %s statement at %C must be "
+      if (gfc_pure (NULL) && (k == M_READ || k == M_WRITE))
+	{
+	  gfc_error ("IO UNIT in %s statement at %C must be "
 		     "an internal file in a PURE procedure",
 		     io_kind_name (k));
-
+	  return MATCH_ERROR;
+	}
+	  
       if (k == M_READ || k == M_WRITE)
 	gfc_unset_implicit_pure (NULL);
     }
@@ -3792,6 +3833,21 @@ if (condition) \
 
       if (!is_char_type ("ASYNCHRONOUS", dt->asynchronous))
 	return MATCH_ERROR;
+
+      if (dt->asynchronous->ts.kind != 1)
+	{
+	  gfc_error ("ASYNCHRONOUS= specifier at %L must have default "
+		     "CHARACTER kind", &dt->asynchronous->where);
+	  return MATCH_ERROR;
+	}
+
+      if (dt->asynchronous->expr_type == EXPR_ARRAY
+	  || dt->asynchronous->expr_type == EXPR_STRUCTURE)
+	{
+	  gfc_error ("ASYNCHRONOUS= specifier at %L must be scalar",
+		     &dt->asynchronous->where);
+	  return MATCH_ERROR;
+	}
 
       if (!compare_to_allowed_values
 		("ASYNCHRONOUS", asynchronous, NULL, NULL,
Index: gcc/fortran/match.c
===================================================================
--- gcc/fortran/match.c	(revision 266718)
+++ gcc/fortran/match.c	(working copy)
@@ -2225,6 +2225,9 @@ found:
 	      return MATCH_NO;
 	    }
 
+	  if (e->expr_type != EXPR_CONSTANT)
+	    goto ohno;
+
 	  gfc_next_char (); /* Burn the ')'. */
 	  ts->kind = (int) mpz_get_si (e->value.integer);
 	  if (gfc_validate_kind (ts->type, ts->kind , true) == -1)
@@ -2238,6 +2241,8 @@ found:
 	  return MATCH_YES;
 	}
     }
+
+ohno:
 
   /* If a type is not matched, simply return MATCH_NO.  */
   gfc_current_locus = old_locus;
Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c	(revision 266718)
+++ gcc/fortran/resolve.c	(working copy)
@@ -11544,7 +11544,7 @@ start:
 	case EXEC_ENDFILE:
 	case EXEC_REWIND:
 	case EXEC_FLUSH:
-	  if (!gfc_resolve_filepos (code->ext.filepos))
+	  if (!gfc_resolve_filepos (code->ext.filepos, &code->loc))
 	    break;
 
 	  resolve_branch (code->ext.filepos->err, code);
@@ -15492,7 +15492,10 @@ check_data_variable (gfc_data_variable *var, locus *wh
     e = e->value.function.actual->expr;
 
   if (e->expr_type != EXPR_VARIABLE)
-    gfc_internal_error ("check_data_variable(): Bad expression");
+    {
+      gfc_error ("Expecting definable entity near %L", where);
+      return false;
+    }
 
   sym = e->symtree->n.sym;
 
@@ -15500,6 +15503,7 @@ check_data_variable (gfc_data_variable *var, locus *wh
     {
       gfc_error ("BLOCK DATA element %qs at %L must be in COMMON",
 		 sym->name, &sym->declared_at);
+      return false;
     }
 
   if (e->ref == NULL && sym->as)
Index: gcc/fortran/simplify.c
===================================================================
--- gcc/fortran/simplify.c	(revision 266718)
+++ gcc/fortran/simplify.c	(working copy)
@@ -8360,7 +8360,7 @@ gfc_convert_constant (gfc_expr *e, bt type, int kind)
 
     default:
     oops:
-      gfc_internal_error ("gfc_convert_constant(): Unexpected type");
+      return &gfc_bad_expr;
     }
 
   result = NULL;
Index: gcc/testsuite/gfortran.dg/io_constraints_8.f90
===================================================================
--- gcc/testsuite/gfortran.dg/io_constraints_8.f90	(revision 266718)
+++ gcc/testsuite/gfortran.dg/io_constraints_8.f90	(working copy)
@@ -14,7 +14,7 @@ integer :: i
 
 OPEN(99, access=4_'direct')     ! { dg-error "must be a character string of default kind" }
 OPEN(99, action=4_'read')       ! { dg-error "must be a character string of default kind" }
-OPEN(99, asynchronous=4_'no')   ! { dg-error "must be a character string of default kind" })
+OPEN(99, asynchronous=4_'no')   ! { dg-error "must have default CHARACTER kind" })
 OPEN(99, blank=4_'null')        ! { dg-error "must be a character string of default kind" }
 OPEN(99, decimal=4_'comma')     ! { dg-error "must be a character string of default kind" }
 OPEN(99, delim=4_'quote')       ! { dg-error "must be a character string of default kind" }
Index: gcc/testsuite/gfortran.dg/pr87922.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr87922.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr87922.f90	(working copy)
@@ -0,0 +1,10 @@
+! { dg-do compile }
+! PR fortran/87922
+subroutine p
+   read(1, asynchronous=['no'])           ! { dg-error "must be scalar" }
+   read(1, asynchronous=[character::])    ! { dg-error "must be scalar" }
+end
+subroutine q
+   write(1, asynchronous=['no'])          ! { dg-error "must be scalar" }
+   write(1, asynchronous=[character::])   ! { dg-error "must be scalar" }
+end
Index: gcc/testsuite/gfortran.dg/pr87945_1.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr87945_1.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr87945_1.f90	(working copy)
@@ -0,0 +1,7 @@
+! { dg-do compile }
+! PR fortran/87945
+program p
+   character :: a, b
+   data a%len /1/       ! { dg-error "parameter cannot appear in" }
+   data b%kind /'b'/    ! { dg-error "parameter cannot appear in" }
+end
Index: gcc/testsuite/gfortran.dg/pr87945_2.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr87945_2.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr87945_2.f90	(working copy)
@@ -0,0 +1,7 @@
+! { dg-do compile }
+! PR fortran/87945
+program p
+   character :: a, b
+   a%len = 1      ! { dg-error "to a constant expression" }
+   b%kind = 'b'   ! { dg-error "to a constant expression" }
+end
Index: gcc/testsuite/gfortran.dg/pr87994_1.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr87994_1.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr87994_1.f90	(working copy)
@@ -0,0 +1,7 @@
+! { dg-do run }
+! PR fortran/87994
+program p
+   real :: a, b
+   data b /a%kind/
+   if (b /= kind(a)) stop 1
+end
Index: gcc/testsuite/gfortran.dg/pr87994_2.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr87994_2.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr87994_2.f90	(working copy)
@@ -0,0 +1,7 @@
+! { dg-do run }
+! PR fortran/87994
+program p
+   real, parameter :: a = 1.0
+   data b /a%kind/
+   if (b /= kind(a)) stop 1
+end
Index: gcc/testsuite/gfortran.dg/pr87994_3.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr87994_3.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr87994_3.f90	(working copy)
@@ -0,0 +1,8 @@
+! { dg-do run }
+! PR fortran/87994
+program p
+   integer, parameter :: a = 1
+   integer :: b
+   data b /a%kind/
+   if (b /= kind(a)) stop = 1
+end
Index: gcc/testsuite/gfortran.dg/pr88025.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88025.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88025.f90	(working copy)
@@ -0,0 +1,7 @@
+! { dg-do compile }
+! PR fortran/88025
+program p
+   type t
+      character(('')) :: c = 'c'    ! { dg-error "must be of INTEGER type" }
+   end type
+end
Index: gcc/testsuite/gfortran.dg/pr88048.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88048.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88048.f90	(working copy)
@@ -0,0 +1,7 @@
+! { dg-do compile }
+! PR fortran/88048
+program p
+   integer, parameter :: a(2) = 1
+   data a(2) /a(1)/                 ! { dg-error "definable entity" }
+   print *, a
+end
Index: gcc/testsuite/gfortran.dg/pr88116_1.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88116_1.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88116_1.f90	(working copy)
@@ -0,0 +1,5 @@
+! { dg-do compile }
+! PR fortran/88116
+program p
+   print *, [integer :: 1, [integer(8) :: 2, ['3']]] ! { dg-error "convert" }
+end
Index: gcc/testsuite/gfortran.dg/pr88116_2.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88116_2.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88116_2.f90	(working copy)
@@ -0,0 +1,9 @@
+! { dg-do run }
+! PR fortran/88116
+program p
+  real :: a(2) = [real :: 1, [integer :: (real(k), k=2,1), 2]]
+  real :: b(1) = [real :: [integer :: (dble(k), k=1,0), 2]]
+  if (a(1) /= 1 .or. a(2) /= 2) stop 1
+  if (b(1) /= 2) stop 2
+end
+
Index: gcc/testsuite/gfortran.dg/pr88139.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88139.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88139.f90	(working copy)
@@ -0,0 +1,9 @@
+! { dg-do compile }
+! { dg-options "-fc-prototypes" }
+! PR fortran/88139
+module m
+contains
+   subroutine s(*) bind(c, name='f')   ! { dg-error "sommes tous nes" }
+   end
+end
+! { dg-prune-output "void f" }
Index: gcc/testsuite/gfortran.dg/pr88205.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88205.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88205.f90	(working copy)
@@ -0,0 +1,14 @@
+! { dg-do compile }
+! PR fortran/88205
+subroutine s1
+   real, parameter :: status = 0
+   open (newunit=n, status=status)        ! { dg-error "be a default character" }
+end
+subroutine s2
+   complex, parameter :: status = 0
+   open (newunit=n, status=status)        ! { dg-error "be a default character" }
+end
+program p
+  logical, parameter :: status = .false.
+  open (newunit=a, status=status)         ! { dg-error "be a default character" }
+end
Index: gcc/testsuite/gfortran.dg/pr88206.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88206.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88206.f90	(working copy)
@@ -0,0 +1,8 @@
+! { dg-do compile }
+! PR fortran/88206
+program p
+   integer, parameter :: z(4) = [1,2,3,4]
+   integer :: k = 2
+   print *, [real(z(k))]
+end
+
Index: gcc/testsuite/gfortran.dg/pr88228.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88228.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88228.f90	(working copy)
@@ -0,0 +1,8 @@
+! { dg-do compile }
+! { dg-options "-fdec" }
+! PR fortran/88228
+program p
+   integer :: n = .not. 1
+   integer :: j = .true. .or. 1
+end
+
Index: gcc/testsuite/gfortran.dg/pr88249.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88249.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88249.f90	(working copy)
@@ -0,0 +1,8 @@
+! { dg-do compile }
+! PR fortran/88249
+program p
+   backspace(err=1)  ! { dg-error "number missing in statement" }
+   endfile(err=1)    ! { dg-error "number missing in statement" }
+   flush(err=1)      ! { dg-error "number missing in statement" }
+   rewind(err=1)     ! { dg-error "number missing in statement" }
+end
Index: gcc/testsuite/gfortran.dg/pr88269.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88269.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88269.f90	(working copy)
@@ -0,0 +1,6 @@
+! { dg-do compile }
+! PR fortran/88269
+program p
+   write (end=1e1) ! { dg-error "tag not allowed" }
+end
+
Index: gcc/testsuite/gfortran.dg/pr88328.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr88328.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr88328.f90	(working copy)
@@ -0,0 +1,6 @@
+! { dg-do compile }
+! PR fortran/88328
+program p
+   character(3), parameter :: a(0) = [character(3)::]
+   print a ! { dg-error "zero-sized array" }
+end