re PR fortran/82886 (ICE with -finit-derived in gfc_conv_expr, at fortran/trans-expr.c:7807)

2017-11-10  Fritz Reese <fritzoreese@gmail.com>

    PR fortran/82886

    gcc/fortran/ChangeLog:

	PR fortran/82886
	* gfortran.h (gfc_build_init_expr): New prototype.
	* invoke.texi (finit-derived): Update documentation.
	* expr.c (gfc_build_init_expr): New, from gfc_build_default_init_expr.
	(gfc_build_default_init_expr): Redirect to gfc_build_init_expr(,,false)
	(component_initializer): Force building initializers using
	gfc_build_init_expr(,,true).

    gcc/testsuite/ChangeLog:

	PR fortran/82886
	* gfortran.dg/init_flag_16.f03: New testcase.

From-SVN: r254648

gcc/fortran/ChangeLog

+2017-11-10  Fritz Reese <fritzoreese@gmail.com>
+
+	PR fortran/82886
+	* gfortran.h (gfc_build_init_expr): New prototype.
+	* invoke.texi (finit-derived): Update documentation.
+	* expr.c (gfc_build_init_expr): New, from gfc_build_default_init_expr.
+	(gfc_build_default_init_expr): Redirect to gfc_build_init_expr(,,false)
+	(component_initializer): Force building initializers using
+	gfc_build_init_expr(,,true).
+
 2017-11-10  Martin Sebor  <msebor@redhat.com>
 
 	PR c/81117

gcc/fortran/expr.c

@@ -4013,13 +4013,22 @@ gfc_check_assign_symbol (gfc_symbol *sym, gfc_component *comp, gfc_expr *rvalue)
   return true;
 }
 
+/* Invoke gfc_build_init_expr to create an initializer expression, but do not
+ * require that an expression be built.  */
+
+gfc_expr *
+gfc_build_default_init_expr (gfc_typespec *ts, locus *where)
+{
+  return gfc_build_init_expr (ts, where, false);
+}
 
 /* Build an initializer for a local integer, real, complex, logical, or
    character variable, based on the command line flags finit-local-zero,
-   finit-integer=, finit-real=, finit-logical=, and finit-character=.  */
+   finit-integer=, finit-real=, finit-logical=, and finit-character=.
+   With force, an initializer is ALWAYS generated.  */
 
 gfc_expr *
-gfc_build_default_init_expr (gfc_typespec *ts, locus *where)
+gfc_build_init_expr (gfc_typespec *ts, locus *where, bool force)
 {
   int char_len;
   gfc_expr *init_expr;
@@ -4028,13 +4037,24 @@ gfc_build_default_init_expr (gfc_typespec *ts, locus *where)
   /* Try to build an initializer expression.  */
   init_expr = gfc_get_constant_expr (ts->type, ts->kind, where);
 
+  /* If we want to force generation, make sure we default to zero.  */
+  gfc_init_local_real init_real = flag_init_real;
+  int init_logical = gfc_option.flag_init_logical;
+  if (force)
+    {
+      if (init_real == GFC_INIT_REAL_OFF)
+	init_real = GFC_INIT_REAL_ZERO;
+      if (init_logical == GFC_INIT_LOGICAL_OFF)
+	init_logical = GFC_INIT_LOGICAL_FALSE;
+    }
+
   /* We will only initialize integers, reals, complex, logicals, and
      characters, and only if the corresponding command-line flags
      were set.  Otherwise, we free init_expr and return null.  */
   switch (ts->type)
     {
     case BT_INTEGER:
-      if (gfc_option.flag_init_integer != GFC_INIT_INTEGER_OFF)
+      if (force || gfc_option.flag_init_integer != GFC_INIT_INTEGER_OFF)
         mpz_set_si (init_expr->value.integer,
                          gfc_option.flag_init_integer_value);
       else
@@ -4045,7 +4065,7 @@ gfc_build_default_init_expr (gfc_typespec *ts, locus *where)
       break;
 
     case BT_REAL:
-      switch (flag_init_real)
+      switch (init_real)
         {
         case GFC_INIT_REAL_SNAN:
           init_expr->is_snan = 1;
@@ -4074,7 +4094,7 @@ gfc_build_default_init_expr (gfc_typespec *ts, locus *where)
       break;
 
     case BT_COMPLEX:
-      switch (flag_init_real)
+      switch (init_real)
         {
         case GFC_INIT_REAL_SNAN:
           init_expr->is_snan = 1;
@@ -4106,9 +4126,9 @@ gfc_build_default_init_expr (gfc_typespec *ts, locus *where)
       break;
 
     case BT_LOGICAL:
-      if (gfc_option.flag_init_logical == GFC_INIT_LOGICAL_FALSE)
+      if (init_logical == GFC_INIT_LOGICAL_FALSE)
         init_expr->value.logical = 0;
-      else if (gfc_option.flag_init_logical == GFC_INIT_LOGICAL_TRUE)
+      else if (init_logical == GFC_INIT_LOGICAL_TRUE)
         init_expr->value.logical = 1;
       else
         {
@@ -4120,7 +4140,7 @@ gfc_build_default_init_expr (gfc_typespec *ts, locus *where)
     case BT_CHARACTER:
       /* For characters, the length must be constant in order to
          create a default initializer.  */
-      if (gfc_option.flag_init_character == GFC_INIT_CHARACTER_ON
+      if ((force || gfc_option.flag_init_character == GFC_INIT_CHARACTER_ON)
           && ts->u.cl->length
           && ts->u.cl->length->expr_type == EXPR_CONSTANT)
         {
@@ -4136,7 +4156,8 @@ gfc_build_default_init_expr (gfc_typespec *ts, locus *where)
           gfc_free_expr (init_expr);
           init_expr = NULL;
         }
-      if (!init_expr && gfc_option.flag_init_character == GFC_INIT_CHARACTER_ON
+      if (!init_expr
+	  && (force || gfc_option.flag_init_character == GFC_INIT_CHARACTER_ON)
           && ts->u.cl->length && flag_max_stack_var_size != 0)
         {
           gfc_actual_arglist *arg;
@@ -4391,7 +4412,8 @@ component_initializer (gfc_typespec *ts, gfc_component *c, bool generate)
   /* Treat simple components like locals.  */
   else
     {
-      init = gfc_build_default_init_expr (&c->ts, &c->loc);
+      /* We MUST give an initializer, so force generation.  */
+      init = gfc_build_init_expr (&c->ts, &c->loc, true);
       gfc_apply_init (&c->ts, &c->attr, init);
     }
 

gcc/fortran/gfortran.h

@@ -3174,6 +3174,7 @@ bool gfc_check_pointer_assign (gfc_expr *, gfc_expr *);
 bool gfc_check_assign_symbol (gfc_symbol *, gfc_component *, gfc_expr *);
 
 gfc_expr *gfc_build_default_init_expr (gfc_typespec *, locus *);
+gfc_expr *gfc_build_init_expr (gfc_typespec *, locus *, bool);
 void gfc_apply_init (gfc_typespec *, symbol_attribute *, gfc_expr *);
 bool gfc_has_default_initializer (gfc_symbol *);
 gfc_expr *gfc_default_initializer (gfc_typespec *);

gcc/fortran/invoke.texi

@@ -1714,9 +1714,14 @@ initialization options are provided by the
 the real and imaginary parts of local @code{COMPLEX} variables),
 @option{-finit-logical=@var{<true|false>}}, and
 @option{-finit-character=@var{n}} (where @var{n} is an ASCII character
-value) options.  Components of derived type variables will be initialized
-according to these flags only with @option{-finit-derived}.  These options do
-not initialize
+value) options.
+
+With @option{-finit-derived}, components of derived type variables will be
+initialized according to these flags.  Components whose type is not covered by
+an explicit @option{-finit-*} flag will be treated as described above with
+@option{-finit-local-zero}.
+
+These options do not initialize
 @itemize @bullet
 @item
 objects with the POINTER attribute

gcc/testsuite/ChangeLog

+2017-11-10  Fritz Reese <fritzoreese@gmail.com>
+
+	PR fortran/82886
+	* gfortran.dg/init_flag_16.f03: New testcase.
+
 2017-11-10  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	* gcc.target/powerpc/p9-xxbr-3.c: New test.

gcc/testsuite/gfortran.dg/init_flag_16.f03

+! { dg-do compile }
+! { dg-options "-finit-derived" }
+!
+! PR fortran/82886
+!
+! Test a regression which caused an ICE when -finit-derived was given without
+! other -finit-* flags, especially for derived-type components with potentially
+! hidden basic integer components.
+!
+
+program pr82886
+
+  use, intrinsic :: iso_c_binding, only: c_ptr, c_null_ptr
+  type t
+    type(c_ptr) :: my_c_ptr
+  end type
+
+contains
+
+  subroutine sub0() bind(c)
+    type(t), target :: my_f90_type
+    my_f90_type%my_c_ptr = c_null_ptr
+  end subroutine
+
+end