Remove max symbol length check from gfc_new_symbol

gfc_match_name does check for too long names already. Since
gfc_new_symbol is also called for symbols with internal names containing
compiler-generated prefixes, these internal names can easily exceed the
max_identifier_length mandated by the standard.

gcc/fortran/ChangeLog

2018-09-04  Bernhard Reutner-Fischer  <aldot@gcc.gnu.org>

	PR fortran/87103
	* expr.c (gfc_check_conformance): Check vsnprintf for truncation.
	* iresolve.c (gfc_get_string): Likewise.
	* symbol.c (gfc_new_symbol): Remove check for maximum symbol
	name length.  Remove redundant 0 setting of new calloc()ed
	gfc_symbol.

diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index c5bf822cd24..6b5671390ec 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -3225,8 +3225,10 @@ gfc_check_conformance (gfc_expr *op1, gfc_expr *op2, const char *optype_msgid, .
     return true;
 
   va_start (argp, optype_msgid);
-  vsnprintf (buffer, 240, optype_msgid, argp);
+  d = vsnprintf (buffer, sizeof (buffer), optype_msgid, argp);
   va_end (argp);
+  if (d < 1 || d >= (int) sizeof (buffer)) /* Reject truncation.  */
+    gfc_internal_error ("optype_msgid overflow: %d", d);
 
   if (op1->rank != op2->rank)
     {
diff --git a/gcc/fortran/iresolve.c b/gcc/fortran/iresolve.c
index 61663fec7e5..d7bd0545173 100644
--- a/gcc/fortran/iresolve.c
+++ b/gcc/fortran/iresolve.c
@@ -60,9 +60,12 @@ gfc_get_string (const char *format, ...)
     }
   else
     {
+      int ret;
       va_start (ap, format);
-      vsnprintf (temp_name, sizeof (temp_name), format, ap);
+      ret = vsnprintf (temp_name, sizeof (temp_name), format, ap);
       va_end (ap);
+      if (ret < 1 || ret >= (int) sizeof (temp_name)) /* Reject truncation.  */
+	gfc_internal_error ("identifier overflow: %d", ret);
       temp_name[sizeof (temp_name) - 1] = 0;
       str = temp_name;
     }
diff --git a/gcc/fortran/symbol.c b/gcc/fortran/symbol.c
index cde34c67482..fc3354f0457 100644
--- a/gcc/fortran/symbol.c
+++ b/gcc/fortran/symbol.c
@@ -3142,25 +3142,9 @@ gfc_new_symbol (const char *name, gfc_namespace *ns)
   gfc_clear_ts (&p->ts);
   gfc_clear_attr (&p->attr);
   p->ns = ns;
-
   p->declared_at = gfc_current_locus;
-
-  if (strlen (name) > GFC_MAX_SYMBOL_LEN)
-    gfc_internal_error ("new_symbol(): Symbol name too long");
-
   p->name = gfc_get_string ("%s", name);
 
-  /* Make sure flags for symbol being C bound are clear initially.  */
-  p->attr.is_bind_c = 0;
-  p->attr.is_iso_c = 0;
-
-  /* Clear the ptrs we may need.  */
-  p->common_block = NULL;
-  p->f2k_derived = NULL;
-  p->assoc = NULL;
-  p->dt_next = NULL;
-  p->fn_result_spec = 0;
-
   return p;
 }