[nvptx] Fix handling of extern var with flexible array member

2018-04-12  Tom de Vries  <tom@codesourcery.com>

	PR target/85296
	* config/nvptx/nvptx.c (flexible_array_member_type_p): New function.
	(nvptx_assemble_decl_begin): Add undefined param.  Declare undefined
	array with flexible array member as array without given dimension.
	(nvptx_assemble_undefined_decl): Set nvptx_assemble_decl_begin call
	argument for undefined param to true.

From-SVN: r259337

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ff66dd4ba53d4ec68d8ffda008e4677b89394b02..c4d0882950ab0e1cd27a9bdb861226431d621a4d 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2018-04-12  Tom de Vries  <tom@codesourcery.com>
+
+       PR target/85296
+       * config/nvptx/nvptx.c (flexible_array_member_type_p): New function.
+       (nvptx_assemble_decl_begin): Add undefined param.  Declare undefined
+       array with flexible array member as array without given dimension.
+       (nvptx_assemble_undefined_decl): Set nvptx_assemble_decl_begin call
+       argument for undefined param to true.
+
 2018-04-11  Aaron Sawdey  <acsawdey@linux.ibm.com>
 
        PR target/85321

diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index a9a3053f3365d022da7bf9a636b11a5542214d80..131b495098eaba1e99b17af74f1405c3a46f9e64 100644 (file)
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -2021,6 +2021,30 @@ nvptx_output_ascii (FILE *, const char *str, unsigned HOST_WIDE_INT size)
     nvptx_assemble_value (str[i], 1);
 }
 
+/* Return true if TYPE is a record type where the last field is an array without
+   given dimension.  */
+
+static bool
+flexible_array_member_type_p (const_tree type)
+{
+  if (TREE_CODE (type) != RECORD_TYPE)
+    return false;
+
+  const_tree last_field = NULL_TREE;
+  for (const_tree f = TYPE_FIELDS (type); f; f = TREE_CHAIN (f))
+    last_field = f;
+
+  if (!last_field)
+    return false;
+
+  const_tree last_field_type = TREE_TYPE (last_field);
+  if (TREE_CODE (last_field_type) != ARRAY_TYPE)
+    return false;
+
+  return (! TYPE_DOMAIN (last_field_type)
+         || ! TYPE_MAX_VALUE (TYPE_DOMAIN (last_field_type)));
+}
+
 /* Emit a PTX variable decl and prepare for emission of its
    initializer.  NAME is the symbol name and SETION the PTX data
    area. The type is TYPE, object size SIZE and alignment is ALIGN.
@@ -2031,11 +2055,18 @@ nvptx_output_ascii (FILE *, const char *str, unsigned HOST_WIDE_INT size)
 
 static void
 nvptx_assemble_decl_begin (FILE *file, const char *name, const char *section,
-                          const_tree type, HOST_WIDE_INT size, unsigned align)
+                          const_tree type, HOST_WIDE_INT size, unsigned align,
+                          bool undefined = false)
 {
   bool atype = (TREE_CODE (type) == ARRAY_TYPE)
     && (TYPE_DOMAIN (type) == NULL_TREE);
 
+  if (undefined && flexible_array_member_type_p (type))
+    {
+      size = 0;
+      atype = true;
+    }
+
   while (TREE_CODE (type) == ARRAY_TYPE)
     type = TREE_TYPE (type);
 
@@ -2172,7 +2203,7 @@ nvptx_assemble_undefined_decl (FILE *file, const char *name, const_tree decl)
   tree size = DECL_SIZE_UNIT (decl);
   nvptx_assemble_decl_begin (file, name, section_for_decl (decl),
                             TREE_TYPE (decl), size ? tree_to_shwi (size) : 0,
-                            DECL_ALIGN (decl));
+                            DECL_ALIGN (decl), true);
   nvptx_assemble_decl_end ();
 }