Change the name of array_at_struct_end_p to array_ref_flexible_size_p

The name of the utility routine "array_at_struct_end_p" is misleading
and should be changed to a new name that more accurately reflects its
real meaning.

The routine "array_at_struct_end_p" is used to check whether an array
reference is to an array whose actual size might be larger than its
upper bound implies, which includes 3 different cases:

   A. a ref to a flexible array member at the end of a structure;
   B. a ref to an array with a different type against the original decl;
   C. a ref to an array that was passed as a parameter;

The old name only reflects the above case A, therefore very confusing
when reading the corresponding gcc source code.

In this patch, A new name "array_ref_flexible_size_p" is used to replace
the old name.

All the references to the routine "array_at_struct_end_p" was replaced
with this new name, and the corresponding comments were updated to make
them clean and consistent.

gcc/ChangeLog:

	* gimple-array-bounds.cc (trailing_array): Replace
	array_at_struct_end_p with new name and update comments.
	* gimple-fold.cc (get_range_strlen_tree): Likewise.
	* gimple-ssa-warn-restrict.cc (builtin_memref::builtin_memref):
	Likewise.
	* graphite-sese-to-poly.cc (bounds_are_valid): Likewise.
	* tree-if-conv.cc (idx_within_array_bound): Likewise.
	* tree-object-size.cc (addr_object_size): Likewise.
	* tree-ssa-alias.cc (component_ref_to_zero_sized_trailing_array_p):
	Likewise.
	(stmt_kills_ref_p): Likewise.
	* tree-ssa-loop-niter.cc (idx_infer_loop_bounds): Likewise.
	* tree-ssa-strlen.cc (maybe_set_strlen_range): Likewise.
	* tree.cc (array_at_struct_end_p): Rename to ...
	(array_ref_flexible_size_p): ... this.
	(component_ref_size): Replace array_at_struct_end_p with new name.
	* tree.h (array_at_struct_end_p): Rename to ...
	(array_ref_flexible_size_p): ... this.

1 files changed, 6 insertions, 5 deletions

diff --git a/gcc/tree.cc b/gcc/tree.cc
index 1720987..574bd2e 100644
--- a/gcc/tree.cc
+++ b/gcc/tree.cc
@@ -12727,8 +12727,8 @@ array_ref_up_bound (tree exp)
   return NULL_TREE;
 }
 
-/* Returns true if REF is an array reference, component reference,
-   or memory reference to an array whose actual size might be larger
+/* Returns true if REF is an array reference, a component reference,
+   or a memory reference to an array whose actual size might be larger
    than its upper bound implies, there are multiple cases:
    A. a ref to a flexible array member at the end of a structure;
    B. a ref to an array with a different type against the original decl;
@@ -12743,10 +12743,10 @@ array_ref_up_bound (tree exp)
    int test (uint8_t *p, uint32_t t[1][1], int n) {
    for (int i = 0; i < 4; i++, p++)
      t[i][0] = ...;
+*/
 
-   FIXME, the name of this routine need to be changed to be more accurate.  */
 bool
-array_at_struct_end_p (tree ref)
+array_ref_flexible_size_p (tree ref)
 {
   /* the TYPE for this array referece.  */
   tree atype = NULL_TREE;
@@ -12879,6 +12879,7 @@ array_at_struct_end_p (tree ref)
   return afield_decl ? !DECL_NOT_FLEXARRAY (afield_decl) : true;
 }
 
+
 /* Return a tree representing the offset, in bytes, of the field referenced
    by EXP.  This does not include any offset in DECL_FIELD_BIT_OFFSET.  */
 
@@ -12974,7 +12975,7 @@ component_ref_size (tree ref, special_array_member *sam /* = NULL */)
 	return (tree_int_cst_equal (memsize, TYPE_SIZE_UNIT (memtype))
 		? memsize : NULL_TREE);
 
-      bool trailing = array_at_struct_end_p (ref);
+      bool trailing = array_ref_flexible_size_p (ref);
       bool zero_length = integer_zerop (memsize);
       if (!trailing && !zero_length)
 	/* MEMBER is either an interior array or is an array with