re PR c++/7598 (offsetof broken)

cp:
	PR c++/7598
	* typeck.c (build_unary_op): Fold offsetof idiom. Fixes
	regression caused by my 2002-08-08 patch.
testsuite:
	* g++.dg/other/offsetof1.C: New test

From-SVN: r56346

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 0ab00f6c2b98a011ea2e0513124645a69b9154d0..27e5bc72e8a8530bd3196b28a002b2af1d3d50f6 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2002-08-15  Nathan Sidwell  <nathan@codesourcery.com>
+
+       PR c++/7598
+       * typeck.c (build_unary_op): Fold offsetof idiom. Fixes
+       regression caused by my 2002-08-08 patch.
+
 2002-08-13  Mark Mitchell  <mark@codesourcery.com>
 
        * decl.c (pushdecl_class_level): Honor requests to bind names to

diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index f8bc3786358bfeb0f5186dde56acc2bedb2b1251..de3c0596e3c0fcab6dea4be6f8e70c9b29032c9c 100644 (file)
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -4256,6 +4256,24 @@ build_unary_op (code, xarg, noconvert)
                   TREE_OPERAND (arg, 1));
            return error_mark_node;
          }
+       else if (TREE_CODE (arg) == COMPONENT_REF
+                && TREE_CODE (TREE_OPERAND (arg, 0)) == INDIRECT_REF
+                && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg, 0), 0))
+                    == INTEGER_CST))
+         {
+           /* offsetof idiom, fold it. */
+           tree field = TREE_OPERAND (arg, 1);
+           tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
+           tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
+                                     decl_type_context (field),
+                                     ba_check, NULL);
+           
+           rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
+           rval = build1 (NOP_EXPR, argtype, rval);
+           TREE_CONSTANT (rval) = TREE_CONSTANT (TREE_OPERAND (rval, 0));
+           addr = fold (build (PLUS_EXPR, argtype, rval,
+                               cp_convert (argtype, byte_position (field))));
+         }
        else
          addr = build1 (ADDR_EXPR, argtype, arg);
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 69a99ff071f71570d52eabf6aeb27679bfdb46e1..d0694f380cbc3a66eedfd5b55d84a7b95ecb41e4 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2002-08-15  Nathan Sidwell  <nathan@codesourcery.com>
+
+       * g++.dg/other/offsetof1.C: New test.
+
 2002-08-14  Richard Henderson  <rth@redhat.com>
 
        * gcc.dg/tls/diag-3.c: Fix expected message strings.

diff --git a/gcc/testsuite/g++.dg/other/offsetof1.C b/gcc/testsuite/g++.dg/other/offsetof1.C
new file mode 100644 (file)
index 0000000..1051cd2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/other/offsetof1.C
@@ -0,0 +1,14 @@
+// { dg-do compile }
+
+// Copyright (C) 2002 Free Software Foundation, Inc.
+// Contributed by Nathan Sidwell 14 Aug 2002 <nathan@codesourcery.com>
+
+// PR c++ 7598, offsetof broke
+
+struct F
+{
+  char i;
+  char j;
+};
+
+static int ary[((unsigned) &((struct F *)0)->j)];