diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 833eb115eefd9a79521598cf427a193efd3e4c2c..dd1101499a54ca5df1f22a727b50e09bc1575a70 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2006-09-06 Jason Merrill <jason@redhat.com>
+
+ PR c++/27371
+ * tree-inline.c (copy_result_decl_to_var): New fn.
+ (declare_return_variable): Use it. Call declare_inline_vars here.
+ (expand_call_inline): Not here.
+
2006-09-06 Diego Novillo <dnovillo@redhat.com>
* doc/contrib.texi: Update my entry.
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 60d2fb29868acf3b54a8cf4bc5b8292f27b91093..9e17ccef773b35605f8ae63ba528cd6083f96cbf 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -10,6 +10,11 @@
2006-09-06 Jason Merrill <jason@redhat.com>
+ PR c++/27371
+ * cvt.c (convert_to_void): Strip useless TARGET_EXPR.
+ * cp-tree.h (TARGET_EXPR_IMPLICIT_P): New macro.
+ * tree.c (build_cplus_new): Set it.
+
PR c++/26696
* cvt.c (convert_to_void): Replace a subexpression with no side
effects with void_zero_node.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 3c20afed5ec14397538b180cdc8f25a9f17ea3b1..f864487702758553452c152338cbc4057a701242 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -55,6 +55,7 @@ struct diagnostic_context;
OMP_ATOMIC_DEPENDENT_P (in OMP_ATOMIC)
OMP_FOR_GIMPLIFYING_P (in OMP_FOR)
BASELINK_QUALIFIED_P (in BASELINK)
+ TARGET_EXPR_IMPLICIT_P (in TARGET_EXPR)
1: IDENTIFIER_VIRTUAL_P (in IDENTIFIER_NODE)
TI_PENDING_TEMPLATE_FLAG.
TEMPLATE_PARMS_FOR_INLINE.
@@ -3091,6 +3092,11 @@ extern void decl_shadowed_for_var_insert (tree, tree);
expression statement. */
#define EXPR_STMT_EXPR(NODE) TREE_OPERAND (EXPR_STMT_CHECK (NODE), 0)
+/* True if this TARGET_EXPR was created by build_cplus_new, and so we can
+ discard it if it isn't useful. */
+#define TARGET_EXPR_IMPLICIT_P(NODE) \
+ TREE_LANG_FLAG_0 (TARGET_EXPR_CHECK (NODE))
+
/* An enumeration of the kind of tags that C++ accepts. */
enum tag_types {
none_type = 0, /* Not a tag type. */
diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
index 83b35d6fc763c0cfed4a9808fd6e1e8c587735cc..52b5be46eeb77e4c314eeff865ddab400cdcae5d 100644
--- a/gcc/cp/cvt.c
+++ b/gcc/cp/cvt.c
@@ -892,6 +892,25 @@ convert_to_void (tree expr, const char *implicit)
break;
}
+ case TARGET_EXPR:
+ /* Don't bother with the temporary object returned from a function if
+ we don't use it and don't need to destroy it. We'll still
+ allocate space for it in expand_call or declare_return_variable,
+ but we don't need to track it through all the tree phases. */
+ if (0 && TARGET_EXPR_IMPLICIT_P (expr)
+ && TYPE_HAS_TRIVIAL_DESTRUCTOR (TREE_TYPE (expr)))
+ {
+ tree init = TARGET_EXPR_INITIAL (expr);
+ if (TREE_CODE (init) == AGGR_INIT_EXPR
+ && !AGGR_INIT_VIA_CTOR_P (init))
+ {
+ tree fn = TREE_OPERAND (init, 0);
+ expr = build3 (CALL_EXPR, TREE_TYPE (TREE_TYPE (TREE_TYPE (fn))),
+ fn, TREE_OPERAND (init, 1), NULL_TREE);
+ }
+ }
+ break;
+
default:;
}
{
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 89941cc554282927427fc13cc8b51146316cb8df..526077a43e9b9282910a0c01a5ebad388a1b1fc4 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -312,6 +312,7 @@ build_cplus_new (tree type, tree init)
rval = init;
rval = build_target_expr (slot, rval);
+ TARGET_EXPR_IMPLICIT_P (rval) = 1;
return rval;
}
diff --git a/gcc/testsuite/g++.dg/warn/unused-result1.C b/gcc/testsuite/g++.dg/warn/unused-result1.C
new file mode 100644
index 0000000000000000000000000000000000000000..1b9ef8af786bfe8f695335ad0cce7d95f48a389f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/unused-result1.C
@@ -0,0 +1,10 @@
+// PR c++/27371
+
+class QByteArray {
+public:
+ QByteArray(const QByteArray &);
+};
+class QString {
+ QByteArray toLocal8Bit() const __attribute__ ((warn_unused_result));
+ void fooWarnHere() const { toLocal8Bit(); } // { dg-warning "ignoring" }
+};
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index e77c9b8771342d8fe17d89e036a97c03a43ebfd2..baca834048603c9c9b971ec5114df2858cff65c8 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -120,6 +120,7 @@ static void declare_inline_vars (tree, tree);
static void remap_save_expr (tree *, void *, int *);
static void add_lexical_block (tree current_block, tree new_block);
static tree copy_decl_to_var (tree, copy_body_data *);
+static tree copy_result_decl_to_var (tree, copy_body_data *);
static tree copy_decl_no_change (tree, copy_body_data *);
static tree copy_decl_maybe_to_var (tree, copy_body_data *);
@@ -1261,7 +1262,7 @@ declare_return_variable (copy_body_data *id, tree return_slot_addr,
gcc_assert (TREE_CODE (TYPE_SIZE_UNIT (callee_type)) == INTEGER_CST);
- var = copy_decl_to_var (result, id);
+ var = copy_result_decl_to_var (result, id);
DECL_SEEN_IN_BIND_EXPR_P (var) = 1;
DECL_STRUCT_FUNCTION (caller)->unexpanded_var_list
@@ -1272,6 +1273,8 @@ declare_return_variable (copy_body_data *id, tree return_slot_addr,
not be visible to the user. */
TREE_NO_WARNING (var) = 1;
+ declare_inline_vars (id->block, var);
+
/* Build the use expr. If the return type of the function was
promoted, convert it back to the expected type. */
use = var;
@@ -1280,6 +1283,9 @@ declare_return_variable (copy_body_data *id, tree return_slot_addr,
STRIP_USELESS_TYPE_CONVERSION (use);
+ if (DECL_BY_REFERENCE (result))
+ var = build_fold_addr_expr (var);
+
done:
/* Register the VAR_DECL as the equivalent for the RESULT_DECL; that
way, when the RESULT_DECL is encountered, it will be
@@ -1926,7 +1932,6 @@ expand_call_inline (basic_block bb, tree stmt, tree *tp, void *data)
bool successfully_inlined = FALSE;
tree t_step;
tree var;
- tree decl;
/* See what we've got. */
id = (copy_body_data *) data;
@@ -2103,11 +2108,8 @@ expand_call_inline (basic_block bb, tree stmt, tree *tp, void *data)
modify_dest = NULL;
/* Declare the return variable for the function. */
- decl = declare_return_variable (id, return_slot_addr,
- modify_dest, &use_retvar);
- /* Do this only if declare_return_variable created a new one. */
- if (decl && !return_slot_addr && decl != modify_dest)
- declare_inline_vars (id->block, decl);
+ declare_return_variable (id, return_slot_addr,
+ modify_dest, &use_retvar);
/* This is it. Duplicate the callee body. Assume callee is
pre-gimplified. Note that we must not alter the caller
@@ -2630,6 +2632,34 @@ copy_decl_to_var (tree decl, copy_body_data *id)
return copy_decl_for_dup_finish (id, decl, copy);
}
+/* Like copy_decl_to_var, but create a return slot object instead of a
+ pointer variable for return by invisible reference. */
+
+static tree
+copy_result_decl_to_var (tree decl, copy_body_data *id)
+{
+ tree copy, type;
+
+ gcc_assert (TREE_CODE (decl) == PARM_DECL
+ || TREE_CODE (decl) == RESULT_DECL);
+
+ type = TREE_TYPE (decl);
+ if (DECL_BY_REFERENCE (decl))
+ type = TREE_TYPE (type);
+
+ copy = build_decl (VAR_DECL, DECL_NAME (decl), type);
+ TREE_READONLY (copy) = TREE_READONLY (decl);
+ TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (decl);
+ if (!DECL_BY_REFERENCE (decl))
+ {
+ TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (decl);
+ DECL_COMPLEX_GIMPLE_REG_P (copy) = DECL_COMPLEX_GIMPLE_REG_P (decl);
+ }
+
+ return copy_decl_for_dup_finish (id, decl, copy);
+}
+
+
static tree
copy_decl_no_change (tree decl, copy_body_data *id)
{