On 06/29/2011 05:15 PM, Jason Merrill wrote:
This patch adds support for use of 'this' (implicitly or explicitly) in
the trailing-return-type of a member function.
The above patch wasn't enough, though. The following patch fixes some
issues that arose with real uses, including mangling.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit ef43a979a3f46150f383b9deab70dd412d66f96b
Author: Jason Merrill <ja...@redhat.com>
Date: Sun Jul 3 17:14:56 2011 -0400
DR 1207
PR c++/49589
* mangle.c (write_expression): Handle 'this'.
* parser.c (cp_parser_postfix_dot_deref_expression): Allow
incomplete *this.
* semantics.c (potential_constant_expression_1): Check that
DECL_CONTEXT is set on 'this'.
diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index 134c9ea..81b772f 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -2495,6 +2495,11 @@ write_expression (tree expr)
else if (TREE_CODE_CLASS (code) == tcc_constant
|| (abi_version_at_least (2) && code == CONST_DECL))
write_template_arg_literal (expr);
+ else if (code == PARM_DECL && DECL_ARTIFICIAL (expr))
+ {
+ gcc_assert (!strcmp ("this", IDENTIFIER_POINTER (DECL_NAME (expr))));
+ write_string ("fpT");
+ }
else if (code == PARM_DECL)
{
/* A function parameter used in a late-specified return type. */
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index d79326d..6bb15ed 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -5281,7 +5281,11 @@ cp_parser_postfix_dot_deref_expression (cp_parser *parser,
postfix_expression);
scope = NULL_TREE;
}
- else
+ /* Unlike the object expression in other contexts, *this is not
+ required to be of complete type for purposes of class member
+ access (5.2.5) outside the member function body. */
+ else if (scope != current_class_ref
+ && !(processing_template_decl && scope == current_class_type))
scope = complete_type_or_else (scope, NULL_TREE);
/* Let the name lookup machinery know that we are processing a
class member access expression. */
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index e29705c..619c058 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -7791,7 +7791,8 @@ potential_constant_expression_1 (tree t, bool want_rval, tsubst_flags_t flags)
STRIP_NOPS (x);
if (is_this_parameter (x))
{
- if (DECL_CONSTRUCTOR_P (DECL_CONTEXT (x)) && want_rval)
+ if (want_rval && DECL_CONTEXT (x)
+ && DECL_CONSTRUCTOR_P (DECL_CONTEXT (x)))
{
if (flags & tf_error)
sorry ("use of the value of the object being constructed "
diff --git a/gcc/testsuite/g++.dg/abi/mangle48.C b/gcc/testsuite/g++.dg/abi/mangle48.C
new file mode 100644
index 0000000..dc9c492
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/mangle48.C
@@ -0,0 +1,23 @@
+// Testcase for 'this' mangling
+// { dg-options -std=c++0x }
+
+struct B
+{
+ template <class U> U f();
+};
+
+struct A
+{
+ B b;
+ // { dg-final { scan-assembler "_ZN1A1fIiEEDTcldtdtdefpT1b1fIT_EEEv" } }
+ template <class U> auto f() -> decltype (b.f<U>());
+ // { dg-final { scan-assembler "_ZN1A1gIiEEDTcldtptfpT1b1fIT_EEEv" } }
+ template <class U> auto g() -> decltype (this->b.f<U>());
+};
+
+int main()
+{
+ A a;
+ a.f<int>();
+ a.g<int>();
+}
commit acbc60694bf95f13f9088ed4d5b3d18780aaf754
Author: Jason Merrill <ja...@redhat.com>
Date: Mon Jul 4 10:44:29 2011 -0400
* cp-demangle.c (d_expression): Handle 'this'.
(d_print_comp) [DEMANGLE_COMPONENT_FUNCTION_PARAM]: Likewise.
diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c
index f136322..29badbb 100644
--- a/libiberty/cp-demangle.c
+++ b/libiberty/cp-demangle.c
@@ -2738,10 +2738,18 @@ d_expression (struct d_info *di)
/* Function parameter used in a late-specified return type. */
int index;
d_advance (di, 2);
- index = d_compact_number (di);
- if (index < 0)
- return NULL;
-
+ if (d_peek_char (di) == 'T')
+ {
+ /* 'this' parameter. */
+ d_advance (di, 1);
+ index = 0;
+ }
+ else
+ {
+ index = d_compact_number (di) + 1;
+ if (index == 0)
+ return NULL;
+ }
return d_make_function_param (di, index);
}
else if (IS_DIGIT (peek)
@@ -4400,9 +4408,17 @@ d_print_comp (struct d_print_info *dpi, int options,
return;
case DEMANGLE_COMPONENT_FUNCTION_PARAM:
- d_append_string (dpi, "{parm#");
- d_append_num (dpi, dc->u.s_number.number + 1);
- d_append_char (dpi, '}');
+ {
+ long num = dc->u.s_number.number;
+ if (num == 0)
+ d_append_string (dpi, "this");
+ else
+ {
+ d_append_string (dpi, "{parm#");
+ d_append_num (dpi, num);
+ d_append_char (dpi, '}');
+ }
+ }
return;
case DEMANGLE_COMPONENT_GLOBAL_CONSTRUCTORS:
diff --git a/libiberty/testsuite/demangle-expected b/libiberty/testsuite/demangle-expected
index 4980cf1..2dc74be 100644
--- a/libiberty/testsuite/demangle-expected
+++ b/libiberty/testsuite/demangle-expected
@@ -3905,6 +3905,10 @@ decltype ({parm#1}+{parm#2}) add<int, double>(int, double)
--format=gnu-v3
_Z4add3IidEDTclL_Z1gEfp_fp0_EET_T0_
decltype (g({parm#1}, {parm#2})) add3<int, double>(int, double)
+# 'this' test
+--format=gnu-v3
+_ZN1A1fIiEEDTcldtdtdefpT1b1fIT_EEEv
+decltype ((((*this).b).(f<int>))()) A::f<int>()
# new (2008) built in types test
--format=gnu-v3
_Z1fDfDdDeDhDsDi
