My earlier work to support return type deduction omitted support for
debugging information; this patch fixes that oversight. It also
corrects the mangled name of 'operator auto', which should reflect the
'auto' rather than the deduced return type.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit 2b1d597e10480dfc2aefe251990cacc2af11d7cc
Author: Jason Merrill <ja...@redhat.com>
Date: Wed Nov 6 12:02:55 2013 -0500
PR c++/53756
gcc/
* dwarf2out.c (auto_die): New static.
(gen_type_die_with_usage): Handle C++1y 'auto'.
(gen_subprogram_die): If in-class DIE had 'auto', emit type again
on definition.
gcc/cp/
* mangle.c (write_unqualified_name): Handle operator auto.
diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index be3c698..add73cf 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -1231,6 +1231,9 @@ write_unqualified_name (const tree decl)
fn_type = get_mostly_instantiated_function_type (decl);
type = TREE_TYPE (fn_type);
}
+ else if (FNDECL_USED_AUTO (decl))
+ type = (DECL_STRUCT_FUNCTION (decl)->language
+ ->x_auto_return_pattern);
else
type = DECL_CONV_FN_TYPE (decl);
write_conversion_operator_name (type);
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 22282d8..f6efd1f 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -247,6 +247,9 @@ static GTY(()) bool cold_text_section_used = false;
/* The default cold text section. */
static GTY(()) section *cold_text_section;
+/* The DIE for C++1y 'auto' in a function return type. */
+static GTY(()) dw_die_ref auto_die;
+
/* Forward declarations for functions defined in this file. */
static char *stripattributes (const char *);
@@ -17999,6 +18002,13 @@ gen_subprogram_die (tree decl, dw_die_ref context_die)
add_AT_file (subr_die, DW_AT_decl_file, file_index);
if (get_AT_unsigned (old_die, DW_AT_decl_line) != (unsigned) s.line)
add_AT_unsigned (subr_die, DW_AT_decl_line, s.line);
+
+ /* If the prototype had an 'auto' return type, emit the real
+ type on the definition die. */
+ if (is_cxx() && debug_info_level > DINFO_LEVEL_TERSE
+ && get_AT_ref (old_die, DW_AT_type) == auto_die)
+ add_type_attribute (subr_die, TREE_TYPE (TREE_TYPE (decl)),
+ 0, 0, context_die);
}
}
else
@@ -19820,6 +19830,25 @@ gen_type_die_with_usage (tree type, dw_die_ref context_die,
break;
default:
+ // A C++ function with deduced return type can have
+ // a TEMPLATE_TYPE_PARM named 'auto' in its type.
+ if (is_cxx ())
+ {
+ tree name = TYPE_NAME (type);
+ if (TREE_CODE (name) == TYPE_DECL)
+ name = DECL_NAME (name);
+ if (name == get_identifier ("auto"))
+ {
+ if (!auto_die)
+ {
+ auto_die = new_die (DW_TAG_unspecified_type,
+ comp_unit_die (), NULL_TREE);
+ add_name_attribute (auto_die, "auto");
+ }
+ equate_type_number_to_die (type, auto_die);
+ break;
+ }
+ }
gcc_unreachable ();
}
diff --git a/gcc/testsuite/g++.dg/cpp1y/auto-fn12.C b/gcc/testsuite/g++.dg/cpp1y/auto-fn12.C
index e4e58e8..ab4a1bb 100644
--- a/gcc/testsuite/g++.dg/cpp1y/auto-fn12.C
+++ b/gcc/testsuite/g++.dg/cpp1y/auto-fn12.C
@@ -1,5 +1,5 @@
// { dg-options -std=c++1y }
-// { dg-final { scan-assembler "_ZN1AIiEcviEv" } }
+// { dg-final { scan-assembler "_ZN1AIiEcvDaEv" } }
template <class T>
struct A {
diff --git a/gcc/testsuite/g++.dg/cpp1y/auto-fn22.C b/gcc/testsuite/g++.dg/cpp1y/auto-fn22.C
new file mode 100644
index 0000000..f05cbb9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/auto-fn22.C
@@ -0,0 +1,9 @@
+// { dg-options "-std=c++1y" }
+
+struct A
+{
+ operator auto();
+};
+
+// { dg-final { scan-assembler "_ZN1AcvDaEv" } }
+A::operator auto() { return 42; }
diff --git a/gcc/testsuite/g++.dg/debug/dwarf2/auto1.C b/gcc/testsuite/g++.dg/debug/dwarf2/auto1.C
new file mode 100644
index 0000000..188ca11
--- /dev/null
+++ b/gcc/testsuite/g++.dg/debug/dwarf2/auto1.C
@@ -0,0 +1,30 @@
+// PR c++/53756
+// { dg-options "-std=c++1y -g -dA -fno-debug-types-section" }
+// We're looking for something like
+
+// .uleb128 0x3 # (DIE (0x33) DW_TAG_subprogram)
+// .ascii "a1\0" # DW_AT_name
+// .long 0x4c # DW_AT_type
+//...
+// .uleb128 0x5 # (DIE (0x4c) DW_TAG_unspecified_type)
+// .long .LASF6 # DW_AT_name: "auto"
+//...
+// .uleb128 0x7 # (DIE (0x57) DW_TAG_subprogram)
+// .long 0x33 # DW_AT_specification
+// .long 0x87 # DW_AT_type
+//...
+// .uleb128 0x9 # (DIE (0x87) DW_TAG_base_type)
+// .ascii "int\0" # DW_AT_name
+
+// { dg-final { scan-assembler "a1.*(0x\[0-9a-f\]+)\[ \t\]*# DW_AT_type.*\\1. DW_TAG_unspecified_type.*DW_AT_specification\[\n\r\]{1,2}\[^\n\r\]*(0x\[0-9a-f\]+)\[ \t\]*# DW_AT_type.*\\2. DW_TAG_base_type" } }
+
+struct A
+{
+ auto a1 () { return 42; }
+};
+
+int main()
+{
+ A a;
+ a.a1();
+}
