On 05/01/2017 09:13 PM, Jason Merrill wrote:
> On Wed, Apr 26, 2017 at 6:58 AM, Martin Liška <mli...@suse.cz> wrote:
>> On 04/25/2017 01:58 PM, Jakub Jelinek wrote:
>>> On Tue, Apr 25, 2017 at 01:48:05PM +0200, Martin Liška wrote:
>>>> Hello.
>>>>
>>>> This is patch that was originally installed by Jason and later reverted
>>>> due to PR70422.
>>>> In the later PR Richi suggested a fix for that and Segher verified that it
>>>> helped him
>>>> to survive regression tests. That's reason why I'm resending that.
>>>>
>>>> Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
>>>>
>>>> Ready to be installed?
>>>> Martin
>>>
>>>> >From a34ce0ef37ae00609c9f3ff98a9cb0b7db6a8bd0 Mon Sep 17 00:00:00 2001
>>>> From: marxin <mli...@suse.cz>
>>>> Date: Thu, 20 Apr 2017 14:56:30 +0200
>>>> Subject: [PATCH] Make __FUNCTION__ a mergeable string and do not generate
>>>> symbol entry.
>>>>
>>>> gcc/cp/ChangeLog:
>>>>
>>>> 2017-04-20 Jason Merrill <ja...@redhat.com>
>>>> Martin Liska <mli...@suse.cz>
>>>> Segher Boessenkool <seg...@kernel.crashing.org>
>>>>
>>>> PR c++/64266
>>>> PR c++/70353
>>>> PR bootstrap/70422
>>>> Core issue 1962
>>>> * decl.c (cp_fname_init): Decay the initializer to pointer.
>>>> (cp_make_fname_decl): Set DECL_DECLARED_CONSTEXPR_P,
>>>> * pt.c (tsubst_expr) [DECL_EXPR]: Set DECL_VALUE_EXPR,
>>>> DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P and
>>>> DECL_IGNORED_P. Don't call cp_finish_decl.
>>>
>>> If we don't emit those into the debug info, will the debugger be
>>> able to handle __FUNCTION__ etc. properly?
>>
>> No, debugger with the patch can't handled these. Similar to how clang
>> behaves currently. Maybe it can be conditionally enabled with -g3, or -g?
>>
>>> Admittedly, right now we emit it into debug info only if those decls
>>> are actually used, say on:
>>> const char * foo () { return __FUNCTION__; }
>>> const char * bar () { return ""; }
>>> we'd emit foo::__FUNCTION__, but not bar::__FUNCTION__, so the debugger
>>> has to have some handling of it anyway. But while in functions
>>> that don't refer to __FUNCTION__ it is always the debugger that needs
>>> to synthetize those and thus they will be always pointer-equal,
>>> if there are some uses of it and for other uses the debugger would
>>> synthetize it, there is the possibility that the debugger synthetized
>>> string will not be the same object as actually used in the function.
>>
>> You're right, currently one has to use a special function to be able to
>> print it in debugger. I believe we've already discussed that, according
>> to spec, the strings don't have to point to a same string.
>>
>> Suggestions what we should do with the patch?
>
> We need to emit debug information for these variables. From Jim's
> description in 70422 it seems that the problem is that the reference
> to the string from the debug information is breaking
> function_mergeable_rodata_prefix, which relies on
> current_function_decl. It seems to me that its callers should pass
> along their decl parameter so that f_m_r_p can use the decl's
> DECL_CONTEXT rather than rely on current_function_decl being set
> properly>
> Jason
>
Ok, after some time I returned back to it. I followed your advises and
changed the function function_mergeable_rodata_prefix. Apart from a small
rebase was needed.
May I ask Jim to test the patch?
Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
Martin
>From 8a7a8b421d81c47cf686175f309f79c0b7a8ce76 Mon Sep 17 00:00:00 2001
From: marxin <mli...@suse.cz>
Date: Thu, 20 Apr 2017 14:56:30 +0200
Subject: [PATCH] Make __FUNCTION__ a mergeable string and do not generate
symbol entry.
gcc/cp/ChangeLog:
2017-04-20 Jason Merrill <ja...@redhat.com>
Martin Liska <mli...@suse.cz>
Segher Boessenkool <seg...@kernel.crashing.org>
PR c++/64266
PR c++/70353
PR bootstrap/70422
Core issue 1962
* decl.c (cp_fname_init): Decay the initializer to pointer.
(cp_make_fname_decl): Set DECL_DECLARED_CONSTEXPR_P,
* pt.c (tsubst_expr) [DECL_EXPR]: Set DECL_VALUE_EXPR,
DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P and
DECL_IGNORED_P. Don't call cp_finish_decl.
* decl.c (cp_make_fname_decl): Add only non error mark
expression.
gcc/testsuite/ChangeLog:
2017-04-20 Jason Merrill <ja...@redhat.com>
Segher Boessenkool <seg...@kernel.crashing.org>
PR c++/64266
PR c++/70353
PR bootstrap/70422
Core issue 1962
* g++.dg/cpp0x/constexpr-__func__2.C: Add static assert test.
* g++.dg/ext/fnname5.C: New test.
* g++.old-deja/g++.ext/pretty4.C: Remove.
gcc/ChangeLog:
2017-07-14 Martin Liska <mli...@suse.cz>
* varasm.c (function_mergeable_rodata_prefix): Use DECL_CONTEXT
for function declarations.
---
gcc/cp/decl.c | 24 +++++--
gcc/cp/pt.c | 26 +++++---
gcc/testsuite/g++.dg/cpp0x/constexpr-__func__2.C | 7 +-
gcc/testsuite/g++.dg/ext/fnname5.C | 33 +++++++++
gcc/testsuite/g++.old-deja/g++.ext/pretty4.C | 85 ------------------------
gcc/varasm.c | 7 +-
6 files changed, 76 insertions(+), 106 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/ext/fnname5.C
delete mode 100644 gcc/testsuite/g++.old-deja/g++.ext/pretty4.C
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 5b8e6a22b01..3f27b72052a 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -4294,13 +4294,15 @@ cp_fname_init (const char* name, tree *type_p)
type = cp_build_qualified_type (char_type_node, TYPE_QUAL_CONST);
type = build_cplus_array_type (type, domain);
- *type_p = type;
+ *type_p = type_decays_to (type);
if (init)
TREE_TYPE (init) = type;
else
init = error_mark_node;
+ init = decay_conversion (init, tf_warning_or_error);
+
return init;
}
@@ -4323,23 +4325,35 @@ cp_make_fname_decl (location_t loc, tree id, int type_dep)
if (name)
free (CONST_CAST (char *, name));
- TREE_STATIC (decl) = 1;
+ /* As we're using pushdecl_with_scope, we must set the context. */
+ DECL_CONTEXT (decl) = current_function_decl;
+
TREE_READONLY (decl) = 1;
DECL_ARTIFICIAL (decl) = 1;
+ DECL_IGNORED_P (decl) = 1;
+ DECL_DECLARED_CONSTEXPR_P (decl) = 1;
TREE_USED (decl) = 1;
+ if (init)
+ {
+ SET_DECL_VALUE_EXPR (decl, init);
+ DECL_HAS_VALUE_EXPR_P (decl) = 1;
+ /* For decl_constant_var_p. */
+ DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = 1;
+ }
+
if (current_function_decl)
{
DECL_CONTEXT (decl) = current_function_decl;
decl = pushdecl_outermost_localscope (decl);
- cp_finish_decl (decl, init, /*init_const_expr_p=*/false, NULL_TREE,
- LOOKUP_ONLYCONVERTING);
+ if (decl != error_mark_node)
+ add_decl_expr (decl);
}
else
{
DECL_THIS_STATIC (decl) = true;
- pushdecl_top_level_and_finish (decl, init);
+ pushdecl_top_level_and_finish (decl, NULL_TREE);
}
return decl;
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index bd02951cb85..f8e096b9b52 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -15862,21 +15862,25 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
DECL_CONTEXT (decl) = current_function_decl;
cp_check_omp_declare_reduction (decl);
}
+ else if (VAR_P (decl)
+ && DECL_PRETTY_FUNCTION_P (decl))
+ {
+ /* For __PRETTY_FUNCTION__ we have to adjust the
+ initializer. */
+ const char *const name
+ = cxx_printable_name (current_function_decl, 2);
+ init = cp_fname_init (name, &TREE_TYPE (decl));
+ SET_DECL_VALUE_EXPR (decl, init);
+ DECL_HAS_VALUE_EXPR_P (decl) = 1;
+ DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = 1;
+ maybe_push_decl (decl);
+ }
else
{
int const_init = false;
maybe_push_decl (decl);
- if (VAR_P (decl)
- && DECL_PRETTY_FUNCTION_P (decl))
- {
- /* For __PRETTY_FUNCTION__ we have to adjust the
- initializer. */
- const char *const name
- = cxx_printable_name (current_function_decl, 2);
- init = cp_fname_init (name, &TREE_TYPE (decl));
- }
- else
- init = tsubst_init (init, decl, args, complain, in_decl);
+
+ init = tsubst_init (init, decl, args, complain, in_decl);
if (VAR_P (decl))
const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-__func__2.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-__func__2.C
index e6782905423..673fb4f3a93 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-__func__2.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-__func__2.C
@@ -1,5 +1,5 @@
// PR c++/70353
-// { dg-do link { target c++11 } }
+// { dg-do compile { target c++11 } }
constexpr const char* ce ()
{
@@ -8,6 +8,5 @@ constexpr const char* ce ()
const char *c = ce();
-int main()
-{
-}
+#define SA(X) static_assert((X),#X)
+SA(ce()[0] == 'c');
diff --git a/gcc/testsuite/g++.dg/ext/fnname5.C b/gcc/testsuite/g++.dg/ext/fnname5.C
new file mode 100644
index 00000000000..04fa7d3f92d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/fnname5.C
@@ -0,0 +1,33 @@
+// PR c++/64266
+/* { dg-do compile } */
+
+extern "C" int printf (const char *, ...);
+
+struct A
+{
+ void foo(int i)
+ {
+ printf ("__FUNCTION__ = %s\n", __FUNCTION__);
+ printf ("__PRETTY_FUNCTION__ = %s\n", __PRETTY_FUNCTION__);
+ }
+
+ void foo()
+ {
+ printf ("__FUNCTION__ = %s\n", __FUNCTION__);
+ }
+};
+
+int
+main ()
+{
+ A a;
+ a.foo (0);
+ a.foo ();
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "_ZZN1A3fooEvE12__FUNCTION__" } } */
+/* { dg-final { scan-assembler-not "_ZZN1A3fooEiE12__FUNCTION__" } } */
+/* { dg-final { scan-assembler-not "_ZZN1A3fooEiE19__PRETTY_FUNCTION__" } } */
+/* { dg-final { scan-assembler ".(string|ascii)\\s+\"void A::foo\\(int\\)(.0)?\"" } } */
+/* { dg-final { scan-assembler ".(string|ascii)\\s+\"foo(.0)?\"" } } */
diff --git a/gcc/testsuite/g++.old-deja/g++.ext/pretty4.C b/gcc/testsuite/g++.old-deja/g++.ext/pretty4.C
deleted file mode 100644
index 9017d567132..00000000000
--- a/gcc/testsuite/g++.old-deja/g++.ext/pretty4.C
+++ /dev/null
@@ -1,85 +0,0 @@
-// { dg-do run }
-// Copyright (C) 2000 Free Software Foundation, Inc.
-// Contributed by Nathan Sidwell 3 Mar 2000 <nat...@codesourcery.com>
-
-// __PRETTY_FUNCTION__, __FUNCTION__ and __function__ should have the
-// type char const [X], where X is the right value for that particular function
-
-static void const *strings[4];
-static void const *tpls[4];
-static unsigned pos = 0;
-static int fail;
-static void const *ptr = 0;
-
-void unover (char const (*)[5]) {}
-void foo (char const (*)[5]) {}
-void foo (void *) {fail = 1;}
-void foo (void const *) {fail = 1;}
-void baz (char const (&)[5]) {}
-
-template<unsigned I> void PV (char const (&objRef)[I])
-{
- strings[pos] = objRef;
- tpls[pos] = __PRETTY_FUNCTION__;
- pos++;
-}
-
-void fn ()
-{
- PV (__FUNCTION__);
- PV (__func__);
- PV (__PRETTY_FUNCTION__);
- PV ("wibble");
-}
-
-void baz ()
-{
- ptr = __FUNCTION__;
- // there should be no string const merging
- if (ptr == "baz")
- fail = 1;
- // but all uses should be the same.
- if (ptr != __FUNCTION__)
- fail = 1;
-}
-int baz (int)
-{
- return ptr == __FUNCTION__;
-}
-
-int main ()
-{
- // make sure we actually emit the VAR_DECL when needed, and things have the
- // expected type.
- foo (&__FUNCTION__);
- baz (__FUNCTION__);
- unover (&__FUNCTION__);
- if (fail)
- return 1;
-
- // __FUNCTION__ should be unique across functions with the same base name
- // (it's a local static, _not_ a string).
- baz ();
- if (fail)
- return 1;
- if (baz (1))
- return 1;
- fn ();
-
- // Check the names of fn. They should all be distinct strings (though two
- // will have the same value).
- if (strings[0] == strings[1])
- return 1;
- if (strings[0] == strings[2])
- return 1;
- if (strings[1] == strings[2])
- return 1;
-
- // check the names of the template functions so invoked
- if (tpls[0] != tpls[1])
- return 1;
- if (tpls[0] == tpls[2])
- return 1;
-
- return 0;
-}
diff --git a/gcc/varasm.c b/gcc/varasm.c
index fbaebc1b5c0..0b56898d8f3 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -760,7 +760,12 @@ default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
static const char *
function_mergeable_rodata_prefix (void)
{
- section *s = targetm.asm_out.function_rodata_section (current_function_decl);
+ tree decl = current_function_decl;
+ if (decl && DECL_CONTEXT (decl)
+ && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL)
+ decl = DECL_CONTEXT (decl);
+
+ section *s = targetm.asm_out.function_rodata_section (decl);
if (SECTION_STYLE (s) == SECTION_NAMED)
return s->named.name;
else
--
2.13.2
