[Bug testsuite/42854] New: [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[Bug testsuite/42854] New: [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[dominiq at lps dot ens dot fr]

Since revision 155920 (see
http://gcc.gnu.org/ml/gcc-testresults/2010-01/msg01286.html or
http://gcc.gnu.org/ml/gcc-testresults/2010-01/msg02004.html ) there are the
following failures on *-apple-darwin*:

FAIL: gcc.dg/darwin-weakimport-1.c scan-assembler-not weak_[a-z \\t]*_b
FAIL: gcc.dg/darwin-weakimport-3.c scan-assembler-not coalesced

[karma] f90/bug% gcc45 -S
/opt/gcc/gcc-4.5-work/gcc/testsuite/gcc.dg/darwin-weakimport-1.c
[karma] f90/bug% grep weak darwin-weakimport-1.s
        .weak_definition _b
        .weak_reference _a
[karma] f90/bug% gcc45 -S
/opt/gcc/gcc-4.5-work/gcc/testsuite/gcc.dg/darwin-weakimport-3.c
[karma] f90/bug% grep coalesced darwin-weakimport-3.s 
        .section __TEXT,__textcoal_nt,coalesced,pure_instructions

The tests pass at revision: 155908 (see
http://gcc.gnu.org/ml/gcc-testresults/2010-01/msg01246.html ).

Likely due to revision 155919:

Author: jakub
Date:   Thu Jan 14 22:41:02 2010 UTC (9 days, 15 hours ago)
Changed paths:  4
Log Message:    
        PR c++/42608
        * varasm.c (declare_weak): Add weak attribute to decl if it
        doesn't have one already.
        (assemble_external): Only add decls to weak_decls if they also
        have weak attribute.

        * g++.dg/template/instantiate11.C: New test.

This is also seen on 4.4.3 (see
http://gcc.gnu.org/ml/gcc-testresults/2010-01/msg02202.html or
http://gcc.gnu.org/ml/gcc-testresults/2010-01/msg02196.html ), this seems a
regression since gcc4.4.2 gives:

[karma] f90/bug% gcc-4 -S
/opt/gcc/gcc-4.5-work/gcc/testsuite/gcc.dg/darwin-weakimport-1.c
[karma] f90/bug% grep weak darwin-weakimport-1.s
        .weak_reference _a
        .weak_reference _a
[karma] f90/bug% gcc-4 -S
/opt/gcc/gcc-4.5-work/gcc/testsuite/gcc.dg/darwin-weakimport-3.c
[karma] f90/bug% grep coalesced darwin-weakimport-3.s


-- 
           Summary: [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-
                    [13].c scan-assembler-not *
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: testsuite
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dominiq at lps dot ens dot fr
 GCC build triplet: *-apple-darwin*
  GCC host triplet: *-apple-darwin*
GCC target triplet: *-apple-darwin*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.4.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[jakub at gcc dot gnu dot org]

------- Comment #1 from jakub at gcc dot gnu dot org  2010-01-25 12:03 -------
This is completely undocumented attribute, so you first need to get Apple to
actually document what it does and get the documentation into doc/extend.texi.
Especially nothing explains the relationship between weak attribute,
weak_import attribute and #pragma weak.  Unless this is clarified, there is
nothing that can be done about this, complain to Apple.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[dominiq at lps dot ens dot fr]

------- Comment #2 from dominiq at lps dot ens dot fr  2010-01-25 12:53 -------
> This is completely undocumented attribute ...

What is the "undocumented attribute"? If you mean
"-fno-asynchronous-unwind-tables", you don't need it for the tests to fail.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[jakub at gcc dot gnu dot org]

------- Comment #3 from jakub at gcc dot gnu dot org  2010-01-25 12:59 -------
I mean that
grep weak_import doc/*
yields nothing at all (and google for weak_import doesn't show up any useful
documentation either).
It seems that Geoff Keating's implementation of the attribute (how could it be
committed without documentation nor at least some words on what it is meant to
do?) basically ignored it if weak attribute was also specified.  Just removing
those lookup_attribute (, "weak") tests would cure this.  That really depends
on
what __attribute__((weak, weak_import)) is supposed to mean (if anything).
Or what means combination of #pragma weak and weak_import attribute for the
same decl name.  Also, what matters is if undefined weak_import symbols are
supposed to generate weak directives or not.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[howarth at nitro dot med dot uc dot edu]

------- Comment #4 from howarth at nitro dot med dot uc dot edu  2010-01-25 20:20 -------
Mike Stump's comment on Geoff's implementation of the attribute weak_import in
FSF gcc is...

> Not earth shattering, it just sets .weak_definition or .weak_reference for
> the assembler.  google can find tidbits about the programming model, how
> they are used and the assembler manual and so on... if your curious.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[dominiq at lps dot ens dot fr]

------- Comment #5 from dominiq at lps dot ens dot fr  2010-01-25 21:59 -------
> Mike Stump's comment on Geoff's implementation of the attribute weak_import in
> FSF gcc is...

 Could you give a pointer?

The first test was introduced by this patch

http://gcc.gnu.org/ml/gcc-patches/2004-10/msg02441.html

and updated by this one

http://gcc.gnu.org/ml/gcc-patches/2005-01/msg00146.html

The second test was introduce by this patch

http://gcc.gnu.org/ml/gcc-patches/2005-12/msg00378.html

Note the introduction:

> weak_import is more-or-less deprecated on Darwin, by which I mean that
> it has a bunch of known bugs but we aren't trying very hard to convince
> people to stop using it.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[howarth at nitro dot med dot uc dot edu]

------- Comment #6 from howarth at nitro dot med dot uc dot edu  2010-02-11 02:04 -------
This section in darwin.c seems a bit strange...

  if (!DECL_EXTERNAL (decl)
      && (!TREE_PUBLIC (decl) || !DECL_WEAK (decl))
      && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))
      && ((TREE_STATIC (decl)
           && (!DECL_COMMON (decl) || !TREE_PUBLIC (decl)))
          || (!DECL_COMMON (decl) && DECL_INITIAL (decl)
              && DECL_INITIAL (decl) != error_mark_node)))
    SYMBOL_REF_FLAGS (sym_ref) |= MACHO_SYMBOL_FLAG_DEFINED;

Since they already test against...

  !DECL_WEAK (decl))

, I wonder if it might also need to test against...

 ! lookup_attribute ("weak", DECL_ATTRIBUTES (decl))


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[howarth at nitro dot med dot uc dot edu]

------- Comment #7 from howarth at nitro dot med dot uc dot edu  2010-02-13 05:09 -------
The weak_import attribute is described fairly well in this technote....

http://developer.apple.com/mac/library/technotes/tn2002/tn2064.html#SECTION2


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[howarth at nitro dot med dot uc dot edu]

------- Comment #8 from howarth at nitro dot med dot uc dot edu  2010-02-13 06:09 -------
On darwin, it would appear that the change in r155919 is unnecessary. Using...

--- /Users/howarth/gcc-4.5-20100211/gcc/varasm.c        2010-01-20
18:46:25.000000000 -0500
+++ gcc/varasm.c        2010-02-13 00:23:56.000000000 -0500
@@ -2345,7 +2345,9 @@
         for declarations that can be weak, it happens to be
         match.  */
       && !TREE_STATIC (decl)
+#ifndef __APPLE__
       && lookup_attribute ("weak", DECL_ATTRIBUTES (decl))
+#endif
       && value_member (decl, weak_decls) == NULL_TREE)
     weak_decls = tree_cons (NULL, decl, weak_decls);

@@ -5290,9 +5292,11 @@
     warning (0, "weak declaration of %q+D not supported", decl);

   mark_weak (decl);
+#ifndef __APPLE__
   if (!lookup_attribute ("weak", DECL_ATTRIBUTES (decl)))
     DECL_ATTRIBUTES (decl)
       = tree_cons (get_identifier ("weak"), NULL, DECL_ATTRIBUTES (decl));
+#endif
 }

I find that g++.dg/template/instantiate11.C doesn't produce weak symbols in
instantiate11.s. The problem with r155919 on darwin is that it forces the
weak_import attribute to become weak in declare_weak and drops the decls for
weak_imports in assemble_external since it looks only for the weak attribute
and not weak_import (which is set in darwin.c).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[howarth at nitro dot med dot uc dot edu]

------- Comment #9 from howarth at nitro dot med dot uc dot edu  2010-02-13 15:41 -------
This should probably be a P2 since it causes a regression on darwin which
breaks their weak linking.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[howarth at nitro dot med dot uc dot edu]

------- Comment #10 from howarth at nitro dot med dot uc dot edu  2010-02-13 16:04 -------
This alternative fix works as well...

--- /Users/howarth/gcc-4.5-20100211/gcc/varasm.c        2010-01-20
18:46:25.000000000 -0500
+++ gcc/varasm.c        2010-02-13 10:58:45.000000000 -0500
@@ -2345,7 +2345,8 @@
         for declarations that can be weak, it happens to be
         match.  */
       && !TREE_STATIC (decl)
-      && lookup_attribute ("weak", DECL_ATTRIBUTES (decl))
+      && ( lookup_attribute ("weak", DECL_ATTRIBUTES (decl)) ||
+      lookup_attribute ("weak_import", DECL_ATTRIBUTES (decl)))
       && value_member (decl, weak_decls) == NULL_TREE)
     weak_decls = tree_cons (NULL, decl, weak_decls);

@@ -5290,9 +5291,11 @@
     warning (0, "weak declaration of %q+D not supported", decl);

   mark_weak (decl);
+#ifndef ASM_WEAKEN_DECL
   if (!lookup_attribute ("weak", DECL_ATTRIBUTES (decl)))
     DECL_ATTRIBUTES (decl)
       = tree_cons (get_identifier ("weak"), NULL, DECL_ATTRIBUTES (decl));
+#endif
 }

 static void


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[howarth at nitro dot med dot uc dot edu]

------- Comment #11 from howarth at nitro dot med dot uc dot edu  2010-02-14 02:12 -------
Proposed patch at http://gcc.gnu.org/ml/gcc-patches/2010-02/msg00532.html and
testsuite resuilts for proposed patch at
http://gcc.gnu.org/ml/gcc-testresults/2010-02/msg01258.html.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug testsuite/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[howarth at nitro dot med dot uc dot edu]

------- Comment #12 from howarth at nitro dot med dot uc dot edu  2010-02-14 23:34 -------
Posted revised patch at http://gcc.gnu.org/ml/gcc-patches/2010-02/msg00549.html
with regression test results at
http://gcc.gnu.org/ml/gcc-testresults/2010-02/msg01339.html.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug target/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[jakub at gcc dot gnu dot org]

------- Comment #13 from jakub at gcc dot gnu dot org  2010-02-15 23:53 -------
Subject: Bug 42854

Author: jakub
Date: Mon Feb 15 23:52:53 2010
New Revision: 156786

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=156786
Log:
        PR target/42854
        * config/darwin.h (ASM_WEAKEN_DECL): Don't check weak attribute
        if weak_import attribute is present.
        * config/darwin.c (machopic_select_section): Likewise.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/darwin.c
    trunk/gcc/config/darwin.h


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854

[Bug target/42854] [4.4/4.5 Regression] FAIL: gcc.dg/darwin-weakimport-[13].c scan-assembler-not *

[dominiq at lps dot ens dot fr]

------- Comment #14 from dominiq at lps dot ens dot fr  2010-02-21 12:47 -------
Closing as fixed. Thanks for the patch.


-- 

dominiq at lps dot ens dot fr changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854