[Bug debug/26364] New: [4.1/4.2 regression]: Uninlined function is marked as inlined

[Bug debug/26364] New: [4.1/4.2 regression]: Uninlined function is marked as inlined

[hjl at lucon dot org]

Gcc 4.1/4.2 generates wrong DWARF info when it fails to inline a static
function.


-- 
           Summary: [4.1/4.2 regression]: Uninlined function is marked as
                    inlined
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hjl at lucon dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.1/4.2 regression]: Uninlined function is marked as inlined

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2006-02-19 20:13 -------
Testcase????


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.1/4.2 regression]: Uninlined function is marked as inlined

[hjl at lucon dot org]

------- Comment #2 from hjl at lucon dot org  2006-02-19 20:15 -------
Created an attachment (id=10877)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10877&action=view)
A testcase

This is the preprocess Linux kernel code for gcc 4.1 and 4.2. There are many
static functions, like pageout, have DWARF2 info like:

<1><9aee>: Abbrev Number: 78 (DW_TAG_subprogram)
     DW_AT_sibling     : <9bd1>
     DW_AT_name        : (indirect string, offset: 0x44b6): pageout
     DW_AT_decl_file   : 1
     DW_AT_decl_line   : 318
     DW_AT_prototyped  : 1
     DW_AT_type        : <8df5>
     DW_AT_inline      : 1      (inlined)

where pageout isn't inlined at all. Gcc 3.4.6 generates:

 <1><8eb1>: Abbrev Number: 84 (DW_TAG_subprogram)
     DW_AT_sibling     : <8fe0>
     DW_AT_name        : (indirect string, offset: 0x4182): pageout
     DW_AT_decl_file   : 1
     DW_AT_decl_line   : 295
     DW_AT_prototyped  : 1
     DW_AT_type        : <84b0>
     DW_AT_low_pc      : 0x318
     DW_AT_high_pc     : 0x3e4
     DW_AT_frame_base  : 1 byte block: 54       (DW_OP_reg4)


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.1/4.2 regression]: Uninlined function is marked as inlined

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2006-02-19 20:18 -------
Next time don't attach a tar ball, please.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.0.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[wilson at gcc dot gnu dot org]

------- Comment #4 from wilson at gcc dot gnu dot org  2006-02-22 00:28 -------
The debug info looks OK to me, though it is more verbose than it needs to be.

I think you may be reading the debug info wrong.  The entry you are looking at
is the abstract origin for pageout.  If you take the offset of this entry, 9aee
in your case, and search for that, you will find the real debug info for
pageout, which has an abstract origin attribute pointing at the 9aee entry.  I
get slightly different addresses, but here is what I get
        .uleb128 0x4e   # (DIE (0x9af3) DW_TAG_subprogram)
        .long   0x9bd6  # DW_AT_sibling
        .long   .LASF1677       # DW_AT_name: "pageout"
        .byte   0x1     # DW_AT_decl_file
        .value  0x13e   # DW_AT_decl_line
        .byte   0x1     # DW_AT_prototyped
        .long   0x8df5  # DW_AT_type
        .byte   0x1     # DW_AT_inline
        ...
        .uleb128 0x3e   # (DIE (0x9bd6) DW_TAG_subprogram)
        .long   0x9d39  # DW_AT_sibling
        .long   0x9af3  # DW_AT_abstract_origin
        .long   .LFB813 # DW_AT_low_pc
        .long   .LFE813 # DW_AT_high_pc
        .long   .LLST34 # DW_AT_frame_base
So the debug info is correct, in the sense it correctly describes the program.

The debug is more verbose than it should be though, since there is no need for
the abstract origin if the function was never inlined.  This is due to problems
with cgraph.  Now that cgraph controls when and how we emit code for functions,
we really need to move the debug output calls into cgraph, so that functions
are finalized by cgraph before we try to emit debug info for them.  There are a
few other bugzilla bug reports concerning the same issue, though it may not be
easy to find them.  It is probably also not easy to fix this.

See cgraph_function_possibly_inlined_p.

What is the real bug that you are trying to report here?  Are you complaining
because the debug info is unnecessarily verbose?  Do you have a debugger that
doesn't handle this debug info correctly?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[wilson at gcc dot gnu dot org]

------- Comment #5 from wilson at gcc dot gnu dot org  2006-02-22 00:39 -------
I should mention that your testcase uses -Os, and -Os enables
-finline-functions-called-once.  This is why the function is marked as
"inline".  If you don't want this feature, you can turn it off.

Also, -fno-unit-at-a-time is expected to disappear at some point, so problems
that only appear with this option may not be worth fixing if they are too hard
to fix.  

Using both -finline-functions-called-once and -fno-unit-at-a-time is
contradictory, so it isn't surprising there is a problem.  We could try to
detect that and turn one of them off, possibly with a warning.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[wilson at gcc dot gnu dot org]

------- Comment #6 from wilson at gcc dot gnu dot org  2006-02-22 00:43 -------
Created an attachment (id=10888)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10888&action=view)
small testcase

Compile this with 
     ./xgcc -B./ -Os -fno-unit-at-a-time -g -dA -S tmp.c -fverbose-asm
and notice that we have an abstract_origin die for sub, even though it was
never inlined.  Also notice the -finline* options listed at the top of the .s
file.  These are enabled by -Os.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[mmitchel at gcc dot gnu dot org]

------- Comment #7 from mmitchel at gcc dot gnu dot org  2006-02-23 23:46 -------
This problem concerns quasi-invalid debug information in an obscure compilation
mode; P2.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[mmitchel at gcc dot gnu dot org]

------- Comment #8 from mmitchel at gcc dot gnu dot org  2006-02-24 00:27 -------
This issue will not be resolved in GCC 4.1.0; retargeted at GCC 4.1.1.


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mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.0.3                       |4.1.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[mmitchel at gcc dot gnu dot org]

------- Comment #9 from mmitchel at gcc dot gnu dot org  2006-05-25 02:34 -------
Will not be fixed in 4.1.1; adjust target milestone to 4.1.2.


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mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.1                       |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2/4.3 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.2                       |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2/4.3 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[steven at gcc dot gnu dot org]

------- Comment #10 from steven at gcc dot gnu dot org  2007-12-16 23:24 -------
Could this be fixed by rejecting -finline-functions-called-once if
-fno-unit-at-a-time is given?  A patch to do this should be quite trivial.


-- 

steven at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2/4.3 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[steven at gcc dot gnu dot org]

------- Comment #11 from steven at gcc dot gnu dot org  2008-01-08 12:53 -------
Created an attachment (id=14899)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=14899&action=view)
Reject combination of -fno-unit-at-a-time and -finline-functions-called-once

Untested, but shows how easy it should be to "fix" this bug by disallowing this
strange combination of flags.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.0/4.1/4.2/4.3 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[rguenth at gcc dot gnu dot org]

------- Comment #12 from rguenth at gcc dot gnu dot org  2008-01-09 10:34 -------
Subject: Bug 26364

Author: rguenth
Date: Wed Jan  9 10:33:55 2008
New Revision: 131423

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=131423
Log:
2008-01-09  Steven Bosscher  <stevenb.gcc@gmail.com>

        PR debug/26364
        * opts.c (decode_options): Disable inlining of functions called
        once if not in unit-at-a-time mode.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/opts.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.1/4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[rguenth at gcc dot gnu dot org]

------- Comment #13 from rguenth at gcc dot gnu dot org  2008-01-09 10:38 -------
Fixed on the trunk.


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rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
     Ever Confirmed|0                           |1
      Known to work|3.4.6                       |3.4.6 4.3.0
   Last reconfirmed|0000-00-00 00:00:00         |2008-01-09 10:38:03
               date|                            |
            Summary|[4.0/4.1/4.2/4.3 regression]|[4.1/4.2 regression] [no
                   |[no unit-at-a-time mode]    |unit-at-a-time mode]
                   |Uninlined function is marked|Uninlined function is marked
                   |as inlined                  |as inlined


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[jsm28 at gcc dot gnu dot org]

------- Comment #14 from jsm28 at gcc dot gnu dot org  2008-07-04 20:21 -------
Closing 4.1 branch.


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jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.1/4.2 regression] [no    |[4.2 regression] [no unit-
                   |unit-at-a-time mode]        |at-a-time mode] Uninlined
                   |Uninlined function is marked|function is marked as
                   |as inlined                  |inlined
   Target Milestone|4.1.3                       |4.2.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364

[Bug debug/26364] [4.2 regression] [no unit-at-a-time mode] Uninlined function is marked as inlined

[jsm28 at gcc dot gnu dot org]

------- Comment #15 from jsm28 at gcc dot gnu dot org  2009-03-30 15:49 -------
Closing 4.2 branch, fixed in 4.3.


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jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
      Known to fail|4.1.0 4.2.0 4.0.0           |4.1.0 4.2.0 4.0.0 4.2.5
         Resolution|                            |FIXED
   Target Milestone|4.2.5                       |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26364