[Mingw-notify] [ mingw-Bugs-991565 ] Optimization/link problem at gcc -O1

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Bugs item #991565, was opened at 2004-07-16 00:54
Message generated for change (Settings changed) made by dannysmith
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=102435&aid=991565&group_id=2435

Category: binutils
Group: None
>Status: Closed
>Resolution: Fixed
Priority: 5
Submitted By: Aaron W. LaFramboise (aaronwl)
Assigned to: Nobody/Anonymous (nobody)
Summary: Optimization/link problem at gcc -O1

Initial Comment:
This fails on MinGW GCC 3.4.1 RC, as well as vanilla FSF 
GCC 3.4.0 and FSF GCC head.

It's not a minimal testcase, and not even proper C, and 
I have not done too much past this to analyze the 
failure beyond get this testcase.  I'm sort of frazzled at 
the moment.

ixx reported that this causing build failures in dna 
analysis tool.  a websearch indicates that this may be 
causing failures in quite a few other programs also.  the 
code itself is distilled from mingwrt head.

This fails with:
gcc -O1 -shared p.c -o p.dll
but not with:
gcc -O1 -shared p.c -o p.dll

Errors:
Info: resolving ___mb_cur_max by linking to 
__imp____mb_cur_max (auto-import)
Info: resolving __pctype by linking to __imp___pctype 
(auto-import)
fu000001.o(.idata$3+0xc): undefined reference to 
`libmsvcrt_a_iname'
fu000003.o(.idata$3+0xc): undefined reference to 
`libmsvcrt_a_iname'
nmth000000.o(.idata$4+0x0): undefined reference to 
`_nm____mb_cur_max'
nmth000002.o(.idata$4+0x0): undefined reference to 
`_nm___pctype'

Testcase:

extern int __mb_cur_max;
extern unsigned short* _pctype;

extern __inline__ int isdigit(int c) {
  return (__mb_cur_max == 1 ? (_pctype[c] & 0x0004)
    : _isctype(c, 0x0004));
}

extern __inline__ int isspace(int c) {
  return (__mb_cur_max == 1 ? (_pctype[c] & 0x0008)
  : _isctype(c, 0x0008));
}

int llama() {
  if (!isdigit(0) && isspace(0))
    return 1;

  return 0;
}


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Comment By: Aaron W. LaFramboise (aaronwl)
Date: 2004-07-21 17:33

Message:
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user_id=1040098

This appears to be primarily due to a perl bug.  While I would 
prefer more descriptive or intuitive messages or behavior from 
the compiler or linker, the tools are working properly here.  
This ticket can be closed.

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Comment By: Danny Smith (dannysmith)
Date: 2004-07-16 10:56

Message:
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I remember a similar problem occurring over a year ago.  In 
that case, an outdated check for GCC version was causing a  
#define __attribute__(x)  /* Nothing */

This disabled the dllimport attribute for   __mb_cur_max and 
so engaged the auto-import functionality.

Danny


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Comment By: Danny Smith (dannysmith)
Date: 2004-07-16 08:12

Message:
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The auto-import extension doesn't work when linking against 
an import lib built with dlltool -- in this case libmsvcrt.a.  You 
actually need to build a dll from source to allow auto-
importing from that dll

Danny

----------------------------------------------------------------------

Comment By: Aaron W. LaFramboise (aaronwl)
Date: 2004-07-16 00:59

Message:
Logged In: YES 
user_id=1040098

This also fails on gcc 3.2.3, so its not a regression from
that.  I don't know anything anything earlier.


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