Alexandre Ganea via llvm-dev
2019-Sep-30 18:39 UTC
[llvm-dev] lld-link with MSVC6 object files
The CodeView library in LLVM only supports Codeview C13 types, that is, MSVC 7.0
/ Visual Studio 2002 or after.
De : llvm-dev <llvm-dev-bounces at lists.llvm.org> De la part de David
Blaikie via llvm-dev
Envoyé : September 30, 2019 2:38 PM
À : Paul Moran <bankybooks at gmail.com>; Rui Ueyama <ruiu at
google.com>
Cc : llvm-dev at lists.llvm.org
Objet : Re: [llvm-dev] lld-link with MSVC6 object files
MSVC 6 as in the Visual Studio released in 1989? Yes, I imagine that's a bit
outside the intended support window.
On Mon, Sep 30, 2019 at 11:18 AM Paul Moran via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
Hi,
I have a question about lld-link. What obj file formats should it support? When
I try to use an obj from msvc 6.0 it complains that the file magic is not valid.
However when running llvm-objdump it reports:
test1.obj: file format COFF-i386
Disassembly of section .text:
0000000000000000 _main:
0: 68 00 00 00 00 pushl $0
5: e8 00 00 00 00 calll 0 <_main+0xa>
a: 83 c4 04 addl $4, %esp
d: 33 c0 xorl %eax, %eax
f: c3 retl
Thanks,
Paul
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MSVC 6 is 1998 not 1989 :) The latest MSVC linker can link these object files. Is this just because it has support for C13 types and some other code path for whatever MSVC6 uses? After some digging around it appears to be this format: https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#coff-file-header-object-and-image Which is COFF object file format? Does lld link support this format? On Mon, Sep 30, 2019 at 7:39 PM Alexandre Ganea <alexandre.ganea at ubisoft.com> wrote:> The CodeView library in LLVM only supports Codeview C13 types, that is, > MSVC 7.0 / Visual Studio 2002 or after. > > > > *De :* llvm-dev <llvm-dev-bounces at lists.llvm.org> *De la part de* David > Blaikie via llvm-dev > *Envoyé :* September 30, 2019 2:38 PM > *À :* Paul Moran <bankybooks at gmail.com>; Rui Ueyama <ruiu at google.com> > *Cc :* llvm-dev at lists.llvm.org > *Objet :* Re: [llvm-dev] lld-link with MSVC6 object files > > > > MSVC 6 as in the Visual Studio released in 1989? Yes, I imagine that's a > bit outside the intended support window. > > > > On Mon, Sep 30, 2019 at 11:18 AM Paul Moran via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > > Hi, > > > > I have a question about lld-link. What obj file formats should it support? > When I try to use an obj from msvc 6.0 it complains that the file magic is > not valid. > > > > However when running llvm-objdump it reports: > > > > test1.obj: file format COFF-i386 > > Disassembly of section .text: > 0000000000000000 _main: > 0: 68 00 00 00 00 pushl $0 > 5: e8 00 00 00 00 calll 0 <_main+0xa> > a: 83 c4 04 addl $4, %esp > d: 33 c0 xorl %eax, %eax > > f: c3 retl > > > > Thanks, > > Paul > > > > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20190930/efb61b09/attachment.html>
David Blaikie via llvm-dev
2019-Sep-30 21:14 UTC
[llvm-dev] lld-link with MSVC6 object files
On Mon, Sep 30, 2019 at 2:07 PM Paul Moran <bankybooks at gmail.com> wrote:> MSVC 6 is 1998 not 1989 :) >Ah, I just glanced briefly at the Wikipedia article ( https://en.wikipedia.org/wiki/Microsoft_Visual_C%2B%2B ) & misread the "C 6.0" and didn't notice it was distinct from "Visual C++ 6.0" - thanks for the catch!> > The latest MSVC linker can link these object files. Is this just because > it has support for C13 types and some other code path for whatever MSVC6 > uses? After some digging around it appears to be this format: > > > https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#coff-file-header-object-and-image > > > Which is COFF object file format? Does lld link support this format? >COFF is still the windows object file format, and the Windows support in lld is COFF support, yeah. I guess there might be some format variations that haven't been implemented in lld, though. It's mostly an "on demand" sort of approach.> > > On Mon, Sep 30, 2019 at 7:39 PM Alexandre Ganea < > alexandre.ganea at ubisoft.com> wrote: > >> The CodeView library in LLVM only supports Codeview C13 types, that is, >> MSVC 7.0 / Visual Studio 2002 or after. >> >> >> >> *De :* llvm-dev <llvm-dev-bounces at lists.llvm.org> *De la part de* David >> Blaikie via llvm-dev >> *Envoyé :* September 30, 2019 2:38 PM >> *À :* Paul Moran <bankybooks at gmail.com>; Rui Ueyama <ruiu at google.com> >> *Cc :* llvm-dev at lists.llvm.org >> *Objet :* Re: [llvm-dev] lld-link with MSVC6 object files >> >> >> >> MSVC 6 as in the Visual Studio released in 1989? Yes, I imagine that's a >> bit outside the intended support window. >> >> >> >> On Mon, Sep 30, 2019 at 11:18 AM Paul Moran via llvm-dev < >> llvm-dev at lists.llvm.org> wrote: >> >> Hi, >> >> >> >> I have a question about lld-link. What obj file formats should it >> support? When I try to use an obj from msvc 6.0 it complains that the file >> magic is not valid. >> >> >> >> However when running llvm-objdump it reports: >> >> >> >> test1.obj: file format COFF-i386 >> >> Disassembly of section .text: >> 0000000000000000 _main: >> 0: 68 00 00 00 00 pushl $0 >> 5: e8 00 00 00 00 calll 0 <_main+0xa> >> a: 83 c4 04 addl $4, %esp >> d: 33 c0 xorl %eax, %eax >> >> f: c3 retl >> >> >> >> Thanks, >> >> Paul >> >> >> >> _______________________________________________ >> LLVM Developers mailing list >> llvm-dev at lists.llvm.org >> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >> >>-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20190930/2c2ef856/attachment.html>