llvm dev - May 2014 - [LLVMdev] clang build (Debug+Asserts) fails with Cygwin and Mingw (ASTContext.o: File too big)

Hello,

After switching from a Linux development host to Windows7 with Cygwin, I 
notice the following problem when building clang (trunk, HEAD):
(also happens with Mingw)

...

llvm[4]: Compiling ParseInit.cpp for Debug+Asserts build
as: 
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
too many sections (33066)
/tmp/ccmtDH7w.s: Assembler messages:
/tmp/ccmtDH7w.s: Fatal error: can't write 
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
File too big
as: 
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
too many sections (33066)
/tmp/ccmtDH7w.s: Fatal error: can't close 
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
File too big
/cygdrive/d/Projects/Cpp/llvm/Makefile.rules:1509: recipe for target 
'/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o'
failed
make[4]: *** 
[/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o]
Error 1
make[4]: Leaving directory 
'/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST'
/cygdrive/d/Projects/Cpp/llvm/Makefile.rules:936: recipe for target 
'AST/.makeall' failed
make[3]: *** [AST/.makeall] Error 2

...


The reason for this seems to be that the COFF object format in Windows 
only supports a maximum of 2^15 sections (32768) for obj files.

To work around this issue, Microsoft's compiler cl has a flag called 
/bigobj that allocates 32 bits in order to store the number of sections 
(instead of 16 bits, as this standard specifies: 
http://msdn.microsoft.com/en-us/library/gg463119.aspx )

Also check this for /bigobj:
http://msdn.microsoft.com/en-us/library/ms173499.aspx

Anybody else having this problem with Mingw/Cygwin? If yes, how did you 
overcome it?

My Cygwin version is this:
$ uname -a
CYGWIN_NT-6.1 livghe-i5 1.7.29(0.272/5/3) 2014-04-07 13:46 x86_64 Cygwin

The only option I currently see is to split the mammoth cpp file 
(ASTContext.cpp)  in 2 parts, or to get rid of the debug info (not desired).


-- 
Best Regards,
-Liviu

Any idea what all those sections are - comdat inline functions?

Does the debug info in COFF do something weird and emit a section per
type or function?

On Fri, May 2, 2014 at 1:11 PM, Liviu Gheorghisan <livghe at gmx.com>
wrote:
> Hello,
>
> After switching from a Linux development host to Windows7 with Cygwin, I
> notice the following problem when building clang (trunk, HEAD):
> (also happens with Mingw)
>
> ...
>
> llvm[4]: Compiling ParseInit.cpp for Debug+Asserts build
> as:
>
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
> too many sections (33066)
> /tmp/ccmtDH7w.s: Assembler messages:
> /tmp/ccmtDH7w.s: Fatal error: can't write
>
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
> File too big
> as:
>
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
> too many sections (33066)
> /tmp/ccmtDH7w.s: Fatal error: can't close
>
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
> File too big
> /cygdrive/d/Projects/Cpp/llvm/Makefile.rules:1509: recipe for target
>
'/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o'
> failed
> make[4]: ***
>
[/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o]
> Error 1
> make[4]: Leaving directory
> '/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST'
> /cygdrive/d/Projects/Cpp/llvm/Makefile.rules:936: recipe for target
> 'AST/.makeall' failed
> make[3]: *** [AST/.makeall] Error 2
>
> ...
>
>
> The reason for this seems to be that the COFF object format in Windows only
> supports a maximum of 2^15 sections (32768) for obj files.
>
> To work around this issue, Microsoft's compiler cl has a flag called
/bigobj
> that allocates 32 bits in order to store the number of sections (instead of
> 16 bits, as this standard specifies:
> http://msdn.microsoft.com/en-us/library/gg463119.aspx )
>
> Also check this for /bigobj:
> http://msdn.microsoft.com/en-us/library/ms173499.aspx
>
> Anybody else having this problem with Mingw/Cygwin? If yes, how did you
> overcome it?
>
> My Cygwin version is this:
> $ uname -a
> CYGWIN_NT-6.1 livghe-i5 1.7.29(0.272/5/3) 2014-04-07 13:46 x86_64 Cygwin
>
> The only option I currently see is to split the mammoth cpp file
> (ASTContext.cpp)  in 2 parts, or to get rid of the debug info (not
desired).
>
>
> --
> Best Regards,
> -Liviu
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

On 5/2/2014 11:41 PM, David Blaikie wrote:
> Any idea what all those sections are - comdat inline functions?
>
No idea, as I cannot run objdump -h on a object file that I couldn't 
build :)
  Anyhow, I have an old, successful Debug+Asserts build of clang, made 
with Mingw also, for clang revision 206070. Apparently, the ASTContext.o 
file there contained 16453 sections, not 33066, as there are today.
> Does the debug info in COFF do something weird and emit a section per
> type or function?
>
I will do a release build tomorrow and check the sections. (in my 
timezone it's night) - I will let you know!
> On Fri, May 2, 2014 at 1:11 PM, Liviu Gheorghisan <livghe at gmx.com>
wrote:
>> Hello,
>>
>> After switching from a Linux development host to Windows7 with Cygwin,
I
>> notice the following problem when building clang (trunk, HEAD):
>> (also happens with Mingw)
>>
>> ...
>>
>> llvm[4]: Compiling ParseInit.cpp for Debug+Asserts build
>> as:
>>
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
>> too many sections (33066)
>> /tmp/ccmtDH7w.s: Assembler messages:
>> /tmp/ccmtDH7w.s: Fatal error: can't write
>>
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
>> File too big
>> as:
>>
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
>> too many sections (33066)
>> /tmp/ccmtDH7w.s: Fatal error: can't close
>>
/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o:
>> File too big
>> /cygdrive/d/Projects/Cpp/llvm/Makefile.rules:1509: recipe for target
>>
'/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o'
>> failed
>> make[4]: ***
>>
[/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST/Debug+Asserts/ASTContext.o]
>> Error 1
>> make[4]: Leaving directory
>> '/cygdrive/d/Projects/Cpp/llvm/cfgCygwin/tools/clang/lib/AST'
>> /cygdrive/d/Projects/Cpp/llvm/Makefile.rules:936: recipe for target
>> 'AST/.makeall' failed
>> make[3]: *** [AST/.makeall] Error 2
>>
>> ...
>>
>>
>> The reason for this seems to be that the COFF object format in Windows
only
>> supports a maximum of 2^15 sections (32768) for obj files.
>>
>> To work around this issue, Microsoft's compiler cl has a flag
called /bigobj
>> that allocates 32 bits in order to store the number of sections
(instead of
>> 16 bits, as this standard specifies:
>> http://msdn.microsoft.com/en-us/library/gg463119.aspx )
>>
>> Also check this for /bigobj:
>> http://msdn.microsoft.com/en-us/library/ms173499.aspx
>>
>> Anybody else having this problem with Mingw/Cygwin? If yes, how did you
>> overcome it?
>>
>> My Cygwin version is this:
>> $ uname -a
>> CYGWIN_NT-6.1 livghe-i5 1.7.29(0.272/5/3) 2014-04-07 13:46 x86_64
Cygwin
>>
>> The only option I currently see is to split the mammoth cpp file
>> (ASTContext.cpp)  in 2 parts, or to get rid of the debug info (not
desired).
>>
>>
>> --
>> Best Regards,
>> -Liviu
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
-- 
Best Regards,
-Liviu