[LLVMdev] src to src conversion

[Ryan M. Lefever]

This seems to work.  Thank you for the help!

John Criswell wrote:
> Ryan M. Lefever wrote:
> 
>> I am trying to use LLVM as a source to source C compiler.  I use 
>> llvm-gcc to convert file.c->file.bc.  Then I use opt to run my own 
>> compiler passes to convert file.bc->file.opt.bc.  Then I use llc to 
>> convert file.opt.bc->file.opt.c.  Now, I want to use normal gcc to 
>> compile file.opt.c into an executable.  However, I'm getting the 
>> following errors:
> 
> 
> Please try the following:
> 
> llvm-gcc -o final file.opt.bc -lcrtend
> llc -march=c final.bc
> gcc -o finalexec final.cbe.c
> 
> The first line uses llvm-gcc to link libcrtend.a to your optimized 
> bytecode file.  Using llvm-gcc ensures that it picks up the version of 
> libcrtend.a located within your llvm-gcc distribution (which should work).
> 
> The second and third lines generate the C code and compile it into a 
> final executable.
> 
> If that doesn't work, please let me know.
> 
>>
>> test.opt.c:89: warning: conflicting types for built-in function 'malloc'
>> test.opt.o(.text+0xe7): In function `main':
>> : undefined reference to `__main'
>> collect2: ld returned 1 exit status
>> make: *** [test.opt.exe] Error 1
>>
>> ------
>>
>> I think the problem with main and __main is that I need to link in 
>> some LLVM runtime libraries.  So, I tried to link in crtend (which 
>> defines __main).  However, I get the following error:
>>
>> /home/testbed1/lefever/work/llvm/install/lib/libcrtend.a: could not 
>> read symbols: Archive has no index; run ranlib to add one
>> collect2: ld returned 1 exit status
>> make: *** [test.opt.exe] Error 1
>>
>> I tried creating a copy of the libcrtend.a and running ranlib on it 
>> and I also separately tried running llvm-ranlib on it.  Neither of 
>> those actions worked though.  Am I linking the correct library, i.e., 
>> crtend?  Why am I getting the error about the archive having no index?
>>
>> -----
>>
>> As far as the warning about conflicting types for malloc, it appears 
>> that llvm is using the declaration where the output of malloc is a 
>> "signed char *" rather than "void *".  Why is that?
> 
> 
> My memory is foggy, but it's probably because either the LLVM libraries 
> (from llvm/runtime) or the LLVM code you're compiling has a prototype 
> for malloc that returns "signed char *," but the header file being 
> pulled in by GCC when compiling the .cbe.c file has a prototype for 
> "void *."  It's also possible that llc is adding the malloc prototype as 
> well.  If you're really curious, some simple experimentation should 
> indicate which of the above it is.
> 
> 
>>
>> Thanks in advance for any help.
>>
>> Regards,
>> Ryan
>>
> 
> -- John T.
> 

-- 
Ryan M. Lefever  [217.333.7231]  [http://www.ews.uiuc.edu/~lefever]