On Wed, 14 Apr 2004, Eric Zimmerman wrote:> I'm working on a CS326 compiler project, and I'm having some
problems
> using string functions. Some LLVM programs produced are either
> aborting or giving incorrect results; however, if I disassemble the
> LLVM bytecode and recompile with GCC, everything works fine.
>
> I encountered the following error when running lli with
> '-force-interpreter' option:
> "Tried to execute an unknown external function: sbyte * (sbyte
> *, sbyte *, uint) * strncpy"
This is one of the "features" of the interpreter: it only supports
external functions that it "knows" about. Why not use the JIT,
without
-force-interpreter? Are you on a machine that we don't support? If so,
you can either add support for strncpy (to
lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp) or use the C
backend.
-Chris
> Strncpy is used as part of my compiler's run-time library, and it was
> compiled with the C-frontend for LLVM. Looking at the assembly, the
> function is declared at the top of the file;
>
> declare sbyte* %strncpy(sbyte*,sbyte*,uint) ;; __builtin_strncpy
>
> And it is called like this:
> %tmp.12 = call sbyte* (sbyte*, sbyte*, uint)* %strncpy(sbyte*
> %tmp.15, sbyte* %tmp.23, uint %tmp.27)
>
> What am I forgetting to do? What is the right way to link to the
> string functions? Thanks,
>
> -Eric Zimmerman
>
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>
-Chris
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