Linking strncpy

Hi,

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"

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

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