[LLVMdev] "Function" file name

Mishne, Alon alon.mishne at intel.com
Thu Jan 30 04:19:23 PST 2014

This should work, but I think a more standard approach (though arguably slower) is to use DebugInfoFinder (from DebugInfo.h).

So create a DebugInfoFinder, process the module with it, and then iterate over all the subprograms to find the one matching your function. Roughly something like:

DebugInfoFinder Finder;
for (DebugInfoFinder::iterator Iter = Finder.subprogram_begin(),
    End = Finder.subprogram_end(); Iter != End; ++Iter) {
  const MDNode* node = *Iter;
  DISubprogram SP(node);
  if (SP.describes(F)) return SP.getFilename();

-----Original Message-----
From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Tim Northover
Sent: Thursday, January 30, 2014 10:07
To: nizam at cse.iitm.ac.in
Cc: LLVM Developers Mailing List
Subject: Re: [LLVMdev] "Function" file name

Hi Nizam,

> I am writing a simple pass that inherits from ModulePass. I override 
> the runOnModule method. In the method, i am attempting to print all 
> the function in the module and the source-file they appear in. I could 
> print the name of the function using the Module::iterator. I am, 
> however, not able to figure-out the way to identify the source-file for a given "Function".

That information is generally only present if the file was compiled with debug info ("clang -g"), and even then I believe it's only attached to the instructions in a function rather than the function itself. Inlining can complicate things further, so you need to pick the *right* instruction (some may come from a different file entirely).

Some grubbing around the class hierarchy suggests this procedure:
1. Find a "ret" instruction in the function (actually, a function can rarely exist with "unreachable" instead of "ret" so be careful).
2. Call Instruction::getDebugLoc on it
3. Call DebugLoc::getAsMDNode to convert it into an MDNode 4. Create a DILocation from that MDNode and query it for your info.

There may be a simpler way, but hopefully that will do the job.


LLVM Developers mailing list
LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
Intel Israel (74) Limited

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.

More information about the llvm-dev mailing list