[PATCH] D159485: [DebugInfo][RemoveDIs] Use getStableDebugLoc when picking IRBuilder source locations

[Augie Fackler via Phabricator via llvm-commits]

durin42 added inline comments.


================
Comment at: llvm/include/llvm/IR/IRBuilder.h:200
     if (IP != TheBB->end())
-      SetCurrentDebugLocation(IP->getDebugLoc());
+      SetCurrentDebugLocation(IP->getStableDebugLoc());
   }
----------------
durin42 wrote:
> jmorse wrote:
> > durin42 wrote:
> > > The crash I'm seeing is on this line, I can give you the stack trace if you want to look in parallel with my investigation.
> > Rather than the stack, the contents of the block would be super-useful -- if you can attach an interactive debugger before the crash, then when the crash occurs, running:
> >     call IP->dump()
> >     call IP->getParent()->dump()
> > Will print all the relevant information to the terminal / output
> How does this as a follow-up look to you?
> 
> ```
> diff --git a/llvm/lib/IR/Instruction.cpp b/llvm/lib/IR/Instruction.cpp
> index 6b0348f8f691..37cce7729741 100644
> --- a/llvm/lib/IR/Instruction.cpp
> +++ b/llvm/lib/IR/Instruction.cpp
> @@ -886,8 +886,11 @@ Instruction::getPrevNonDebugInstruction(bool SkipPseudoOp) const {
>  }
> 
>  const DebugLoc &Instruction::getStableDebugLoc() const {
> -  if (isa<DbgInfoIntrinsic>(this))
> -    return getNextNonDebugInstruction()->getDebugLoc();
> +  if (isa<DbgInfoIntrinsic>(this)) {
> +    const Instruction* next = getNextNonDebugInstruction();
> +    if (next)
> +      return next->getDebugLoc();
> +  }
>    return getDebugLoc();
>  }
> ```
Finally got the dump (had to write it to a file in /tmp, sigh):

```
  call void @llvm.dbg.declare(metadata ptr %x, metadata !4697, metadata !DIExpression()), !dbg !4698

start:
  call void @llvm.dbg.declare(metadata ptr %x, metadata !562, metadata !DIExpression()), !dbg !563

```


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D159485/new/

https://reviews.llvm.org/D159485