[PATCH] D131631: [MSAN] Separate id ptr from constant string for variable names used in track origins.

[Kevin Athey via Phabricator via llvm-commits]

kda added inline comments.


================
Comment at: llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp:239
        cl::Hidden, cl::init(0xff));
 
 static cl::opt<bool> ClPoisonUndef("msan-poison-undef",
----------------
vitalybuka wrote:
> ```
> static cl::opt<bool> ClPrintStacklNames("msan-print-stack-names",
>        cl::desc("Print name of local stack variable"),
>        cl::Hidden, cl::init(true));
> ```
What is this meant to do?


================
Comment at: llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp:3904
+      Value *Descr = getLocalVarDescription(I);
       IRB.CreateCall(MS.MsanSetAllocaOriginFn,
                      {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len,
----------------
vitalybuka wrote:
> ```
> if (ClPrintLocalVNames) {
>   IRB.CreateCall(MS.MsanSetAllocaOriginNameFn, ...
> } else {
>   IRB.CreateCall(MS.MsanSetAllocaOriginFn, ...
> }
> ```
What is the goal here?
Is this to allow the variable names to be dropped from the binary to save even more size?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D131631/new/

https://reviews.llvm.org/D131631