[compiler-rt] [llvm] [msan] Automatically print shadow for failing outlined checks (PR #145107)

[Vitaly Buka via llvm-commits]

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@@ -1432,18 +1434,38 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     const DataLayout &DL = F.getDataLayout();
     TypeSize TypeSizeInBits = DL.getTypeSizeInBits(ConvertedShadow->getType());
     unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
-    if (instrumentWithCalls(ConvertedShadow) &&
-        SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) {
-      FunctionCallee Fn = MS.MaybeWarningFn[SizeIndex];
+    if (instrumentWithCalls(ConvertedShadow) && !MS.CompileKernel) {
       // ZExt cannot convert between vector and scalar
       ConvertedShadow = convertShadowToScalar(ConvertedShadow, IRB);
       Value *ConvertedShadow2 =
           IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
-      CallBase *CB = IRB.CreateCall(
-          Fn, {ConvertedShadow2,
-               MS.TrackOrigins && Origin ? Origin : (Value *)IRB.getInt32(0)});
-      CB->addParamAttr(0, Attribute::ZExt);
-      CB->addParamAttr(1, Attribute::ZExt);
+
+      if (SizeIndex < kNumberOfAccessSizes) {
+        FunctionCallee Fn = MS.MaybeWarningFn[SizeIndex];
+        CallBase *CB = IRB.CreateCall(
+            Fn,
+            {ConvertedShadow2,
+             MS.TrackOrigins && Origin ? Origin : (Value *)IRB.getInt32(0)});
+        CB->addParamAttr(0, Attribute::ZExt);
+        CB->addParamAttr(1, Attribute::ZExt);
+      } else {
+        FunctionCallee Fn = MS.MaybeWarningVarSizeFn;
+
+        // Note: we can only dump the current shadow value, not an entire
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vitalybuka wrote:

this file should be a separate PR with LLVM IR test, and not mention of "dump"

https://github.com/llvm/llvm-project/pull/145107