From f1b5d9ae6e34c8dc278e5f8da85f1840462ef76e Mon Sep 17 00:00:00 2001
From: Evgeniy Stepanov <eugeni.stepanov@gmail.com>
Date: Mon, 1 Dec 2014 09:53:51 +0000
Subject: [PATCH] [msan] Add compile-time checks for missing origins.

This change makes MemorySanitizer instrumentation a bit more strict
about instructions that have no origin id assigned to them.

This would have caught the bug that was fixed in r222918.

No functional change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222997 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../Instrumentation/MemorySanitizer.cpp       | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index 15a67d7c697..40e0e013257 100644
--- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -921,6 +921,8 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
             Value *OriginPtr =
                 getOriginPtrForArgument(&FArg, EntryIRB, ArgOffset);
             setOrigin(A, EntryIRB.CreateLoad(OriginPtr));
+          } else {
+            setOrigin(A, getCleanOrigin());
           }
         }
         ArgOffset += RoundUpToAlignment(Size, kShadowTLSAlignment);
@@ -940,15 +942,13 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
   /// \brief Get the origin for a value.
   Value *getOrigin(Value *V) {
     if (!MS.TrackOrigins) return nullptr;
-    if (isa<Instruction>(V) || isa<Argument>(V)) {
-      Value *Origin = OriginMap[V];
-      if (!Origin) {
-        DEBUG(dbgs() << "NO ORIGIN: " << *V << "\n");
-        Origin = getCleanOrigin();
-      }
-      return Origin;
-    }
-    return getCleanOrigin();
+    if (!PropagateShadow) return getCleanOrigin();
+    if (isa<Constant>(V)) return getCleanOrigin();
+    assert((isa<Instruction>(V) || isa<Argument>(V)) &&
+           "Unexpected value type in getOrigin()");
+    Value *Origin = OriginMap[V];
+    assert(Origin && "Missing origin");
+    return Origin;
   }
 
   /// \brief Get the origin for i-th argument of the instruction I.
@@ -1088,6 +1088,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     IRB.CreateStore(getCleanShadow(&I), ShadowPtr);
 
     setShadow(&I, getCleanShadow(&I));
+    setOrigin(&I, getCleanOrigin());
   }
 
   void visitAtomicRMWInst(AtomicRMWInst &I) {
-- 
2.40.0