[llvm] 0a22510 - [value-tracking] see through returned attribute.

[Florian Mayer via llvm-commits]

Author: Florian Mayer
Date: 2021-09-13T20:52:26+01:00
New Revision: 0a22510f3e649d5d84cc404690cfb374fab46238

URL: https://github.com/llvm/llvm-project/commit/0a22510f3e649d5d84cc404690cfb374fab46238
DIFF: https://github.com/llvm/llvm-project/commit/0a22510f3e649d5d84cc404690cfb374fab46238.diff

LOG: [value-tracking] see through returned attribute.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D109675

Added: 
    

Modified: 
    llvm/lib/Analysis/ValueTracking.cpp
    llvm/test/Instrumentation/HWAddressSanitizer/stack-safety-analysis.ll
    llvm/unittests/Analysis/ValueTrackingTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 53d7ddf075266..8d18d1332ea12 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -4533,6 +4533,12 @@ AllocaInst *llvm::findAllocaForValue(Value *V, bool OffsetZero) {
       if (OffsetZero && !GEP->hasAllZeroIndices())
         return nullptr;
       AddWork(GEP->getPointerOperand());
+    } else if (CallBase *CB = dyn_cast<CallBase>(V)) {
+      Value *Returned = CB->getReturnedArgOperand();
+      if (Returned)
+        AddWork(Returned);
+      else
+        return nullptr;
     } else {
       return nullptr;
     }

diff  --git a/llvm/test/Instrumentation/HWAddressSanitizer/stack-safety-analysis.ll b/llvm/test/Instrumentation/HWAddressSanitizer/stack-safety-analysis.ll
index b14445bde1f03..51d7cb56608df 100644
--- a/llvm/test/Instrumentation/HWAddressSanitizer/stack-safety-analysis.ll
+++ b/llvm/test/Instrumentation/HWAddressSanitizer/stack-safety-analysis.ll
@@ -164,8 +164,7 @@ entry:
   ; SAFETY: call {{.*}}__hwasan_generate_tag
   ; SAFETY-NOT: call {{.*}}__hwasan_store
   ; NOSTACK-NOT: call {{.*}}__hwasan_generate_tag
-  ; TODO: Do not emit this store.
-  ; NOSTACK: call {{.*}}__hwasan_store
+  ; NOSTACK-NOT: call {{.*}}__hwasan_store
   %buf.sroa.0 = alloca i8, align 4
   call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull %buf.sroa.0)
   %ptr = call i8* @retptr(i8* %buf.sroa.0)

diff  --git a/llvm/unittests/Analysis/ValueTrackingTest.cpp b/llvm/unittests/Analysis/ValueTrackingTest.cpp
index c07c76c0b3ced..4c4067ea920b8 100644
--- a/llvm/unittests/Analysis/ValueTrackingTest.cpp
+++ b/llvm/unittests/Analysis/ValueTrackingTest.cpp
@@ -2256,6 +2256,22 @@ const FindAllocaForValueTestParams FindAllocaForValueTests[] = {
         ret void
       })",
      false, false},
+    {R"(
+      declare i32* @retptr(i32* returned)
+      define void @test(i1 %cond) {
+        %a = alloca i32
+        %r = call i32* @retptr(i32* %a)
+        ret void
+      })",
+     true, true},
+    {R"(
+      declare i32* @fun(i32*)
+      define void @test(i1 %cond) {
+        %a = alloca i32
+        %r = call i32* @fun(i32* %a)
+        ret void
+      })",
+     false, false},
 };
 
 TEST_P(FindAllocaForValueTest, findAllocaForValue) {