[clang] 2d1b55e - [CodeGen] Make element type in emitArrayDestroy() predictable

[Nikita Popov via cfe-commits]

Author: Nikita Popov
Date: 2022-01-11T09:25:29+01:00
New Revision: 2d1b55ebea88547d153fcd980b88c946cffc5ca5

URL: https://github.com/llvm/llvm-project/commit/2d1b55ebea88547d153fcd980b88c946cffc5ca5
DIFF: https://github.com/llvm/llvm-project/commit/2d1b55ebea88547d153fcd980b88c946cffc5ca5.diff

LOG: [CodeGen] Make element type in emitArrayDestroy() predictable

When calling emitArrayDestroy(), the pointer will usually have
ConvertTypeForMem(EltType) as the element type, as one would expect.
However, globals with initializers sometimes don't use the same
types as values normally would, e.g. here the global uses
{ double, i32 } rather than %struct.T as element type.

Add an early cast to the global destruction path to avoid this
special case. The cast would happen lateron anyway, it only gets
moved to an earlier point.

Differential Revision: https://reviews.llvm.org/D116219

Added: 
    

Modified: 
    clang/lib/CodeGen/CGDecl.cpp
    clang/lib/CodeGen/CGDeclCXX.cpp
    clang/test/CodeGenCXX/global-array-destruction.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 36185faf942f9..18d6584360866 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -2252,16 +2252,17 @@ void CodeGenFunction::emitArrayDestroy(llvm::Value *begin,
 
   // Shift the address back by one element.
   llvm::Value *negativeOne = llvm::ConstantInt::get(SizeTy, -1, true);
+  llvm::Type *llvmElementType = ConvertTypeForMem(elementType);
   llvm::Value *element = Builder.CreateInBoundsGEP(
-      elementPast->getType()->getPointerElementType(), elementPast, negativeOne,
-      "arraydestroy.element");
+      llvmElementType, elementPast, negativeOne, "arraydestroy.element");
 
   if (useEHCleanup)
     pushRegularPartialArrayCleanup(begin, element, elementType, elementAlign,
                                    destroyer);
 
   // Perform the actual destruction there.
-  destroyer(*this, Address(element, elementAlign), elementType);
+  destroyer(*this, Address(element, llvmElementType, elementAlign),
+            elementType);
 
   if (useEHCleanup)
     PopCleanupBlock();

diff  --git a/clang/lib/CodeGen/CGDeclCXX.cpp b/clang/lib/CodeGen/CGDeclCXX.cpp
index 3579761f14293..7b880c1354e19 100644
--- a/clang/lib/CodeGen/CGDeclCXX.cpp
+++ b/clang/lib/CodeGen/CGDeclCXX.cpp
@@ -136,6 +136,7 @@ static void EmitDeclDestroy(CodeGenFunction &CGF, const VarDecl &D,
     }
   // Otherwise, the standard logic requires a helper function.
   } else {
+    Addr = Addr.getElementBitCast(CGF.ConvertTypeForMem(Type));
     Func = CodeGenFunction(CGM)
            .generateDestroyHelper(Addr, Type, CGF.getDestroyer(DtorKind),
                                   CGF.needsEHCleanup(DtorKind), &D);

diff  --git a/clang/test/CodeGenCXX/global-array-destruction.cpp b/clang/test/CodeGenCXX/global-array-destruction.cpp
index 0f280e0001127..686c8a6c580ad 100644
--- a/clang/test/CodeGenCXX/global-array-destruction.cpp
+++ b/clang/test/CodeGenCXX/global-array-destruction.cpp
@@ -39,7 +39,7 @@ struct T {
 T t[2][3] = { 1.0, 2, 3.0, 4, 5.0, 6, 7.0, 8, 9.0, 10, 11.0, 12 };
 
 // CHECK: call {{.*}} @__cxa_atexit
-// CHECK: getelementptr inbounds ([2 x [3 x {{.*}}]], [2 x [3 x {{.*}}]]* @t, i64 1, i64 0, i64 0)
+// CHECK: getelementptr inbounds ([2 x [3 x %struct.T]], [2 x [3 x %struct.T]]* bitcast ([2 x [3 x { double, i32 }]]* @t to [2 x [3 x %struct.T]]*), i64 1, i64 0, i64 0)
 // CHECK: call void @_ZN1TD1Ev
 // CHECK: icmp eq {{.*}} @t
 // CHECK: br i1 {{.*}}
@@ -47,7 +47,7 @@ T t[2][3] = { 1.0, 2, 3.0, 4, 5.0, 6, 7.0, 8, 9.0, 10, 11.0, 12 };
 static T t2[2][3] = { 1.0, 2, 3.0, 4, 5.0, 6, 7.0, 8, 9.0, 10, 11.0, 12 };
 
 // CHECK: call {{.*}} @__cxa_atexit
-// CHECK: getelementptr inbounds ([2 x [3 x {{.*}}]], [2 x [3 x {{.*}}]]* @_ZL2t2, i64 1, i64 0, i64 0)
+// CHECK: getelementptr inbounds ([2 x [3 x %struct.T]], [2 x [3 x %struct.T]]* bitcast ([2 x [3 x { double, i32 }]]* @_ZL2t2 to [2 x [3 x %struct.T]]*), i64 1, i64 0, i64 0)
 // CHECK: call void @_ZN1TD1Ev
 // CHECK: icmp eq {{.*}} @_ZL2t2
 // CHECK: br i1 {{.*}}
@@ -56,7 +56,7 @@ using U = T[2][3];
 U &&u = U{ {{1.0, 2}, {3.0, 4}, {5.0, 6}}, {{7.0, 8}, {9.0, 10}, {11.0, 12}} };
 
 // CHECK: call {{.*}} @__cxa_atexit
-// CHECK: getelementptr inbounds ([2 x [3 x {{.*}}]], [2 x [3 x {{.*}}]]* @_ZGR1u_, i64 1, i64 0, i64 0)
+// CHECK: getelementptr inbounds ([2 x [3 x %struct.T]], [2 x [3 x %struct.T]]* @_ZGR1u_, i64 1, i64 0, i64 0)
 // CHECK: call void @_ZN1TD1Ev
 // CHECK: icmp eq {{.*}} @_ZGR1u_
 // CHECK: br i1 {{.*}}