[Clang][CFG] check children statements of asm goto

When performing CFG based analyses, don't forget to check the child
statements of an asm goto, such as the expressions used for
inputs+outputs.

Fixes: https://github.com/llvm/llvm-project/issues/51024
Fixes: https://github.com/ClangBuiltLinux/linux/issues/1439

Reviewed By: void, jyknight, jyu2, efriedma

Differential Revision: https://reviews.llvm.org/D116059

1 files changed, 4 insertions, 5 deletions

diff --git a/clang/lib/Analysis/UninitializedValues.cpp b/clang/lib/Analysis/UninitializedValues.cpp
index a38ae34..811146e 100644
--- a/clang/lib/Analysis/UninitializedValues.cpp
+++ b/clang/lib/Analysis/UninitializedValues.cpp
@@ -819,12 +819,11 @@ void TransferFunctions::VisitGCCAsmStmt(GCCAsmStmt *as) {
     while (const auto *UO = dyn_cast<UnaryOperator>(Ex))
       Ex = stripCasts(C, UO->getSubExpr());
 
+    // Mark the variable as potentially uninitialized for those cases where
+    // it's used on an indirect path, where it's not guaranteed to be
+    // defined.
     if (const VarDecl *VD = findVar(Ex).getDecl())
-      if (vals[VD] != Initialized)
-        // If the variable isn't initialized by the time we get here, then we
-        // mark it as potentially uninitialized for those cases where it's used
-        // on an indirect path, where it's not guaranteed to be defined.
-        vals[VD] = MayUninitialized;
+      vals[VD] = MayUninitialized;
   }
 }