[PATCH] D64678: [Sema] Fix -Wuninitialized for struct assignment from GNU C statement expression

[Nathan Huckleberry via Phabricator via cfe-commits]

Nathan-Huckleberry updated this revision to Diff 209905.
Nathan-Huckleberry marked 3 inline comments as done.
Nathan-Huckleberry added a comment.

- Change cast type


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D64678/new/

https://reviews.llvm.org/D64678

Files:
  clang/lib/Sema/SemaDecl.cpp
  clang/test/Sema/warn-uninitialized-statement-expression.c


Index: clang/test/Sema/warn-uninitialized-statement-expression.c
===================================================================
--- /dev/null
+++ clang/test/Sema/warn-uninitialized-statement-expression.c
@@ -0,0 +1,55 @@
+// RUN: %clang_cc1 -fsyntax-only -Wuninitialized -verify %s
+
+void init(int *);
+
+void foo(void) {
+  int i = ({
+    init(&i);
+    i;
+  });
+}
+
+void foo_bad(void) {
+  int i = ({
+    int z = i; // expected-warning{{variable 'i' is uninitialized when used within its own initialization}}
+    init(&i);
+    i;
+  });
+}
+
+struct widget {
+  int x, y;
+};
+void init2(struct widget *);
+
+void bar(void) {
+  struct widget my_widget = ({
+    init2(&my_widget);
+    my_widget;
+  });
+}
+
+void bar_bad(void) {
+  struct widget my_widget = ({
+    struct widget z = my_widget; // expected-warning{{variable 'my_widget' is uninitialized when used within its own initialization}}
+    int x = my_widget.x;         //FIXME: There should be an uninitialized warning here
+    init2(&my_widget);
+    my_widget;
+  });
+}
+
+void baz(void) {
+  struct widget a = ({
+    struct widget b = ({
+      b = a; // expected-warning{{variable 'a' is uninitialized when used within its own initialization}}
+    });
+    a;
+  });
+}
+
+void f(void) {
+  struct widget *a = ({
+    init2(a); // expected-warning{{variable 'a' is uninitialized when used within its own initialization}}
+    a;
+  });
+}
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -10886,6 +10886,11 @@
             if (DRE->getDecl() == OrigDecl)
               return;
 
+    if (cast<VarDecl>(OrigDecl)->getType()->isRecordType() &&
+        dyn_cast<StmtExpr>(E)) {
+      return;
+    }
+
     SelfReferenceChecker(S, OrigDecl).CheckExpr(E);
   }
 } // end anonymous namespace


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