[PATCH] D48204: [analyzer] Make getDerefExpr() skip cleanups.

[Artem Dergachev via Phabricator via cfe-commits]

NoQ created this revision.
NoQ added reviewers: dcoughlin, xazax.hun, a.sidorin, george.karpenkov, szepet, rnkovacs.
Herald added subscribers: cfe-commits, mikhail.ramalho, baloghadamsoftware, eraman.

`ExprWithCleanups` that cleans up function arguments (or any other stuff) at the end of the full-expression may break AST pattern-matching for figuring out that a null pointer was produced by the inlined function during `trackNullOrUndefValue()`. Because this expression doesn't do anything, skip it during `getDerefExpr()`.


Repository:
  rC Clang

https://reviews.llvm.org/D48204

Files:
  lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
  test/Analysis/inlining/inline-defensive-checks.cpp


Index: test/Analysis/inlining/inline-defensive-checks.cpp
===================================================================
--- test/Analysis/inlining/inline-defensive-checks.cpp
+++ test/Analysis/inlining/inline-defensive-checks.cpp
@@ -84,3 +84,18 @@
   int &x = b->x; // no-warning
   x = 5;
 }
+
+namespace get_deref_expr_with_cleanups {
+struct S {
+~S();
+};
+S *conjure();
+S *get_conjured(S _) {
+  S *s = conjure();
+  if (s) {}
+  return s;
+}
+void test_conjured() {
+  S &s = *get_conjured(S()); // no-warning
+}
+} // namespace get_deref_expr_with_cleanups
Index: lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
===================================================================
--- lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
+++ lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
@@ -140,6 +140,8 @@
       E = AE->getBase();
     } else if (const auto *PE = dyn_cast<ParenExpr>(E)) {
       E = PE->getSubExpr();
+    } else if (const auto *EWC = dyn_cast<ExprWithCleanups>(E)) {
+      E = EWC->getSubExpr();
     } else {
       // Other arbitrary stuff.
       break;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D48204.151450.patch
Type: text/x-patch
Size: 1091 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20180615/1232612f/attachment.bin>