From 92910f69a06e299beafb537ca08bc63e75a38612 Mon Sep 17 00:00:00 2001 From: Steven Wu Date: Thu, 10 Mar 2016 02:02:48 +0000 Subject: [PATCH] Fix false positives for for-loop-analysis warning Summary: For PseudoObjectExpr, the DeclMatcher need to search only all the semantics but also need to search pass OpaqueValueExpr for all potential uses for the Decl. Reviewers: thakis, rtrieu, rjmccall, doug.gregor Subscribers: xazax.hun, rjmccall, doug.gregor, cfe-commits Differential Revision: http://reviews.llvm.org/D17627 llvm-svn: 263087 --- clang/lib/Sema/SemaStmt.cpp | 12 ++++++++++++ clang/test/SemaObjC/warn-loop-analysis.m | 15 +++++++++++++++ 2 files changed, 27 insertions(+) create mode 100644 clang/test/SemaObjC/warn-loop-analysis.m diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp index b73b4f0..1975fcb 100644 --- a/clang/lib/Sema/SemaStmt.cpp +++ b/clang/lib/Sema/SemaStmt.cpp @@ -1440,6 +1440,18 @@ namespace { FoundDecl = true; } + void VisitPseudoObjectExpr(PseudoObjectExpr *POE) { + // Only need to visit the semantics for POE. + // SyntaticForm doesn't really use the Decal. + for (auto *S : POE->semantics()) { + if (auto *OVE = dyn_cast(S)) + // Look past the OVE into the expression it binds. + Visit(OVE->getSourceExpr()); + else + Visit(S); + } + } + bool FoundDeclInUse() { return FoundDecl; } }; // end class DeclMatcher diff --git a/clang/test/SemaObjC/warn-loop-analysis.m b/clang/test/SemaObjC/warn-loop-analysis.m new file mode 100644 index 0000000..8ae7375 --- /dev/null +++ b/clang/test/SemaObjC/warn-loop-analysis.m @@ -0,0 +1,15 @@ +// RUN: %clang_cc1 -fsyntax-only -Wloop-analysis -verify %s +// expected-no-diagnostics + +@interface MyArray +- (id)objectAtIndexedSubscript:(unsigned int)idx; +@end + +// Do not warn on objc classes has objectAtIndexedSubscript method. +MyArray *test; +void foo() +{ + unsigned int i; + for (i = 42; i > 0;) // No warnings here + (void)test[--i]; +} -- 2.7.4