From fd0b0894090f6b4f01f778346ab3e8af86d6aced Mon Sep 17 00:00:00 2001 From: Matthias Gehre Date: Sat, 14 Nov 2015 00:36:50 +0000 Subject: [PATCH] CFG: Delay creating Dtors for CompoundStmts which end in ReturnStmt Summary: VisitReturnStmt would create a new block with including Dtors, so the Dtors created in VisitCompoundStmts would be in an unreachable block. Example: struct S { ~S(); }; void f() { S s; return; } void g() { S s; } Before this patch, f has one additional unreachable block containing just the destructor of S. With this patch, both f and g have the same blocks. Reviewers: krememek Subscribers: cfe-commits Differential Revision: http://reviews.llvm.org/D13973 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@253107 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/CFG.cpp | 10 +++++++++- test/Analysis/no-unreachable-dtors.cpp | 11 +++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-) create mode 100644 test/Analysis/no-unreachable-dtors.cpp diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp index 6cb63f2b17..fba9a41f23 100644 --- a/lib/Analysis/CFG.cpp +++ b/lib/Analysis/CFG.cpp @@ -1942,7 +1942,15 @@ CFGBlock *CFGBuilder::VisitChooseExpr(ChooseExpr *C, CFGBlock *CFGBuilder::VisitCompoundStmt(CompoundStmt *C) { - addLocalScopeAndDtors(C); + LocalScope::const_iterator scopeBeginPos = ScopePos; + if (BuildOpts.AddImplicitDtors) { + addLocalScopeForStmt(C); + } + if (!C->body_empty() && !isa(*C->body_rbegin())) { + // If the body ends with a ReturnStmt, the dtors will be added in VisitReturnStmt + addAutomaticObjDtors(ScopePos, scopeBeginPos, C); + } + CFGBlock *LastBlock = Block; for (CompoundStmt::reverse_body_iterator I=C->body_rbegin(), E=C->body_rend(); diff --git a/test/Analysis/no-unreachable-dtors.cpp b/test/Analysis/no-unreachable-dtors.cpp new file mode 100644 index 0000000000..e0893b3f4e --- /dev/null +++ b/test/Analysis/no-unreachable-dtors.cpp @@ -0,0 +1,11 @@ +// RUN: %clang_cc1 -analyze -analyzer-checker=debug.Stats -verify -Wno-unreachable-code %s + +struct S { + ~S(); +}; + +// the return at the end of an CompoundStmt does not lead to an unreachable block containing the dtors +void test() { // expected-warning-re{{test -> Total CFGBlocks: {{[0-9]+}} | Unreachable CFGBlocks: 0 | Exhausted Block: no | Empty WorkList: yes}} + S s; + return; +} -- 2.40.0