replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

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

llvm-svn: 253107
This commit is contained in:
Matthias Gehre 2015-11-14 00:36:50 +00:00
parent 6d048942c5
commit 09a134eca3
2 changed files with 20 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
clang/lib/Analysis/CFG.cpp
View File

@ -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<ReturnStmt>(*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();

11
clang/test/Analysis/no-unreachable-dtors.cpp Normal file
View File

@ -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;
}