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Don't construct two CFGs just to run -Wuninitialized. While this causes new warnings to be flagged under -Wconditional-uninitialized, this is something we 

can improve over time.

llvm-svn: 127802
This commit is contained in:
Ted Kremenek 2011-03-17 05:29:57 +00:00
parent b4d763b37d
commit 2551fbe928
2 changed files with 24 additions and 18 deletions
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19
clang/lib/Sema/AnalysisBasedWarnings.cpp
View File

@ -611,24 +611,7 @@ AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P,
!= Diagnostic::Ignored ||
Diags.getDiagnosticLevel(diag::warn_maybe_uninit_var, D->getLocStart())
!= Diagnostic::Ignored) {
ASTContext &ctx = D->getASTContext();
llvm::OwningPtr<CFG> tmpCFG;
bool useAlternateCFG = false;
if (ctx.getLangOptions().CPlusPlus) {
// Temporary workaround: implicit dtors in the CFG can confuse
// the path-sensitivity in the uninitialized values analysis.
// For now create (if necessary) a separate CFG without implicit dtors.
// FIXME: We should not need to do this, as it results in multiple
// CFGs getting constructed.
CFG::BuildOptions B;
B.AddEHEdges = false;
B.AddImplicitDtors = false;
B.AddInitializers = true;
tmpCFG.reset(CFG::buildCFG(D, AC.getBody(), &ctx, B));
useAlternateCFG = true;
}
CFG *cfg = useAlternateCFG ? tmpCFG.get() : AC.getCFG();
if (cfg) {
if (CFG *cfg = AC.getCFG()) {
UninitValsDiagReporter reporter(S);
runUninitializedVariablesAnalysis(*cast<DeclContext>(D), *cfg, AC,
reporter);

23
clang/test/SemaCXX/uninit-variables-conditional.cpp Normal file
View File

@ -0,0 +1,23 @@
// RUN: %clang_cc1 -fsyntax-only -Wconditional-uninitialized -fsyntax-only %s -verify
class Foo {
public:
Foo();
~Foo();
operator bool();
};
int bar();
int baz();
int init(double *);
// This case flags a false positive under -Wconditional-uninitialized because
// the destructor in Foo fouls about the minor bit of path-sensitivity in
// -Wuninitialized.
double test() {
double x; // expected-note {{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
if (bar() || baz() || Foo() || init(&x)) {
return x; // expected-warning {{variable 'x' is possibly uninitialized when used here}}
}
return 1.0;
}