Author: dergachev
Date: Mon Jun 4 13:18:37 2018
New Revision: 333946
URL: http://llvm.org/viewvc/llvm-project?rev=333946&view=rev
Log:
[analyzer] Re-enable constructors when lifetime extension through fields occurs.
Temporary object constructor inlining was disabled in r326240 for code like
const int &x = A().x;
because automatic destructor for the lifetime-extended object A() was not
working correctly in CFG.
CFG was fixed in r333941, so inlining can be re-enabled. CFG for lifetime
extension through aggregates still needs to be fixed.
Differential Revision: https://reviews.llvm.org/D44239
Modified:
cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp
cfe/trunk/test/Analysis/lifetime-extension.cpp
Modified: cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h?rev=333946&r1=333945&r2=333946&view=diff
==============================================================================
--- cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
(original)
+++ cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h Mon
Jun 4 13:18:37 2018
@@ -106,11 +106,6 @@ public:
bool IsTemporaryCtorOrDtor = false;
/// This call is a constructor for a temporary that is lifetime-extended
- /// by binding a smaller object within it to a reference, for example
- /// 'const int &x = C().x;'.
- bool IsTemporaryLifetimeExtendedViaSubobject = false;
-
- /// This call is a constructor for a temporary that is lifetime-extended
/// by binding it to a reference-type field within an aggregate,
/// for example 'A { const C &c; }; A a = { C() };'
bool IsTemporaryLifetimeExtendedViaAggregate = false;
Modified: cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp?rev=333946&r1=333945&r2=333946&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp Mon Jun 4 13:18:37 2018
@@ -181,22 +181,13 @@ SVal ExprEngine::getLocationForConstruct
const auto *TOCC = cast<TemporaryObjectConstructionContext>(CC);
if (const auto *MTE = TOCC->getMaterializedTemporaryExpr()) {
if (const ValueDecl *VD = MTE->getExtendingDecl()) {
- // Pattern-match various forms of lifetime extension that aren't
- // currently supported by the CFG.
- // FIXME: Is there a better way to retrieve this information from
- // the MaterializeTemporaryExpr?
assert(MTE->getStorageDuration() != SD_FullExpression);
- if (VD->getType()->isReferenceType()) {
- assert(VD->getType()->isReferenceType());
- if (VD->getType()->getPointeeType().getCanonicalType() !=
- MTE->GetTemporaryExpr()->getType().getCanonicalType()) {
- // We're lifetime-extended via our field. Automatic destructors
- // aren't quite working in this case.
- CallOpts.IsTemporaryLifetimeExtendedViaSubobject = true;
- }
- } else {
+ if (!VD->getType()->isReferenceType()) {
// We're lifetime-extended by a surrounding aggregate.
- // Automatic destructors aren't quite working in this case.
+ // Automatic destructors aren't quite working in this case
+ // on the CFG side. We should warn the caller about that.
+ // FIXME: Is there a better way to retrieve this information from
+ // the MaterializeTemporaryExpr?
CallOpts.IsTemporaryLifetimeExtendedViaAggregate = true;
}
}
Modified: cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp?rev=333946&r1=333945&r2=333946&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp Mon Jun 4
13:18:37 2018
@@ -696,12 +696,7 @@ ExprEngine::mayInlineCallKind(const Call
if (CallOpts.IsCtorOrDtorWithImproperlyModeledTargetRegion)
return CIP_DisallowedOnce;
- // If the temporary is lifetime-extended by binding a smaller object
- // within it to a reference, automatic destructors don't work properly.
- if (CallOpts.IsTemporaryLifetimeExtendedViaSubobject)
- return CIP_DisallowedOnce;
-
- // If the temporary is lifetime-extended by binding it to a reference-typ
+ // If the temporary is lifetime-extended by binding it to a
reference-type
// field within an aggregate, automatic destructors don't work properly.
if (CallOpts.IsTemporaryLifetimeExtendedViaAggregate)
return CIP_DisallowedOnce;
Modified: cfe/trunk/test/Analysis/lifetime-extension.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/lifetime-extension.cpp?rev=333946&r1=333945&r2=333946&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/lifetime-extension.cpp (original)
+++ cfe/trunk/test/Analysis/lifetime-extension.cpp Mon Jun 4 13:18:37 2018
@@ -46,10 +46,18 @@ void f() {
const int &y = A().j[1]; // no-crash
const int &z = (A().j[1], A().j[0]); // no-crash
- // FIXME: All of these should be TRUE, but constructors aren't inlined.
- clang_analyzer_eval(x == 1); // expected-warning{{UNKNOWN}}
- clang_analyzer_eval(y == 3); // expected-warning{{UNKNOWN}}
- clang_analyzer_eval(z == 2); // expected-warning{{UNKNOWN}}
+ clang_analyzer_eval(x == 1);
+ clang_analyzer_eval(y == 3);
+ clang_analyzer_eval(z == 2);
+#ifdef TEMPORARIES
+ // expected-warning@-4{{TRUE}}
+ // expected-warning@-4{{TRUE}}
+ // expected-warning@-4{{TRUE}}
+#else
+ // expected-warning@-8{{UNKNOWN}}
+ // expected-warning@-8{{UNKNOWN}}
+ // expected-warning@-8{{UNKNOWN}}
+#endif
}
} // end namespace pr19539_crash_on_destroying_an_integer
@@ -144,8 +152,12 @@ void f5() {
{
const bool &x = C(true, &after, &before).x; // no-crash
}
- // FIXME: Should be TRUE. Should not warn about garbage value.
- clang_analyzer_eval(after == before); // expected-warning{{UNKNOWN}}
+ clang_analyzer_eval(after == before);
+#ifdef TEMPORARIES
+ // expected-warning@-2{{TRUE}}
+#else
+ // expected-warning@-4{{UNKNOWN}}
+#endif
}
struct A { // A is an aggregate.
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