commit ad4a5130277776d8f15f40ac5a6dede6ad3aabfb
Author: Timm B├Ąder <tbaeder@redhat.com>
Date: Tue Aug 8 14:11:33 2023 +0200
[clang][CFG] Cleanup functions
Add declarations declared with attribute(cleanup(...)) to the CFG,
similar to destructors.
Differential Revision: https://reviews.llvm.org/D157385
diff --git a/clang/include/clang/Analysis/CFG.h b/clang/include/clang/Analysis/CFG.h
index cf4fa2da2a35..67383bb316d3 100644
--- a/clang/include/clang/Analysis/CFG.h
+++ b/clang/include/clang/Analysis/CFG.h
@@ -14,10 +14,11 @@
#ifndef LLVM_CLANG_ANALYSIS_CFG_H
#define LLVM_CLANG_ANALYSIS_CFG_H
-#include "clang/Analysis/Support/BumpVector.h"
-#include "clang/Analysis/ConstructionContext.h"
+#include "clang/AST/Attr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
+#include "clang/Analysis/ConstructionContext.h"
+#include "clang/Analysis/Support/BumpVector.h"
#include "clang/Basic/LLVM.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/GraphTraits.h"
@@ -74,7 +75,8 @@ public:
MemberDtor,
TemporaryDtor,
DTOR_BEGIN = AutomaticObjectDtor,
- DTOR_END = TemporaryDtor
+ DTOR_END = TemporaryDtor,
+ CleanupFunction,
};
protected:
@@ -383,6 +385,32 @@ private:
}
};
+class CFGCleanupFunction final : public CFGElement {
+public:
+ CFGCleanupFunction() = default;
+ CFGCleanupFunction(const VarDecl *VD)
+ : CFGElement(Kind::CleanupFunction, VD) {
+ assert(VD->hasAttr<CleanupAttr>());
+ }
+
+ const VarDecl *getVarDecl() const {
+ return static_cast<VarDecl *>(Data1.getPointer());
+ }
+
+ /// Returns the function to be called when cleaning up the var decl.
+ const FunctionDecl *getFunctionDecl() const {
+ const CleanupAttr *A = getVarDecl()->getAttr<CleanupAttr>();
+ return A->getFunctionDecl();
+ }
+
+private:
+ friend class CFGElement;
+
+ static bool isKind(const CFGElement E) {
+ return E.getKind() == Kind::CleanupFunction;
+ }
+};
+
/// Represents C++ object destructor implicitly generated for automatic object
/// or temporary bound to const reference at the point of leaving its local
/// scope.
@@ -1142,6 +1170,10 @@ public:
Elements.push_back(CFGAutomaticObjDtor(VD, S), C);
}
+ void appendCleanupFunction(const VarDecl *VD, BumpVectorContext &C) {
+ Elements.push_back(CFGCleanupFunction(VD), C);
+ }
+
void appendLifetimeEnds(VarDecl *VD, Stmt *S, BumpVectorContext &C) {
Elements.push_back(CFGLifetimeEnds(VD, S), C);
}
diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
index b82f9010a83f..03ab4c6fdf29 100644
--- a/clang/lib/Analysis/CFG.cpp
+++ b/clang/lib/Analysis/CFG.cpp
@@ -881,6 +881,10 @@ private:
B->appendAutomaticObjDtor(VD, S, cfg->getBumpVectorContext());
}
+ void appendCleanupFunction(CFGBlock *B, VarDecl *VD) {
+ B->appendCleanupFunction(VD, cfg->getBumpVectorContext());
+ }
+
void appendLifetimeEnds(CFGBlock *B, VarDecl *VD, Stmt *S) {
B->appendLifetimeEnds(VD, S, cfg->getBumpVectorContext());
}
@@ -1346,7 +1350,8 @@ private:
return {};
}
- bool hasTrivialDestructor(VarDecl *VD);
+ bool hasTrivialDestructor(const VarDecl *VD) const;
+ bool needsAutomaticDestruction(const VarDecl *VD) const;
};
} // namespace
@@ -1861,14 +1866,14 @@ void CFGBuilder::addAutomaticObjDestruction(LocalScope::const_iterator B,
if (B == E)
return;
- SmallVector<VarDecl *, 10> DeclsNonTrivial;
- DeclsNonTrivial.reserve(B.distance(E));
+ SmallVector<VarDecl *, 10> DeclsNeedDestruction;
+ DeclsNeedDestruction.reserve(B.distance(E));
for (VarDecl* D : llvm::make_range(B, E))
- if (!hasTrivialDestructor(D))
- DeclsNonTrivial.push_back(D);
+ if (needsAutomaticDestruction(D))
+ DeclsNeedDestruction.push_back(D);
- for (VarDecl *VD : llvm::reverse(DeclsNonTrivial)) {
+ for (VarDecl *VD : llvm::reverse(DeclsNeedDestruction)) {
if (BuildOpts.AddImplicitDtors) {
// If this destructor is marked as a no-return destructor, we need to
// create a new block for the destructor which does not have as a
@@ -1879,7 +1884,8 @@ void CFGBuilder::addAutomaticObjDestruction(LocalScope::const_iterator B,
Ty = getReferenceInitTemporaryType(VD->getInit());
Ty = Context->getBaseElementType(Ty);
- if (Ty->getAsCXXRecordDecl()->isAnyDestructorNoReturn())
+ const CXXRecordDecl *CRD = Ty->getAsCXXRecordDecl();
+ if (CRD && CRD->isAnyDestructorNoReturn())
Block = createNoReturnBlock();
}
@@ -1890,8 +1896,10 @@ void CFGBuilder::addAutomaticObjDestruction(LocalScope::const_iterator B,
// objects, we end lifetime with scope end.
if (BuildOpts.AddLifetime)
appendLifetimeEnds(Block, VD, S);
- if (BuildOpts.AddImplicitDtors)
+ if (BuildOpts.AddImplicitDtors && !hasTrivialDestructor(VD))
appendAutomaticObjDtor(Block, VD, S);
+ if (VD->hasAttr<CleanupAttr>())
+ appendCleanupFunction(Block, VD);
}
}
@@ -1922,7 +1930,7 @@ void CFGBuilder::addScopeExitHandling(LocalScope::const_iterator B,
// is destroyed, for automatic variables, this happens when the end of the
// scope is added.
for (VarDecl* D : llvm::make_range(B, E))
- if (hasTrivialDestructor(D))
+ if (!needsAutomaticDestruction(D))
DeclsTrivial.push_back(D);
if (DeclsTrivial.empty())
@@ -2095,7 +2103,11 @@ LocalScope* CFGBuilder::addLocalScopeForDeclStmt(DeclStmt *DS,
return Scope;
}
-bool CFGBuilder::hasTrivialDestructor(VarDecl *VD) {
+bool CFGBuilder::needsAutomaticDestruction(const VarDecl *VD) const {
+ return !hasTrivialDestructor(VD) || VD->hasAttr<CleanupAttr>();
+}
+
+bool CFGBuilder::hasTrivialDestructor(const VarDecl *VD) const {
// Check for const references bound to temporary. Set type to pointee.
QualType QT = VD->getType();
if (QT->isReferenceType()) {
@@ -2149,7 +2161,7 @@ LocalScope* CFGBuilder::addLocalScopeForVarDecl(VarDecl *VD,
return Scope;
if (!BuildOpts.AddLifetime && !BuildOpts.AddScopes &&
- hasTrivialDestructor(VD)) {
+ !needsAutomaticDestruction(VD)) {
assert(BuildOpts.AddImplicitDtors);
return Scope;
}
@@ -5287,6 +5299,7 @@ CFGImplicitDtor::getDestructorDecl(ASTContext &astContext) const {
case CFGElement::CXXRecordTypedCall:
case CFGElement::ScopeBegin:
case CFGElement::ScopeEnd:
+ case CFGElement::CleanupFunction:
llvm_unreachable("getDestructorDecl should only be used with "
"ImplicitDtors");
case CFGElement::AutomaticObjectDtor: {
@@ -5830,6 +5843,11 @@ static void print_elem(raw_ostream &OS, StmtPrinterHelper &Helper,
break;
}
+ case CFGElement::Kind::CleanupFunction:
+ OS << "CleanupFunction ("
+ << E.castAs<CFGCleanupFunction>().getFunctionDecl()->getName() << ")\n";
+ break;
+
case CFGElement::Kind::LifetimeEnds:
Helper.handleDecl(E.castAs<CFGLifetimeEnds>().getVarDecl(), OS);
OS << " (Lifetime ends)\n";
diff --git a/clang/lib/Analysis/PathDiagnostic.cpp b/clang/lib/Analysis/PathDiagnostic.cpp
index 348afc42319e..0cb03943c547 100644
--- a/clang/lib/Analysis/PathDiagnostic.cpp
+++ b/clang/lib/Analysis/PathDiagnostic.cpp
@@ -567,6 +567,7 @@ getLocationForCaller(const StackFrameContext *SFC,
}
case CFGElement::ScopeBegin:
case CFGElement::ScopeEnd:
+ case CFGElement::CleanupFunction:
llvm_unreachable("not yet implemented!");
case CFGElement::LifetimeEnds:
case CFGElement::LoopExit:
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index 0e2ac78f7089..d7c5bd1d4042 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -993,6 +993,7 @@ void ExprEngine::processCFGElement(const CFGElement E, ExplodedNode *Pred,
ProcessLoopExit(E.castAs<CFGLoopExit>().getLoopStmt(), Pred);
return;
case CFGElement::LifetimeEnds:
+ case CFGElement::CleanupFunction:
case CFGElement::ScopeBegin:
case CFGElement::ScopeEnd:
return;
diff --git a/clang/test/Analysis/scopes-cfg-output.cpp b/clang/test/Analysis/scopes-cfg-output.cpp
index 6877d124e67a..4eb8967e3735 100644
--- a/clang/test/Analysis/scopes-cfg-output.cpp
+++ b/clang/test/Analysis/scopes-cfg-output.cpp
@@ -1419,3 +1419,68 @@ label:
}
}
}
+
+// CHECK: [B1]
+// CHECK-NEXT: 1: CFGScopeBegin(i)
+// CHECK-NEXT: 2: int i __attribute__((cleanup(cleanup_int)));
+// CHECK-NEXT: 3: CleanupFunction (cleanup_int)
+// CHECK-NEXT: 4: CFGScopeEnd(i)
+void cleanup_int(int *i);
+void test_cleanup_functions() {
+ int i __attribute__((cleanup(cleanup_int)));
+}
+
+// CHECK: [B1]
+// CHECK-NEXT: 1: 10
+// CHECK-NEXT: 2: i
+// CHECK-NEXT: 3: [B1.2] = [B1.1]
+// CHECK-NEXT: 4: return;
+// CHECK-NEXT: 5: CleanupFunction (cleanup_int)
+// CHECK-NEXT: 6: CFGScopeEnd(i)
+// CHECK-NEXT: Preds (1): B3
+// CHECK-NEXT: Succs (1): B0
+// CHECK: [B2]
+// CHECK-NEXT: 1: return;
+// CHECK-NEXT: 2: CleanupFunction (cleanup_int)
+// CHECK-NEXT: 3: CFGScopeEnd(i)
+// CHECK-NEXT: Preds (1): B3
+// CHECK-NEXT: Succs (1): B0
+// CHECK: [B3]
+// CHECK-NEXT: 1: CFGScopeBegin(i)
+// CHECK-NEXT: 2: int i __attribute__((cleanup(cleanup_int)));
+// CHECK-NEXT: 3: m
+// CHECK-NEXT: 4: [B3.3] (ImplicitCastExpr, LValueToRValue, int)
+// CHECK-NEXT: 5: 1
+// CHECK-NEXT: 6: [B3.4] == [B3.5]
+// CHECK-NEXT: T: if [B3.6]
+// CHECK-NEXT: Preds (1): B4
+// CHECK-NEXT: Succs (2): B2 B1
+void test_cleanup_functions2(int m) {
+ int i __attribute__((cleanup(cleanup_int)));
+
+ if (m == 1) {
+ return;
+ }
+
+ i = 10;
+ return;
+}
+
+// CHECK: [B1]
+// CHECK-NEXT: 1: CFGScopeBegin(f)
+// CHECK-NEXT: 2: (CXXConstructExpr, [B1.3], F)
+// CHECK-NEXT: 3: F f __attribute__((cleanup(cleanup_F)));
+// CHECK-NEXT: 4: CleanupFunction (cleanup_F)
+// CHECK-NEXT: 5: [B1.3].~F() (Implicit destructor)
+// CHECK-NEXT: 6: CFGScopeEnd(f)
+// CHECK-NEXT: Preds (1): B2
+// CHECK-NEXT: Succs (1): B0
+class F {
+public:
+ ~F();
+};
+void cleanup_F(F *f);
+
+void test() {
+ F f __attribute((cleanup(cleanup_F)));
+}