clang/tsa.patch

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2023-12-06 13:00:51 +00:00
commit cf8e189a99f988398a48148b9ea7901948665ab0
Author: Timm Bäder <tbaeder@redhat.com>
Date: Wed Sep 6 12:19:20 2023 +0200
[clang][TSA] Thread safety cleanup functions
Consider cleanup functions in thread safety analysis.
Differential Revision: https://reviews.llvm.org/D152504
diff --git a/clang/include/clang/Analysis/Analyses/ThreadSafetyCommon.h b/clang/include/clang/Analysis/Analyses/ThreadSafetyCommon.h
index 9d28325c1ea6..13e37ac2b56b 100644
--- a/clang/include/clang/Analysis/Analyses/ThreadSafetyCommon.h
+++ b/clang/include/clang/Analysis/Analyses/ThreadSafetyCommon.h
@@ -361,7 +361,7 @@ public:
unsigned NumArgs = 0;
// Function arguments
- const Expr *const *FunArgs = nullptr;
+ llvm::PointerUnion<const Expr *const *, til::SExpr *> FunArgs = nullptr;
// is Self referred to with -> or .?
bool SelfArrow = false;
diff --git a/clang/lib/Analysis/ThreadSafety.cpp b/clang/lib/Analysis/ThreadSafety.cpp
index 3107d035254d..3e6ceb7d54c4 100644
--- a/clang/lib/Analysis/ThreadSafety.cpp
+++ b/clang/lib/Analysis/ThreadSafety.cpp
@@ -1773,7 +1773,8 @@ void BuildLockset::checkPtAccess(const Expr *Exp, AccessKind AK,
///
/// \param Exp The call expression.
/// \param D The callee declaration.
-/// \param Self If \p Exp = nullptr, the implicit this argument.
+/// \param Self If \p Exp = nullptr, the implicit this argument or the argument
+/// of an implicitly called cleanup function.
/// \param Loc If \p Exp = nullptr, the location.
void BuildLockset::handleCall(const Expr *Exp, const NamedDecl *D,
til::LiteralPtr *Self, SourceLocation Loc) {
@@ -2417,6 +2418,15 @@ void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) {
AD.getTriggerStmt()->getEndLoc());
break;
}
+
+ case CFGElement::CleanupFunction: {
+ const CFGCleanupFunction &CF = BI.castAs<CFGCleanupFunction>();
+ LocksetBuilder.handleCall(/*Exp=*/nullptr, CF.getFunctionDecl(),
+ SxBuilder.createVariable(CF.getVarDecl()),
+ CF.getVarDecl()->getLocation());
+ break;
+ }
+
case CFGElement::TemporaryDtor: {
auto TD = BI.castAs<CFGTemporaryDtor>();
diff --git a/clang/lib/Analysis/ThreadSafetyCommon.cpp b/clang/lib/Analysis/ThreadSafetyCommon.cpp
index b8286cef396c..63cc66852a9e 100644
--- a/clang/lib/Analysis/ThreadSafetyCommon.cpp
+++ b/clang/lib/Analysis/ThreadSafetyCommon.cpp
@@ -110,7 +110,8 @@ static StringRef ClassifyDiagnostic(QualType VDT) {
/// \param D The declaration to which the attribute is attached.
/// \param DeclExp An expression involving the Decl to which the attribute
/// is attached. E.g. the call to a function.
-/// \param Self S-expression to substitute for a \ref CXXThisExpr.
+/// \param Self S-expression to substitute for a \ref CXXThisExpr in a call,
+/// or argument to a cleanup function.
CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
const NamedDecl *D,
const Expr *DeclExp,
@@ -144,7 +145,11 @@ CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
if (Self) {
assert(!Ctx.SelfArg && "Ambiguous self argument");
- Ctx.SelfArg = Self;
+ assert(isa<FunctionDecl>(D) && "Self argument requires function");
+ if (isa<CXXMethodDecl>(D))
+ Ctx.SelfArg = Self;
+ else
+ Ctx.FunArgs = Self;
// If the attribute has no arguments, then assume the argument is "this".
if (!AttrExp)
@@ -312,8 +317,14 @@ til::SExpr *SExprBuilder::translateDeclRefExpr(const DeclRefExpr *DRE,
? (cast<FunctionDecl>(D)->getCanonicalDecl() == Canonical)
: (cast<ObjCMethodDecl>(D)->getCanonicalDecl() == Canonical)) {
// Substitute call arguments for references to function parameters
- assert(I < Ctx->NumArgs);
- return translate(Ctx->FunArgs[I], Ctx->Prev);
+ if (const Expr *const *FunArgs =
+ Ctx->FunArgs.dyn_cast<const Expr *const *>()) {
+ assert(I < Ctx->NumArgs);
+ return translate(FunArgs[I], Ctx->Prev);
+ }
+
+ assert(I == 0);
+ return Ctx->FunArgs.get<til::SExpr *>();
}
}
// Map the param back to the param of the original function declaration
diff --git a/clang/test/Sema/warn-thread-safety-analysis.c b/clang/test/Sema/warn-thread-safety-analysis.c
index 355616b73d96..642ea88ec3c9 100644
--- a/clang/test/Sema/warn-thread-safety-analysis.c
+++ b/clang/test/Sema/warn-thread-safety-analysis.c
@@ -72,6 +72,8 @@ int get_value(int *p) SHARED_LOCKS_REQUIRED(foo_.mu_){
return *p;
}
+void unlock_scope(struct Mutex *const *mu) __attribute__((release_capability(**mu)));
+
int main(void) {
Foo_fun1(1); // expected-warning{{calling function 'Foo_fun1' requires holding mutex 'mu2'}} \
@@ -127,6 +129,13 @@ int main(void) {
// expected-note@-1{{mutex released here}}
mutex_shared_unlock(&mu1); // expected-warning {{releasing mutex 'mu1' that was not held}}
+ /// Cleanup functions
+ {
+ struct Mutex* const __attribute__((cleanup(unlock_scope))) scope = &mu1;
+ mutex_exclusive_lock(scope); // Note that we have to lock through scope, because no alias analysis!
+ // Cleanup happens automatically -> no warning.
+ }
+
return 0;
}