https://github.com/higher-performance updated
https://github.com/llvm/llvm-project/pull/112047
>From 5a7cd2a5cf5275d408fac91dd03363137457b0e1 Mon Sep 17 00:00:00 2001
From: higher-performance <higher.performance.git...@gmail.com>
Date: Fri, 11 Oct 2024 17:09:13 -0400
Subject: [PATCH] Make [[clang::lifetimebound]] work for expressions coming
from default arguments
---
.../clang/Basic/DiagnosticSemaKinds.td | 2 ++
clang/lib/Sema/CheckExprLifetime.cpp | 31 ++++++++++++++++---
clang/test/SemaCXX/attr-lifetimebound.cpp | 11 +++++++
3 files changed, 39 insertions(+), 5 deletions(-)
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td
b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index ce08bd60f76449..f49c874207585f 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10107,6 +10107,8 @@ def note_lambda_capture_initializer : Note<
" via initialization of lambda capture %0}1">;
def note_init_with_default_member_initializer : Note<
"initializing field %0 with default member initializer">;
+def note_init_with_default_argument : Note<
+ "initializing parameter %0 with default argument">;
// Check for initializing a member variable with the address or a reference to
// a constructor parameter.
diff --git a/clang/lib/Sema/CheckExprLifetime.cpp
b/clang/lib/Sema/CheckExprLifetime.cpp
index f62e18543851c1..958f16a4c8a31e 100644
--- a/clang/lib/Sema/CheckExprLifetime.cpp
+++ b/clang/lib/Sema/CheckExprLifetime.cpp
@@ -194,6 +194,7 @@ struct IndirectLocalPathEntry {
GslReferenceInit,
GslPointerInit,
GslPointerAssignment,
+ DefaultArg,
} Kind;
Expr *E;
union {
@@ -371,25 +372,33 @@ static bool implicitObjectParamIsLifetimeBound(const
FunctionDecl *FD) {
static void visitFunctionCallArguments(IndirectLocalPath &Path, Expr *Call,
LocalVisitor Visit) {
const FunctionDecl *Callee;
- ArrayRef<Expr *> Args;
+ llvm::SmallVector<Expr *, 8> Args;
if (auto *CE = dyn_cast<CallExpr>(Call)) {
Callee = CE->getDirectCallee();
- Args = llvm::ArrayRef(CE->getArgs(), CE->getNumArgs());
+ Args.append(CE->getArgs(), CE->getArgs() + CE->getNumArgs());
} else {
auto *CCE = cast<CXXConstructExpr>(Call);
Callee = CCE->getConstructor();
- Args = llvm::ArrayRef(CCE->getArgs(), CCE->getNumArgs());
+ Args.append(CCE->getArgs(), CCE->getArgs() + CCE->getNumArgs());
}
if (!Callee)
return;
+ for (Expr *&Arg : Args) {
+ if (auto *DAE = dyn_cast<CXXDefaultArgExpr>(Arg)) {
+ Path.push_back(
+ {IndirectLocalPathEntry::DefaultArg, DAE, DAE->getParam()});
+ Arg = DAE->getExpr();
+ }
+ }
+
bool EnableGSLAnalysis = !Callee->getASTContext().getDiagnostics().isIgnored(
diag::warn_dangling_lifetime_pointer, SourceLocation());
Expr *ObjectArg = nullptr;
if (isa<CXXOperatorCallExpr>(Call) && Callee->isCXXInstanceMember()) {
ObjectArg = Args[0];
- Args = Args.slice(1);
+ Args.erase(Args.begin() + 1);
} else if (auto *MCE = dyn_cast<CXXMemberCallExpr>(Call)) {
ObjectArg = MCE->getImplicitObjectArgument();
}
@@ -916,6 +925,9 @@ static SourceRange nextPathEntryRange(const
IndirectLocalPath &Path, unsigned I,
if (!Path[I].Capture->capturesVariable())
continue;
return Path[I].E->getSourceRange();
+
+ case IndirectLocalPathEntry::DefaultArg:
+ return cast<CXXDefaultArgExpr>(Path[I].E)->getUsedLocation();
}
}
return E->getSourceRange();
@@ -1221,7 +1233,7 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
break;
}
- case IndirectLocalPathEntry::LambdaCaptureInit:
+ case IndirectLocalPathEntry::LambdaCaptureInit: {
if (!Elem.Capture->capturesVariable())
break;
// FIXME: We can't easily tell apart an init-capture from a nested
@@ -1234,6 +1246,15 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
<< nextPathEntryRange(Path, I + 1, L);
break;
}
+
+ case IndirectLocalPathEntry::DefaultArg: {
+ const auto *DAE = cast<CXXDefaultArgExpr>(Elem.E);
+ SemaRef.Diag(DAE->getParam()->getDefaultArgRange().getBegin(),
+ diag::note_init_with_default_argument)
+ << DAE->getParam() << nextPathEntryRange(Path, I + 1, L);
+ break;
+ }
+ }
}
// We didn't lifetime-extend, so don't go any further; we don't need more
diff --git a/clang/test/SemaCXX/attr-lifetimebound.cpp
b/clang/test/SemaCXX/attr-lifetimebound.cpp
index 0fb997a5671085..a1dba5c6a2473e 100644
--- a/clang/test/SemaCXX/attr-lifetimebound.cpp
+++ b/clang/test/SemaCXX/attr-lifetimebound.cpp
@@ -18,9 +18,13 @@ namespace usage_invalid {
namespace usage_ok {
struct IntRef { int *target; };
+ using IntArray = int[];
+ const int *defaultparam(const int &def1 [[clang::lifetimebound]] = 0); //
#def1
int &refparam(int ¶m [[clang::lifetimebound]]);
int &classparam(IntRef param [[clang::lifetimebound]]);
+ const int *c = defaultparam(); // expected-warning {{temporary whose address
is used as value of local variable 'c' will be destroyed at the end of the
full-expression}} expected-note@#def1 {{initializing parameter 'def1' with
default argument}}
+ const int &defaultparam_array([[clang::lifetimebound]] const int *p =
IntArray{1, 2, 3}); // #def2
// Do not diagnose non-void return types; they can still be lifetime-bound.
long long ptrintcast(int ¶m [[clang::lifetimebound]]) {
@@ -34,13 +38,20 @@ namespace usage_ok {
struct A {
A();
A(int);
+ A(const char*, const int& def3 [[clang::lifetimebound]] = 0); // #def3
int *class_member() [[clang::lifetimebound]];
operator int*() [[clang::lifetimebound]];
+ static const int &defaulted_param(const int &def4 [[clang::lifetimebound]]
= 0); // #def4
+ static const int &defaulted_param2(const int &def5
[[clang::lifetimebound]] = defaulted_param()); // #def5
};
int *p = A().class_member(); // expected-warning {{temporary whose address
is used as value of local variable 'p' will be destroyed at the end of the
full-expression}}
int *q = A(); // expected-warning {{temporary whose address is used as value
of local variable 'q' will be destroyed at the end of the full-expression}}
int *r = A(1); // expected-warning {{temporary whose address is used as
value of local variable 'r' will be destroyed at the end of the
full-expression}}
+ A a = A(""); // expected-warning {{temporary whose address is used as value
of local variable 'a' will be destroyed at the end of the full-expression}}
expected-note@#def3 {{initializing parameter 'def3' with default argument}}
+ const int &s = A::defaulted_param(); // expected-warning {{temporary bound
to local reference 's' will be destroyed at the end of the full-expression}}
expected-note@#def4 {{initializing parameter 'def4' with default argument}}
+ const int &t = A::defaulted_param2(); // expected-warning {{temporary bound
to local reference 't' will be destroyed at the end of the full-expression}}
expected-note@#def4 {{initializing parameter 'def4' with default argument}}
expected-note@#def5 {{initializing parameter 'def5' with default argument}}
+ const int &u = defaultparam_array(); // expected-warning {{temporary bound
to local reference 'u' will be destroyed at the end of the full-expression}}
expected-note@#def2 {{initializing parameter 'p' with default argument}}
void test_assignment() {
p = A().class_member(); // expected-warning {{object backing the pointer p
will be destroyed at the end of the full-expression}}
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