[clang] 41b09c5 - [Clang] omit parentheses in fold expressions with a single expansion (#110761)
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cfe-commits at lists.llvm.org
Mon Oct 7 11:14:49 PDT 2024
Author: Oleksandr T.
Date: 2024-10-07T20:14:46+02:00
New Revision: 41b09c5346324fc0fd2642f3df216a246f9fb98b
URL: https://github.com/llvm/llvm-project/commit/41b09c5346324fc0fd2642f3df216a246f9fb98b
DIFF: https://github.com/llvm/llvm-project/commit/41b09c5346324fc0fd2642f3df216a246f9fb98b.diff
LOG: [Clang] omit parentheses in fold expressions with a single expansion (#110761)
Fixes #101863
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/include/clang/AST/Expr.h
clang/include/clang/AST/Stmt.h
clang/lib/Sema/SemaExpr.cpp
clang/lib/Sema/TreeTransform.h
clang/lib/Serialization/ASTReaderStmt.cpp
clang/lib/Serialization/ASTWriterStmt.cpp
clang/test/SemaCXX/warn-assignment-condition.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 3d03766d55a8aa..9762db9209b79a 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -378,6 +378,8 @@ Improvements to Clang's diagnostics
- Clang now emits a diagnostic note at the class declaration when the method definition does not match any declaration (#GH110638).
+- Clang now omits warnings for extra parentheses in fold expressions with single expansion (#GH101863).
+
Improvements to Clang's time-trace
----------------------------------
diff --git a/clang/include/clang/AST/Expr.h b/clang/include/clang/AST/Expr.h
index 57353855c51e7c..607bf313c4d95e 100644
--- a/clang/include/clang/AST/Expr.h
+++ b/clang/include/clang/AST/Expr.h
@@ -2170,11 +2170,13 @@ class SYCLUniqueStableNameExpr final : public Expr {
class ParenExpr : public Expr {
SourceLocation L, R;
Stmt *Val;
+
public:
ParenExpr(SourceLocation l, SourceLocation r, Expr *val)
: Expr(ParenExprClass, val->getType(), val->getValueKind(),
val->getObjectKind()),
L(l), R(r), Val(val) {
+ ParenExprBits.ProducedByFoldExpansion = false;
setDependence(computeDependence(this));
}
@@ -2206,6 +2208,13 @@ class ParenExpr : public Expr {
const_child_range children() const {
return const_child_range(&Val, &Val + 1);
}
+
+ bool isProducedByFoldExpansion() const {
+ return ParenExprBits.ProducedByFoldExpansion != 0;
+ }
+ void setIsProducedByFoldExpansion(bool ProducedByFoldExpansion = true) {
+ ParenExprBits.ProducedByFoldExpansion = ProducedByFoldExpansion;
+ }
};
/// UnaryOperator - This represents the unary-expression's (except sizeof and
diff --git a/clang/include/clang/AST/Stmt.h b/clang/include/clang/AST/Stmt.h
index 7aed83e9c68bb7..83fafbabb1d460 100644
--- a/clang/include/clang/AST/Stmt.h
+++ b/clang/include/clang/AST/Stmt.h
@@ -719,6 +719,18 @@ class alignas(void *) Stmt {
unsigned Kind : 3;
};
+ class ParenExprBitfields {
+ friend class ASTStmtReader;
+ friend class ASTStmtWriter;
+ friend class ParenExpr;
+
+ LLVM_PREFERRED_TYPE(ExprBitfields)
+ unsigned : NumExprBits;
+
+ LLVM_PREFERRED_TYPE(bool)
+ unsigned ProducedByFoldExpansion : 1;
+ };
+
class StmtExprBitfields {
friend class ASTStmtReader;
friend class StmtExpr;
@@ -1241,6 +1253,7 @@ class alignas(void *) Stmt {
GenericSelectionExprBitfields GenericSelectionExprBits;
PseudoObjectExprBitfields PseudoObjectExprBits;
SourceLocExprBitfields SourceLocExprBits;
+ ParenExprBitfields ParenExprBits;
// GNU Extensions.
StmtExprBitfields StmtExprBits;
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 959f0739f03fb9..f930a21ea870ec 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -20223,6 +20223,8 @@ void Sema::DiagnoseEqualityWithExtraParens(ParenExpr *ParenE) {
return;
Expr *E = ParenE->IgnoreParens();
+ if (ParenE->isProducedByFoldExpansion() && ParenE->getSubExpr() == E)
+ return;
if (BinaryOperator *opE = dyn_cast<BinaryOperator>(E))
if (opE->getOpcode() == BO_EQ &&
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index ed9412c93c62b3..01c086a602dd5a 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -15661,12 +15661,14 @@ TreeTransform<Derived>::TransformCXXFoldExpr(CXXFoldExpr *E) {
return true;
}
+ if (ParenExpr *PE = dyn_cast_or_null<ParenExpr>(Result.get()))
+ PE->setIsProducedByFoldExpansion();
+
// If we had no init and an empty pack, and we're not retaining an expansion,
// then produce a fallback value or error.
if (Result.isUnset())
return getDerived().RebuildEmptyCXXFoldExpr(E->getEllipsisLoc(),
E->getOperator());
-
return Result;
}
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 2038fe7829af9b..6aaafb2e8d71cc 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -706,6 +706,7 @@ void ASTStmtReader::VisitCharacterLiteral(CharacterLiteral *E) {
void ASTStmtReader::VisitParenExpr(ParenExpr *E) {
VisitExpr(E);
+ E->setIsProducedByFoldExpansion(Record.readInt());
E->setLParen(readSourceLocation());
E->setRParen(readSourceLocation());
E->setSubExpr(Record.readSubExpr());
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 64e4894dc29fb7..321e0031661ee2 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -786,6 +786,7 @@ void ASTStmtWriter::VisitCharacterLiteral(CharacterLiteral *E) {
void ASTStmtWriter::VisitParenExpr(ParenExpr *E) {
VisitExpr(E);
+ Record.push_back(E->isProducedByFoldExpansion());
Record.AddSourceLocation(E->getLParen());
Record.AddSourceLocation(E->getRParen());
Record.AddStmt(E->getSubExpr());
diff --git a/clang/test/SemaCXX/warn-assignment-condition.cpp b/clang/test/SemaCXX/warn-assignment-condition.cpp
index 09084e36bb4916..65332846bd0911 100644
--- a/clang/test/SemaCXX/warn-assignment-condition.cpp
+++ b/clang/test/SemaCXX/warn-assignment-condition.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -Wparentheses -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wparentheses -std=c++2a -verify %s
struct A {
int foo();
@@ -144,3 +144,48 @@ void test() {
f(S()); // expected-note {{in instantiation}}
}
}
+
+namespace GH101863 {
+void t1(auto... args) {
+ if (((args == 0) or ...)) { }
+}
+
+template <typename... Args>
+void t2(Args... args) {
+ if (((args == 0) or ...)) { }
+}
+
+void t3(auto... args) {
+ if ((... && (args == 0))) { }
+}
+
+void t4(auto... a, auto... b) {
+ if (((a == 0) or ...) && ((b == 0) or ...)) { }
+}
+
+void t5(auto... args) {
+ if ((((args == 0) or ...))) { }
+}
+
+void t6(auto a, auto... b) {
+ static_assert(__is_same_as(decltype((a)), int&));
+ static_assert(__is_same_as(decltype(((b), ...)), int&));
+};
+
+void t7(auto... args) {
+ if ((((args == 0)) or ...)) { } // expected-warning {{equality comparison with extraneous parentheses}} \
+ // expected-note {{use '=' to turn this equality comparison into an assignment}} \
+ // expected-note {{remove extraneous parentheses around the comparison to silence this warning}}
+}
+
+void test() {
+ t1(0, 1);
+ t2<>();
+ t3(1, 2, 3);
+ t3(0, 1);
+ t4(0, 1);
+ t5(0, 1);
+ t6(0, 0);
+ t7(0); // expected-note {{in instantiation of function template specialization 'GH101863::t7<int>' requested here}}
+}
+}
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