[clang] 2fd01d7 - [clang] Construct ExprRequirement with SubstitutionDiagnostic on SubstFailure
Younan Zhang via cfe-commits
cfe-commits at lists.llvm.org
Fri Sep 1 00:49:47 PDT 2023
Author: Younan Zhang
Date: 2023-09-01T15:49:39+08:00
New Revision: 2fd01d75a863184766ee0c82b5c0fc8be172448a
URL: https://github.com/llvm/llvm-project/commit/2fd01d75a863184766ee0c82b5c0fc8be172448a
DIFF: https://github.com/llvm/llvm-project/commit/2fd01d75a863184766ee0c82b5c0fc8be172448a.diff
LOG: [clang] Construct ExprRequirement with SubstitutionDiagnostic on SubstFailure
We're expecting a SubstitutionDiagnostic in diagnoseUnsatisfiedRequirement
if the status of ExprRequirement is SubstFailure. Previously, the Requirement
was created with Expr on SubstFailure by mistake, which could lead to the
assertion failure in the subsequent diagnosis.
Fixes https://github.com/clangd/clangd/issues/1726
Fixes https://github.com/llvm/llvm-project/issues/64723
Fixes https://github.com/llvm/llvm-project/issues/64172
In addition, this patch also fixes an invalid test from D129499.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D158061
Added:
clang/test/SemaCXX/concept-crash-on-diagnostic.cpp
Modified:
clang/docs/ReleaseNotes.rst
clang/include/clang/AST/ExprConcepts.h
clang/lib/Sema/SemaExprCXX.cpp
clang/lib/Sema/SemaTemplateInstantiate.cpp
clang/test/SemaCXX/concept-fatal-error.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 15d318ef75f05a..fc96ccb992ed78 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -250,6 +250,10 @@ Bug Fixes to C++ Support
(`#64962 <https://github.com/llvm/llvm-project/issues/64962>`_) and
(`#28679 <https://github.com/llvm/llvm-project/issues/28679>`_).
+- Fix a crash caused by substitution failure in expression requirements.
+ (`#64172 <https://github.com/llvm/llvm-project/issues/64172>`_) and
+ (`#64723 <https://github.com/llvm/llvm-project/issues/64723>`_).
+
Bug Fixes to AST Handling
^^^^^^^^^^^^^^^^^^^^^^^^^
- Fixed an import failure of recursive friend class template.
diff --git a/clang/include/clang/AST/ExprConcepts.h b/clang/include/clang/AST/ExprConcepts.h
index 6449f1b56821f0..6f38b2c4b05714 100644
--- a/clang/include/clang/AST/ExprConcepts.h
+++ b/clang/include/clang/AST/ExprConcepts.h
@@ -14,20 +14,21 @@
#ifndef LLVM_CLANG_AST_EXPRCONCEPTS_H
#define LLVM_CLANG_AST_EXPRCONCEPTS_H
-#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTConcept.h"
+#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
-#include "clang/AST/DeclarationName.h"
#include "clang/AST/DeclTemplate.h"
+#include "clang/AST/DeclarationName.h"
#include "clang/AST/Expr.h"
#include "clang/AST/NestedNameSpecifier.h"
#include "clang/AST/TemplateBase.h"
#include "clang/AST/Type.h"
#include "clang/Basic/SourceLocation.h"
+#include "llvm/ADT/STLFunctionalExtras.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TrailingObjects.h"
-#include <utility>
#include <string>
+#include <utility>
namespace clang {
class ASTStmtReader;
@@ -486,6 +487,13 @@ class NestedRequirement : public Requirement {
}
};
+using EntityPrinter = llvm::function_ref<void(llvm::raw_ostream &)>;
+
+/// \brief create a Requirement::SubstitutionDiagnostic with only a
+/// SubstitutedEntity and DiagLoc using Sema's allocator.
+Requirement::SubstitutionDiagnostic *
+createSubstDiagAt(Sema &S, SourceLocation Location, EntityPrinter Printer);
+
} // namespace concepts
/// C++2a [expr.prim.req]:
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 472fbdbdb5d0e6..833223f7968944 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -19,6 +19,7 @@
#include "clang/AST/CharUnits.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/ExprCXX.h"
+#include "clang/AST/ExprConcepts.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/Type.h"
@@ -9080,16 +9081,22 @@ Sema::BuildExprRequirement(
MLTAL.addOuterRetainedLevels(TPL->getDepth());
const TypeConstraint *TC = Param->getTypeConstraint();
assert(TC && "Type Constraint cannot be null here");
- ExprResult Constraint =
- SubstExpr(TC->getImmediatelyDeclaredConstraint(), MLTAL);
+ auto *IDC = TC->getImmediatelyDeclaredConstraint();
+ assert(IDC && "ImmediatelyDeclaredConstraint can't be null here.");
+ ExprResult Constraint = SubstExpr(IDC, MLTAL);
if (Constraint.isInvalid()) {
- Status = concepts::ExprRequirement::SS_ExprSubstitutionFailure;
- } else {
- SubstitutedConstraintExpr =
- cast<ConceptSpecializationExpr>(Constraint.get());
- if (!SubstitutedConstraintExpr->isSatisfied())
- Status = concepts::ExprRequirement::SS_ConstraintsNotSatisfied;
- }
+ return new (Context) concepts::ExprRequirement(
+ concepts::createSubstDiagAt(*this, IDC->getExprLoc(),
+ [&](llvm::raw_ostream &OS) {
+ IDC->printPretty(OS, /*Helper=*/nullptr,
+ getPrintingPolicy());
+ }),
+ IsSimple, NoexceptLoc, ReturnTypeRequirement);
+ }
+ SubstitutedConstraintExpr =
+ cast<ConceptSpecializationExpr>(Constraint.get());
+ if (!SubstitutedConstraintExpr->isSatisfied())
+ Status = concepts::ExprRequirement::SS_ConstraintsNotSatisfied;
}
return new (Context) concepts::ExprRequirement(E, IsSimple, NoexceptLoc,
ReturnTypeRequirement, Status,
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 810e0322f0a3bc..3b1731edec9523 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -2271,9 +2271,9 @@ QualType TemplateInstantiator::TransformSubstTemplateTypeParmPackType(
getPackIndex(Pack), Arg, TL.getNameLoc());
}
-template<typename EntityPrinter>
static concepts::Requirement::SubstitutionDiagnostic *
-createSubstDiag(Sema &S, TemplateDeductionInfo &Info, EntityPrinter Printer) {
+createSubstDiag(Sema &S, TemplateDeductionInfo &Info,
+ concepts::EntityPrinter Printer) {
SmallString<128> Message;
SourceLocation ErrorLoc;
if (Info.hasSFINAEDiagnostic()) {
@@ -2297,6 +2297,19 @@ createSubstDiag(Sema &S, TemplateDeductionInfo &Info, EntityPrinter Printer) {
StringRef(MessageBuf, Message.size())};
}
+concepts::Requirement::SubstitutionDiagnostic *
+concepts::createSubstDiagAt(Sema &S, SourceLocation Location,
+ EntityPrinter Printer) {
+ SmallString<128> Entity;
+ llvm::raw_svector_ostream OS(Entity);
+ Printer(OS);
+ char *EntityBuf = new (S.Context) char[Entity.size()];
+ llvm::copy(Entity, EntityBuf);
+ return new (S.Context) concepts::Requirement::SubstitutionDiagnostic{
+ /*SubstitutedEntity=*/StringRef(EntityBuf, Entity.size()),
+ /*DiagLoc=*/Location, /*DiagMessage=*/StringRef()};
+}
+
ExprResult TemplateInstantiator::TransformRequiresTypeParams(
SourceLocation KWLoc, SourceLocation RBraceLoc, const RequiresExpr *RE,
RequiresExprBodyDecl *Body, ArrayRef<ParmVarDecl *> Params,
diff --git a/clang/test/SemaCXX/concept-crash-on-diagnostic.cpp b/clang/test/SemaCXX/concept-crash-on-diagnostic.cpp
new file mode 100644
index 00000000000000..00a39f9f03b79c
--- /dev/null
+++ b/clang/test/SemaCXX/concept-crash-on-diagnostic.cpp
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++20 -verify %s
+
+template <typename Iterator> class normal_iterator {};
+
+template <typename From, typename To> struct is_convertible {};
+
+template <typename From, typename To>
+inline constexpr bool is_convertible_v = is_convertible<From, To>::value; // expected-error {{no member named 'value' in 'is_convertible<bool, bool>'}}
+
+template <typename From, typename To>
+concept convertible_to = is_convertible_v<From, To>; // #1
+
+template <typename IteratorL, typename IteratorR>
+ requires requires(IteratorL lhs, IteratorR rhs) { // #2
+ { lhs == rhs } -> convertible_to<bool>; // #3
+ }
+constexpr bool compare(normal_iterator<IteratorL> lhs, normal_iterator<IteratorR> rhs) { // #4
+ return false;
+}
+
+class Object;
+
+void function() {
+ normal_iterator<Object *> begin, end;
+ compare(begin, end); // expected-error {{no matching function for call to 'compare'}} #5
+}
+
+// expected-note@#1 {{in instantiation of variable template specialization 'is_convertible_v<bool, bool>' requested here}}
+// expected-note@#1 {{substituting template arguments into constraint expression here}}
+// expected-note@#3 {{checking the satisfaction of concept 'convertible_to<bool, bool>'}}
+// expected-note@#2 {{substituting template arguments into constraint expression here}}
+// expected-note@#5 {{checking constraint satisfaction for template 'compare<Object *, Object *>'}}
+// expected-note@#5 {{in instantiation of function template specialization 'compare<Object *, Object *>' requested here}}
+
+// expected-note@#4 {{candidate template ignored: constraints not satisfied [with IteratorL = Object *, IteratorR = Object *]}}
+// We don't know exactly the substituted type for `lhs == rhs`, thus a placeholder 'expr-type' is emitted.
+// expected-note@#3 {{because 'convertible_to<expr-type, bool>' would be invalid}}
diff --git a/clang/test/SemaCXX/concept-fatal-error.cpp b/clang/test/SemaCXX/concept-fatal-error.cpp
index c299b39fdeb233..c606b9e21a3646 100644
--- a/clang/test/SemaCXX/concept-fatal-error.cpp
+++ b/clang/test/SemaCXX/concept-fatal-error.cpp
@@ -1,4 +1,4 @@
-// RUN: not %clang_cc1 -fsyntax-only -std=c++20 -ferror-limit 1 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -std=c++20 -ferror-limit 1 -verify %s
template <class>
concept f = requires { 42; };
@@ -6,5 +6,5 @@ struct h {
// The missing semicolon will trigger an error and -ferror-limit=1 will make it fatal
// We test that we do not crash in such cases (#55401)
int i = requires { { i } f } // expected-error {{expected ';' at end of declaration list}}
- // expected-error@* {{too many errros emitted}}
+ // expected-error@* {{too many errors emitted}}
};
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