aaron.ballman created this revision.
aaron.ballman added reviewers: rsmith, erichkeane, rjmccall, arthur.j.odwyer.
aaron.ballman requested review of this revision.
Herald added a project: clang.
When parsing the following construct, we parse it as an erroneous deduction
guide declaration and correctly diagnose the issues with it.
template<class> struct B;
struct A { B() noexcept(false); };
However, we then go on to finish late parsing the declaration and this expects
that what we've parsed is a `CXXMethodDecl`. A `CXXDeductionGuideDecl` is not a
`CXXMethodDecl` (it's a `FunctionDecl`), and so we assert on the cast.
This fixes the crash by switching from `cast<>` to `dyn_cast<>` and not setting
up a "this" scope when the declaration is not a `CXXMethodDecl`. This fixes
PR49735.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D112616
Files:
clang/lib/Parse/ParseCXXInlineMethods.cpp
clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
Index: clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
===================================================================
--- clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
+++ clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
@@ -230,3 +230,21 @@
template<int ...N> struct Z { Y<X(N)...> y; };
}
+
+namespace PR49735 {
+// Ensure that we do not crash when parsing code which looks like an invalid
+// deduction guide declaration.
+template<class> struct B; // expected-note 2{{template is declared here}}
+struct A1 {
+ B() noexcept(false); // expected-error {{deduction guide must be declared in
the same scope as template 'PR49735::B'}} \
+ // expected-error {{deduction guide declaration without
trailing return type}}
+};
+
+struct A2 {
+ template <typename Ty> // expected-note {{non-deducible template parameter
'Ty'}}
+ B() noexcept(false); // expected-error {{deduction guide must be declared in
the same scope as template 'PR49735::B'}} \
+ // expected-error {{deduction guide template contains a
template parameter that cannot be deduced}} \
+ // expected-error {{deduction guide declaration without
trailing return type}}
+};
+
+}
Index: clang/lib/Parse/ParseCXXInlineMethods.cpp
===================================================================
--- clang/lib/Parse/ParseCXXInlineMethods.cpp
+++ clang/lib/Parse/ParseCXXInlineMethods.cpp
@@ -452,13 +452,14 @@
CXXMethodDecl *Method;
if (FunctionTemplateDecl *FunTmpl
= dyn_cast<FunctionTemplateDecl>(LM.Method))
- Method = cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
+ Method = dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
else
- Method = cast<CXXMethodDecl>(LM.Method);
+ Method = dyn_cast<CXXMethodDecl>(LM.Method);
- Sema::CXXThisScopeRAII ThisScope(Actions, Method->getParent(),
- Method->getMethodQualifiers(),
- getLangOpts().CPlusPlus11);
+ Sema::CXXThisScopeRAII ThisScope(
+ Actions, Method ? Method->getParent() : nullptr,
+ Method ? Method->getMethodQualifiers() : Qualifiers{},
+ Method && getLangOpts().CPlusPlus11);
// Parse the exception-specification.
SourceRange SpecificationRange;
Index: clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
===================================================================
--- clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
+++ clang/test/Parser/cxx1z-class-template-argument-deduction.cpp
@@ -230,3 +230,21 @@
template<int ...N> struct Z { Y<X(N)...> y; };
}
+
+namespace PR49735 {
+// Ensure that we do not crash when parsing code which looks like an invalid
+// deduction guide declaration.
+template<class> struct B; // expected-note 2{{template is declared here}}
+struct A1 {
+ B() noexcept(false); // expected-error {{deduction guide must be declared in the same scope as template 'PR49735::B'}} \
+ // expected-error {{deduction guide declaration without trailing return type}}
+};
+
+struct A2 {
+ template <typename Ty> // expected-note {{non-deducible template parameter 'Ty'}}
+ B() noexcept(false); // expected-error {{deduction guide must be declared in the same scope as template 'PR49735::B'}} \
+ // expected-error {{deduction guide template contains a template parameter that cannot be deduced}} \
+ // expected-error {{deduction guide declaration without trailing return type}}
+};
+
+}
Index: clang/lib/Parse/ParseCXXInlineMethods.cpp
===================================================================
--- clang/lib/Parse/ParseCXXInlineMethods.cpp
+++ clang/lib/Parse/ParseCXXInlineMethods.cpp
@@ -452,13 +452,14 @@
CXXMethodDecl *Method;
if (FunctionTemplateDecl *FunTmpl
= dyn_cast<FunctionTemplateDecl>(LM.Method))
- Method = cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
+ Method = dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
else
- Method = cast<CXXMethodDecl>(LM.Method);
+ Method = dyn_cast<CXXMethodDecl>(LM.Method);
- Sema::CXXThisScopeRAII ThisScope(Actions, Method->getParent(),
- Method->getMethodQualifiers(),
- getLangOpts().CPlusPlus11);
+ Sema::CXXThisScopeRAII ThisScope(
+ Actions, Method ? Method->getParent() : nullptr,
+ Method ? Method->getMethodQualifiers() : Qualifiers{},
+ Method && getLangOpts().CPlusPlus11);
// Parse the exception-specification.
SourceRange SpecificationRange;
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