Representation of template type parameters and non-type template
parameters, with some semantic analysis:
- Template parameters are introduced into template parameter scope
- Complain about template parameter shadowing (except in Microsoft mode)
Note that we leak template parameter declarations like crazy, a
problem we'll remedy once we actually create proper declarations for
templates.
Next up: dependent types and value-dependent/type-dependent
expressions.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60597 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/CMakeLists.txt b/lib/Sema/CMakeLists.txt
index cb28fca..fd961fa 100644
--- a/lib/Sema/CMakeLists.txt
+++ b/lib/Sema/CMakeLists.txt
@@ -18,5 +18,6 @@
SemaNamedCast.cpp
SemaOverload.cpp
SemaStmt.cpp
+ SemaTemplate.cpp
SemaType.cpp
)
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index ef15064..f1d0ee2 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -988,6 +988,17 @@
bool CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl);
+ //===--------------------------------------------------------------------===//
+ // C++ Templates [C++ 14]
+ //
+ bool isTemplateParameterDecl(Decl *D);
+ bool DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl);
+ virtual DeclTy *ActOnTypeParameter(Scope *S, bool Typename,
+ SourceLocation KeyLoc,
+ IdentifierInfo *ParamName,
+ SourceLocation ParamNameLoc);
+ virtual DeclTy *ActOnNonTypeTemplateParameter(Scope *S, Declarator &D);
+
// Objective-C declarations.
virtual DeclTy *ActOnStartClassInterface(SourceLocation AtInterfaceLoc,
IdentifierInfo *ClassName,
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 4fd13c3..c893d27 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -39,7 +39,8 @@
if (IIDecl && (isa<TypedefDecl>(IIDecl) ||
isa<ObjCInterfaceDecl>(IIDecl) ||
- isa<TagDecl>(IIDecl)))
+ isa<TagDecl>(IIDecl) ||
+ isa<TemplateTypeParmDecl>(IIDecl)))
return IIDecl;
return 0;
}
@@ -148,7 +149,8 @@
void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
if (S->decl_empty()) return;
- assert((S->getFlags() & Scope::DeclScope) &&"Scope shouldn't contain decls!");
+ assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) &&
+ "Scope shouldn't contain decls!");
for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end();
I != E; ++I) {
@@ -165,7 +167,10 @@
// We only want to remove the decls from the identifier decl chains for
// local scopes, when inside a function/method.
- if (S->getFnParent() != 0)
+ // However, we *always* remove template parameters, since they are
+ // purely lexically scoped (and can never be found by qualified
+ // name lookup).
+ if (S->getFnParent() != 0 || isa<TemplateTypeParmDecl>(D))
IdResolver.RemoveDecl(D);
// Chain this decl to the containing DeclContext.
@@ -863,6 +868,15 @@
}
}
+ if (PrevDecl && isTemplateParameterDecl(PrevDecl)) {
+ // Maybe we will complain about the shadowed template parameter.
+ InvalidDecl
+ = InvalidDecl || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
+ PrevDecl);
+ // Just pretend that we didn't see the previous declaration.
+ PrevDecl = 0;
+ }
+
// In C++, the previous declaration we find might be a tag type
// (class or enum). In this case, the new declaration will hide the
// tag type.
@@ -1991,7 +2005,12 @@
// among each other. Here they can only shadow globals, which is ok.
IdentifierInfo *II = D.getIdentifier();
if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) {
- if (S->isDeclScope(PrevDecl)) {
+ if (isTemplateParameterDecl(PrevDecl)) {
+ // Maybe we will complain about the shadowed template parameter.
+ DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
+ // Just pretend that we didn't see the previous declaration.
+ PrevDecl = 0;
+ } else if (S->isDeclScope(PrevDecl)) {
Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II;
// Recover by removing the name
@@ -2250,6 +2269,13 @@
PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S));
}
+ if (PrevDecl && isTemplateParameterDecl(PrevDecl)) {
+ // Maybe we will complain about the shadowed template parameter.
+ DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
+ // Just pretend that we didn't see the previous declaration.
+ PrevDecl = 0;
+ }
+
if (PrevDecl) {
assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) &&
"unexpected Decl type");
@@ -2386,6 +2412,13 @@
PrevDecl = dyn_cast_or_null<ScopedDecl>(LookupDecl(Name, Decl::IDNS_Tag,S));
}
+ if (PrevDecl && isTemplateParameterDecl(PrevDecl)) {
+ // Maybe we will complain about the shadowed template parameter.
+ DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
+ // Just pretend that we didn't see the previous declaration.
+ PrevDecl = 0;
+ }
+
if (PrevDecl) {
assert((isa<TagDecl>(PrevDecl) || isa<NamespaceDecl>(PrevDecl)) &&
"unexpected Decl type");
@@ -2875,7 +2908,15 @@
// Verify that there isn't already something declared with this name in this
// scope.
- if (Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S)) {
+ Decl *PrevDecl = LookupDecl(Id, Decl::IDNS_Ordinary, S);
+ if (PrevDecl && isTemplateParameterDecl(PrevDecl)) {
+ // Maybe we will complain about the shadowed template parameter.
+ DiagnoseTemplateParameterShadow(IdLoc, PrevDecl);
+ // Just pretend that we didn't see the previous declaration.
+ PrevDecl = 0;
+ }
+
+ if (PrevDecl) {
// When in C++, we may get a TagDecl with the same name; in this case the
// enum constant will 'hide' the tag.
assert((getLangOptions().CPlusPlus || !isa<TagDecl>(PrevDecl)) &&
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 9da662e..01a453d 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -66,6 +66,13 @@
// Check for another declaration kind with the same name.
Decl *PrevDecl = LookupDecl(ClassName, Decl::IDNS_Ordinary, TUScope);
+ if (PrevDecl && isTemplateParameterDecl(PrevDecl)) {
+ // Maybe we will complain about the shadowed template parameter.
+ DiagnoseTemplateParameterShadow(ClassLoc, PrevDecl);
+ // Just pretend that we didn't see the previous declaration.
+ PrevDecl = 0;
+ }
+
if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
Diag(ClassLoc, diag::err_redefinition_different_kind) << ClassName;
Diag(PrevDecl->getLocation(), diag::note_previous_definition);
@@ -742,6 +749,13 @@
for (unsigned i = 0; i != NumElts; ++i) {
// Check for another declaration kind with the same name.
Decl *PrevDecl = LookupDecl(IdentList[i], Decl::IDNS_Ordinary, TUScope);
+ if (PrevDecl && isTemplateParameterDecl(PrevDecl)) {
+ // Maybe we will complain about the shadowed template parameter.
+ DiagnoseTemplateParameterShadow(AtClassLoc, PrevDecl);
+ // Just pretend that we didn't see the previous declaration.
+ PrevDecl = 0;
+ }
+
if (PrevDecl && !isa<ObjCInterfaceDecl>(PrevDecl)) {
// GCC apparently allows the following idiom:
//
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
new file mode 100644
index 0000000..749d181
--- /dev/null
+++ b/lib/Sema/SemaTemplate.cpp
@@ -0,0 +1,116 @@
+//===------- SemaTemplate.cpp - Semantic Analysis for C++ Templates -------===/
+
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//+//===----------------------------------------------------------------------===/
+
+//
+// This file implements semantic analysis for C++ templates.
+//+//===----------------------------------------------------------------------===/
+
+#include "Sema.h"
+#include "clang/Parse/DeclSpec.h"
+#include "clang/Basic/LangOptions.h"
+
+using namespace clang;
+
+/// isTemplateParameterDecl - Determines whether the given declaration
+/// 'D' names a template parameter.
+bool Sema::isTemplateParameterDecl(Decl *D) {
+ return isa<TemplateTypeParmDecl>(D) || isa<NonTypeTemplateParmDecl>(D);
+}
+
+/// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
+/// that the template parameter 'PrevDecl' is being shadowed by a new
+/// declaration at location Loc. Returns true to indicate that this is
+/// an error, and false otherwise.
+bool Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) {
+ assert(isTemplateParameterDecl(PrevDecl) && "Not a template parameter");
+
+ // Microsoft Visual C++ permits template parameters to be shadowed.
+ if (getLangOptions().Microsoft)
+ return false;
+
+ // C++ [temp.local]p4:
+ // A template-parameter shall not be redeclared within its
+ // scope (including nested scopes).
+ Diag(Loc, diag::err_template_param_shadow)
+ << cast<NamedDecl>(PrevDecl)->getDeclName();
+ Diag(PrevDecl->getLocation(), diag::note_template_param_here);
+ return true;
+}
+
+/// ActOnTypeParameter - Called when a C++ template type parameter
+/// (e.g., "typename T") has been parsed. Typename specifies whether
+/// the keyword "typename" was used to declare the type parameter
+/// (otherwise, "class" was used), and KeyLoc is the location of the
+/// "class" or "typename" keyword. ParamName is the name of the
+/// parameter (NULL indicates an unnamed template parameter) and
+/// ParamName is the location of the parameter name (if any).
+/// If the type parameter has a default argument, it will be added
+/// later via ActOnTypeParameterDefault.
+Sema::DeclTy *Sema::ActOnTypeParameter(Scope *S, bool Typename,
+ SourceLocation KeyLoc,
+ IdentifierInfo *ParamName,
+ SourceLocation ParamNameLoc) {
+ assert(S->isTemplateParamScope() &&
+ "Template type parameter not in template parameter scope!");
+ bool Invalid = false;
+
+ if (ParamName) {
+ Decl *PrevDecl = LookupDecl(ParamName, Decl::IDNS_Tag, S);
+ if (PrevDecl && isTemplateParameterDecl(PrevDecl))
+ Invalid = Invalid || DiagnoseTemplateParameterShadow(ParamNameLoc,
+ PrevDecl);
+ }
+
+ TemplateTypeParmDecl *Param
+ = TemplateTypeParmDecl::Create(Context, CurContext,
+ ParamNameLoc, ParamName, Typename);
+ if (Invalid)
+ Param->setInvalidDecl();
+
+ if (ParamName) {
+ // Add the template parameter into the current scope.
+ S->AddDecl(Param);
+ IdResolver.AddDecl(Param);
+ }
+
+ return Param;
+}
+
+/// ActOnNonTypeTemplateParameter - Called when a C++ non-type
+/// template parameter (e.g., "int Size" in "template<int Size>
+/// class Array") has been parsed. S is the current scope and D is
+/// the parsed declarator.
+Sema::DeclTy *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D) {
+ QualType T = GetTypeForDeclarator(D, S);
+
+ assert(S->isTemplateParamScope() &&
+ "Template type parameter not in template parameter scope!");
+ bool Invalid = false;
+
+ IdentifierInfo *ParamName = D.getIdentifier();
+ if (ParamName) {
+ Decl *PrevDecl = LookupDecl(ParamName, Decl::IDNS_Tag, S);
+ if (PrevDecl && isTemplateParameterDecl(PrevDecl))
+ Invalid = Invalid || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
+ PrevDecl);
+ }
+
+ NonTypeTemplateParmDecl *Param
+ = NonTypeTemplateParmDecl::Create(Context, CurContext, D.getIdentifierLoc(),
+ ParamName, T);
+ if (Invalid)
+ Param->setInvalidDecl();
+
+ if (D.getIdentifier()) {
+ // Add the template parameter into the current scope.
+ S->AddDecl(Param);
+ IdResolver.AddDecl(Param);
+ }
+ return Param;
+}