[cfe-commits] r71773 - in /cfe/trunk: include/clang/Basic/DiagnosticGroups.td include/clang/Basic/DiagnosticSemaKinds.td lib/Sema/Sema.h lib/Sema/SemaDecl.cpp lib/Sema/SemaTemplate.cpp test/SemaCXX/struct-class-redecl.cpp
Douglas Gregor
dgregor at apple.com
Thu May 14 09:41:43 PDT 2009
Author: dgregor
Date: Thu May 14 11:41:31 2009
New Revision: 71773
URL: http://llvm.org/viewvc/llvm-project?rev=71773&view=rev
Log:
In C++, warn when something previously declared as a "struct" is later
declared as a "class", or vice-versa. This warning is under the
control of -Wmismatched-tags, which is off by default.
Modified:
cfe/trunk/include/clang/Basic/DiagnosticGroups.td
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/lib/Sema/Sema.h
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/lib/Sema/SemaTemplate.cpp
cfe/trunk/test/SemaCXX/struct-class-redecl.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticGroups.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticGroups.td?rev=71773&r1=71772&r2=71773&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticGroups.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticGroups.td Thu May 14 11:41:31 2009
@@ -86,6 +86,8 @@
def : DiagGroup<"strict-prototypes">;
def : DiagGroup<"strict-selector-match">;
def Switch : DiagGroup<"switch">;
+def MismatchedTags : DiagGroup<"mismatched-tags">;
+
def : DiagGroup<"type-limits">;
def Uninitialized : DiagGroup<"uninitialized">;
def UnknownPragmas : DiagGroup<"unknown-pragmas">;
@@ -107,6 +109,7 @@
Comment,
Format,
Implicit,
+ MismatchedTags,
MultiChar,
Switch,
Trigraphs,
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=71773&r1=71772&r2=71773&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Thu May 14 11:41:31 2009
@@ -812,6 +812,10 @@
def err_nested_redefinition : Error<"nested redefinition of %0">;
def err_use_with_wrong_tag : Error<
"use of %0 with tag type that does not match previous declaration">;
+def warn_struct_class_tag_mismatch : Warning<
+ "%select{struct|class}0 %select{|template}1 %2 was previously declared "
+ "as a %select{struct|class}3 %select{|template}1">,
+ InGroup<MismatchedTags>, DefaultIgnore;
def ext_forward_ref_enum : Extension<
"ISO C forbids forward references to 'enum' types">;
def err_forward_ref_enum : Error<
Modified: cfe/trunk/lib/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.h?rev=71773&r1=71772&r2=71773&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/Sema.h (original)
+++ cfe/trunk/lib/Sema/Sema.h Thu May 14 11:41:31 2009
@@ -430,32 +430,10 @@
virtual DeclPtrTy BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
RecordDecl *Record);
- /// \brief Determine whether a tag with a given kind is acceptable
- /// for a redeclaration of a tag type declared with another tag.
- ///
- /// \p T1 and \p T2 are the tag kinds. Since the rules for
- /// redeclaration of tags are symmetric, it does not matter which is
- /// the previous declaration and which is the new declaration.
- bool isAcceptableTagRedeclaration(TagDecl::TagKind T1, TagDecl::TagKind T2) {
- // C++ [dcl.type.elab]p3:
- // The class-key ore num keyword present in the
- // elaborated-type-specifier shall agree in kind with the
- // declaration to which the name in theelaborated-type-specifier
- // refers. This rule also applies to the form of
- // elaborated-type-specifier that declares a class-name or
- // friend class since it can be construed as referring to the
- // definition of the class. Thus, in any
- // elaborated-type-specifier, the enum keyword shall be used to
- // refer to an enumeration (7.2), the union class-keyshall be
- // used to refer to a union (clause 9), and either the class or
- // struct class-key shall be used to refer to a class (clause 9)
- // declared using the class or struct class-key.
- if (T1 == T2)
- return true;
-
- return (T1 == TagDecl::TK_struct || T1 == TagDecl::TK_class) &&
- (T2 == TagDecl::TK_struct || T2 == TagDecl::TK_class);
- }
+ bool isAcceptableTagRedeclaration(const TagDecl *Previous,
+ TagDecl::TagKind NewTag,
+ SourceLocation NewTagLoc,
+ const IdentifierInfo &Name);
virtual DeclPtrTy ActOnTag(Scope *S, unsigned TagSpec, TagKind TK,
SourceLocation KWLoc, const CXXScopeSpec &SS,
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=71773&r1=71772&r2=71773&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Thu May 14 11:41:31 2009
@@ -3245,6 +3245,51 @@
return NewTD;
}
+
+/// \brief Determine whether a tag with a given kind is acceptable
+/// as a redeclaration of the given tag declaration.
+///
+/// \returns true if the new tag kind is acceptable, false otherwise.
+bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous,
+ TagDecl::TagKind NewTag,
+ SourceLocation NewTagLoc,
+ const IdentifierInfo &Name) {
+ // C++ [dcl.type.elab]p3:
+ // The class-key or enum keyword present in the
+ // elaborated-type-specifier shall agree in kind with the
+ // declaration to which the name in theelaborated-type-specifier
+ // refers. This rule also applies to the form of
+ // elaborated-type-specifier that declares a class-name or
+ // friend class since it can be construed as referring to the
+ // definition of the class. Thus, in any
+ // elaborated-type-specifier, the enum keyword shall be used to
+ // refer to an enumeration (7.2), the union class-keyshall be
+ // used to refer to a union (clause 9), and either the class or
+ // struct class-key shall be used to refer to a class (clause 9)
+ // declared using the class or struct class-key.
+ TagDecl::TagKind OldTag = Previous->getTagKind();
+ if (OldTag == NewTag)
+ return true;
+
+ if ((OldTag == TagDecl::TK_struct || OldTag == TagDecl::TK_class) &&
+ (NewTag == TagDecl::TK_struct || NewTag == TagDecl::TK_class)) {
+ // Warn about the struct/class tag mismatch.
+ bool isTemplate = false;
+ if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous))
+ isTemplate = Record->getDescribedClassTemplate();
+
+ Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch)
+ << (NewTag == TagDecl::TK_class)
+ << isTemplate << &Name
+ << (OldTag == TagDecl::TK_class)
+ << CodeModificationHint::CreateReplacement(SourceRange(NewTagLoc),
+ OldTag == TagDecl::TK_class? "class" : "struct");
+ Diag(Previous->getLocation(), diag::note_previous_use);
+ return true;
+ }
+ return false;
+}
+
/// ActOnTag - This is invoked when we see 'struct foo' or 'struct {'. In the
/// former case, Name will be non-null. In the later case, Name will be null.
/// TagSpec indicates what kind of tag this is. TK indicates whether this is a
@@ -3347,7 +3392,7 @@
if (TK == TK_Reference || isDeclInScope(PrevDecl, SearchDC, S)) {
// Make sure that this wasn't declared as an enum and now used as a
// struct or something similar.
- if (!isAcceptableTagRedeclaration(PrevTagDecl->getTagKind(), Kind)) {
+ if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, KWLoc, *Name)) {
bool SafeToContinue
= (PrevTagDecl->getTagKind() != TagDecl::TK_enum &&
Kind != TagDecl::TK_enum);
Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=71773&r1=71772&r2=71773&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplate.cpp Thu May 14 11:41:31 2009
@@ -461,7 +461,7 @@
// the class-key shall agree in kind with the original class
// template declaration (7.1.5.3).
RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
- if (!isAcceptableTagRedeclaration(PrevRecordDecl->getTagKind(), Kind)) {
+ if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind, KWLoc, *Name)) {
Diag(KWLoc, diag::err_use_with_wrong_tag)
<< Name
<< CodeModificationHint::CreateReplacement(KWLoc,
@@ -2026,9 +2026,9 @@
case DeclSpec::TST_union: Kind = TagDecl::TK_union; break;
case DeclSpec::TST_class: Kind = TagDecl::TK_class; break;
}
- if (!isAcceptableTagRedeclaration(
- ClassTemplate->getTemplatedDecl()->getTagKind(),
- Kind)) {
+ if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
+ Kind, KWLoc,
+ *ClassTemplate->getIdentifier())) {
Diag(KWLoc, diag::err_use_with_wrong_tag)
<< ClassTemplate
<< CodeModificationHint::CreateReplacement(KWLoc,
@@ -2182,9 +2182,9 @@
case DeclSpec::TST_union: Kind = TagDecl::TK_union; break;
case DeclSpec::TST_class: Kind = TagDecl::TK_class; break;
}
- if (!isAcceptableTagRedeclaration(
- ClassTemplate->getTemplatedDecl()->getTagKind(),
- Kind)) {
+ if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
+ Kind, KWLoc,
+ *ClassTemplate->getIdentifier())) {
Diag(KWLoc, diag::err_use_with_wrong_tag)
<< ClassTemplate
<< CodeModificationHint::CreateReplacement(KWLoc,
Modified: cfe/trunk/test/SemaCXX/struct-class-redecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/struct-class-redecl.cpp?rev=71773&r1=71772&r2=71773&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/struct-class-redecl.cpp (original)
+++ cfe/trunk/test/SemaCXX/struct-class-redecl.cpp Thu May 14 11:41:31 2009
@@ -1,8 +1,8 @@
-// RUN: clang-cc -fsyntax-only -verify %s
-class X; // expected-note{{here}}
-typedef struct X * X_t;
+// RUN: clang-cc -fsyntax-only -Wmismatched-tags -verify %s
+class X; // expected-note 2{{here}}
+typedef struct X * X_t; // expected-warning{{previously declared}}
-template<typename T> class Y;
-template<class U> struct Y { };
+template<typename T> struct Y; // expected-note{{previous}}
+template<class U> class Y { }; // expected-warning{{previously declared}}
union X { int x; float y; }; // expected-error{{use of 'X' with tag type that does not match previous declaration}}
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