aaron.ballman created this revision.
aaron.ballman added reviewers: rsmith, echristo, dblaikie.
Herald added a subscriber: krytarowski.
Currently, we only accept `clang` as the scoped attribute identifier for double
square bracket attributes provided by Clang, but this has the potential to
conflict with user-defined macros. To help alleviate these concerns, this patch
introduces the `_Clang` scoped attribute identifier as an alias for `clang`.
GCC elected to go with `__gnu__` for their protected name, but we cannot follow
suit due to `__clang__` being a predefined macro that identifies the
implementation. I added a warning with a fixit on the off chance someone
attempts to use `__clang__` as the scoped attribute identifier, but do not
support the spelling fully (for instance, `__has_cpp_attribute` does not
support `__clang__`).
https://reviews.llvm.org/D53700
Files:
include/clang/Basic/DiagnosticParseKinds.td
lib/Basic/Attributes.cpp
lib/Parse/ParseDeclCXX.cpp
lib/Sema/ParsedAttr.cpp
test/FixIt/fixit-cxx11-attributes.cpp
test/Parser/cxx0x-attributes.cpp
test/Preprocessor/has_attribute.cpp
test/SemaCXX/attr-optnone.cpp
Index: test/SemaCXX/attr-optnone.cpp
===================================================================
--- test/SemaCXX/attr-optnone.cpp
+++ test/SemaCXX/attr-optnone.cpp
@@ -71,3 +71,9 @@
static void bar();
};
+// Verify that we can handle the [[_Clang::optnone]] and
+// [[__clang__::optnone]] spellings.
+[[_Clang::optnone]] int foo3();
+[[__clang__::optnone]] int foo4(); // expected-warning {{'__clang__' is a predefined macro name, not an attribute scope specifier; did you mean '_Clang' instead?}}
+
+[[_Clang::optnone]] int foo5; // expected-warning {{'optnone' attribute only applies to functions}}
Index: test/Preprocessor/has_attribute.cpp
===================================================================
--- test/Preprocessor/has_attribute.cpp
+++ test/Preprocessor/has_attribute.cpp
@@ -21,11 +21,27 @@
int has_clang_fallthrough_2();
#endif
-// The scope cannot be bracketed with double underscores unless it is for gnu.
+// The scope cannot be bracketed with double underscores unless it is
+// for gnu or clang.
+// CHECK: does_not_have___gsl___suppress
+#if !__has_cpp_attribute(__gsl__::suppress)
+ int does_not_have___gsl___suppress();
+#endif
+
+// We do somewhat support the __clang__ vendor namespace, but it is a
+// predefined macro and thus we encourage users to use _Clang instead.
+// Because of this, we do not support __has_cpp_attribute for that
+// vendor namespace.
// CHECK: does_not_have___clang___fallthrough
#if !__has_cpp_attribute(__clang__::fallthrough)
int does_not_have___clang___fallthrough();
#endif
+
+// CHECK: does_have_Clang_fallthrough
+#if __has_cpp_attribute(_Clang::fallthrough)
+ int does_have_Clang_fallthrough();
+#endif
+
// CHECK: has_gnu_const
#if __has_cpp_attribute(__gnu__::__const__)
int has_gnu_const();
Index: test/Parser/cxx0x-attributes.cpp
===================================================================
--- test/Parser/cxx0x-attributes.cpp
+++ test/Parser/cxx0x-attributes.cpp
@@ -373,3 +373,11 @@
[[attr_name, attr_name_2(bitor), attr_name_3(com, pl)]] int macro_attrs; // expected-warning {{unknown attribute 'compl' ignored}} \
expected-warning {{unknown attribute 'bitor' ignored}} \
expected-warning {{unknown attribute 'bitand' ignored}}
+
+// Check that we can parse an attribute in our vendor namespace.
+[[clang::annotate("test")]] void annotate1();
+[[_Clang::annotate("test")]] void annotate2();
+// Note: __clang__ is a predefined macro, which is why _Clang is the
+// prefered "protected" vendor namespace. We support __clang__ only for
+// people expecting it to behave the same as __gnu__.
+[[__clang__::annotate("test")]] void annotate3(); // expected-warning {{'__clang__' is a predefined macro name, not an attribute scope specifier; did you mean '_Clang' instead?}}
Index: test/FixIt/fixit-cxx11-attributes.cpp
===================================================================
--- test/FixIt/fixit-cxx11-attributes.cpp
+++ test/FixIt/fixit-cxx11-attributes.cpp
@@ -16,15 +16,15 @@
// CHECK: fix-it:{{.*}}:{14:37-14:51}
class base {};
- class [[]] [[]] final_class
+ class [[]] [[]] final_class
alignas(float) [[]] final // expected-error {{an attribute list cannot appear here}}
alignas(float) [[]] [[]] alignas(float): base{}; // expected-error {{an attribute list cannot appear here}}
// CHECK: fix-it:{{.*}}:{19:19-19:19}
// CHECK: fix-it:{{.*}}:{20:5-20:25}
// CHECK: fix-it:{{.*}}:{19:19-19:19}
// CHECK: fix-it:{{.*}}:{21:5-21:44}
- class [[]] [[]] final_class_another
+ class [[]] [[]] final_class_another
[[]] [[]] alignas(16) final // expected-error {{an attribute list cannot appear here}}
[[]] [[]] alignas(16) [[]]{}; // expected-error {{an attribute list cannot appear here}}
// CHECK: fix-it:{{.*}}:{27:19-27:19}
@@ -49,3 +49,6 @@
// CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:26-[[@LINE-4]]:26}:"[{{\[}}d]]"
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:33-[[@LINE-2]]:39}:""
}
+
+[[__clang__::annotate("test")]] void annotate3(); // expected-warning {{'__clang__' is a predefined macro name, not an attribute scope specifier; did you mean '_Clang' instead?}}
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"_Clang"
Index: lib/Sema/ParsedAttr.cpp
===================================================================
--- lib/Sema/ParsedAttr.cpp
+++ lib/Sema/ParsedAttr.cpp
@@ -105,11 +105,15 @@
static StringRef normalizeAttrScopeName(StringRef ScopeName,
ParsedAttr::Syntax SyntaxUsed) {
- // We currently only normalize the "__gnu__" scope name to be "gnu".
- if ((SyntaxUsed == ParsedAttr::AS_CXX11 ||
- SyntaxUsed == ParsedAttr::AS_C2x) &&
- ScopeName == "__gnu__")
- ScopeName = ScopeName.slice(2, ScopeName.size() - 2);
+ // Normalize the "__gnu__" scope name to be "gnu" and the "_Clang" scope name
+ // to be "clang".
+ if (SyntaxUsed == ParsedAttr::AS_CXX11 ||
+ SyntaxUsed == ParsedAttr::AS_C2x) {
+ if (ScopeName == "__gnu__")
+ ScopeName = "gnu";
+ else if (ScopeName == "_Clang")
+ ScopeName = "clang";
+ }
return ScopeName;
}
Index: lib/Parse/ParseDeclCXX.cpp
===================================================================
--- lib/Parse/ParseDeclCXX.cpp
+++ lib/Parse/ParseDeclCXX.cpp
@@ -3790,6 +3790,28 @@
}
return nullptr;
+ case tok::numeric_constant: {
+ // If we got a numeric constant, check to see if it comes from a macro that
+ // corresponds to the predefined __clang__ macro. If it does, warn the user
+ // and recover by pretending they said _Clang instead.
+ if (Tok.getLocation().isMacroID()) {
+ SmallString<8> ExpansionBuf;
+ SourceLocation ExpansionLoc =
+ PP.getSourceManager().getExpansionLoc(Tok.getLocation());
+ StringRef Spelling = PP.getSpelling(ExpansionLoc, ExpansionBuf);
+ if (Spelling == "__clang__") {
+ SourceRange TokRange(
+ ExpansionLoc,
+ PP.getSourceManager().getExpansionLoc(Tok.getEndLoc()));
+ Diag(Tok, diag::warn_wrong_clang_attr_namespace)
+ << FixItHint::CreateReplacement(TokRange, "_Clang");
+ Loc = ConsumeToken();
+ return &PP.getIdentifierTable().get("_Clang");
+ }
+ }
+ return nullptr;
+ }
+
case tok::ampamp: // 'and'
case tok::pipe: // 'bitor'
case tok::pipepipe: // 'or'
@@ -3868,8 +3890,7 @@
return false;
}
- if (ScopeName &&
- (ScopeName->getName() == "gnu" || ScopeName->getName() == "__gnu__")) {
+ if (ScopeName && (ScopeName->isStr("gnu") || ScopeName->isStr("__gnu__"))) {
// GNU-scoped attributes have some special cases to handle GNU-specific
// behaviors.
ParseGNUAttributeArgs(AttrName, AttrNameLoc, Attrs, EndLoc, ScopeName,
@@ -3879,10 +3900,9 @@
unsigned NumArgs;
// Some Clang-scoped attributes have some special parsing behavior.
- if (ScopeName && ScopeName->getName() == "clang")
- NumArgs =
- ParseClangAttributeArgs(AttrName, AttrNameLoc, Attrs, EndLoc, ScopeName,
- ScopeLoc, Syntax);
+ if (ScopeName && (ScopeName->isStr("clang") || ScopeName->isStr("_Clang")))
+ NumArgs = ParseClangAttributeArgs(AttrName, AttrNameLoc, Attrs, EndLoc,
+ ScopeName, ScopeLoc, Syntax);
else
NumArgs =
ParseAttributeArgsCommon(AttrName, AttrNameLoc, Attrs, EndLoc,
Index: lib/Basic/Attributes.cpp
===================================================================
--- lib/Basic/Attributes.cpp
+++ lib/Basic/Attributes.cpp
@@ -12,10 +12,12 @@
if (Name.size() >= 4 && Name.startswith("__") && Name.endswith("__"))
Name = Name.substr(2, Name.size() - 4);
- // Normalize the scope name, but only for gnu attributes.
+ // Normalize the scope name, but only for gnu and clang attributes.
StringRef ScopeName = Scope ? Scope->getName() : "";
if (ScopeName == "__gnu__")
- ScopeName = ScopeName.slice(2, ScopeName.size() - 2);
+ ScopeName = "gnu";
+ else if (ScopeName == "_Clang")
+ ScopeName = "clang";
#include "clang/Basic/AttrHasAttributeImpl.inc"
Index: include/clang/Basic/DiagnosticParseKinds.td
===================================================================
--- include/clang/Basic/DiagnosticParseKinds.td
+++ include/clang/Basic/DiagnosticParseKinds.td
@@ -575,6 +575,9 @@
def warn_cxx98_compat_nullptr : Warning<
"'nullptr' is incompatible with C++98">, InGroup<CXX98Compat>, DefaultIgnore;
+def warn_wrong_clang_attr_namespace : Warning<
+ "'__clang__' is a predefined macro name, not an attribute scope specifier; "
+ "did you mean '_Clang' instead?">, InGroup<IgnoredAttributes>;
def ext_ns_enum_attribute : Extension<
"attributes on %select{a namespace|an enumerator}0 declaration are "
"a C++17 extension">, InGroup<CXX17>;
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
