Implement double underscore names support in __has_attribute
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151809 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LanguageExtensions.html b/docs/LanguageExtensions.html
index be26d62..23aa4fe 100644
--- a/docs/LanguageExtensions.html
+++ b/docs/LanguageExtensions.html
@@ -257,6 +257,11 @@
</pre>
</blockquote>
+<p>The attribute name can also be specified with a preceding and
+following <code>__</code> (double underscore) to avoid interference from a macro
+with the same name. For instance, <code>__always_inline__</code> can be used
+instead of <code>always_inline</code>.</p>
+
<!-- ======================================================================= -->
<h2 id="has_include">Include File Checking Macros</h2>
<!-- ======================================================================= -->
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 007be3b..56ce407 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -760,7 +760,12 @@
/// HasAttribute - Return true if we recognize and implement the attribute
/// specified by the given identifier.
static bool HasAttribute(const IdentifierInfo *II) {
- return llvm::StringSwitch<bool>(II->getName())
+ StringRef Name = II->getName();
+ // Normalize the attribute name, __foo__ becomes foo.
+ if (Name.startswith("__") && Name.endswith("__") && Name.size() >= 4)
+ Name = Name.substr(2, Name.size() - 4);
+
+ return llvm::StringSwitch<bool>(Name)
#include "clang/Lex/AttrSpellings.inc"
.Default(false);
}
diff --git a/test/Preprocessor/has_attribute.c b/test/Preprocessor/has_attribute.c
new file mode 100644
index 0000000..825fa06
--- /dev/null
+++ b/test/Preprocessor/has_attribute.c
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 %s
+// RUN: %clang_cc1 %s -E
+#ifndef __has_attribute
+#error Should have __has_attribute
+#endif
+
+#if __has_attribute(something_we_dont_have)
+#error Bad
+#endif
+
+#if !__has_attribute(__always_inline__) || \
+ !__has_attribute(always_inline)
+#error Clang should have this
+#endif