[Sema] Allow unmarked overloadable functions.
This patch extends the `overloadable` attribute to allow for one
function with a given name to not be marked with the `overloadable`
attribute. The overload without the `overloadable` attribute will not
have its name mangled.
So, the following code is now legal:
void foo(void) __attribute__((overloadable));
void foo(int);
void foo(float) __attribute__((overloadable));
In addition, this patch fixes a bug where we'd accept code with
`__attribute__((overloadable))` inconsistently applied. In other words,
we used to accept:
void foo(void);
void foo(void) __attribute__((overloadable));
But we will do this no longer, since it defeats the original purpose of
requiring `__attribute__((overloadable))` on all redeclarations of a
function.
This breakage seems to not be an issue in practice, since the only code
I could find that had this pattern often looked like:
void foo(void);
void foo(void) __attribute__((overloadable)) __asm__("foo");
void foo(int) __attribute__((overloadable));
...Which can now be simplified by simply removing the asm label and
overloadable attribute from the redeclaration of `void foo(void);`
Differential Revision: https://reviews.llvm.org/D32332
llvm-svn: 306467
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp
index a6bfc32..8af9a50 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -1315,6 +1315,8 @@
.Case("cxx_binary_literals", true)
.Case("cxx_init_captures", LangOpts.CPlusPlus11)
.Case("cxx_variable_templates", LangOpts.CPlusPlus)
+ // Miscellaneous language extensions
+ .Case("overloadable_unmarked", true)
.Default(false);
}