Commit Graph

2 Commits

Author SHA1 Message Date
George Burgess IV d3cf025ae2 [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
2017-06-27 21:31:31 +00:00
Peter Collingbourne eeebc41b58 AST: Implement mangling support for function types without a prototype.
Function types without prototypes can arise when mangling a function type
within an overloadable function in C. We mangle these as the absence of
any parameter types (not even an empty parameter list).

Differential Revision: http://reviews.llvm.org/D11848

llvm-svn: 244374
2015-08-07 23:25:47 +00:00