Dragonegg doesn't handle __attribute__((alias(...)))

[llvmbot]

Bugzilla Link	10587
Resolution	FIXED
Resolved on	Aug 06, 2011 12:08
Version	trunk
OS	Linux
Reporter	LLVM Bugzilla Contributor

Extended Description

With the source file:

foo.c

int foo(int x) { return x; }

extern typeof(foo) foo2 __attribute((alias("foo")));

compiling with dragonegg results in only foo being defined while compiling with vanilla gcc results in both foo and foo2 being defined.

[llvmbot]

The problem to be solved here is to find a way for dragonegg to discover the
existence of foo2. It doesn't seem to be in any of the info that dragonegg
currently processes...

[llvmbot]

What is the best source of information on the gcc plugin system? The relevant information seems like it might be in the GENERIC tree representation:

http://gcc.gnu.org/onlinedocs/gccint/Function-Properties.html#Function-Properties

at least that seems to have a way to process external symbols. From what I can tell, dragonegg doesn't process extern declarations at all, it just adds a var arg function for external symbols. Is that right?

The problem to be solved here is to find a way for dragonegg to discover the
existence of foo2. It doesn't seem to be in any of the info that dragonegg
currently processes...

[llvmbot]

Actually, this is a regression: I changed the way that aliases are handled
recently, and that broke this example (which used to work). In short: I
understand everything and have a fix :)

[llvmbot]

Fixed here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110801/125618.html

As for the question "From what I can tell, dragonegg doesn't process extern
declarations at all, it just adds a var arg function for external symbols.
Is that right?": dragonegg only processes external declarations if they are
used by something. But when it does process an external declaration it outputs
it properly (except for Fortran, where the Fortran frontend is so buggy I gave
up and forced all external functions to be declared as varargs).