and extern_weak_odr. These are the same as the non-odr versions,
except that they indicate that the global will only be overridden
by an *equivalent* global. In C, a function with weak linkage can
be overridden by a function which behaves completely differently.
This means that IP passes have to skip weak functions, since any
deductions made from the function definition might be wrong, since
the definition could be replaced by something completely different
at link time. This is not allowed in C++, thanks to the ODR
(One-Definition-Rule): if a function is replaced by another at
link-time, then the new function must be the same as the original
function. If a language knows that a function or other global can
only be overridden by an equivalent global, it can give it the
weak_odr linkage type, and the optimizers will understand that it
is alright to make deductions based on the function body. The
code generators on the other hand map weak and weak_odr linkage
to the same thing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66339 91177308-0d34-0410-b5e6-96231b3b80d8
them are generic changes.
- Use the "fast" flag that's already being passed into the asm printers instead
of shoving it into the DwarfWriter.
- Instead of calling "MI->getParent()->getParent()" for every MI, set the
machine function when calling "runOnMachineFunction" in the asm printers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65379 91177308-0d34-0410-b5e6-96231b3b80d8
Now Users request DwarfWriter through getAnalysisUsage() instead of creating an instance of DwarfWriter object directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61955 91177308-0d34-0410-b5e6-96231b3b80d8
well as 2 files that use "Registrator"s. These are to be used by the
MSVC builds, as the Win32 linker does not include libs that are
otherwise unreferenced, even if global constructors in the lib have
side-effects.
Patch by Scott Graham!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59378 91177308-0d34-0410-b5e6-96231b3b80d8
FIXME: it seems, that most of targets don't support
offsets wrt CPI/GlobalAddress', was it intentional?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58917 91177308-0d34-0410-b5e6-96231b3b80d8
This is a temporary fix for the -print-emitted-asm option, where
errs() is used as the stream, in the case where other code is
using stderr without using errs()' buffer. Hopefully soon we'll
fix errs() to be non-buffered instead. Patch by Preston Gurd.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58859 91177308-0d34-0410-b5e6-96231b3b80d8
information is in an unreachable block, then it's possible that the high/low pc
values won't be set for the dwarf information. E.g., this function:
void abort(void) __attribute__((__noreturn__));
void dead_beef(void) __attribute__ ((noreturn));
int *b;
void dead_beef(void) {
*b=0xdeadbeef;
abort();
}
has a call to "@llvm.dbg.region.end" only in the unreachable block:
define void @dead_beef() noreturn nounwind {
entry:
call void @llvm.dbg.func.start(...)
call void @llvm.dbg.stoppoint(...)
...
call void @abort( ) noreturn nounwind
unreachable
return: ; No predecessors!
call void @llvm.dbg.stoppoint(...)
call void @llvm.dbg.region.end(...)
ret void
}
The dwarf information emitted is something like:
0x00000084: TAG_subprogram [5]
AT_name( "dead_beef" )
AT_external( 0x01 )
AT_prototyped( 0x01 )
AT_decl_file( 0x01 )
AT_decl_line( 0x08 )
Note that this is *not* the best fix for this problem, but a band-aid for an
gaping wound. This code needs to be changed when we revamp our debugging
information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56628 91177308-0d34-0410-b5e6-96231b3b80d8
