The tools/lto API is not the best choice for implementing a gold plugin. Among
other issues:
* It is an stable ABI. Old errors stay and we have to be really careful
before adding new features.
* It has to support two fairly different linkers: gold and ld64.
* We end up with a plugin that depends on a shared lib, something quiet
unusual in LLVM land.
* It hides LLVM. For some features in the gold plugin it would be really
nice to be able to just get a Module or a GlobalValue.
This change is intended to be a very direct translation from the C API. It
will just enable other fixes and cleanups.
Tested with a LTO bootstrap on linux.
llvm-svn: 211315
dynamic-no-pic is just another output type. If gnu ld gets support for MachO,
it should also add something like LDPO_DYN_NO_PIC to the plugin interface.
llvm-svn: 211305
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.
llvm-svn: 203083
There are two ways one could implement hiding of linkonce_odr symbols in LTO:
* LLVM tells the linker which symbols can be hidden if not used from native
files.
* The linker tells LLVM which symbols are not used from other object files,
but will be put in the dso symbol table if present.
GOLD's API is the second option. It was implemented almost 1:1 in llvm by
passing the list down to internalize.
LLVM already had partial support for the first option. It is also very similar
to how ld64 handles hiding these symbols when *not* doing LTO.
This patch then
* removes the APIs for the DSO list.
* marks LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN all linkonce_odr unnamed_addr
global values and other linkonce_odr whose address is not used.
* makes the gold plugin responsible for handling the API mismatch.
llvm-svn: 193800
Generalize the API so we can distinguish symbols that are needed just for a DSO
symbol table from those that are used from some native .o.
The symbols that are only wanted for the dso symbol table can be dropped if
llvm can prove every other dso has a copy (linkonce_odr) and the address is not
important (unnamed_addr).
llvm-svn: 191922
In order to appease people (in Apple) who accuse me for committing "huge change" (?) without proper review.
Thank Eric for fixing a compile-warning.
llvm-svn: 188204
1. Add some helper classes for partitions. They are designed in a
way such that the top-level LTO driver will not see much difference
with or without partitioning.
2. Introduce work-dir. Now all intermediate files generated during
LTO phases will be saved under work-dir. User can specify the workdir
via -lto-workdir=/path/to/dir. By default the work-dir will be
erased before linker exit. To keep the workdir, do -lto-keep, or -lto-keep=1.
TODO: Erase the workdir, if the linker exit prematurely.
We are currently not able to remove directory on signal. The support
routines simply ignore directory.
3. Add one new API lto_codegen_get_files_need_remove().
Linker and LTO plugin will communicate via this API about which files
(including directories) need to removed before linker exit.
llvm-svn: 188188
The main observation is that we never need both the filesize and the map size.
When mapping a slice of a file, it doesn't make sense to request a null
terminator and that would be the only case where the filesize would be used.
There are other cleanups that should be done in this area:
* A client should not have to pass the size (even an explicit -1) to say if
it wants a null terminator or not, so we should probably swap the argument
order.
* The default should be to not require a null terminator. Very few clients
require this, but many end up asking for it just because it is the default.
llvm-svn: 186984
The gold plugin was passing the desired map size as the file size. This was
working for two reasons:
* Recent version of gold provide the get_view callback, so this code was not
used.
* In older versions, getOpenFile was called, but the file size is never used
if we don't require null terminated buffers and map size defaults to the
file size.
Thanks to Eli Bendersky for noticing this.
I will try to make this api a bit less error prone.
llvm-svn: 186978
The error message was:
/home/espindola/llvm/llvm/tools/gold/gold-plugin.cpp: In function ‘ld_plugin_status cleanup_hook()’:
/home/espindola/llvm/llvm/tools/gold/gold-plugin.cpp:461:30: error: cannot pass objects of non-trivially-copyable type ‘std::string {aka class std::basic_string<char>}’ through ‘...’
I will check if this was a clang or gcc issue.
llvm-svn: 184138
Again, tools are trickier to pick the main module header for than
library source files. I've started to follow the pattern of using
LLVMContext.h when it is included as a stub for program source files.
llvm-svn: 169252
to hack around this in the gold plugin by deleting a module if no symbol was
needed. Unfortunately, the hack is wrong in the case of o module having no
visible symbols but still having side effects via static constructors.
The bug will have to be fixed in libLTO itself.
llvm-svn: 166745
gold to work. Since the enum value LDPO_PIE has just been added to plugin-api.h,
use a numeric constant for now so that we don't require an unreleased
version of gold to build.
llvm-svn: 158402
gold plugin is built with Large File Support (sizeof(off_t) == 64 on i686)
and the rest of LLVM is built w/o Large File Support
(sizeof(off_t) == 32 on i686) which corrupts the stack.
llvm-svn: 139873
having a library both as bitcode and native code. We want to use the
bitcode first, but if codegen produces new undefined references we have to use
the native code to satisfy those references.
Gold has no notion of bitcode and native search directories, so instead it has
an API where the plugin can instruct it to look for the libraries it is passing
to it. This patch uses that API.
llvm-svn: 106674
ask the linker to take another look into some library or object. The case when
one might want to do this is when codegen introduces a new undefined reference.
The canonical example is libgcc.
llvm-svn: 106303
This is conventional command-line tool behavior. -f now just means
"enable binary output on terminals".
Add a -f option to llvm-extract and llvm-link, for consistency.
Remove F_Force from raw_fd_ostream and enable overwriting and
truncating by default. Introduce an F_Excl flag to permit users to
enable a failure when the file already exists. This flag is
currently unused.
Update Makefiles and documentation accordingly.
llvm-svn: 79990
instead of as two bools. Use this to add a F_Append flag
which has the obvious behavior.
Other unrelated changes conflated into this patch:
1. REmove EH stuff from llvm-dis and llvm-as, the try blocks
are dead.
2. Simplify the filename inference code in llvm-as/llvm-dis,
because raw_fd_ostream does the right thing with '-'.
3. Switch machine verifier to use raw_ostream instead of ostream
(Which is the thing that needed append in the first place).
llvm-svn: 79807
an existing file is considered an error. Convert several tools
to use raw_fd_ostream instead of std::ostream, and to use this
new option instead of doing a manual check.
llvm-svn: 75801
Look for as in the path. Doing it here instead
of llvm-gcc because llvm-gcc has nothing as
convenient as sys::Program::FindProgramByName.
llvm-svn: 73383
run when assembling.
Wire this up to the gold plugin. You can now pass --plugin-opt gcc=/foo/bar/gcc
and it will run that gcc instead of looking for it on the path.
llvm-svn: 70490
list that can in turn be passed to -internalize pass through
-internalize-public-api-file.
Pass gold -plugin-opt=generate-api-file to produce "apifile.txt" in the current
directory.
llvm-svn: 65295
Before this change, the program:
int var;
int main(void) { return 0; }
when run under 'nm -g' would show 'U var' with the gold plugin and
'B var' with gcc.
llvm-svn: 64616
Rafael Espindola