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
This reverts commit r193255 and instead creates an lto_bool_t typedef
that points to bool, _Bool, or unsigned char depending on what is
available. Only recent versions of MSVC provide a stdbool.h header.
Reviewers: rafael.espindola
Differential Revision: http://llvm-reviews.chandlerc.com/D2019
llvm-svn: 193377
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
Enable building the LTO library (.lib and.dll) and llvm-lto.exe on Windows with
MSVC and Mingw as well as re-enabling the associated test.
Patch by Greg Bedwell!
llvm-svn: 191823
Enable building the LTO library (.lib and.dll) and llvm-lto.exe on Windows with
MSVC and Mingw as well as re-enabling the associated test.
Patch by Greg Bedwell!
llvm-svn: 191670
----
Add new API lto_codegen_compile_parallel().
This API is proposed by Nick Kledzik. The semantic is:
--------------------------------------------------------------------------
Generate code for merged module into an array of native object files. On
success returns a pointer to an array of NativeObjectFile. The count
parameter returns the number of elements in the array. Each element is
a pointer/length for a generated mach-o/ELF buffer. The buffer is owned
by the lto_code_gen_t and will be freed when lto_codegen_dispose() is called,
or lto_codegen_compile() is called again. On failure, returns NULL
(check lto_get_error_message() for details).
extern const struct NativeObjectFile*
lto_codegen_compile_parallel(lto_code_gen_t cg, size_t *count);
---------------------------------------------------------------------------
This API is currently only called on OSX platform. Linux or other Unixes
using GNU gold are not supposed to call this function, because on these systems,
object files are fed back to linker via disk file instead of memory buffer.
In this commit, lto_codegen_compile_parallel() simply calls
lto_codegen_compile() to return a single object file. In the near future,
this function is the entry point for compilation with partition. Linker can
blindly call this function even if partition is turned off; in this case,
compiler will return only one object file.
llvm-svn: 189386
This API is proposed by Nick Kledzik. The semantic is:
--------------------------------------------------------------------------
Generate code for merged module into an array of native object files. On
success returns a pointer to an array of NativeObjectFile. The count
parameter returns the number of elements in the array. Each element is
a pointer/length for a generated mach-o/ELF buffer. The buffer is owned
by the lto_code_gen_t and will be freed when lto_codegen_dispose() is called,
or lto_codegen_compile() is called again. On failure, returns NULL
(check lto_get_error_message() for details).
extern const struct NativeObjectFile*
lto_codegen_compile_parallel(lto_code_gen_t cg, size_t *count);
---------------------------------------------------------------------------
This API is currently only called on OSX platform. Linux or other Unixes
using GNU gold are not supposed to call this function, because on these systems,
object files are fed back to linker via disk file instead of memory buffer.
In this commit, lto_codegen_compile_parallel() simply calls
lto_codegen_compile() to return a single object file. In the near future,
this function is the entry point for compilation with partition. Linker can
blindly call this function even if partition is turned off; in this case,
compiler will return only one object file.
llvm-svn: 189297
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
Currently, when an invalid attribute is encountered on processing a .s file,
clang will abort due to llvm_unreachable. Invalid user input should not cause
an abnormal termination of the compiler. Change the interface to return a
boolean to indicate the failure as a first step towards improving hanlding of
malformed user input to clang.
Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
llvm-svn: 188047
Function attributes are the future! So just query whether we want to realign the
stack directly from the function instead of through a random target options
structure.
llvm-svn: 187618
Merge consecutive if-regions if they contain identical statements.
Both transformations reduce number of branches. The transformation
is guarded by a target-hook, and is currently enabled only for +R600,
but the correctness has been tested on X86 target using a variety of
CPU benchmarks.
Patch by: Mei Ye
llvm-svn: 187278
There's no need to specify a flag to omit frame pointer elimination on non-leaf
nodes...(Honestly, I can't parse that option out.) Use the function attribute
stuff instead.
llvm-svn: 187093
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
Use the function attributes to pass along the stack protector buffer size.
Now that we have robust function attributes, don't use a command line option to
specify the stack protecto buffer size.
llvm-svn: 186863
There already have two "dead" functions, initialize{IPO|IPA}, defined for
similar purpose. I decide not to call these two functions for two reasons:
o. they don't cover all LTO passes (which will soon be separated into IPO
and post-IPO passes)
o. We have not yet figured out the right passes and the ordering for IPO
and post-IPO stages, meaning this change is only for the time being.
Since LTO passes are registered, we are now able to print IR before and
after particular point.
For OSX users:
--------------
"...-Wl,-mllvm -Wl,-print-after=<pass-name>" will print IR after the
specified pass.
For Other UNIX with GNU gold linker:
------------------------------------
"-Wl,-plugin-opt=-print-after=<pass-name>" should work.
(NOTE: no need for "-Wl,-mllvm")
Strip "-Wl," if flags are fed directly to linker instead of clang/clang++.
llvm-svn: 186853
The problem with running internalize before we're ready to output an object file
is that it may change a 'weak' symbol into an internal one, but that symbol
could be needed by an external object file --- e.g. with arclite.
<rdar://problem/14334895>
llvm-svn: 185882
This is dead code since PIC16 was removed in 2010. The result was an odd mix,
where some parts would carefully pass it along and others would assert it was
zero (most of the object streamer for example).
llvm-svn: 185436
