This change unifies how LTOModule and the backend obtain linker flags
for globals: via a new TargetLoweringObjectFile member function named
emitLinkerFlagsForGlobal. A new function LTOModule::getLinkerOpts() returns
the list of linker flags as a single concatenated string.
This change affects the C libLTO API: the function lto_module_get_*deplibs now
exposes an empty list, and lto_module_get_*linkeropts exposes a single element
which combines the contents of all observed flags. libLTO should never have
tried to parse the linker flags; it is the linker's job to do so. Because
linkers will need to be able to parse flags in regular object files, it
makes little sense for libLTO to have a redundant mechanism for doing so.
The new API is compatible with the old one. It is valid for a user to specify
multiple linker flags in a single pragma directive like this:
#pragma comment(linker, "/defaultlib:foo /defaultlib:bar")
The previous implementation would not have exposed
either flag via lto_module_get_*deplibs (as the test in
TargetLoweringObjectFileCOFF::getDepLibFromLinkerOpt was case sensitive)
and would have exposed "/defaultlib:foo /defaultlib:bar" as a single flag via
lto_module_get_*linkeropts. This may have been a bug in the implementation,
but it does give us a chance to fix the interface.
Differential Revision: http://reviews.llvm.org/D10548
llvm-svn: 241010
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
llvm-svn: 240137
Start using C++ types such as StringRef and MemoryBuffer in the C++ LTO
API. In doing so, clarify the ownership of the native object file: the caller
now owns it, not the LTOCodeGenerator. The C libLTO library has been modified
to use a derived class of LTOCodeGenerator that owns the object file.
Differential Revision: http://reviews.llvm.org/D10114
llvm-svn: 238776
Reverse libLTO's default behaviour for preserving use-list order in
bitcode, and add API for controlling it. The default setting is now
`false` (don't preserve them), which is consistent with `clang`'s
default behaviour.
Users of libLTO should call `lto_codegen_should_embed_uselists(CG,true)`
prior to calling `lto_codegen_write_merged_modules()` whenever the
output file isn't part of the production workflow in order to reproduce
results with subsequent calls to `llc`.
(I haven't added tests since `llvm-lto` (the test tool for LTO) doesn't
support bitcode output, and even if it did: there isn't actually a good
way to test whether a tool has passed the flag. If the order is already
"natural" (if the order will already round-trip) then no use-list
directives are emitted at all. At some point I'll circle back to add
tests to `llvm-as` (etc.) that they actually respect the flag, at which
point I can somehow add a test here as well.)
llvm-svn: 235943
When debugging LTO issues with ld64, we use -save-temps to save the merged
optimized bitcode file, then invoke ld64 again on the single bitcode file.
The saved bitcode file is already internalized, so we can call
lto_codegen_set_should_internalize and skip running internalization again.
rdar://20227235
llvm-svn: 235211
This change also introduces a link-time optimization level of 1. This
optimization level runs only the globaldce pass as well as cleanup passes for
passes that run at -O0, specifically simplifycfg which cleans up lowerbitsets.
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150316/266951.html
llvm-svn: 232769
When debugging LTO issues with ld64, we use -save-temps to save the merged
optimized bitcode file, then invoke ld64 again on the single bitcode file to
speed up debugging code generation passes and ld64 stuff after code generation.
llvm linking a single bitcode file via lto_codegen_add_module will generate a
different bitcode file from the single input. With the newly-added
lto_codegen_set_module, we can make sure the destination module is the same as
the input.
lto_codegen_set_module will transfer the ownship of the module to code
generator.
rdar://19024554
llvm-svn: 230290
lto_codegen_compile_optimized. Also add lto_api_version.
Before this commit, we can only dump the optimized bitcode after running
lto_codegen_compile, but it includes some impacts of running codegen passes,
one example is StackProtector pass. We will get assertion failure when running
llc on the optimized bitcode, because StackProtector is effectively run twice.
After splitting lto_codegen_compile, the linker can choose to dump the bitcode
before running lto_codegen_compile_optimized.
lto_api_version is added so ld64 can check for runtime-availability of the new
API.
rdar://19565500
llvm-svn: 228000
Having two ways to do this doesn't seem terribly helpful and
consistently using the insert version (which we already has) seems like
it'll make the code easier to understand to anyone working with standard
data structures. (I also updated many references to the Entry's
key and value to use first() and second instead of getKey{Data,Length,}
and get/setValue - for similar consistency)
Also removes the GetOrCreateValue functions so there's less surface area
to StringMap to fix/improve/change/accommodate move semantics, etc.
llvm-svn: 222319
We used to always vectorize (slp and loop vectorize) in the LTO pass pipeline.
r220345 changed it so that we used the PassManager's fields 'LoopVectorize' and
'SLPVectorize' out of the desire to be able to disable vectorization using the
cl::opt flags 'vectorize-loops'/'slp-vectorize' which the before mentioned
fields default to.
Unfortunately, this turns off vectorization because those fields
default to false.
This commit adds flags to the LTO library to disable lto vectorization which
reconciles the desire to optionally disable vectorization during LTO and
the desired behavior of defaulting to enabled vectorization.
We really want tools to set PassManager flags directly to enable/disable
vectorization and not go the route via cl::opt flags *in*
PassManagerBuilder.cpp.
llvm-svn: 220652
Owning the buffer is somewhat inflexible. Some Binaries have sub Binaries
(like Archive) and we had to create dummy buffers just to handle that. It is
also a bad fit for IRObjectFile where the Module wants to own the buffer too.
Keeping this ownership would make supporting IR inside native objects
particularly painful.
This patch focuses in lib/Object. If something elsewhere used to own an Binary,
now it also owns a MemoryBuffer.
This patch introduces a few new types.
* MemoryBufferRef. This is just a pair of StringRefs for the data and name.
This is to MemoryBuffer as StringRef is to std::string.
* OwningBinary. A combination of Binary and a MemoryBuffer. This is needed
for convenience functions that take a filename and return both the
buffer and the Binary using that buffer.
The C api now uses OwningBinary to avoid any change in semantics. I will start
a new thread to see if we want to change it and how.
llvm-svn: 216002
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)
Changes made by clang-tidy with minor tweaks.
llvm-svn: 215558
IRObjectFile provides all the logic for producing mangled names and getting
symbols from inline assembly.
LTOModule then adds logic for linking specific tasks, like constructing
llvm.compiler_user or extracting linker options from the bitcode.
The rule of the thumb is that IRObjectFile has the functionality that is
needed by both LTO and llvm-ar.
llvm-svn: 212349
We want to encourage users of the C++ LTO API to reuse memory buffers instead
of repeatedly opening and reading the same file contents.
This reverts commit r212305 and implements a tidier scheme.
llvm-svn: 212308
This rename makes it easier to identify the specific overload being called
in each particular case and makes future refactorings easier.
Differential Revision: http://reviews.llvm.org/D4370
llvm-svn: 212302
This adds support for an -mattr option to the gold plugin and to llvm-lto. This
allows the caller to specify details of the subtarget architecture, like +aes,
or +ssse3 on x86. Note that this requires a change to the include/llvm-c/lto.h
interface: it adds a function lto_codegen_set_attr and it increments the
version of the interface.
llvm-svn: 207279
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
This function adds an extra path argument to lto_module_create_from_memory.
The path argument will be passed to makeBuffer to make sure the MemoryBuffer
has a name and the created module has a module identifier.
This is mainly for emitting warning messages from the linker. When we emit
warning message on a module, we can use the module identifier.
rdar://15985737
llvm-svn: 201114
Add a hook in the C API of LTO so that clients of the code generator can set
their own handler for the LLVM diagnostics.
The handler is defined like this:
typedef void (*lto_diagnostic_handler_t)(lto_codegen_diagnostic_severity_t
severity, const char *diag, void *ctxt)
- severity says how bad this is.
- diag is a string that contains the diagnostic message.
- ctxt is the registered context for this handler.
This hook is more general than the lto_get_error_message, since this function
keeps only the latest message and can only be queried when something went wrong
(no warning for instance).
<rdar://problem/15517596>
llvm-svn: 199338
Reapply r199191, reverted in r199197 because it carelessly broke
Other/link-opts.ll. The problem was that calling
createInternalizePass("main") would select
createInternalizePass(bool("main")) instead of
createInternalizePass(ArrayRef<const char *>("main")). This commit
fixes the bug.
The original commit message follows.
Add API to LTOCodeGenerator to specify a strategy for the -internalize
pass.
This is a new attempt at Bill's change in r185882, which he reverted in
r188029 due to problems with the gold linker. This puts the onus on the
linker to decide whether (and what) to internalize.
In particular, running internalize before outputting an object file may
change a 'weak' symbol into an internal one, even though that symbol
could be needed by an external object file --- e.g., with arclite.
This patch enables three strategies:
- LTO_INTERNALIZE_FULL: the default (and the old behaviour).
- LTO_INTERNALIZE_NONE: skip -internalize.
- LTO_INTERNALIZE_HIDDEN: only -internalize symbols with hidden
visibility.
LTO_INTERNALIZE_FULL should be used when linking an executable.
Outputting an object file (e.g., via ld -r) is more complicated, and
depends on whether hidden symbols should be internalized. E.g., for
ld -r, LTO_INTERNALIZE_NONE can be used when -keep_private_externs, and
LTO_INTERNALIZE_HIDDEN can be used otherwise. However,
LTO_INTERNALIZE_FULL is inappropriate, since the output object file will
eventually need to link with others.
lto_codegen_set_internalize_strategy() sets the strategy for subsequent
calls to lto_codegen_write_merged_modules() and lto_codegen_compile*().
<rdar://problem/14334895>
llvm-svn: 199244
Add API to LTOCodeGenerator to specify a strategy for the -internalize
pass.
This is a new attempt at Bill's change in r185882, which he reverted in
r188029 due to problems with the gold linker. This puts the onus on the
linker to decide whether (and what) to internalize.
In particular, running internalize before outputting an object file may
change a 'weak' symbol into an internal one, even though that symbol
could be needed by an external object file --- e.g., with arclite.
This patch enables three strategies:
- LTO_INTERNALIZE_FULL: the default (and the old behaviour).
- LTO_INTERNALIZE_NONE: skip -internalize.
- LTO_INTERNALIZE_HIDDEN: only -internalize symbols with hidden
visibility.
LTO_INTERNALIZE_FULL should be used when linking an executable.
Outputting an object file (e.g., via ld -r) is more complicated, and
depends on whether hidden symbols should be internalized. E.g., for
ld -r, LTO_INTERNALIZE_NONE can be used when -keep_private_externs, and
LTO_INTERNALIZE_HIDDEN can be used otherwise. However,
LTO_INTERNALIZE_FULL is inappropriate, since the output object file will
eventually need to link with others.
lto_codegen_set_internalize_strategy() sets the strategy for subsequent
calls to lto_codegen_write_merged_modules() and lto_codegen_compile*().
<rdar://problem/14334895>
llvm-svn: 199191
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.
Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.
llvm-svn: 198685
