Summary:
Several changes were required for ThinLTO links involving bitcode
archive static libraries. With this patch clang/llvm bootstraps with
ThinLTO and gold.
The first is that the gold callbacks get_input_file and
release_input_file can normally be used to get file information for
each constituent bitcode file within an archive. However, these
interfaces lock the underlying file and can't be for each archive
constituent for ThinLTO backends where we get all the input files up
front and don't release any until after the backend threads complete.
However, it is sufficient to only get and release once per file, and
then each consituent bitcode file can be accessed via get_view. This
required saving some information to identify which file handle is the
"leader" for each claimed file sharing the same file descriptor, and
other information so that get_input_file isn't necessary later when
processing the backends.
Second, the module paths in the index need to distinguish between
different constituent bitcode files within the same archive file,
otherwise they will all end up with the same archive file path.
Do this by appending the offset within the archive for the start of the
bitcode file, returned by get_input_file when we claim each bitcode file,
and saving that along with the file handle.
Third, rather than have the function importer try to load a file based
on the module path identifier (which now contains a suffix to
distinguish different bitcode files within an archive), use a custom
module loader. This is the same approach taken in libLTO, and I am using
the support refactored into the new LTO.h header in r270509. The module
loader parses the bitcode files out of the memory buffers returned from
gold via the get_view callback and saved in a map. This also means that
we call the function importer directly, rather than add it to the pass
pipeline (which was in the plan to do already for other reasons).
Reviewers: pcc, joker.eph
Subscribers: llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D20559
llvm-svn: 270814
This is a support COFF feature. Ensure that we can display the weak externals
auxiliary symbol. It contains useful information (such as the default binding
and how to resolve the symbol).
This reapplies the previous patch with a modification which hopefully should fix
the endianness issues. The variadic call would promote the ulittle32_t to a
uint32_t which would lose the byte-swapping behaviour desired.
llvm-svn: 270813
There is only one caller of MemorySSA::createNewAccess, and it passes true
as the IgnoreNonMemory argument. Remove that argument and fold its behavior
into createNewAccess.
llvm-svn: 270812
This fixes the example so that it matches the pass's behavior. I was a
little confused by the example until I tried running it and realized that
there was a mistake.
Differential Revision: http://reviews.llvm.org/D20657
llvm-svn: 270811
If there is already debug info in the assembly file, and user hope to
use -g option for compiling, we think we should not directly report an
error.
According to what GNU assembler did, it just reused the debug info in
the assembly file, and turned off the DEBUG_TYPE option so that there
will be no new debug info emitted by assembler. This fix is just as what
GNU assembler did.
The concern is the situation that there are two .text sections in the
assembly file, one with debug info and the other one without. Currently
with this fix, the assembler will no longer generate any debug info for
the second .text section. And this is what GNU assembler exactly did for
this situation. So I think this still make some sense.
Patch by Zhizhou Yang!
Differential Revision: http://reviews.llvm.org/D20002
llvm-svn: 270806
After this change, we do the expected thing for cases like
```
Check0Passed = /* range check IRCE can optimize */
Check1Passed = /* range check IRCE can optimize */
if (!(Check0Passed && Check1Passed))
throw_Exception();
```
llvm-svn: 270804
Richard Smith identified this in post commit review of r270466. The
string sections in particular (in the future, possibly all sections - so
I'm not going to bother pulling out just the string sections for the
extra lifetime handling right now) need to remain valid during
processing of all inputs so that elements of the DWPStringPool can be
looked up repeatedly without having to make in-memory copies of string
contents in the noncompressed case (more common in dwp+dwp merge steps
where the memory is a bigger problem because the files are larger).
Using the SmallVector (or any vector) a reallocation on push_back could
cause any of the nested SmallStrings in small mode to move in memory and
invalid pointers to their contents. Using a deque the SmallStrings will
never move around since no elements are removed from the container.
llvm-svn: 270797
Summary:
This allows the linker to discard unused symbol information for comdat
functions that were discarded during the link. Before this change,
searching for the name of an inline function in the debugger would
return multiple results, one per symbol subsection in the object file.
After this change, there is only one result, the result for the function
chosen by the linker.
Reviewers: zturner, majnemer
Subscribers: aaboud, amccarth, llvm-commits
Differential Revision: http://reviews.llvm.org/D20642
llvm-svn: 270792
When we have "Image Info Version" module flag but don't have "Class Properties"
module flag, set "Class Properties" module flag to 0, so we can correctly emit
errors when one module has the flag set and another module does not.
rdar://26469641
llvm-svn: 270791
This matches the behavior of GNU assembler which supports symbolic
expressions in absolute expressions used in assembly directives.
Differential Revision: http://reviews.llvm.org/D20337
llvm-svn: 270786
If a we have (a) a GEP and (b) a pointer based on an alloca, and the
beginning of the object the GEP points would have a negative offset with
repsect to the alloca, then the GEP can not alias pointer (b).
For example, consider code like:
struct { int f0, int f1, ...} foo;
...
foo alloca;
foo *random = bar(alloca);
int *f0 = &alloca.f0
int *f1 = &random->f1;
Which is lowered, approximately, to:
%alloca = alloca %struct.foo
%random = call %struct.foo* @random(%struct.foo* %alloca)
%f0 = getelementptr inbounds %struct, %struct.foo* %alloca, i32 0, i32 0
%f1 = getelementptr inbounds %struct, %struct.foo* %random, i32 0, i32 1
Assume %f1 and %f0 alias. Then %f1 would point into the object allocated
by %alloca. Since the %f1 GEP is inbounds, that means %random must also
point into the same object. But since %f0 points to the beginning of %alloca,
the highest %f1 can be is (%alloca + 3). This means %random can not be higher
than (%alloca - 1), and so is not inbounds, a contradiction.
Differential Revision: http://reviews.llvm.org/D20495
llvm-svn: 270777
This patch modifies the LiveDebugValues pass to use more efficient set
data structures as outlined in PR26055. Both VarLocSet and VarLocList are
now SparseBitVectors which allows us to perform much faster bitvector
arithmetic on them.
The speedup can be in the order of minutes especially on ASANified code.
The change is not NFC in the assembler output because the inserted
DBG_VALUEs are now sorted by variable and location.
Many thanks to Daniel Berlin for helping design the improved algorithm and
reviewing the patch.
https://llvm.org/bugs/show_bug.cgi?id=26055http://reviews.llvm.org/D20178
rdar://problem/24091200
llvm-svn: 270776
Getting accurate locations for loops is important, because those locations are
used by the frontend to generate optimization remarks. Currently, optimization
remarks for loops often appear on the wrong line, often the first line of the
loop body instead of the loop itself. This is confusing because that line might
itself be another loop, or might be somewhere else completely if the body was
inlined function call. This happens because of the way we find the loop's
starting location. First, we look for a preheader, and if we find one, and its
terminator has a debug location, then we use that. Otherwise, we look for a
location on an instruction in the loop header.
The fallback heuristic is not bad, but will almost always find the beginning of
the body, and not the loop statement itself. The preheader location search
often fails because there's often not a preheader, and even when there is a
preheader, depending on how it was formed, it sometimes carries the location of
some preceeding code.
I don't see any good theoretical way to fix this problem. On the other hand,
this seems like a straightforward solution: Put the debug location in the
loop's llvm.loop metadata. A companion Clang patch will cause Clang to insert
llvm.loop metadata with appropriate locations when generating debugging
information. With these changes, our loop remarks have much more accurate
locations.
Differential Revision: http://reviews.llvm.org/D19738
llvm-svn: 270771
Since r268966 the modern Verifier pass defaults to stripping invalid debug info
in nonasserts builds. This patch ports this behavior back to the legacy
Verifier pass as well. The primary motivation is that the clang frontend
accepts bitcode files as input but is still using the legacy pass pipeline.
Background: The problem I'm trying to solve with this sequence of patches is
that historically we've done a really bad job at verifying debug info. We want
to be able to make the verifier stricter without having to worry about breaking
bitcode compatibility with existing producers. For example, we don't necessarily
want IR produced by an older version of clang to be rejected by an LTO link just
because of malformed debug info, and rather provide an option to strip it. Note
that merely outdated (but well-formed) debug info would continue to be
auto-upgraded in this scenario.
http://reviews.llvm.org/D20629
<rdar://problem/26448800>
llvm-svn: 270768
As a result of D18634 we no longer infer certain attributes on linkonce_odr
functions at compile time, and may only infer them at LTO time. The readnone
attribute in particular is required for virtual constant propagation (part
of whole-program virtual call optimization) to work correctly.
This change moves the whole-program virtual call optimization pass after
the function attribute inference passes, and enables the attribute inference
passes at opt level 1, so that virtual constant propagation has a chance to
work correctly for linkonce_odr functions.
Differential Revision: http://reviews.llvm.org/D20643
llvm-svn: 270765
It may materialize a declaration, or a definition. The name could
be misleading. This is following a merge of materializeInitFor()
into materializeDeclFor().
Differential Revision: http://reviews.llvm.org/D20593
llvm-svn: 270759
They were originally separated to handle the co-recursion between
the ValueMapper and the ValueMaterializer. This recursion does not
exist anymore: the ValueMapper now uses a Worklist and the
ValueMaterializer is scheduling job on the Worklist.
Differential Revision: http://reviews.llvm.org/D20593
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 270758
This test was hitting an assertion in the value mapper because
the IRLinker was trying to map two times @A while materializing
the initializer for @C.
Fix http://llvm.org/PR27850
Differential Revision: http://reviews.llvm.org/D20586
llvm-svn: 270757
We have need to reuse this functionality, including making
additional generic stream types that are smarter about how and
when they copy memory versus referencing the original memory.
So all of these structures belong in the common library
rather than being pdb specific.
llvm-svn: 270751
