[ThinLTO] Only emit referenced type id records in index files

Summary:
Currently all type ids are emitted into the index file when it is
written. For distributed ThinLTO, that meant that all type id

[ThinLTO] Only emit referenced type id records in index files

Summary:
Currently all type ids are emitted into the index file when it is
written. For distributed ThinLTO, that meant that all type ids were
being duplicated into every single distributed index file, regardless of
whether they were referenced, leading to huge amounts of unnecessary
duplication and size bloat.

Keep track of the type id GUIDs actually referenced by the GV summary
records being emitted, and only emit those type IDs.

Add a new test, and fix test/Assembler/thinlto-summary.ll so that all
type ids are referenced to prevent deletion in that test.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, vitalybuka, llvm-commits

Differential Revision: https://reviews.llvm.org/D49565

llvm-svn: 337503

show more ...

[ThinLTO] Parse module summary index from assembly

Summary:
Adds assembly parsing support for the module summary index (follow on
to r333335 which added the assembly writing support).

I added suppo

[ThinLTO] Parse module summary index from assembly

Summary:
Adds assembly parsing support for the module summary index (follow on
to r333335 which added the assembly writing support).

I added support to llvm-as to invoke the index parsing, so that it can
create either a bitcode file with a Module and a per-module index, or
a combined index without a Module.

I will send follow on patches soon to do the following:
- add support to tools such as llvm-lto2 to parse the per-module indexes
from assembly instead of bitcode when testing the thin link.
- verification support.

Depends on D47844 and D47842.

Reviewers: pcc, dexonsmith, mehdi_amini

Subscribers: inglorion, eraman, steven_wu, llvm-commits

Differential Revision: https://reviews.llvm.org/D47905

llvm-svn: 335602

show more ...

[ThinLTO] Compute GUID directly from GV when building per-module index

Summary:
I discovered when writing the summary parsing support that the
per-module index builder and writer are computing the G

[ThinLTO] Compute GUID directly from GV when building per-module index

Summary:
I discovered when writing the summary parsing support that the
per-module index builder and writer are computing the GUID from the
value name alone (ignoring the linkage type). This was ok since those
GUID were not emitted in the bitcode, and there are never multiple
conflicting names in a single module.

However, I don't see a reason for making the GUID computation different
for the per-module case. It also makes things simpler on the parsing
side to have the GUID computation consistent. So this patch changes the
summary analysis phase and the per-module summary writer to compute the
GUID using the facility on the GlobalValue.

Reviewers: pcc, dexonsmith

Subscribers: llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D47844

llvm-svn: 335560

show more ...

[DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.

In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
nam

[DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.

In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is

!DILabel(scope: !1, name: "foo", file: !2, line: 3)

We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is

llvm.dbg.label(metadata !1)

It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.

We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.

Differential Revision: https://reviews.llvm.org/D45024

Patch by Hsiangkai Wang.

llvm-svn: 331841

show more ...

IWYU for llvm-config.h in llvm, additions.

See r331124 for how I made a list of files missing the include.
I then ran this Python script:

for f in open('filelist.txt'):
f = f.strip()

IWYU for llvm-config.h in llvm, additions.

See r331124 for how I made a list of files missing the include.
I then ran this Python script:

for f in open('filelist.txt'):
f = f.strip()
fl = open(f).readlines()

found = False
for i in xrange(len(fl)):
p = '#include "llvm/'
if not fl[i].startswith(p):
continue
if fl[i][len(p):] > 'Config':
fl.insert(i, '#include "llvm/Config/llvm-config.h"\n')
found = True
break
if not found:
print 'not found', f
else:
open(f, 'w').write(''.join(fl))

and then looked through everything with `svn diff | diffstat -l | xargs -n 1000 gvim -p`
and tried to fix include ordering and whatnot.

No intended behavior change.

llvm-svn: 331184

show more ...

[Bitcode] Change std::sort to llvm::sort in response to r327219

Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-det

[Bitcode] Change std::sort to llvm::sort in response to r327219

Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.

To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.

Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.

Reviewers: pcc, mehdi_amini, dexonsmith

Reviewed By: dexonsmith

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45132

llvm-svn: 329334

show more ...

Add the ShadowCallStack attribute

Summary:
Introduce the ShadowCallStack function attribute. It's added to
functions compiled with -fsanitize=shadow-call-stack in order to mark
functions to be instr

Add the ShadowCallStack attribute

Summary:
Introduce the ShadowCallStack function attribute. It's added to
functions compiled with -fsanitize=shadow-call-stack in order to mark
functions to be instrumented by a ShadowCallStack pass to be submitted
in a separate change.

Reviewers: pcc, kcc, kubamracek

Reviewed By: pcc, kcc

Subscribers: cryptoad, mehdi_amini, javed.absar, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D44800

llvm-svn: 329108

show more ...

[ThinLTO] Add an option to force summary call edges cold for debugging

Summary:
Useful to selectively disable importing into specific modules for
debugging/triaging/workarounds.

Reviewers: eraman

[ThinLTO] Add an option to force summary call edges cold for debugging

Summary:
Useful to selectively disable importing into specific modules for
debugging/triaging/workarounds.

Reviewers: eraman

Subscribers: inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D45062

llvm-svn: 328909

show more ...

[SimplifyCFG] Create attribute for fuzzing-specific optimizations.

Summary:
When building with libFuzzer, converting control flow to selects or
obscuring the original operands of CMPs reduces the ef

[SimplifyCFG] Create attribute for fuzzing-specific optimizations.

Summary:
When building with libFuzzer, converting control flow to selects or
obscuring the original operands of CMPs reduces the effectiveness of
libFuzzer's heuristics.

This patch provides an attribute to disable or modify certain optimizations
for optimal fuzzing signal.

Provides a less aggressive alternative to https://reviews.llvm.org/D44057.

Reviewers: vitalybuka, davide, arsenm, hfinkel

Reviewed By: vitalybuka

Subscribers: junbuml, mehdi_amini, wdng, javed.absar, hiraditya, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D44232

llvm-svn: 328214

show more ...

[X86] Added support for nocf_check attribute for indirect Branch Tracking

X86 Supports Indirect Branch Tracking (IBT) as part of Control-Flow Enforcement Technology (CET).
IBT instruments ENDBR inst

[X86] Added support for nocf_check attribute for indirect Branch Tracking

X86 Supports Indirect Branch Tracking (IBT) as part of Control-Flow Enforcement Technology (CET).
IBT instruments ENDBR instructions used to specify valid targets of indirect call / jmp.
The `nocf_check` attribute has two roles in the context of X86 IBT technology:
1. Appertains to a function - do not add ENDBR instruction at the beginning of the function.
2. Appertains to a function pointer - do not track the target function of this pointer by adding nocf_check prefix to the indirect-call instruction.

This patch implements `nocf_check` context for Indirect Branch Tracking.
It also auto generates `nocf_check` prefixes before indirect branchs to jump tables that are guarded by range checks.

Differential Revision: https://reviews.llvm.org/D41879

llvm-svn: 327767

show more ...

[DebugInfo] Support DWARF v5 source code embedding extension

In DWARF v5 the Line Number Program Header is extensible, allowing values with
new content types. In this extension a content type is add

[DebugInfo] Support DWARF v5 source code embedding extension

In DWARF v5 the Line Number Program Header is extensible, allowing values with
new content types. In this extension a content type is added,
DW_LNCT_LLVM_source, which contains the embedded source code of the file.

Add new optional attribute for !DIFile IR metadata called source which contains
source text. Use this to output the source to the DWARF line table of code
objects. Analogously extend METADATA_FILE in Bitcode and .file directive in ASM
to support optional source.

Teach llvm-dwarfdump and llvm-objdump about the new values. Update the output
format of llvm-dwarfdump to make room for the new attribute on file_names
entries, and support embedded sources for the -source option in llvm-objdump.

Differential Revision: https://reviews.llvm.org/D42765

llvm-svn: 325970

show more ...

bitcode support change for fast flags compatibility

Summary: The discussion and as per need, each vendor needs a way to keep the old fast flags and the new fast flags in the auto upgrade path of the

bitcode support change for fast flags compatibility

Summary: The discussion and as per need, each vendor needs a way to keep the old fast flags and the new fast flags in the auto upgrade path of the IR upgrader. This revision addresses that issue.

Patched by Michael Berg

Reviewers: qcolombet, hans, steven_wu

Reviewed By: qcolombet, steven_wu

Subscribers: dexonsmith, vsk, mehdi_amini, andrewrk, MatzeB, wristow, spatel

Differential Revision: https://reviews.llvm.org/D43253

llvm-svn: 325525

show more ...

[ThinLTO] Allow indexing to request backend to ignore the module

Summary:
Gold plugin does not add pass to ThinLTO modules without useful symbols.
In this case ThinLTO can't create corresponding ind

[ThinLTO] Allow indexing to request backend to ignore the module

Summary:
Gold plugin does not add pass to ThinLTO modules without useful symbols.
In this case ThinLTO can't create corresponding index file and some features, like CFI,
cannot be processes by backed correctly without index.
Given that we don't need the backed output we can request it to avoid
processing the module. This is implemented by this patch using new
"SkipModuleByDistributedBackend" flag.

Reviewers: pcc, tejohnson

Subscribers: mehdi_amini, inglorion, eraman, cfe-commits

Differential Revision: https://reviews.llvm.org/D42995

llvm-svn: 325411

show more ...

[ThinLTO/CFI] Include TYPE_ID summaries into GLOBALVAL_SUMMARY_BLOCK

Summary:
TypeID summaries are used by CFI and need to be serialized by ThinLTO
indexing for later use by LTO Backend.

Reviewers:

[ThinLTO/CFI] Include TYPE_ID summaries into GLOBALVAL_SUMMARY_BLOCK

Summary:
TypeID summaries are used by CFI and need to be serialized by ThinLTO
indexing for later use by LTO Backend.

Reviewers: tejohnson, pcc

Subscribers: mehdi_amini, inglorion, eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D42611

llvm-svn: 325182

show more ...

Pass a reference to a module to the bitcode writer.

This simplifies most callers as they are already using references or
std::unique_ptr.

llvm-svn: 325155

[DebugInfo] Unify ChecksumKind and Checksum value in DIFile

Rather than encode the absence of a checksum with a Kind variant, instead put
both the kind and value in a struct and wrap it in an Option

[DebugInfo] Unify ChecksumKind and Checksum value in DIFile

Rather than encode the absence of a checksum with a Kind variant, instead put
both the kind and value in a struct and wrap it in an Optional.

Differential Revision: http://reviews.llvm.org/D43043

llvm-svn: 324928

show more ...

Re-commit r324489: [DebugInfo] Improvements to representation of enumeration types (PR36168)

Differential Revision: https://reviews.llvm.org/D42734

llvm-svn: 324899

Revert "[DebugInfo] Improvements to representation of enumeration types (PR36168)"

Revert commit r324489, it broke LLDB tests.

llvm-svn: 324511

[DebugInfo] Improvements to representation of enumeration types (PR36168)

This patch is the LLVM part of fixing the issues, described in
https://bugs.llvm.org/show_bug.cgi?id=36168

* The representa

[DebugInfo] Improvements to representation of enumeration types (PR36168)

This patch is the LLVM part of fixing the issues, described in
https://bugs.llvm.org/show_bug.cgi?id=36168

* The representation of enumerator values in the debug info metadata now
contains a boolean flag isUnsigned, which determines how the bits of
the value are interpreted.
* The DW_TAG_enumeration type DIE now always (for DWARF version >= 3)
includes a DW_AT_type attribute, which refers to the underlying
integer type, as suggested in DWARFv4 (5.7 Enumeration Type Entries).
* The debug info metadata for enumeration type contains (in flags)
indication whether this is a C++11 "fixed enum".
* For C++11 enumeration with a fixed underlying type, the DIE also
includes the DW_AT_enum_class attribute (for DWARF version >= 4).
* Encoding of enumerator constants uses DW_FORM_sdata for signed values
and DW_FORM_udata for unsigned values, as suggested by DWARFv4 (7.5.4
Attribute Encodings).

The changes should be backwards compatible:

* the isUnsigned attribute is optional and defaults to false.
* if the underlying type for the enumeration is not available, the
enumerator values are considered signed.
* the FixedEnum flag defaults to clear.
* the bitcode format for DIEnumerator stores the unsigned flag bit #1 of
the first record element, so the format does not change and the zero
previously stored there is consistent with the false default for
IsUnsigned.

Differential Revision: https://reviews.llvm.org/D42734

llvm-svn: 324489

show more ...

[ThinLTO] Serialize WithGlobalValueDeadStripping index flag for distributed backends

Summary:
A recent fix to drop dead symbols (r323633) did not work for ThinLTO
distributed backends because we los

[ThinLTO] Serialize WithGlobalValueDeadStripping index flag for distributed backends

Summary:
A recent fix to drop dead symbols (r323633) did not work for ThinLTO
distributed backends because we lose the WithGlobalValueDeadStripping
set on the index during the thin link. This patch adds a new flags
record to the bitcode format for the index, and serializes this flag
for the combined index (it would always be 0 for the per-module index
generated by the compile step, so no need to serialize the new flags
record there until/unless we add another flag that applies to the
per-module indexes).

Generally this flag should always be set for the distributed backends,
which are necessarily performed after the thin link. However, if we were
to simply set this flag on the index applied to the distributed backends
(invoked via clang), we would lose the ability to disable dead stripping
via -compute-dead=false for debugging purposes.

Reviewers: grimar, pcc

Subscribers: mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D42799

llvm-svn: 324444

show more ...

Add DWARF for discriminated unions

n Rust, an enum that carries data in the variants is, essentially, a
discriminated union. Furthermore, the Rust compiler will perform
space optimizations on such e

Add DWARF for discriminated unions

n Rust, an enum that carries data in the variants is, essentially, a
discriminated union. Furthermore, the Rust compiler will perform
space optimizations on such enums in some situations. Previously,
DWARF for these constructs was emitted using a hack (a magic field
name); but this approach stopped working when more space optimizations
were added in https://github.com/rust-lang/rust/pull/45225.

This patch changes LLVM to allow discriminated unions to be
represented in DWARF. It adds createDiscriminatedUnionType and
createDiscriminatedMemberType to DIBuilder and then arranges for this
to be emitted using DWARF's DW_TAG_variant_part and DW_TAG_variant.

Note that DWARF requires that a discriminated union be represented as
a structure with a variant part. However, as Rust only needs to emit
pure discriminated unions, this is what I chose to expose on
DIBuilder.

Patch by Tom Tromey!

Differential Revision: https://reviews.llvm.org/D42082

llvm-svn: 324426

show more ...

Re-land "[ThinLTO] Add call edges' relative block frequency to per-module summary."

It was reverted after buildbot regressions.

Original commit message:

This allows relative block frequency of cal

Re-land "[ThinLTO] Add call edges' relative block frequency to per-module summary."

It was reverted after buildbot regressions.

Original commit message:

This allows relative block frequency of call edges to be passed
to the thinlink stage where it will be used to compute synthetic
entry counts of functions.

llvm-svn: 323460

show more ...

Revert "[ThinLTO] Add call edges' relative block frequency to per-module summary."

Causes buildbot regressions.

llvm-svn: 323358

[ThinLTO] Add call edges' relative block frequency to per-module summary.

Summary:
This allows relative block frequency of call edges to be passed to the
thinlink stage where it will be used to comp

[ThinLTO] Add call edges' relative block frequency to per-module summary.

Summary:
This allows relative block frequency of call edges to be passed to the
thinlink stage where it will be used to compute synthetic entry counts
of functions.

Reviewers: tejohnson, pcc

Subscribers: mehdi_amini, llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D42212

llvm-svn: 323349

show more ...

[Metadata] Extend 'count' field of DISubrange to take a metadata node

Summary:
This patch extends the DISubrange 'count' field to take either a
(signed) constant integer value or a reference to a DI

[Metadata] Extend 'count' field of DISubrange to take a metadata node

Summary:
This patch extends the DISubrange 'count' field to take either a
(signed) constant integer value or a reference to a DILocalVariable
or DIGlobalVariable.

This is patch [1/3] in a series to extend LLVM's DISubrange Metadata
node to support debugging of C99 variable length arrays and vectors with
runtime length like the Scalable Vector Extension for AArch64. It is
also a first step towards representing more complex cases like arrays
in Fortran.

Reviewers: echristo, pcc, aprantl, dexonsmith, clayborg, kristof.beyls, dblaikie

Reviewed By: aprantl

Subscribers: rnk, probinson, fhahn, aemerson, rengolin, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D41695

llvm-svn: 323313

show more ...