612 Commits

Author SHA1 Message Date
Cameron McInally
b538c2a07b [Bitcode] Update naming of UNOP_NEG to UNOP_FNEG
Differential Revision: https://reviews.llvm.org/D68588

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373958 91177308-0d34-0410-b5e6-96231b3b80d8
2019-10-07 20:41:25 +00:00
Francis Visoiu Mistrih
fcf99c532d Reland: [Remarks] Add an LLVM-bitstream-based remark serializer
Add a new serializer, using a binary format based on the LLVM bitstream
format.

This format provides a way to serialize the remarks in two modes:

1) Separate mode: the metadata is separate from the remark entries.
2) Standalone mode: the metadata and the remark entries are in the same
file.

The format contains:

* a meta block: container version, container type, string table,
external file path, remark version
* a remark block: type, remark name, pass name, function name, debug
file, debug line, debug column, hotness, arguments (key, value, debug
file, debug line, debug column)

A string table is required for this format, which will be dumped in the
meta block to be consumed before parsing the remark blocks.

On clang itself, we noticed a size reduction of 13.4x compared to YAML,
and a compile-time reduction of between 1.7% and 3.5% on CTMark.

Differential Revision: https://reviews.llvm.org/D63466

Original llvm-svn: 367364
Revert llvm-svn: 367370

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367372 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-31 00:13:51 +00:00
Francis Visoiu Mistrih
16956a6979 Revert "[Remarks] Add an LLVM-bitstream-based remark serializer"
This reverts commit r367364.

Breaks some bots: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-gn/builds/3161/steps/annotate/logs/stdio

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367370 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-31 00:01:34 +00:00
Francis Visoiu Mistrih
6038bea1b8 [Remarks] Add an LLVM-bitstream-based remark serializer
Add a new serializer, using a binary format based on the LLVM bitstream
format.

This format provides a way to serialize the remarks in two modes:

1) Separate mode: the metadata is separate from the remark entries.
2) Standalone mode: the metadata and the remark entries are in the same
file.

The format contains:

* a meta block: container version, container type, string table,
external file path, remark version
* a remark block: type, remark name, pass name, function name, debug
file, debug line, debug column, hotness, arguments (key, value, debug
file, debug line, debug column)

A string table is required for this format, which will be dumped in the
meta block to be consumed before parsing the remark blocks.

On clang itself, we noticed a size reduction of 13.4x compared to YAML,
and a compile-time reduction of between 1.7% and 3.5% on CTMark.

Differential Revision: https://reviews.llvm.org/D63466

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367364 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-30 23:11:57 +00:00
Evgeniy Stepanov
8060f84343 ARM MTE stack sanitizer.
Add "memtag" sanitizer that detects and mitigates stack memory issues
using armv8.5 Memory Tagging Extension.

It is similar in principle to HWASan, which is a software implementation
of the same idea, but there are enough differencies to warrant a new
sanitizer type IMHO. It is also expected to have very different
performance properties.

The new sanitizer does not have a runtime library (it may grow one
later, along with a "debugging" mode). Similar to SafeStack and
StackProtector, the instrumentation pass (in a follow up change) will be
inserted in all cases, but will only affect functions marked with the
new sanitize_memtag attribute.

Reviewers: pcc, hctim, vitalybuka, ostannard

Subscribers: srhines, mehdi_amini, javed.absar, kristof.beyls, hiraditya, cryptoad, steven_wu, dexonsmith, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D64169

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366123 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-15 20:02:23 +00:00
Stefan Stipanovic
52d4c048b3 [Attributor] Deduce "nosync" function attribute.
Introduce and deduce "nosync" function attribute to indicate that a function
does not synchronize with another thread in a way that other thread might free memory.

Reviewers: jdoerfert, jfb, nhaehnle, arsenm

Subscribers: wdng, hfinkel, nhaenhle, mehdi_amini, steven_wu,
dexonsmith, arsenm, uenoku, hiraditya, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D62766

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365830 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-11 21:37:40 +00:00
Brian Homerding
7597e7f179 Add, and infer, a nofree function attribute
This patch adds a function attribute, nofree, to indicate that a function does
not, directly or indirectly, call a memory-deallocation function (e.g., free,
C++'s operator delete).

Reviewers: jdoerfert

Differential Revision: https://reviews.llvm.org/D49165


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365336 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-08 15:57:56 +00:00
Francis Visoiu Mistrih
767b1fe69e [llvm-bcanalyzer] Refactor and move to libLLVMBitReader
This allows us to use the analyzer from unit tests.

* Refactor the interface to use proper error handling for most functions
  after JF's work.
* Move everything into a BitstreamAnalyzer class.
* Move that to Bitcode/BitcodeAnalyzer.h.

Differential Revision: https://reviews.llvm.org/D64116

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365286 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-08 02:06:34 +00:00
Francis Visoiu Mistrih
742690b61b [Bitcode] Move Bitstream to a separate library
This moves Bitcode/Bitstream*, Bitcode/BitCodes.h to Bitstream/.

This is needed to avoid a circular dependency when using the bitstream
code for parsing optimization remarks.

Since Bitcode uses Core for the IR part:

libLLVMRemarks -> Bitcode -> Core

and Core uses libLLVMRemarks to generate remarks (see
IR/RemarkStreamer.cpp):

Core -> libLLVMRemarks

we need to separate the Bitstream and Bitcode part.

For clang-doc, it seems that it doesn't need the whole bitcode layer, so
I updated the CMake to only use the bitstream part.

Differential Revision: https://reviews.llvm.org/D63899

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365091 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-03 22:40:07 +00:00
Teresa Johnson
7a71aab330 [ThinLTO] Add summary entries for index-based WPD
Summary:
If LTOUnit splitting is disabled, the module summary analysis computes
the summary information necessary to perform single implementation
devirtualization during the thin link with the index and no IR. The
information collected from the regular LTO IR in the current hybrid WPD
algorithm is summarized, including:
1) For vtable definitions, record the function pointers and their offset
within the vtable initializer (subsumes the information collected from
IR by tryFindVirtualCallTargets).
2) A record for each type metadata summarizing the vtable definitions
decorated with that metadata (subsumes the TypeIdentiferMap collected
from IR).

Also added are the necessary bitcode records, and the corresponding
assembly support.

The follow-on index-based WPD patch is D55153.

Depends on D53890.

Reviewers: pcc

Subscribers: mehdi_amini, Prazek, inglorion, eraman, steven_wu, dexonsmith, arphaman, llvm-commits

Differential Revision: https://reviews.llvm.org/D54815

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364960 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-02 19:38:02 +00:00
Johannes Doerfert
8a0fc5ba4f [Attr] Add "willreturn" function attribute
This patch introduces a new function attribute, willreturn, to indicate
that a call of this function will either exhibit undefined behavior or
comes back and continues execution at a point in the existing call stack
that includes the current invocation.

This attribute guarantees that the function does not have any endless
loops, endless recursion, or terminating functions like abort or exit.

Patch by Hideto Ueno (@uenoku)

Reviewers: jdoerfert

Subscribers: mehdi_amini, hiraditya, steven_wu, dexonsmith, lebedev.ri, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62801

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364555 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-27 15:51:40 +00:00
Hans Wennborg
9e71fe14b1 Fix GCC 4 build after r364464
It was failing with:

In file included from /b/s/w/ir/cache/builder/src/third_party/llvm/llvm/lib/Bitcode/Reader/BitstreamReader.cpp:9:0:
/b/s/w/ir/cache/builder/src/third_party/llvm/llvm/include/llvm/Bitcode/BitstreamReader.h:
In member function 'llvm::Expected<long unsigned int> llvm::SimpleBitstreamCursor::ReadVBR64(unsigned int)':
/b/s/w/ir/cache/builder/src/third_party/llvm/llvm/include/llvm/Bitcode/BitstreamReader.h:262:14:
error: could not convert 'MaybeRead' from 'llvm::Expected<unsigned int>' to 'llvm::Expected<long unsigned int>'
       return MaybeRead;
              ^
/b/s/w/ir/cache/builder/src/third_party/llvm/llvm/include/llvm/Bitcode/BitstreamReader.h:279:16:
error: could not convert 'MaybeRead' from 'llvm::Expected<unsigned int>' to 'llvm::Expected<long unsigned int>'
         return MaybeRead;
                ^

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364504 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-27 07:32:10 +00:00
JF Bastien
22d9c5c34d BitStream reader: propagate errors
The bitstream reader handles errors poorly. This has two effects:

 * Bugs in file handling (especially modules) manifest as an "unexpected end of
   file" crash
 * Users of clang as a library end up aborting because the code unconditionally
   calls `report_fatal_error`

The bitstream reader should be more resilient and return Expected / Error as
soon as an error is encountered, not way late like it does now. This patch
starts doing so and adopting the error handling where I think it makes sense.
There's plenty more to do: this patch propagates errors to be minimally useful,
and follow-ups will propagate them further and improve diagnostics.

https://bugs.llvm.org/show_bug.cgi?id=42311
<rdar://problem/33159405>

Differential Revision: https://reviews.llvm.org/D63518

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364464 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-26 19:50:12 +00:00
Jan Korous
04a8fcbdb1 [BitstreamWriter][NFC] Remove obsolete comment.
The Abbv parameter was just a raw pointer when the comment was written.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362046 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-30 01:08:38 +00:00
Adrian Prantl
f09c6d5b71 Add LLVM IR debug info support for Fortran COMMON blocks
COMMON blocks are a feature of Fortran that has no direct analog in C languages, but they are similar to data sections in assembly language programming. A COMMON block is a named area of memory that holds a collection of variables. Fortran subprograms may map the COMMON block memory area to their own, possibly distinct, non-empty list of variables. A Fortran COMMON block might look like the following example.

    COMMON /ALPHA/ I, J

    For this construct, the compiler generates a new scope-like DI construct (!DICommonBlock) into which variables (see I, J above) can be placed. As the common block implies a range of storage with global lifetime, the !DICommonBlock refers to a !DIGlobalVariable. The Fortran variable that comprise the COMMON block are also linked via metadata to offsets within the global variable that stands for the entire common block.

    @alpha_ = common global %alphabytes_ zeroinitializer, align 64, !dbg !27, !dbg !30, !dbg !33
    !14 = distinct !DISubprogram(…)
    !20 = distinct !DICommonBlock(scope: !14, declaration: !25, name: "alpha")
    !25 = distinct !DIGlobalVariable(scope: !20, name: "common alpha", type: !24)
    !27 = !DIGlobalVariableExpression(var: !25, expr: !DIExpression())
    !29 = distinct !DIGlobalVariable(scope: !20, name: "i", file: !3, type: !28)
    !30 = !DIGlobalVariableExpression(var: !29, expr: !DIExpression())
    !31 = distinct !DIGlobalVariable(scope: !20, name: "j", file: !3, type: !28)
    !32 = !DIExpression(DW_OP_plus_uconst, 4)
    !33 = !DIGlobalVariableExpression(var: !31, expr: !32)

    The DWARF generated for this is as follows.

    DW_TAG_common_block:
    DW_AT_name: alpha
    DW_AT_location: @alpha_+0
    DW_TAG_variable:
    DW_AT_name: common alpha
    DW_AT_type: array of 8 bytes
    DW_AT_location: @alpha_+0
    DW_TAG_variable:
    DW_AT_name: i
    DW_AT_type: integer*4
    DW_AT_location: @Alpha+0
    DW_TAG_variable:
    DW_AT_name: j
    DW_AT_type: integer*4
    DW_AT_location: @Alpha+4

Patch by Eric Schweitz!

Differential Revision: https://reviews.llvm.org/D54327

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357934 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-08 19:13:55 +00:00
Fangrui Song
9cc714957f Change some StringRef::data() reinterpret_cast to bytes_begin() or arrayRefFromStringRef()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357852 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-07 03:58:42 +00:00
Matt Arsenault
6e8fb99b69 IR: Add immarg attribute
This indicates an intrinsic parameter is required to be a constant,
and should not be replaced with a non-constant value.

Add the attribute to all AMDGPU and generic intrinsics that comments
indicate it should apply to. I scanned other target intrinsics, but I
don't see any obvious comments indicating which arguments are intended
to be only immediates.

This breaks one questionable testcase for the autoupgrade. I'm unclear
on whether the autoupgrade is supposed to really handle declarations
which were never valid. The verifier fails because the attributes now
refer to a parameter past the end of the argument list.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355981 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-12 21:02:54 +00:00
Craig Topper
e3696113b6 Implementation of asm-goto support in LLVM
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html

This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.

This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.

There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.

Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii

Differential Revision: https://reviews.llvm.org/D53765

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353563 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-08 20:48:56 +00:00
Julian Lettner
a1e328df4a Revert "[Sanitizers] UBSan unreachable incompatible with ASan in the presence of noreturn calls"
This reverts commit cea84ab93aeb079a358ab1c8aeba6d9140ef8b47.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352069 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-24 18:04:21 +00:00
Julian Lettner
2e1beed270 [Sanitizers] UBSan unreachable incompatible with ASan in the presence of noreturn calls
Summary:
UBSan wants to detect when unreachable code is actually reached, so it
adds instrumentation before every `unreachable` instruction. However,
the optimizer will remove code after calls to functions marked with
`noreturn`. To avoid this UBSan removes `noreturn` from both the call
instruction as well as from the function itself. Unfortunately, ASan
relies on this annotation to unpoison the stack by inserting calls to
`_asan_handle_no_return` before `noreturn` functions. This is important
for functions that do not return but access the the stack memory, e.g.,
unwinder functions *like* `longjmp` (`longjmp` itself is actually
"double-proofed" via its interceptor). The result is that when ASan and
UBSan are combined, the `noreturn` attributes are missing and ASan
cannot unpoison the stack, so it has false positives when stack
unwinding is used.

Changes:
  # UBSan now adds the `expect_noreturn` attribute whenever it removes
    the `noreturn` attribute from a function
  # ASan additionally checks for the presence of this attribute

Generated code:
```
call void @__asan_handle_no_return    // Additionally inserted to avoid false positives
call void @longjmp
call void @__asan_handle_no_return
call void @__ubsan_handle_builtin_unreachable
unreachable
```

The second call to `__asan_handle_no_return` is redundant. This will be
cleaned up in a follow-up patch.

rdar://problem/40723397

Reviewers: delcypher, eugenis

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D56624

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352003 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-24 01:06:19 +00:00
Matt Arsenault
52f6127659 Reapply "IR: Add fp operations to atomicrmw"
This reapplies commits r351778 and r351782 with
RISCV test fixes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351850 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-22 18:18:02 +00:00
Chandler Carruth
73f9a1d617 Revert r351778: IR: Add fp operations to atomicrmw
This broke the RISCV build, and even with that fixed, one of the RISCV
tests behaves surprisingly differently with asserts than without,
leaving there no clear test pattern to use. Generally it seems bad for
hte IR to differ substantially due to asserts (as in, an alloca is used
with asserts that isn't needed without!) and nothing I did simply would
fix it so I'm reverting back to green.

This also required reverting the RISCV build fix in r351782.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351796 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-22 10:29:58 +00:00
Matt Arsenault
020dc8d94b IR: Add fp operations to atomicrmw
Add just fadd/fsub for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351778 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-22 03:32:36 +00:00
Serge Guelton
cb39a85070 Replace llvm::isPodLike<...> by llvm::is_trivially_copyable<...>
As noted in https://bugs.llvm.org/show_bug.cgi?id=36651, the specialization for
isPodLike<std::pair<...>> did not match the expectation of
std::is_trivially_copyable which makes the memcpy optimization invalid.

This patch renames the llvm::isPodLike trait into llvm::is_trivially_copyable.
Unfortunately std::is_trivially_copyable is not portable across compiler / STL
versions. So a portable version is provided too.

Note that the following specialization were invalid:

    std::pair<T0, T1>
    llvm::Optional<T>

Tests have been added to assert that former specialization are respected by the
standard usage of llvm::is_trivially_copyable, and that when a decent version
of std::is_trivially_copyable is available, llvm::is_trivially_copyable is
compared to std::is_trivially_copyable.

As of this patch, llvm::Optional is no longer considered trivially copyable,
even if T is. This is to be fixed in a later patch, as it has impact on a
long-running bug (see r347004)

Note that GCC warns about this UB, but this got silented by https://reviews.llvm.org/D50296.

Differential Revision: https://reviews.llvm.org/D54472



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351701 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-20 21:19:56 +00:00
Chandler Carruth
6b547686c5 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 08:50:56 +00:00
Teresa Johnson
5b5290a1ba Revert "[ThinLTO] Add summary entries for index-based WPD"
Mistaken commit of something still under review!

This reverts commit r351453.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351455 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-17 16:05:04 +00:00
Teresa Johnson
70c3a1bd4a [ThinLTO] Add summary entries for index-based WPD
Summary:
If LTOUnit splitting is disabled, the module summary analysis computes
the summary information necessary to perform single implementation
devirtualization during the thin link with the index and no IR. The
information collected from the regular LTO IR in the current hybrid WPD
algorithm is summarized, including:
1) For vtable definitions, record the function pointers and their offset
within the vtable initializer (subsumes the information collected from
IR by tryFindVirtualCallTargets).
2) A record for each type metadata summarizing the vtable definitions
decorated with that metadata (subsumes the TypeIdentiferMap collected
from IR).

Also added are the necessary bitcode records, and the corresponding
assembly support.

The index-based WPD will be sent as a follow-on.

Depends on D53890.

Reviewers: pcc

Subscribers: mehdi_amini, Prazek, inglorion, eraman, steven_wu, dexonsmith, arphaman, llvm-commits

Differential Revision: https://reviews.llvm.org/D54815

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351453 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-17 15:49:03 +00:00
Teresa Johnson
e39377580b [LTO] Record whether LTOUnit splitting is enabled in index
Summary:
Records in the module summary index whether the bitcode was compiled
with the option necessary to enable splitting the LTO unit
(e.g. -fsanitize=cfi, -fwhole-program-vtables, or -fsplit-lto-unit).

The information is passed down to the ModuleSummaryIndex builder via a
new module flag "EnableSplitLTOUnit", which is propagated onto a flag
on the summary index.

This is then used during the LTO link to check whether all linked
summaries were built with the same value of this flag. If not, an error
is issued when we detect a situation requiring whole program visibility
of the class hierarchy. This is the case when both of the following
conditions are met:
1) We are performing LowerTypeTests or Whole Program Devirtualization.
2) There are type tests or type checked loads in the code.

Note I have also changed the ThinLTOBitcodeWriter to also gate the
module splitting on the value of this flag.

Reviewers: pcc

Subscribers: ormris, mehdi_amini, Prazek, inglorion, eraman, steven_wu, dexonsmith, arphaman, dang, llvm-commits

Differential Revision: https://reviews.llvm.org/D53890

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350948 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-11 18:31:57 +00:00
Cameron McInally
ca8cb6852b [IR] Add a dedicated FNeg IR Instruction
The IEEE-754 Standard makes it clear that fneg(x) and
fsub(-0.0, x) are two different operations. The former is a bitwise
operation, while the latter is an arithmetic operation. This patch
creates a dedicated FNeg IR Instruction to model that behavior.

Differential Revision: https://reviews.llvm.org/D53877



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346774 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-13 18:15:47 +00:00
Chandler Carruth
d2b1fb11d3 [x86/SLH] Add a real Clang flag and LLVM IR attribute for Speculative
Load Hardening.

Wires up the existing pass to work with a proper IR attribute rather
than just a hidden/internal flag. The internal flag continues to work
for now, but I'll likely remove it soon.

Most of the churn here is adding the IR attribute. I talked about this
Kristof Beyls and he seemed at least initially OK with this direction.
The idea of using a full attribute here is that we *do* expect at least
some forms of this for other architectures. There isn't anything
*inherently* x86-specific about this technique, just that we only have
an implementation for x86 at the moment.

While we could potentially expose this as a Clang-level attribute as
well, that seems like a good question to defer for the moment as it
isn't 100% clear whether that or some other programmer interface (or
both?) would be best. We'll defer the programmer interface side of this
for now, but at least get to the point where the feature can be enabled
without relying on implementation details.

This also allows us to do something that was really hard before: we can
enable *just* the indirect call retpolines when using SLH. For x86, we
don't have any other way to mitigate indirect calls. Other architectures
may take a different approach of course, and none of this is surfaced to
user-level flags.

Differential Revision: https://reviews.llvm.org/D51157

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341363 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-04 12:38:00 +00:00
Teresa Johnson
06b7597991 Fix for llvm-dis/llvm-bcanalyzer overflows
Summary:
These tools failed for a very large bitcode file produced by LTO due to
64-bit values being assigned to 32-bit types. For the BitstreamReader.h
fix, the value initially fit into the 32-bit unsigned, but there was an
overflow when multiplying by 32 furter below to compute the bit offset.

No test case in the patch as this requires a huge bitcode file.

Reviewers: pcc, george.karpenkov

Subscribers: mehdi_amini, a.sidorin, llvm-commits

Differential Revision: https://reviews.llvm.org/D47731

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333942 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-04 19:20:02 +00:00
Vedant Kumar
f66cfed61f [Debugify] Don't apply DI before the bitcode writer pass
Applying synthetic debug info before the bitcode writer pass has no
testing-related purpose. This commit prevents that from happening.

It also adds tests which check that IR produced with/without
-debugify-each enabled is identical after stripping. This makes it
possible to check that individual passes (or full pipelines) are
invariant to debug info.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333861 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-04 00:11:49 +00:00
Shiva Chen
a8a13bc662 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331841 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-09 02:40:45 +00:00
Adrian Prantl
26b584c691 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331272 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-01 15:54:18 +00:00
Vlad Tsyrklevich
45013b2e67 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329108 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-03 20:10:40 +00:00
Matt Morehouse
7d085b607d [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328214 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-22 17:07:51 +00:00
Oren Ben Simhon
10c992c085 [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327767 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-17 13:29:46 +00:00
Steven Wu
d57c7490c5 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325525 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-19 19:22:28 +00:00
Vitaly Buka
4a81fc6db8 [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325182 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-14 22:41:15 +00:00
Rafael Espindola
06d6207c1c Pass a reference to a module to the bitcode writer.
This simplifies most callers as they are already using references or
std::unique_ptr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325155 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-14 19:11:32 +00:00
Momchil Velikov
0c69bf465f Re-commit r324489: [DebugInfo] Improvements to representation of enumeration types (PR36168)
Differential Revision: https://reviews.llvm.org/D42734


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324899 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-12 16:10:09 +00:00
Momchil Velikov
0b268d60e8 Revert "[DebugInfo] Improvements to representation of enumeration types (PR36168)"
Revert commit r324489, it broke LLDB tests.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324511 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-07 20:28:47 +00:00
Momchil Velikov
a3b503f022 [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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324489 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-07 16:46:33 +00:00
Teresa Johnson
d3f03a6227 [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324444 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-07 04:05:59 +00:00
Easwaran Raman
bdb305ac14 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323460 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-25 19:27:17 +00:00
Easwaran Raman
a9daa08738 Revert "[ThinLTO] Add call edges' relative block frequency to per-module summary."
Causes buildbot regressions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323358 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-24 18:15:29 +00:00
Easwaran Raman
cd25118a7f [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323349 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-24 17:51:23 +00:00
Evgeniy Stepanov
d47b5b3974 Hardware-assisted AddressSanitizer (llvm part).
Summary:
This is LLVM instrumentation for the new HWASan tool. It is basically
a stripped down copy of ASan at this point, w/o stack or global
support. Instrumenation adds a global constructor + runtime callbacks
for every load and store.

HWASan comes with its own IR attribute.

A brief design document can be found in
clang/docs/HardwareAssistedAddressSanitizerDesign.rst (submitted earlier).

Reviewers: kcc, pcc, alekseyshl

Subscribers: srhines, mehdi_amini, mgorny, javed.absar, eraman, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D40932

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320217 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-09 00:21:41 +00:00
Eugene Zelenko
f95cab8de6 [Bitcode] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312760 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-07 23:28:24 +00:00
Andrew Kaylor
68d0bd1ed4 Add strictfp attribute to prevent unwanted optimizations of libm calls
Differential Revision: https://reviews.llvm.org/D34163



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310885 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-14 21:15:13 +00:00