Commit Graph

89 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith e274180f0e DebugInfo: Move new hierarchy into place
Move the specialized metadata nodes for the new debug info hierarchy
into place, finishing off PR22464.  I've done bootstraps (and all that)
and I'm confident this commit is NFC as far as DWARF output is
concerned.  Let me know if I'm wrong :).

The code changes are fairly mechanical:

  - Bumped the "Debug Info Version".
  - `DIBuilder` now creates the appropriate subclass of `MDNode`.
  - Subclasses of DIDescriptor now expect to hold their "MD"
    counterparts (e.g., `DIBasicType` expects `MDBasicType`).
  - Deleted a ton of dead code in `AsmWriter.cpp` and `DebugInfo.cpp`
    for printing comments.
  - Big update to LangRef to describe the nodes in the new hierarchy.
    Feel free to make it better.

Testcase changes are enormous.  There's an accompanying clang commit on
its way.

If you have out-of-tree debug info testcases, I just broke your build.

  - `upgrade-specialized-nodes.sh` is attached to PR22564.  I used it to
    update all the IR testcases.
  - Unfortunately I failed to find way to script the updates to CHECK
    lines, so I updated all of these by hand.  This was fairly painful,
    since the old CHECKs are difficult to reason about.  That's one of
    the benefits of the new hierarchy.

This work isn't quite finished, BTW.  The `DIDescriptor` subclasses are
almost empty wrappers, but not quite: they still have loose casting
checks (see the `RETURN_FROM_RAW()` macro).  Once they're completely
gutted, I'll rename the "MD" classes to "DI" and kill the wrappers.  I
also expect to make a few schema changes now that it's easier to reason
about everything.

llvm-svn: 231082
2015-03-03 17:24:31 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
David Blaikie 79e6c74981 [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

llvm-svn: 230786
2015-02-27 19:29:02 +00:00
Evgeniy Stepanov 4e12057760 [msan] Fix "missing origin" in atomic store.
An atomic store always make the target location fully initialized (in the
current implementation). It should not store origin. Initialized memory can't
have meaningful origin, and, due to origin granularity (4 bytes) there is a
chance that this extra store would overwrite meaningfull origin for an adjacent
location.

llvm-svn: 228444
2015-02-06 21:47:39 +00:00
Evgeniy Stepanov 79ca0fd1a0 [msan] Update origin for the entire destination range on memory store.
Previously we always stored 4 bytes of origin at the destination address
even for 8-byte (and longer) stores.

This should fix rare missing, or incorrect, origin stacks in MSan reports.

llvm-svn: 226658
2015-01-21 13:21:31 +00:00
Evgeniy Stepanov c5b974e6d2 [msan] Optimize -msan-check-constant-shadow.
The new code does not create new basic blocks in the case when shadow is a
compile-time constant; it generates either an unconditional __msan_warning
call or nothing instead.

llvm-svn: 226569
2015-01-20 15:21:35 +00:00
Duncan P. N. Exon Smith 9885469922 IR: Move MDLocation into place
This commit moves `MDLocation`, finishing off PR21433.  There's an
accompanying clang commit for frontend testcases.  I'll attach the
testcase upgrade script I used to PR21433 to help out-of-tree
frontends/backends.

This changes the schema for `DebugLoc` and `DILocation` from:

    !{i32 3, i32 7, !7, !8}

to:

    !MDLocation(line: 3, column: 7, scope: !7, inlinedAt: !8)

Note that empty fields (line/column: 0 and inlinedAt: null) don't get
printed by the assembly writer.

llvm-svn: 226048
2015-01-14 22:27:36 +00:00
Duncan P. N. Exon Smith be7ea19b58 IR: Make metadata typeless in assembly
Now that `Metadata` is typeless, reflect that in the assembly.  These
are the matching assembly changes for the metadata/value split in
r223802.

  - Only use the `metadata` type when referencing metadata from a call
    intrinsic -- i.e., only when it's used as a `Value`.

  - Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
    when referencing it from call intrinsics.

So, assembly like this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata !{i32 %v}, metadata !0)
      call void @llvm.foo(metadata !{i32 7}, metadata !0)
      call void @llvm.foo(metadata !1, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{metadata !3}, metadata !0)
      ret void, !bar !2
    }
    !0 = metadata !{metadata !2}
    !1 = metadata !{i32* @global}
    !2 = metadata !{metadata !3}
    !3 = metadata !{}

turns into this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata i32 %v, metadata !0)
      call void @llvm.foo(metadata i32 7, metadata !0)
      call void @llvm.foo(metadata i32* @global, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{!3}, metadata !0)
      ret void, !bar !2
    }
    !0 = !{!2}
    !1 = !{i32* @global}
    !2 = !{!3}
    !3 = !{}

I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines).  I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.

This is part of PR21532.

llvm-svn: 224257
2014-12-15 19:07:53 +00:00
Evgeniy Stepanov d85ddee01d [msan] Avoid extra origin address realignment.
Do not realign origin address if the corresponding application
address is at least 4-byte-aligned.

Saves 2.5% code size in track-origins mode.

llvm-svn: 223464
2014-12-05 14:34:03 +00:00
Evgeniy Stepanov a0b6899234 [msan] Fix origin propagation for select of floats.
MSan does not assign origin for instrumentation temps (i.e. the ones that do
not come from the application code), but "select" instrumentation erroneously
tried to use one of those.

https://code.google.com/p/memory-sanitizer/issues/detail?id=78

llvm-svn: 222918
2014-11-28 11:17:58 +00:00
Evgeniy Stepanov e402d9ef4c [msan] Remove indirect call wrapping code.
This functionality was only used in MSanDR, which is deprecated.

llvm-svn: 222889
2014-11-27 14:54:02 +00:00
Evgeniy Stepanov d337a59db5 [msan] Make -msan-check-constant-shadow a bit stronger.
Allow (under the experimental flag) non-Instructions to participate in MSan checks.

llvm-svn: 220601
2014-10-24 23:34:15 +00:00
Evgeniy Stepanov e08633e900 [msan] Fix handling of byval arguments with large alignment.
MSan param-tls slots are 8-byte aligned. This change clips
alignment of memcpy into param-tls to 8.

llvm-svn: 220101
2014-10-17 23:29:44 +00:00
Duncan P. N. Exon Smith 176b691d32 Revert "Revert "DI: Fold constant arguments into a single MDString""
This reverts commit r218918, effectively reapplying r218914 after fixing
an Ocaml bindings test and an Asan crash.  The root cause of the latter
was a tightened-up check in `DILexicalBlock::Verify()`, so I'll file a
PR to investigate who requires the loose check (and why).

Original commit message follows.

--

This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

llvm-svn: 219010
2014-10-03 20:01:09 +00:00
Duncan P. N. Exon Smith 786cd049fc Revert "DI: Fold constant arguments into a single MDString"
This reverts commit r218914 while I investigate some bots.

llvm-svn: 218918
2014-10-02 22:15:31 +00:00
Duncan P. N. Exon Smith 571f97bd90 DI: Fold constant arguments into a single MDString
This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

llvm-svn: 218914
2014-10-02 21:56:57 +00:00
Adrian Prantl 87b7eb9d0f Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

Note: I accidentally committed a bogus older version of this patch previously.
llvm-svn: 218787
2014-10-01 18:55:02 +00:00
Adrian Prantl b458dc2eee Revert r218778 while investigating buldbot breakage.
"Move the complex address expression out of DIVariable and into an extra"

llvm-svn: 218782
2014-10-01 18:10:54 +00:00
Adrian Prantl 25a7174e7a Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

llvm-svn: 218778
2014-10-01 17:55:39 +00:00
Chandler Carruth 3f92ecc2a0 Revert r215415 which causse MSan to crash on a great deal of C++ code.
I've followed up on the original commit as well.

llvm-svn: 215532
2014-08-13 09:19:39 +00:00
Reid Kleckner 3ae6e1528a msan: Handle musttail calls
First, avoid calling setTailCall(false) on musttail calls.  The funciton
prototypes should be "congruent", so the shadow layout should be exactly
the same.

Second, avoid inserting instrumentation after a musttail call to
propagate the return value shadow.  We don't need to propagate the
result of a tail call, it should already be in the right place.

Reviewed By: eugenis

Differential Revision: http://reviews.llvm.org/D4331

llvm-svn: 215415
2014-08-12 00:12:43 +00:00
Evgeniy Stepanov 5997feb7dc [msan] Fix handling of array types.
Switch array type shadow from a single integer to
an array of integers (i.e. make it per-element).
This simplifies instrumentation of extractvalue and fixes PR20493.

llvm-svn: 214398
2014-07-31 11:02:27 +00:00
Evgeniy Stepanov c8227aa14d [msan] Avoid redundant origin stores.
Origin is meaningless for fully initialized values. Avoid
storing origin for function arguments that are known to
be always initialized (i.e. shadow is a compile-time null
constant).

This is not about correctness, but purely an optimization.
Seems to affect compilation time of blacklisted functions
significantly.

llvm-svn: 213239
2014-07-17 09:10:37 +00:00
Evgeniy Stepanov d948a5f3c3 [msan] Fix handling of phi in blacklisted functions.
llvm-svn: 212454
2014-07-07 13:28:31 +00:00
Evgeniy Stepanov 174242c74c [msan] Stop propagating shadow in blacklisted functions.
With this change all values passed through blacklisted functions
become fully initialized. Previous behavior was to initialize all
loads in blacklisted functions, but apply normal shadow propagation
logic for all other operation.

This makes blacklist applicable in a wider range of situations.

It also makes code for blacklisted functions a lot shorter, which
works as yet another workaround for PR17409.

llvm-svn: 212268
2014-07-03 11:56:30 +00:00
Evgeniy Stepanov 89c40a8b2d [msan] Add missing attributes in MemorySanitizer tests.
llvm-svn: 212267
2014-07-03 11:49:50 +00:00
Reid Kleckner 833740ac5e msan: Stop stripping the 'tail' modifier off of calls
This probably isn't necessary since msan started to unpoison the return
value shadow memory before all calls.

llvm-svn: 212061
2014-06-30 20:12:27 +00:00
Evgeniy Stepanov b163f0276f [msan] Fix bad interaction between with-calls mode and chained origin tracking.
Origin history should only be recorded for uninitialized values, because it is
meaningless otherwise. This change moves __msan_chain_origin to the runtime
library side and makes it conditional on the corresponding shadow value.

Previous code was correct, but _very_ inefficient.

llvm-svn: 211700
2014-06-25 14:41:57 +00:00
Evgeniy Stepanov 4ea1647e8b [msan] Handle X86 *.psad.* and *.pmadd.* intrinsics.
llvm-svn: 211156
2014-06-18 12:02:29 +00:00
Evgeniy Stepanov df187feae4 [msan] Fix handling of multiplication by a constant with a number of trailing zeroes.
Multiplication by an integer with a number of trailing zero bits leaves
the same number of lower bits of the result initialized to zero.
This change makes MSan take this into account in the case of multiplication by
a compile-time constant.

We don't handle the general, non-constant, case because
(a) it's not going to be cheap (computation-wise);
(b) multiplication by a partially uninitialized value in user code is
    a bad idea anyway.

Constant case must be handled because it appears from LLVM optimization of a
completely valid user code, as the test case in compiler-rt demonstrates.

llvm-svn: 211092
2014-06-17 09:23:12 +00:00
Tim Northover 420a216817 IR: add "cmpxchg weak" variant to support permitted failure.
This commit adds a weak variant of the cmpxchg operation, as described
in C++11. A cmpxchg instruction with this modifier is permitted to
fail to store, even if the comparison indicated it should.

As a result, cmpxchg instructions must return a flag indicating
success in addition to their original iN value loaded. Thus, for
uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The
second flag is 1 when the store succeeded.

At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been
added as the natural representation for the new cmpxchg instructions.
It is a strong cmpxchg.

By default this gets Expanded to the existing ATOMIC_CMP_SWAP during
Legalization, so existing backends should see no change in behaviour.
If they wish to deal with the enhanced node instead, they can call
setOperationAction on it. Beware: as a node with 2 results, it cannot
be selected from TableGen.

Currently, no use is made of the extra information provided in this
patch. Test updates are almost entirely adapting the input IR to the
new scheme.

Summary for out of tree users:
------------------------------

+ Legacy Bitcode files are upgraded during read.
+ Legacy assembly IR files will be invalid.
+ Front-ends must adapt to different type for "cmpxchg".
+ Backends should be unaffected by default.

llvm-svn: 210903
2014-06-13 14:24:07 +00:00
Evgeniy Stepanov a9b6202d60 Fix test in r210472.
llvm-svn: 210473
2014-06-09 14:48:53 +00:00
Evgeniy Stepanov 70d1b0a818 [msan] Workaround for invalid origins in shufflevector.
Makes origin propagation ignore literal undef operands, and,
in general, any operand we don't have origin for.

https://code.google.com/p/memory-sanitizer/issues/detail?id=56

llvm-svn: 210472
2014-06-09 14:29:34 +00:00
Evgeniy Stepanov f7c29a9e25 [msan] Fix vector pack intrinsic handling.
This fixes a crash on MMX intrinsics, as well as a corner case in handling of
all unsigned pack intrinsics.

PR19953.

llvm-svn: 210454
2014-06-09 08:40:16 +00:00
Evgeniy Stepanov d425a2b169 [msan] Handle x86 vector pack intrinsics.
llvm-svn: 210020
2014-06-02 12:31:44 +00:00
Evgeniy Stepanov c14fc42137 [msan] Fix -fsanitize=memory -fno-integrated-as.
llvm-svn: 208211
2014-05-07 14:10:51 +00:00
Evgeniy Stepanov 65120ec8c6 [msan] Add -msan-instrumentation-with-call-threshold.
This flag replaces inline instrumentation for checks and origin stores with
calls into MSan runtime library. This is a workaround for PR17409.

Disabled by default.

llvm-svn: 206585
2014-04-18 12:17:20 +00:00
Evgeniy Stepanov 86f318e8b4 [msan] Relax the test some more.
This may or may not fix the bots. R204720 did not.

llvm-svn: 204721
2014-03-25 14:32:05 +00:00
Evgeniy Stepanov d2b07ddfac [msan] Make some tests less strict.
This may or may not fix the bots.

llvm-svn: 204720
2014-03-25 14:15:14 +00:00
Evgeniy Stepanov fc742acc8c [msan] More precise instrumentation of select IR.
Some bits of select result may be initialized even if select condition
is not.

https://code.google.com/p/memory-sanitizer/issues/detail?id=50

llvm-svn: 204716
2014-03-25 13:08:34 +00:00
Evgeniy Stepanov 2275a01a44 Set debug info for instructions inserted in SplitBlockAndInsertIfThen.
llvm-svn: 204230
2014-03-19 12:56:38 +00:00
Evgeniy Stepanov 302964ee92 [msan] Origin tracking with history.
LLVM part of MSan implementation of advanced origin tracking,
when we record not only creation point, but all locations where
an uninitialized value was stored to memory, too.

llvm-svn: 204151
2014-03-18 13:30:56 +00:00
Evgeniy Stepanov 7ab838eb56 [msan] Fix handling of byval arguments in VarArg calls.
llvm-svn: 203794
2014-03-13 13:17:11 +00:00
Tim Northover e94a518a22 IR: add a second ordering operand to cmpxhg for failure
The syntax for "cmpxchg" should now look something like:

	cmpxchg i32* %addr, i32 42, i32 3 acquire monotonic

where the second ordering argument gives the required semantics in the case
that no exchange takes place. It should be no stronger than the first ordering
constraint and cannot be either "release" or "acq_rel" (since no store will
have taken place).

rdar://problem/15996804

llvm-svn: 203559
2014-03-11 10:48:52 +00:00
Evgeniy Stepanov 77be532f71 [msan] Handle X86 SIMD bitshift intrinsics.
llvm-svn: 202712
2014-03-03 13:47:42 +00:00
Evgeniy Stepanov a9164e9e2a Add an explicit insert point argument to SplitBlockAndInsertIfThen.
Currently SplitBlockAndInsertIfThen requires that branch condition is an
Instruction itself, which is very inconvenient, because it is sometimes an
Operator, or even a Constant.

llvm-svn: 197677
2013-12-19 13:29:56 +00:00
Evgeniy Stepanov cb5bdffc4e [msan] Propagate condition origin in select instruction.
llvm-svn: 195349
2013-11-21 12:00:24 +00:00
Evgeniy Stepanov b55c7e7cc4 Use multiple filecheck prefixes in msan instrumentation tests.
llvm-svn: 195342
2013-11-21 11:37:16 +00:00
Evgeniy Stepanov b22018abed [msan] Use CHECK-DAG instead of CHECK where order of instructions does not matter.
This may fix hexagon-elf bots.

llvm-svn: 194700
2013-11-14 12:46:12 +00:00
Evgeniy Stepanov 585813e33d [msan] Fast path optimization for wrap-indirect-calls feature of MemorySanitizer.
Indirect call wrapping helps MSanDR (dynamic instrumentation companion tool
for MSan) to catch all cases where execution leaves a compiler-instrumented
module by allowing the tool to rewrite targets of indirect calls.

This change is an optimization that skips wrapping for calls when target is
inside the current module. This relies on the linker providing symbols at the
begin and end of the module code (or code + data, does not really matter).
Gold linker provides such symbols by default. GNU (BFD) linker needs a link
flag: -Wl,--defsym=__executable_start=0.

More info:
https://code.google.com/p/memory-sanitizer/wiki/MSanDR#Native_exec

llvm-svn: 194697
2013-11-14 12:29:04 +00:00