This change adds new attribute called "argmemonly". Function marked with this attribute can only access memory through it's argument pointers. This attribute directly corresponds to the "OnlyAccessesArgumentPointees" ModRef behaviour in alias analysis.
Differential Revision: http://reviews.llvm.org/D10398
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241979 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support. Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.
Reviewers: rnk, JosephTremoulet, reames, nlewycky, rjmccall
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11041
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It is meant to be used to record modules @imported by the current
compile unit, so a debugger an import the same modules to replicate this
environment before dropping into the expression evaluator.
DIModule is a sibling to DINamespace and behaves quite similarly.
In addition to the name of the module it also records the module
configuration details that are necessary to uniquely identify the module.
This includes the configuration macros (e.g., -DNDEBUG), the include path
where the module.map file is to be found, and the isysroot.
The idea is that the backend will turn this into a DW_TAG_module.
http://reviews.llvm.org/D9614
rdar://problem/20965932
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The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
The personality routine currently lives in the LandingPadInst.
This isn't desirable because:
- All LandingPadInsts in the same function must have the same
personality routine. This means that each LandingPadInst beyond the
first has an operand which produces no additional information.
- There is ongoing work to introduce EH IR constructs other than
LandingPadInst. Moving the personality routine off of any one
particular Instruction and onto the parent function seems a lot better
than have N different places a personality function can sneak onto an
exceptional function.
Differential Revision: http://reviews.llvm.org/D10429
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239940 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds the safe stack instrumentation pass to LLVM, which separates
the program stack into a safe stack, which stores return addresses, register
spills, and local variables that are statically verified to be accessed
in a safe way, and the unsafe stack, which stores everything else. Such
separation makes it much harder for an attacker to corrupt objects on the
safe stack, including function pointers stored in spilled registers and
return addresses. You can find more information about the safe stack, as
well as other parts of or control-flow hijack protection technique in our
OSDI paper on code-pointer integrity (http://dslab.epfl.ch/pubs/cpi.pdf)
and our project website (http://levee.epfl.ch).
The overhead of our implementation of the safe stack is very close to zero
(0.01% on the Phoronix benchmarks). This is lower than the overhead of
stack cookies, which are supported by LLVM and are commonly used today,
yet the security guarantees of the safe stack are strictly stronger than
stack cookies. In some cases, the safe stack improves performance due to
better cache locality.
Our current implementation of the safe stack is stable and robust, we
used it to recompile multiple projects on Linux including Chromium, and
we also recompiled the entire FreeBSD user-space system and more than 100
packages. We ran unit tests on the FreeBSD system and many of the packages
and observed no errors caused by the safe stack. The safe stack is also fully
binary compatible with non-instrumented code and can be applied to parts of
a program selectively.
This patch is our implementation of the safe stack on top of LLVM. The
patches make the following changes:
- Add the safestack function attribute, similar to the ssp, sspstrong and
sspreq attributes.
- Add the SafeStack instrumentation pass that applies the safe stack to all
functions that have the safestack attribute. This pass moves all unsafe local
variables to the unsafe stack with a separate stack pointer, whereas all
safe variables remain on the regular stack that is managed by LLVM as usual.
- Invoke the pass as the last stage before code generation (at the same time
the existing cookie-based stack protector pass is invoked).
- Add unit tests for the safe stack.
Original patch by Volodymyr Kuznetsov and others at the Dependable Systems
Lab at EPFL; updates and upstreaming by myself.
Differential Revision: http://reviews.llvm.org/D6094
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239761 91177308-0d34-0410-b5e6-96231b3b80d8
If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.
Call sites were found with the ASTMatcher + some semi-automated cleanup.
memberCallExpr(
argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
hasArgument(0, bindTemporaryExpr(
hasType(recordDecl(hasNonTrivialDestructor())),
has(constructExpr()))),
unless(isInTemplateInstantiation()))
No functional change intended.
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As a space optimization, this instruction would just encode the pointer
type of the first operand and use the knowledge that the second and
third operands would be of the pointee type of the first. When typed
pointers go away, this assumption will no longer be available - so
encode the type of the second operand explicitly and rely on that for
the third.
Test case added to demonstrate the backwards compatibility concern,
which only comes up when the definition of the second operand comes
after the use (hence the weird basic block sequence) - at which point
the type needs to be explicitly encoded in the bitcode and the record
length changes to accommodate this.
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Without pointee types the space optimization of storing only the pointer
type and not the value type won't be viable - so add the extra type
information that would be missing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235475 91177308-0d34-0410-b5e6-96231b3b80d8
Without pointee types the space optimization of storing only the pointer
type and not the value type won't be viable - so add the extra type
information that would be missing.
Storeatomic coming soon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235474 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
If a pointer is marked as dereferenceable_or_null(N), LLVM assumes it
is either `null` or `dereferenceable(N)` or both. This change only
introduces the attribute and adds a token test case for the `llvm-as`
/ `llvm-dis`. It does not hook up other parts of the optimizer to
actually exploit the attribute -- those changes will come later.
For pointers in address space 0, `dereferenceable(N)` is now exactly
equivalent to `dereferenceable_or_null(N)` && `nonnull`. For other
address spaces, `dereferenceable(N)` is potentially weaker than
`dereferenceable_or_null(N)` && `nonnull` (since we could have a null
`dereferenceable(N)` pointer).
The motivating case for this change is Java (and other managed
languages), where pointers are either `null` or dereferenceable up to
some usually known-at-compile-time constant offset.
Reviewers: rafael, hfinkel
Reviewed By: hfinkel
Subscribers: nicholas, llvm-commits
Differential Revision: http://reviews.llvm.org/D8650
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235132 91177308-0d34-0410-b5e6-96231b3b80d8
Change the callers of `WriteToBitcodeFile()` to pass `true` or
`shouldPreserveBitcodeUseListOrder()` explicitly. I left the callers
that want to send `false` alone.
I'll keep pushing the bit higher until hopefully I can delete the global
`cl::opt` entirely.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234957 91177308-0d34-0410-b5e6-96231b3b80d8
We only defer loading metadata inside ParseModule when ShouldLazyLoadMetadata
is true and we have not loaded any Metadata block yet.
This commit implements all-or-nothing loading of Metadata. If there is a
request to load any metadata block, we will load all deferred metadata blocks.
We make sure the deferred metadata blocks are loaded before we materialize any
function or a module.
The default value of the added parameter ShouldLazyLoadMetadata for
getLazyBitcodeModule is false, so the default behavior stays the same.
We only set the parameter to true when creating LTOModule in local contexts.
These can only really be used for parsing symbols, so it's unnecessary to ever
load the metadata blocks.
If we are going to enable lazy-loading of Metadata for other usages of
getLazyBitcodeModule, where deferred metadata blocks need to be loaded, we can
expose BitcodeReader::materializeMetadata to Module, similar to
Module::materialize.
rdar://19804575
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232198 91177308-0d34-0410-b5e6-96231b3b80d8
Like r230414, add bitcode support including backwards compatibility, for
an explicit type parameter to GEP.
At the suggestion of Duncan I tried coalescing the two older bitcodes into a
single new bitcode, though I did hit a wrinkle: I couldn't figure out how to
create an explicit abbreviation for a record with a variable number of
arguments (the indicies to the gep). This means the discriminator between
inbounds and non-inbounds gep is a full variable-length field I believe? Is my
understanding correct? Is there a way to create such an abbreviation? Should I
just use two bitcodes as before?
Reviewers: dexonsmith
Differential Revision: http://reviews.llvm.org/D7736
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