This is used to mark the instructions emitted by Clang to implement
variety of UBSan checks. Generally, we don't want to instrument these
instructions with another sanitizers (like ASan).
Reviewed in http://reviews.llvm.org/D4544
llvm-svn: 213291
Originally committed in r211722, this fixed one case of dtor calls being
emitted without locations (this causes problems for debug info if the
call is then inlined), this caught only some of the cases.
Instead of trying to re-enable the location before the cleanup, simply
re-enable the location immediately after the unconditional branches in
question using a scoped device to ensure the no-location state doesn't
leak out arbitrarily.
llvm-svn: 212761
Now CodeGenFunction is responsible for looking at sanitizer blacklist
(in CodeGenFunction::StartFunction) and turning off instrumentation,
if necessary.
No functionality change.
llvm-svn: 212501
With && at the top level of an expression, the last thing done when
emitting the expression was an unconditional jump to the cleanup block.
To reduce the amount of stepping, the DebugLoc is omitted from the
unconditional jump. This is done by clearing the IRBuilder's
"CurrentDebugLocation"*. If this is not set to some non-empty value
before the cleanup block is emitted, the cleanups don't get a location
either. If a call without a location is emitted in a function with debug
info, and that call is then inlined - bad things happen. (without a
location for the call site, the inliner would just leave the inlined
DebugLocs as they were - pointing to roots in the original function, not
inlined into the current function)
Follow up commit to LLVM will ensure that breaking the invariants of the
DebugLoc chains by having chains that don't lead to the current function
will fail assertions, so we shouldn't accidentally slip any of these
cases in anymore. Those assertions may reveal further cases that need to
be fixed in clang, though I've tried to test heavily to avoid that.
* See r128471, r128513 for the code that clears the
CurrentDebugLocation. Simply removing this code or moving the code
into IRBuilder to apply to all unconditional branches would regress
desired behavior, unfortunately.
llvm-svn: 211722
This is a minimal fix for clang. I'll soon add support for generating
weak variants when requested, but that's not really necessary for the
LLVM change in isolation.
llvm-svn: 210907
Previously, we made one traversal of the AST prior to codegen to assign
counters to the ASTs and then propagated the count values during codegen. This
patch now adds a separate AST traversal prior to codegen for the
-fprofile-instr-use option to propagate the count values. The counts are then
saved in a map from which they can be retrieved during codegen.
This new approach has several advantages:
1. It gets rid of a lot of extra PGO-related code that had previously been
added to codegen.
2. It fixes a serious bug. My original implementation (which was mailed to the
list but never committed) used 3 counters for every loop. Justin improved it to
move 2 of those counters into the less-frequently executed breaks and continues,
but that turned out to produce wrong count values in some cases. The solution
requires visiting a loop body before the condition so that the count for the
condition properly includes the break and continue counts. Changing codegen to
visit a loop body first would be a fairly invasive change, but with a separate
AST traversal, it is easy to control the order of traversal. I've added a
testcase (provided by Justin) to make sure this works correctly.
3. It improves the instrumentation overhead, reducing the number of counters for
a loop from 3 to 1. We no longer need dedicated counters for breaks and
continues, since we can just use the propagated count values when visiting
breaks and continues.
To make this work, I needed to make a change to the way we count case
statements, going back to my original approach of not including the fall-through
in the counter values. This was necessary because there isn't always an AST node
that can be used to record the fall-through count. Now case statements are
handled the same as default statements, with the fall-through paths branching
over the counter increments. While I was at it, I also went back to using this
approach for do-loops -- omitting the fall-through count into the loop body
simplifies some of the calculations and make them behave the same as other
loops. Whenever we start using this instrumentation for coverage, we'll need
to add the fall-through counts into the counter values.
llvm-svn: 201528
A return type is the declared or deduced part of the function type specified in
the declaration.
A result type is the (potentially adjusted) type of the value of an expression
that calls the function.
Rule of thumb:
* Declarations have return types and parameters.
* Expressions have result types and arguments.
llvm-svn: 200082
adjustFallThroughCount isn't a good name, and the documentation was
even worse. This commit attempts to clarify what it's for and when to
use it.
llvm-svn: 199139
Remove UnaryTypeTraitExpr and switch all remaining type trait related handling
over to TypeTraitExpr.
The UTT/BTT/TT enum prefix and evaluation code is retained pending further
cleanup.
This is part of the ongoing work to unify type traits following the removal of
BinaryTypeTraitExpr in r197273.
llvm-svn: 198271
There's nothing special about type traits accepting two arguments.
This commit eliminates BinaryTypeTraitExpr and switches all related handling
over to TypeTraitExpr.
Also fixes a CodeGen failure with variadic type traits appearing in a
non-constant expression.
The BTT/TT prefix and evaluation code is retained as-is for now but will soon
be further cleaned up.
This is part of the ongoing work to unify type traits.
llvm-svn: 197273
With the introduction of explicit address space casts into LLVM, there's
a need to provide a new cast kind the front-end can create for C/OpenCL/CUDA
and code to produce address space casts from those kinds when appropriate.
Patch by Michele Scandale!
llvm-svn: 197036
whether we can safely lower a conditional operator to select was insufficient.
I've left a large comment in place to explaining the sort of problems that this
transform can encounter in clang in the hopes of discouraging others from
reimplementing it wrongly again in the future. (The test should also help with
that, but it's easy to work around any single test I might add and think that
your particular implementation doesn't miscompile any code.)
llvm-svn: 194289
check using the ubsan runtime) and -fsanitize=local-bounds (for the middle-end
check which inserts traps).
Remove -fsanitize=local-bounds from -fsanitize=undefined. It does not produce
useful diagnostics and has false positives (PR17635), and is not a good
compromise position between UBSan's checks and ASan's checks.
Map -fbounds-checking to -fsanitize=local-bounds to restore Clang's historical
behavior for that flag.
llvm-svn: 193205
LLVM supports applying conversion instructions to vectors of the same number of
elements (fptrunc, fptosi, etc.) but there had been no way for a Clang user to
cause such instructions to be generated when using builtin vector types.
C-style casting on vectors is already defined in terms of bitcasts, and so
cannot be used for these conversions as well (without leading to a very
confusing set of semantics). As a result, this adds a __builtin_convertvector
intrinsic (patterned after the OpenCL __builtin_astype intrinsic). This is
intended to aid the creation of vector intrinsic headers that create generic IR
instead of target-dependent intrinsics (in other words, this is a generic
_mm_cvtepi32_ps). As noted in the documentation, the action of
__builtin_convertvector is defined in terms of the action of a C-style cast on
each vector element.
llvm-svn: 190915
Summary:
UBSan was checking for alignment of the derived class on the pointer to
the base class, before converting. With some class hierarchies, this could
generate false positives.
Added test-case.
llvm-svn: 187948
Previously a 2-bit mask was used to mask each element of a vec6 mask before doing the extracts instead of 3-bit mask necessary to cover 0-5. vec3 was the only non-power-of-2 that worked correctly because a +1 conditionally added before calculating floor(log2(elements)).
llvm-svn: 187560
This is the same way GenericSelectionExpr works, and it's generally a
more consistent approach.
A large part of this patch is devoted to caching the value of the condition
of a ChooseExpr; it's needed to avoid threading an ASTContext into
IgnoreParens().
Fixes <rdar://problem/14438917>.
llvm-svn: 186738
Sema needs to be able to accurately determine what will be
emitted as a constant initializer and what will not, so
we get accurate errors in C and accurate -Wglobal-constructors
warnings in C++. This makes Expr::isConstantInitializer match
CGExprConstant as closely as possible.
llvm-svn: 186464
This simplifies the core benefit of -flimit-debug-info by taking a more
systematic approach to avoid emitting debug info definitions for types
that only require declarations. The previous ad-hoc approach (3 cases
removed in this patch) had many holes.
The general approach (adding a bit to TagDecl and callback through
ASTConsumer) has been discussed with Richard Smith - though always open
to revision.
llvm-svn: 186262
Add a CXXDefaultInitExpr, analogous to CXXDefaultArgExpr, and use it both in
CXXCtorInitializers and in InitListExprs to represent a default initializer.
There's an additional complication here: because the default initializer can
refer to the initialized object via its 'this' pointer, we need to make sure
that 'this' points to the right thing within the evaluation.
llvm-svn: 179958
it wasn't taking into account that the float should be truncated *before* the
range check happens. Thus (unsigned)-0.99 and (unsigned char)255.9 have defined
behavior and should not be trapped.
llvm-svn: 177362
aggregate types in a profoundly wrong way that has to be
worked around in every call site, to getEvaluationKind,
which classifies and distinguishes between all of these
cases.
Also, normalize the API for loading and storing complexes.
I'm working on a larger patch and wanted to pull these
changes out, but it would have be annoying to detangle
them from each other.
llvm-svn: 176656
- Generate atomicrmw operations in most of the cases when it's sensible to do
so.
- Don't crash in several common cases (and hopefully don't crash in more of
them).
- Add some better tests.
We now generate significantly better code for things like:
_Atomic(int) x;
...
x++;
On MIPS, this now generates a 4-instruction ll/sc loop, where previously it
generated about 30 instructions in two nested loops. On x86-64, we generate a
single lock incl, instead of a lock cmpxchgl loop (one instruction instead of
ten).
llvm-svn: 176420
calls and declarations.
LLVM has a default CC determined by the target triple. This is
not always the actual default CC for the ABI we've been asked to
target, and so we sometimes find ourselves annotating all user
functions with an explicit calling convention. Since these
calling conventions usually agree for the simple set of argument
types passed to most runtime functions, using the LLVM-default CC
in principle has no effect. However, the LLVM optimizer goes
into histrionics if it sees this kind of formal CC mismatch,
since it has no concept of CC compatibility. Therefore, if this
module happens to define the "runtime" function, or got LTO'ed
with such a definition, we can miscompile; so it's quite
important to get this right.
Defining runtime functions locally is quite common in embedded
applications.
llvm-svn: 176286
Alexey Samsonov