Avoid crashing when printing diagnostics for vtable-related CFI
errors. In diagnostic mode, the frontend does an additional check of
the vtable pointer against the set of all known vtable addresses and
lets the runtime handler know if it is safe to inspect the vtable.
http://reviews.llvm.org/D16823
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@259716 91177308-0d34-0410-b5e6-96231b3b80d8
reclaiming a call result in order to ignore it or assign it
to an __unsafe_unretained variable. This avoids adding
an unwanted retain/release pair when the return value is
not actually returned autoreleased (e.g. when it is returned
from a nonatomic getter or a typical collection accessor).
This runtime function is only available on the latest Apple
OS releases; the backwards-compatibility story is that you
don't get the optimization unless your deployment target is
recent enough. Sorry.
rdar://20530049
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@258962 91177308-0d34-0410-b5e6-96231b3b80d8
Member pointers in the MS ABI are tricky for a variety of reasons.
The size of a member pointer is indeterminate until the program reaches
a point where the representation is required to be known. However,
*pointers* to member pointers may exist without knowing the pointee
type's representation. In these cases, we synthesize an opaque LLVM
type for the pointee type.
However, we can be in a situation where the underlying member pointer's
representation became known mid-way through the program. To account for
this, we attempted to manicure CodeGen's type-cache so that we can
replace the opaque member pointer type with the real deal while leaving
the pointer types unperturbed. This, unfortunately, is a problematic
approach to take as we will violate CodeGen's invariants.
These violations are mostly harmless but let's do the right thing
instead: invalidate the type-cache if a member pointer's LLVM
representation changes.
This fixes PR26313.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@258839 91177308-0d34-0410-b5e6-96231b3b80d8
Proper diagnostic and resolution of mangled names' conflicts in variables.
When there is a declaration and a definition using the same name but different
types, we emit what is in the definition. When there are two conflicting
definitions, we issue an error.
Differential Revision: http://reviews.llvm.org/D15686
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@257754 91177308-0d34-0410-b5e6-96231b3b80d8
Clang-side cross-DSO CFI.
* Adds a command line flag -f[no-]sanitize-cfi-cross-dso.
* Links a runtime library when enabled.
* Emits __cfi_slowpath calls is bitset test fails.
* Emits extra hash-based bitsets for external CFI checks.
* Sets a module flag to enable __cfi_check generation during LTO.
This mode does not yet support diagnostics.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@255694 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r254195.
From the description, I suspect that the wrong patch was committed here,
and this is causing assertion failures in EmitDeferred() when the global
value ends up being a bitcast of a global.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@254823 91177308-0d34-0410-b5e6-96231b3b80d8
type changes when the initializer is attached). Don't hold onto the
GlobalVariable*; recompute it from the VarDecl* instead.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@254359 91177308-0d34-0410-b5e6-96231b3b80d8
This patch changes the generation of CGFunctionInfo to contain
the FunctionProtoType if it is available. This enables the code
generation for call instructions to look into this type for
exception information and therefore generate better quality
IR - it will not create invoke instructions for functions that
are know not to throw.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@253926 91177308-0d34-0410-b5e6-96231b3b80d8
attributes to internal functions.
This patch fixes CodeGenModule::CreateGlobalInitOrDestructFunction to
use SetInternalFunctionAttributes instead of SetLLVMFunctionAttributes
to attach function attributes to internal functions.
Also, make sure the correct CGFunctionInfo is passed instead of always
passing what arrangeNullaryFunction returns.
rdar://problem/20828324
Differential Revision: http://reviews.llvm.org/D13610
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@251734 91177308-0d34-0410-b5e6-96231b3b80d8
This avoids building a fake LLVM IR global variable just to ferry an i32
down into LLVM codegen. It also puts a nail in the coffin of using MS
ABI C++ EH with landingpads, since now we'll assert in the lpad code
when flags are present.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247843 91177308-0d34-0410-b5e6-96231b3b80d8
Current implementation may end up emitting an undefined reference for
an "inline __attribute__((always_inline))" function by generating an
"available_externally alwaysinline" IR function for it and then failing to
inline all the calls. This happens when a call to such function is in dead
code. As the inliner is an SCC pass, it does not process dead code.
Libc++ relies on the compiler never emitting such undefined reference.
With this patch, we emit a pair of
1. internal alwaysinline definition (called F.alwaysinline)
2a. A stub F() { musttail call F.alwaysinline }
-- or, depending on the linkage --
2b. A declaration of F.
The frontend ensures that F.inlinefunction is only used for direct
calls, and the stub is used for everything else (taking the address of
the function, really). Declaration (2b) is emitted in the case when
"inline" is meant for inlining only (like __gnu_inline__ and some
other cases).
This approach, among other nice properties, ensures that alwaysinline
functions are always internal, making it impossible for a direct call
to such function to produce an undefined symbol reference.
This patch is based on ideas by Chandler Carruth and Richard Smith.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247494 91177308-0d34-0410-b5e6-96231b3b80d8
Current implementation may end up emitting an undefined reference for
an "inline __attribute__((always_inline))" function by generating an
"available_externally alwaysinline" IR function for it and then failing to
inline all the calls. This happens when a call to such function is in dead
code. As the inliner is an SCC pass, it does not process dead code.
Libc++ relies on the compiler never emitting such undefined reference.
With this patch, we emit a pair of
1. internal alwaysinline definition (called F.alwaysinline)
2a. A stub F() { musttail call F.alwaysinline }
-- or, depending on the linkage --
2b. A declaration of F.
The frontend ensures that F.inlinefunction is only used for direct
calls, and the stub is used for everything else (taking the address of
the function, really). Declaration (2b) is emitted in the case when
"inline" is meant for inlining only (like __gnu_inline__ and some
other cases).
This approach, among other nice properties, ensures that alwaysinline
functions are always internal, making it impossible for a direct call
to such function to produce an undefined symbol reference.
This patch is based on ideas by Chandler Carruth and Richard Smith.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247465 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce an Address type to bundle a pointer value with an
alignment. Introduce APIs on CGBuilderTy to work with Address
values. Change core APIs on CGF/CGM to traffic in Address where
appropriate. Require alignments to be non-zero. Update a ton
of code to compute and propagate alignment information.
As part of this, I've promoted CGBuiltin's EmitPointerWithAlignment
helper function to CGF and made use of it in a number of places in
the expression emitter.
The end result is that we should now be significantly more correct
when performing operations on objects that are locally known to
be under-aligned. Since alignment is not reliably tracked in the
type system, there are inherent limits to this, but at least we
are no longer confused by standard operations like derived-to-base
conversions and array-to-pointer decay. I've also fixed a large
number of bugs where we were applying the complete-object alignment
to a pointer instead of the non-virtual alignment, although most of
these were hidden by the very conservative approach we took with
member alignment.
Also, because IRGen now reliably asserts on zero alignments, we
should no longer be subject to an absurd but frustrating recurring
bug where an incomplete type would report a zero alignment and then
we'd naively do a alignmentAtOffset on it and emit code using an
alignment equal to the largest power-of-two factor of the offset.
We should also now be emitting much more aggressive alignment
attributes in the presence of over-alignment. In particular,
field access now uses alignmentAtOffset instead of min.
Several times in this patch, I had to change the existing
code-generation pattern in order to more effectively use
the Address APIs. For the most part, this seems to be a strict
improvement, like doing pointer arithmetic with GEPs instead of
ptrtoint. That said, I've tried very hard to not change semantics,
but it is likely that I've failed in a few places, for which I
apologize.
ABIArgInfo now always carries the assumed alignment of indirect and
indirect byval arguments. In order to cut down on what was already
a dauntingly large patch, I changed the code to never set align
attributes in the IR on non-byval indirect arguments. That is,
we still generate code which assumes that indirect arguments have
the given alignment, but we don't express this information to the
backend except where it's semantically required (i.e. on byvals).
This is likely a minor regression for those targets that did provide
this information, but it'll be trivial to add it back in a later
patch.
I partially punted on applying this work to CGBuiltin. Please
do not add more uses of the CreateDefaultAligned{Load,Store}
APIs; they will be going away eventually.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246985 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Dtor sanitization handled amidst other dtor cleanups,
between cleaning bases and fields. Sanitizer call pushed onto
stack of cleanup operations.
Reviewers: eugenis, kcc
Differential Revision: http://reviews.llvm.org/D12022
Refactoring dtor sanitizing emission order.
- Support multiple inheritance by poisoning after
member destructors are invoked, and before base
class destructors are invoked.
- Poison for virtual destructor and virtual bases.
- Repress dtor aliasing when sanitizing in dtor.
- CFE test for dtor aliasing, and repression of aliasing in dtor
code generation.
- Poison members on field-by-field basis, with collective poisoning
of trivial members when possible.
- Check msan flags and existence of fields, before dtor sanitizing,
and when determining if aliasing is allowed.
- Testing sanitizing bit fields.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246815 91177308-0d34-0410-b5e6-96231b3b80d8
Proper diagnostic and resolution of mangled names conflicts between C++ methods
and C functions. This patch implements support for functions/methods only;
support for variables is coming separately.
Differential Revision: http://reviews.llvm.org/D11297
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246438 91177308-0d34-0410-b5e6-96231b3b80d8
Make the copy/move ctors protected and defaulted in the base, make the
derived classes final to avoid exposing any slicing-prone APIs.
Also, while I'm here, simplify the use of buildByrefHelpers by taking
the parameter by value instead of non-const ref. None of the callers
care aobut observing the state after the call.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@244990 91177308-0d34-0410-b5e6-96231b3b80d8
We were previously creating bit set entries at virtual table offset
sizeof(void*) unconditionally under the Microsoft C++ ABI. This is incorrect
if RTTI data is disabled; in that case the "address point" is at offset
0. This change modifies bit set emission to take into account whether RTTI
data is being emitted.
Also make a start on a blacklisting scheme for records.
Differential Revision: http://reviews.llvm.org/D11048
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241845 91177308-0d34-0410-b5e6-96231b3b80d8
In order to produce debug info for clang modules CGDebugInfo it needs
access to macros passed on the command line and the isysroot.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241035 91177308-0d34-0410-b5e6-96231b3b80d8
Member pointers in the MS ABI are made complicated due to the following:
- Virtual methods in the most derived class (MDC) might live in a
vftable in a virtual base.
- There are four different representations of member pointer: single
inheritance, multiple inheritance, virtual inheritance and the "most
general" representation.
- Bases might have a *more* general representation than classes which
derived from them, a most surprising result.
We believed that we could treat all member pointers as-if they were a
degenerate case of the multiple inheritance model. This fell apart once
we realized that implementing standard member pointers using this ABI
requires referencing members with a non-zero vbindex.
On a bright note, all but the virtual inheritance model operate rather
similarly. The virtual inheritance member pointer representation
awkwardly requires a virtual base adjustment in order to refer to
entities in the MDC.
However, the first virtual base might be quite far from the start of the
virtual base. This means that we must add a negative non-virtual
displacement.
However, things get even more complicated. The most general
representation interprets vbindex zero differently from the virtual
inheritance model: it doesn't reference the vbtable at all.
It turns out that this complexity can increase for quite some time:
consider a derived to base conversion from the most general model to the
multiple inheritance model...
To manage this complexity we introduce a concept of "normalized" member
pointer which allows us to treat all three models as the most general
model. Then we try to figure out how to map this generalized member
pointer onto the destination member pointer model. I've done my best to
furnish the code with comments explaining why each adjustment is
performed.
This fixes PR23878.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@240384 91177308-0d34-0410-b5e6-96231b3b80d8
The patch is generated using this command:
$ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
work/llvm/tools/clang
To reduce churn, not touching namespaces spanning less than 10 lines.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@240270 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.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@238601 91177308-0d34-0410-b5e6-96231b3b80d8
This is a follow-up to r238266. It turned out structors are codegened through a different path,
and didn't get the storage class set in EmitGlobalFunctionDefinition.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@238443 91177308-0d34-0410-b5e6-96231b3b80d8
Functions with available_externally linkage will not be emitted to object
files (they will just be undefined symbols), so it does not make sense to
put them in comdats.
Creates a second overload of maybeSetTrivialComdat that uses the GlobalObject
instead of the Decl, and uses that in several places that had the faulty
logic.
Differential Revision: http://reviews.llvm.org/D9580
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236879 91177308-0d34-0410-b5e6-96231b3b80d8
Reverts the code changes from r234675 but keeps the test case.
We were already maintaining a DenseMap of globals with dynamic
initializers anyway.
Fixes the test case from PR23234.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234961 91177308-0d34-0410-b5e6-96231b3b80d8
Looks like the VTable code in particular will need some work to pass
around the pointee type explicitly.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234128 91177308-0d34-0410-b5e6-96231b3b80d8
Utilizing IMAGEREL relocations for synthetic IR constructs isn't
valuable, just clutter. While we are here, simplify HandlerType names
by making the numeric value for the 'adjective' part of the mangled name
instead of appending '.const', etc. The old scheme made for very long
global names and leads to wordy things like '.std_bad_alloc'
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@233503 91177308-0d34-0410-b5e6-96231b3b80d8
The HandlerMap describes, to the runtime, what sort of catches surround
the try. In principle, this structure has to be emitted by the backend
because only it knows the layout of the stack (the runtime needs to know
where on the stack the destination of a copy lives, etc.) but there is
some C++ specific information that the backend can't reason about.
Stick this information in special LLVM globals with the relevant
"const", "volatile", "reference" info mangled into the name.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@232538 91177308-0d34-0410-b5e6-96231b3b80d8
Use llvm.eh.begincatch for Microsoft-style catches.
This moves lots of CGException code into ItaniumCXXABI. Sorry for the
blame pain.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@231105 91177308-0d34-0410-b5e6-96231b3b80d8
This patch introduces the -fsanitize=cfi-vptr flag, which enables a control
flow integrity scheme that checks that virtual calls take place using a vptr of
the correct dynamic type. More details in the new docs/ControlFlowIntegrity.rst
file.
It also introduces the -fsanitize=cfi flag, which is currently a synonym for
-fsanitize=cfi-vptr, but will eventually cover all CFI checks implemented
in Clang.
Differential Revision: http://reviews.llvm.org/D7424
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@230055 91177308-0d34-0410-b5e6-96231b3b80d8
In ItaniumCXXABI::EmitCXXDestructors we first emit the base destructor
and then try to emit the complete one as an alias.
If in the base ends up calling the complete destructor, the GD for the
complete will be in the list of deferred decl by the time we replace
it with an alias and delete the original GV.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@226896 91177308-0d34-0410-b5e6-96231b3b80d8
When combined with llvm not producing implicit comdats, not doing this would
cause code bloat on ELF and link errors on COFF.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@226211 91177308-0d34-0410-b5e6-96231b3b80d8
Sema calls HandleVTable() with a bool parameter which is then threaded through
three layers. The only effect of this bool is an early return at the last
layer.
Instead, remove this parameter and call HandleVTable() only if the bool is
true. No intended behavior change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@226096 91177308-0d34-0410-b5e6-96231b3b80d8
Their linkage can change if they are later explicitly instantiated. We would
previously emit such functions eagerly (as opposed to lazily on first use) if
they have a 'dllexport' or 'used' attribute, and fail an assert when hitting the
explicit instantiation.
This is achieved by replacing the old CodeGenModule::MayDeferGeneration() method
with two new ones: MustBeEmitted() and MayBeEmittedEagerly().
Differential Revision: http://reviews.llvm.org/D6674
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@225570 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In a JIT context it is useful to be able to access the GlobalCtors
and especially clear them once they have been emitted and called.
This adds a public method to be able to access the list.
Subscribers: yaron.keren, cfe-commits
Differential Revision: http://reviews.llvm.org/D6790
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@224982 91177308-0d34-0410-b5e6-96231b3b80d8
ARM ABI specifies that all the libcalls use soft FP ABI
(even hard FP binaries). These days clang emits _mulsc3 / _muldc3
calls with default (C) calling convention which would be translated
into AAPCS_VFP LLVM calling and thus the result of complex
multiplication will be bogus.
Introduce a way for a target to specify explicitly calling
convention for libcalls. Right now this is temporary correctness
fix. Ultimately, we'll end with intrinsic for complex
multiplication and all calling convention decisions for libcalls
will be put into backend.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223123 91177308-0d34-0410-b5e6-96231b3b80d8
For all threadprivate variables which have constructor/destructor emit call to void __kmpc_threadprivate_register(ident_t * <Current Location>, void *<Original Global Addr>, kmpc_ctor <Constructor>, kmpc_cctor NULL, kmpc_dtor <Destructor>);
In expressions all references to such variables are replaced by calls to void *__kmpc_threadprivate_cached(ident_t *<Current Location>, kmp_int32 <Current Thread Id>, void *<Original Global Addr>, size_t <Size of Data>, void ***<Pointer to autogenerated cache – array of private copies of threadprivate variable>);
Test test/OpenMP/threadprivate_codegen.cpp checks that codegen is correct. Also it checks that codegen is correct after serialization/deserialization and one of passes verifies debug info.
Differential Revision: http://reviews.llvm.org/D4002
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221663 91177308-0d34-0410-b5e6-96231b3b80d8
This commit changes the way we blacklist global variables in ASan.
Now the global is excluded from instrumentation (either regular
bounds checking, or initialization-order checking) if:
1) Global is explicitly blacklisted by its mangled name.
This part is left unchanged.
2) SourceLocation of a global is in blacklisted source file.
This changes the old behavior, where instead of looking at the
SourceLocation of a variable we simply considered llvm::Module
identifier. This was wrong, as identifier may not correspond to
the file name, and we incorrectly disabled instrumentation
for globals coming from #include'd files.
3) Global is blacklisted by type.
Now we build the type of a global variable using Clang machinery
(QualType::getAsString()), instead of llvm::StructType::getName().
After this commit, the active users of ASan blacklist files
may have to revisit them (this is a backwards-incompatible change).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220097 91177308-0d34-0410-b5e6-96231b3b80d8
This commit changes the way we blacklist functions in ASan, TSan,
MSan and UBSan. We used to treat function as "blacklisted"
and turned off instrumentation in it in two cases:
1) Function is explicitly blacklisted by its mangled name.
This part is not changed.
2) Function is located in llvm::Module, whose identifier is
contained in the list of blacklisted sources. This is completely
wrong, as llvm::Module may not correspond to the actual source
file function is defined in. Also, function can be defined in
a header, in which case user had to blacklist the .cpp file
this header was #include'd into, not the header itself.
Such functions could cause other problems - for instance, if the
header was included in multiple source files, compiled
separately and linked into a single executable, we could end up
with both instrumented and non-instrumented version of the same
function participating in the same link.
After this change we will make blacklisting decision based on
the SourceLocation of a function definition. If a function is
not explicitly defined in the source file, (for example, the
function is compiler-generated and responsible for
initialization/destruction of a global variable), then it will
be blacklisted if the corresponding global variable is defined
in blacklisted source file, and will be instrumented otherwise.
After this commit, the active users of blacklist files may have
to revisit them. This is a backwards-incompatible change, but
I don't think it's possible or makes sense to support the
old incorrect behavior.
I plan to make similar change for blacklisting GlobalVariables
(which is ASan-specific).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219997 91177308-0d34-0410-b5e6-96231b3b80d8
CodeGen wouldn't mark the aliasee as thread_local if the aliasee was a
tentative definition.
Even if the definition was already emitted, it would never mark the
alias as thread_local.
This fixes PR21288.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219859 91177308-0d34-0410-b5e6-96231b3b80d8
This change moves SanitizerBlacklist.h from lib/CodeGen
to public Clang headers in include/clang/Basic. SanitizerBlacklist
is currently only used in CodeGen to decide which functions/modules
should be instrumented, but this will soon change as ASan will
optionally modify class layouts during AST construction
(http://reviews.llvm.org/D5687). We need blacklist machinery
to be available at this point.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219840 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Previously CodeGen assumed that static locals were emitted before they
could be accessed, which is true for automatic storage duration locals.
However, it is possible to have CodeGen emit a nested function that uses
a static local before emitting the function that defines the static
local, breaking that assumption.
Fix it by creating the static local upon access and ensuring that the
deferred function body gets emitted. We may not be able to emit the
initializer properly from outside the function body, so don't try.
Fixes PR18020. See also previous attempts to fix static locals in
PR6769 and PR7101.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4787
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219265 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This add support for the C++11 feature, thread_local global variables.
The ABI Clang implements is an improvement of the MSVC ABI. Sadly,
further improvements could be made but not without sacrificing ABI
compatibility.
The feature is implemented as follows:
- All thread_local initialization routines are pointed to from the
.CRT$XDU section.
- All non-weak thread_local variables have their initialization routines
call from a single function instead of getting their own .CRT$XDU
section entry. This is done to open up optimization opportunities to
the compiler.
- All weak thread_local variables have their own .CRT$XDU section entry.
This entry is in a COMDAT with the global variable it is initializing;
this ensures that we will initialize the global exactly once.
- Destructors are registered in the initialization function using
__tlregdtor.
Differential Revision: http://reviews.llvm.org/D5597
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219074 91177308-0d34-0410-b5e6-96231b3b80d8
On further investigation, COMDATs should work with .ctors, and the issue
I was hitting probably reproduces with .init_array.
This reverts commit r218287.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@218313 91177308-0d34-0410-b5e6-96231b3b80d8
In particular, pre-.init_array ELF uses the .ctors section mechanism.
MinGW COFF also uses .ctors, now that I think about it. Therefore,
restrict this optimization to the two platforms that are currently known
to work: ELF with .init_array and COFF with .CRT$XCU.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@218287 91177308-0d34-0410-b5e6-96231b3b80d8
This patch makes sure that the dllexport attribute is transferred to the alias when such alias is created. It only affects the Itanium ABI because for the MSVC ABI a workaround is in place to not generate aliases of dllexport ctors/dtors.
A new CodeGenModule function is provided, CodeGenModule::setAliasAttributes, to factor the code for transferring attributes to aliases.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@218159 91177308-0d34-0410-b5e6-96231b3b80d8
The field is defined as:
If the third field is present, non-null, and points to a global variable or function, the initializer function will only run if the associated data from the current module is not discarded.
And without COMDATs we can't implement that.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@218097 91177308-0d34-0410-b5e6-96231b3b80d8
Clang can already handle
-------------------------------------------
struct S {
static const int x;
};
template<typename T> struct U {
static const int k;
};
template<typename T> const int U<T>::k = T::x;
const int S::x = 42;
extern const int *f();
const int *g() { return &U<S>::k; }
int main() {
return *f() + U<S>::k;
}
const int *f() { return &U<S>::k; }
-------------------------------------------
since r217264 which puts the .inint_array section in the same COMDAT
as the variable.
This patch allows the linker to more easily delete some dead code and data by
putting the guard variable and init function in the same COMDAT.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@218089 91177308-0d34-0410-b5e6-96231b3b80d8
There are situations when clang knows that the C1 and C2 constructors
or the D1 and D2 destructors are identical. We already optimize some
of these cases, but cannot optimize it when the GlobalValue is
weak_odr.
The problem with weak_odr is that an old TU seeing the same code will
have a C1 and a C2 comdat with the corresponding symbols. We cannot
suddenly start putting the C2 symbol in the C1 comdat as we cannot
guarantee that the linker will not pick a .o with only C1 in it.
The solution implemented by GCC is to expand the ABI to have a comdat
whose name uses a C5/D5 suffix and always has both symbols. That is
what this patch implements.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@217874 91177308-0d34-0410-b5e6-96231b3b80d8
There were code paths that are duplicated for constructors and destructors just
because we have both CXXCtorType and CXXDtorsTypes.
This patch introduces an unified enum and reduces code deplication a bit.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@217383 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds the '-fcoverage-mapping' option which
allows clang to generate the coverage mapping information
that can be used to provide code coverage analysis using
the execution counts obtained from the instrumentation
based profiling (-fprofile-instr-generate).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214752 91177308-0d34-0410-b5e6-96231b3b80d8
It is responsible for generating metadata consumed by sanitizer instrumentation
passes in the backend. Move several methods from CodeGenModule to SanitizerMetadata.
For now the class is stateless, but soon it won't be the case.
Instead of creating globals providing source-level information to ASan, we will create
metadata nodes/strings which will be turned into actual global variables in the
backend (if needed).
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214564 91177308-0d34-0410-b5e6-96231b3b80d8
lengths! In passing, simplify string literal deduplication by relying on LLVM
to deduplicate the underlying constant values.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214222 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This pragma is very rare. We could *hypothetically* lower some uses of
it down to @llvm.global_ctors, but given that GlobalOpt isn't able to
optimize prioritized global ctors today, there's really no point.
If we wanted to do this in the future, I would check if the section used
in the pragma started with ".CRT$XC" and had up to two characters after
it. Those two characters could form the 16-bit initialization priority
that we support in @llvm.global_ctors. We would have to teach LLVM to
lower prioritized global ctors on COFF as well.
This should let us compile some silly uses of this pragma in WebKit /
Blink.
Reviewers: rsmith, majnemer
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4549
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213593 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change adds description of globals created by UBSan
instrumentation (UBSan handlers, type descriptors, filenames) to
llvm.asan.globals metadata, effectively "blacklisting" them. This can
dramatically decrease the data section in binaries built with UBSan+ASan,
as UBSan tends to create a lot of handlers, and ASan instrumentation
increases the global size to at least 64 bytes.
Test Plan: clang regression test suite
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits, byoungyoung, kcc
Differential Revision: http://reviews.llvm.org/D4575
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213392 91177308-0d34-0410-b5e6-96231b3b80d8
Currently ASan instrumentation pass creates a string with global name
for each instrumented global (to include global names in the error report). Global
name is already mangled at this point, and we may not be able to demangle it
at runtime (e.g. there is no __cxa_demangle on Android).
Instead, create a string with fully qualified global name in Clang, and pass it
to ASan instrumentation pass in llvm.asan.globals metadata. If there is no metadata
for some global, ASan will use the original algorithm.
This fixes https://code.google.com/p/address-sanitizer/issues/detail?id=264.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212872 91177308-0d34-0410-b5e6-96231b3b80d8
Turn llvm::SpecialCaseList into a simple class that parses text files in
a specified format and knows nothing about LLVM IR. Move this class into
LLVMSupport library. Implement two users of this class:
* DFSanABIList in DFSan instrumentation pass.
* SanitizerBlacklist in Clang CodeGen library.
The latter will be modified to use actual source-level information from frontend
(source file names) instead of unstable LLVM IR things (LLVM Module identifier).
Remove dependency edge from ClangCodeGen/ClangDriver to LLVMTransformUtils.
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212643 91177308-0d34-0410-b5e6-96231b3b80d8
Now CodeGenFunction is responsible for looking at sanitizer blacklist
(in CodeGenFunction::StartFunction) and turning off instrumentation,
if necessary.
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212501 91177308-0d34-0410-b5e6-96231b3b80d8
Get rid of cached CodeGenModule::SanOpts, which was used to turn off
sanitizer codegen options if current LLVM Module is blacklisted, and use
plain LangOpts.Sanitize instead.
1) Some codegen decisions (turning TBAA or writable strings on/off)
shouldn't depend on the contents of blacklist.
2) llvm.asan.globals should *always* be created, even if the module
is blacklisted - soon Clang's CodeGen where we read sanitizer
blacklist files, so we should properly report which globals are
blacklisted to the backend.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212499 91177308-0d34-0410-b5e6-96231b3b80d8
Let's not expose ABI specific minutia inside of CodeGenModule and Type.
Instead, let's abstract it through CXXABI.
This gets rid of:
CodeGenModule::getCompleteObjectLocator,
CodeGenModule::EmitFundamentalTypeDescriptor{s,},
CodeGenModule::getMSTypeDescriptor,
CodeGenModule::getMSCompleteObjectLocator,
CGCXXABI::shouldRTTIBeUnique,
CGCXXABI::classifyRTTIUniqueness.
CGRTTI was *almost* entirely centered around providing Itanium-style
RTTI information. Instead of providing interfaces that only it
consumes, move it to the ItaniumCXXABI implementation file. This allows
it to have access to Itanium-specific implementation details without
providing useless expansion points for the Microsoft ABI side.
Differential Revision: http://reviews.llvm.org/D4261
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Summary:
Because a global created by GetOrCreateLLVMGlobal() is not finalised until later viz:
extern char a[];
char f(){ return a[5];}
char a[10];
Change MangledDeclNames to use a MapVector rather than a DenseMap so that the
Metadata is output in order of original declaration, so to make deterministic
and improve human readablity.
Differential Revision: http://reviews.llvm.org/D4176
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212263 91177308-0d34-0410-b5e6-96231b3b80d8
See https://code.google.com/p/address-sanitizer/issues/detail?id=299 for the
original feature request.
Introduce llvm.asan.globals metadata, which Clang (or any other frontend)
may use to report extra information about global variables to ASan
instrumentation pass in the backend. This metadata replaces
llvm.asan.dynamically_initialized_globals that was used to detect init-order
bugs. llvm.asan.globals contains the following data for each global:
1) source location (file/line/column info);
2) whether it is dynamically initialized;
3) whether it is blacklisted (shouldn't be instrumented).
Source location data is then emitted in the binary and can be picked up
by ASan runtime in case it needs to print error report involving some global.
For example:
0x... is located 4 bytes to the right of global variable 'C::array' defined in '/path/to/file:17:8' (0x...) of size 40
These source locations are printed even if the binary doesn't have any
debug info.
This is an ABI-breaking change. ASan initialization is renamed to
__asan_init_v4(). Pre-built libraries compiled with older Clang will not work
with the fresh runtime.
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The pointer for a class's RTTI data comes right before the VFTable but
has no name. To be properly compatible with this, we do the following:
* Create a single GlobalVariable which holds the contents of the VFTable
_and_ the pointer to the RTTI data.
* Create a GlobalAlias, with appropriate linkage/visibility, that points
just after the RTTI data pointer. This ensures that the VFTable
symbol will always refer to VFTable data.
* Create a Comdat with a "Largest" SelectionKind and stick the private
GlobalVariable in it. By transitivity, the GlobalAlias will be a
member of the Comdat group. Using "Largest" ensures that foreign
definitions without an RTTI data pointer will _not_ be chosen in the
final linked image.
Whether or not we emit RTTI data depends on several things:
* The -fno-rtti flag implies that we should never not emit a pointer to
RTTI data before the VFTable.
* __declspec(dllimport) brings in the VFTable from a remote DLL. Use an
available_externally GlobalVariable to provide a local definition of
the VFTable. This means that we won't have any available_externally
definitions of things like complete object locators. This is
acceptable because they are never directly referenced.
To my knowledge, this completes the implementation of MSVC RTTI code
generation.
Further semantic work should be done to properly support /GR-.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212125 91177308-0d34-0410-b5e6-96231b3b80d8
Improve the warning when building with -fprofile-instr-use and a file
appears not to have been profiled at all. This keys on whether a
function is defined in the main file or not to avoid false negatives
when one includes a header with functions that have been profiled.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211760 91177308-0d34-0410-b5e6-96231b3b80d8
Add driver and frontend support for the GCC -Wframe-larger-than=bytes warning.
This is the first GCC-compatible backend diagnostic built around LLVM's
reporting feature.
This commit adds infrastructure to perform reverse lookup from mangled names
emitted after LLVM IR generation. We use that to resolve precise locations and
originating AST functions, lambdas or block declarations to produce seamless
codegen-guided diagnostics.
An associated change, StringMap now maintains unique mangled name strings
instead of allocating copies. This is a net memory saving in C++ and a small
hit for C where we no longer reuse IdentifierInfo storage, pending further
optimisation.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@210293 91177308-0d34-0410-b5e6-96231b3b80d8
Share mode code between these functions and re-structure them in a way
which shows how similar they actually are. The latter function works well
with literals of multi-byte chars and does a GlobalVariable name mangling
(if global strings are non-writable).
No functionality change.
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The only remaining user didn't actually use the non-dynamic storage facility
this class provides.
The std::string is transitional and likely to be StringRefized shortly.
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MSVC doesn't export these functions, so trying to import them doesnt' work.
Also, don't let any dll attributes on the CXXDestructorDecl influence the
thunk's linkage -- they should always be linkonce_odr.
This takes care of the FIXME's for this in Nico's tests.
Differential Revision: http://reviews.llvm.org/D3930
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209706 91177308-0d34-0410-b5e6-96231b3b80d8
Initializers of global data that can appear multiple TUs (static data
members of class templates or __declspec(selectany) data) are now in a
comdat group keyed on the global variable being initialized. On
non-Windows platforms, this is a code size and startup time
optimization. On Windows, this is necessary for ABI compatibility with
MSVC.
Fixes PR16959.
Reviewers: rsmith
Differential Revision: http://reviews.llvm.org/D3811
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209555 91177308-0d34-0410-b5e6-96231b3b80d8
Enables the emission of MS-compatible RTTI data structures for use with
typeid, dynamic_cast and exceptions. Does not implement dynamic_cast
or exceptions. As an artiface, typeid works in some cases but proper
support an testing will coming in a subsequent patch.
majnemer has fuzzed the results. Test cases included.
Differential Revision: http://reviews.llvm.org/D3833
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This was fairly broken. For example,
@__dso_handle would or would not get an unnamed_addr depending on how many
global destructors were used in a translation unit.
The consensus was that not every runtime variable is unnamed_addr and that
__dso_handle handle should not be, so just don't add unnamed_addr in
CreateRuntimeVariable.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209484 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
A reference temporary should inherit the linkage of the variable it
initializes. Otherwise, we may hit cases where a reference temporary
wouldn't have the same value in all translation units.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D3515
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@207451 91177308-0d34-0410-b5e6-96231b3b80d8
Update clang to use the InstrProfReader from LLVM to read
instrumentation based profile data. This also switches us from the
naive text format to the binary format, since that's what's
implemented in the reader.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@206658 91177308-0d34-0410-b5e6-96231b3b80d8
This adds a warning that triggers when profile data doesn't match for
the source that's being compiled with -fprofile-instr-use=. This fires
only once per translation unit, as warning on every mismatched
function would be quite noisy.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@206322 91177308-0d34-0410-b5e6-96231b3b80d8
COFF doesn't have mergeable sections so LLVM/clang's normal tactics for
string deduplication will not have any effect.
To remedy this we place each string inside it's own section and mark
the section as IMAGE_COMDAT_SELECT_ANY. However, we can only do this if the
string has an external name that we can generate from it's contents.
To be compatible with MSVC, we must use their scheme. Otherwise identical
strings in translation units from clang may not be deduplicated with
translation units in MSVC.
This fixes PR18248.
N.B. We will not attempt to do anything with a string literal which is not of
type 'char' or 'wchar_t' because their compiler does not support unicode
string literals as of this date. Further, we avoid doing this if
either -fwritable-strings or -fsanitize=address are present.
This reverts commit r204596.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@204675 91177308-0d34-0410-b5e6-96231b3b80d8
COFF doesn't have mergeable sections so LLVM/clang's normal tactics for
string deduplication will not have any effect.
To remedy this we place each string inside it's own section and mark
the section as IMAGE_COMDAT_SELECT_ANY. However, we can only do this if the
string has an external name that we can generate from it's contents.
To be compatible with MSVC, we must use their scheme. Otherwise identical
strings in translation units from clang may not be deduplicated with
translation units in MSVC.
This fixes PR18248.
N.B. We will not attempt to do anything with a string literal which is not of
type 'char' or 'wchar_t' because their compiler does not support unicode
string literals as of this date.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@204562 91177308-0d34-0410-b5e6-96231b3b80d8
I've clearly done something wrong with how to get this to link
correctly. Reverting for now.
This reverts commit r203711.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203712 91177308-0d34-0410-b5e6-96231b3b80d8
This updates CodeGenPGO to use the ProfileDataReader introduced to
llvm in r203703 and the new API for writing out the profile introduced
to compiler-rt in r203710.
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LLVM currently has a hack (shouldEmitUsedDirectiveFor) that causes it to not
print no_dead_strip for symbols starting with 'l' or 'L'. These are exactly the
ones that the clang's objc codegen is producing. The net result, is that it is
equivalent to llvm.compiler.used.
The need for putting the private symbol in llvm.compiler.used should be clear
(the objc runtime uses them). The reason for also putting the weak symbols in
it is for LTO: ld64 will not ask us to preserve the it.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203172 91177308-0d34-0410-b5e6-96231b3b80d8
'create' functions conventionally return a pointer, not a reference.
Also use an OwningPtr to get replace the delete of a reference member.
No functional change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@198126 91177308-0d34-0410-b5e6-96231b3b80d8
Thread an optional GV down to EmitGlobalFunctionDefinition so that it can
avoid the lookup when we already know the corresponding llvm global value.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@196789 91177308-0d34-0410-b5e6-96231b3b80d8
We can reuse it to avoid a DenseMap+StringMap lookup to find if it was already
emitted or not.
This fixes a 2010 TODO.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@196785 91177308-0d34-0410-b5e6-96231b3b80d8
Before this patch GetOrCreateLLVMFunction would add a decl to
DeferredDeclsToEmit even when it was being called by the function trying to
emit that decl.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@196753 91177308-0d34-0410-b5e6-96231b3b80d8
Produces neater IR in significantly less time.
(~18% faster -O0 compile time for sqlite3 with -fsanitize=undefined)
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194231 91177308-0d34-0410-b5e6-96231b3b80d8
This is a small optimization on linux, but should help more on windows
where msvc only outputs one destructor if there would be two identical ones.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194095 91177308-0d34-0410-b5e6-96231b3b80d8
With this patch we produce alias for cases like
template<typename T>
struct foobar {
foobar() {
}
};
template struct foobar<void>;
We just have to be careful to produce the same aliases in every TU because
of comdats.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194000 91177308-0d34-0410-b5e6-96231b3b80d8
This is a fixed version of r193161. In order to handle
void foo() __attribute__((alias("bar")));
void bar() {}
void zed() __attribute__((alias("foo")));
it is not enough to delay aliases to the end of the TU, we have to do two
passes over them to find if they are defined or not.
This can be implemented by producing alias as we go and just doing the second
pass at the end. This has the advantage that other parts of clang that were
expecting alias to be processed in order don't have to be changed.
This patch also handles cyclic aliases.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193188 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r193161.
It broke
void foo() __attribute__((alias("bar")));
void bar() {}
void zed() __attribute__((alias("foo")));
Looks like we have to fix pr17639 first :-(
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193162 91177308-0d34-0410-b5e6-96231b3b80d8
names. For example, with this patch we now reject
void f1(void) __attribute__((alias("g1")));
This patch is implemented in CodeGen. It is quiet a bit simpler and more
compatible with gcc than implementing it in Sema. The downside is that the
errors only fire during -emit-llvm.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193161 91177308-0d34-0410-b5e6-96231b3b80d8
Refactor the underlying code a bit to remove unnecessary calls to
"hasErrorOccurred" & make them consistently at all the entry points to
the IRGen ASTConsumer.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188707 91177308-0d34-0410-b5e6-96231b3b80d8
Based on Peter Collingbourne's destructor patches.
Prior to this change, clang was considering ?1 to be the complete
destructor and the base destructor, which was wrong. This lead to
crashes when clang tried to emit two LLVM functions with the same name.
In this ABI, TUs with non-inline dtors might not emit a complete
destructor. They are emitted as inline thunks in TUs that need them,
and they always delegate to the base dtors of the complete class and its
virtual bases. This change uses the DeferredDecls machinery to emit
complete dtors as needed.
Currently in clang try body destructors can catch exceptions thrown by
virtual base destructors. In the Microsoft C++ ABI, clang may not have
the destructor definition, in which case clang won't wrap the virtual
virtual base destructor calls in a try-catch. Diagnosing this in user
code is TODO.
Finally, for classes that don't use virtual inheritance, MSVC always
calls the base destructor (?1) directly. This is a useful code size
optimization that avoids emitting lots of extra thunks or aliases.
Implementing it also means our existing tests continue to pass, and is
consistent with MSVC's output.
We can do the same for Itanium by tweaking GetAddrOfCXXDestructor, but
it will require further testing.
Reviewers: rjmccall
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1066
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186828 91177308-0d34-0410-b5e6-96231b3b80d8
The key insight here is that weak linkage for a static local variable
should always mean linkonce_odr, because every file that needs it will
generate a definition. We don't actually care about the precise linkage
of the parent context. I feel a bit silly that I didn't realize this before.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185381 91177308-0d34-0410-b5e6-96231b3b80d8
Peter Collingbourne