Commit Graph

888 Commits

Author SHA1 Message Date
Yaxun (Sam) Liu cefe472c51 [clang] Fix __has_builtin
Fix __has_builtin to return 1 only if the requested target features
of a builtin are enabled by refactoring the code for checking
required target features of a builtin and use it in evaluation
of __has_builtin.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D125829
2022-05-19 11:34:42 -04:00
Mitch Phillips fa34951fbc Reland "[MTE] Add -fsanitize=memtag* and friends."
Differential Revision: https://reviews.llvm.org/D118948
2022-04-08 14:28:33 -07:00
Aaron Ballman 4aaf25b4f7 Revert "[MTE] Add -fsanitize=memtag* and friends."
This reverts commit 8aa1490513.

Broke testing: https://lab.llvm.org/buildbot/#/builders/109/builds/36233
2022-04-08 16:15:58 -04:00
Mitch Phillips 8aa1490513 [MTE] Add -fsanitize=memtag* and friends.
Currently, enablement of heap MTE on Android is specified by an ELF note, which
signals to the linker to enable heap MTE. This change allows
-fsanitize=memtag-heap to synthesize these notes, rather than adding them
through the build system. We need to extend this feature to also signal the
linker to do special work for MTE globals (in future) and MTE stack (currently
implemented in the toolchain, but not implemented in the loader).

Current Android uses a non-backwards-compatible ELF note, called
".note.android.memtag". Stack MTE is an ABI break anyway, so we don't mind that
we won't be able to run executables with stack MTE on Android 11/12 devices.

The current expectation is to support the verbiage used by Android, in
that "SYNC" means MTE Synchronous mode, and "ASYNC" effectively means
"fast", using the Kernel auto-upgrade feature that allows
hardware-specific and core-specific configuration as to whether "ASYNC"
would end up being Asynchronous, Asymmetric, or Synchronous on that
particular core, whichever has a reasonable performance delta. Of
course, this is platform and loader-specific.

Differential Revision: https://reviews.llvm.org/D118948
2022-04-08 12:13:15 -07:00
Phoebe Wang cd26190a10 [X86][regcall] Support passing / returning structures
Currently, the regcall calling conversion in Clang doesn't match with
ICC when passing / returning structures. https://godbolt.org/z/axxKMKrW7

This patch tries to fix the problem to match with ICC.

Reviewed By: LuoYuanke

Differential Revision: https://reviews.llvm.org/D122104
2022-03-29 11:29:57 +08:00
Aaron Ballman 488c772920 Fix a crash with variably-modified parameter types in a naked function
Naked functions have no prolog, so it's not valid to emit prolog code
to evaluate the variably-modified type. This fixes Issue 50541.
2022-03-24 10:39:14 -04:00
Erich Keane 3fb101a691 [NFC] Replace a not-null-check && isa with isa_and_nonnull 2022-03-23 13:09:28 -07:00
Benjamin Kramer 5d2ce7663b Use llvm::append_range instead of push_back loops where applicable. NFCI. 2022-03-18 01:25:34 +01:00
Nikita Popov 6c0af92612 [CodeGen] Avoid some pointer element type accesses 2022-03-17 16:36:14 +01:00
Yonghong Song 3251ba2d0f [Attr] Fix a btf_type_tag AST generation
Current ASTContext.getAttributedType() takes attribute kind,
ModifiedType and EquivType as the hash to decide whether an AST node
has been generated or note. But this is not enough for btf_type_tag
as the attribute might have the same ModifiedType and EquivType, but
still have different string associated with attribute.

For example, for a data structure like below,
  struct map_value {
        int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *a;
        int __attribute__((btf_type_tag("tag2"))) __attribute__((btf_type_tag("tag4"))) *b;
  };
The current ASTContext.getAttributedType() will produce
an AST similar to below:
  struct map_value {
        int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *a;
        int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *b;
  };
and this is incorrect.

It is very difficult to use the current AttributedType as it is hard to
get the tag information. To fix the problem, this patch introduced
BTFTagAttributedType which is similar to AttributedType
in many ways but with an additional BTFTypeTagAttr. The tag itself can
be retrieved with BTFTypeTagAttr.
With the new BTFTagAttributed type, the debuginfo code can be greatly
simplified compared to previous TypeLoc based approach.

Differential Revision: https://reviews.llvm.org/D120296
2022-03-16 08:46:52 -07:00
Simon Moll 0aab344104 [Clang] Allow "ext_vector_type" applied to Booleans
This is the `ext_vector_type` alternative to D81083.

This patch extends Clang to allow 'bool' as a valid vector element type
(attribute ext_vector_type) in C/C++.

This is intended as the canonical type for SIMD masks and facilitates
clean vector intrinsic declarations.  Vectors of i1 are supported on IR
level and below down to many SIMD ISAs, such as AVX512, ARM SVE (fixed
vector length) and the VE target (NEC SX-Aurora TSUBASA).

The RFC on cfe-dev: https://lists.llvm.org/pipermail/cfe-dev/2020-May/065434.html

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D88905
2022-03-16 11:10:32 +01:00
Tong Zhang 17ce89fa80 [SanitizerBounds] Add support for NoSanitizeBounds function
Currently adding attribute no_sanitize("bounds") isn't disabling
-fsanitize=local-bounds (also enabled in -fsanitize=bounds). The Clang
frontend handles fsanitize=array-bounds which can already be disabled by
no_sanitize("bounds"). However, instrumentation added by the
BoundsChecking pass in the middle-end cannot be disabled by the
attribute.

The fix is very similar to D102772 that added the ability to selectively
disable sanitizer pass on certain functions.

In this patch, if no_sanitize("bounds") is provided, an additional
function attribute (NoSanitizeBounds) is attached to IR to let the
BoundsChecking pass know we want to disable local-bounds checking. In
order to support this feature, the IR is extended (similar to D102772)
to make Clang able to preserve the information and let BoundsChecking
pass know bounds checking is disabled for certain function.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D119816
2022-03-01 18:47:02 +01:00
Arthur Eubanks 36e335eeb5 [clang] Remove Address::deprecated() calls in CodeGenFunction.cpp 2022-02-22 18:28:49 -08:00
Alexander Potapenko c85a26454d [asan] Add support for disable_sanitizer_instrumentation attribute
For ASan this will effectively serve as a synonym for
__attribute__((no_sanitize("address"))).

Adding the disable_sanitizer_instrumentation to functions will drop the
sanitize_XXX attributes on the IR level.

This is the third reland of https://reviews.llvm.org/D114421.
Now that TSan test is fixed (https://reviews.llvm.org/D120050) there
should be no deadlocks.

Differential Revision: https://reviews.llvm.org/D120055
2022-02-18 09:51:54 +01:00
Nikita Popov 5065076698 [CodeGen] Rename deprecated Address constructor
To make uses of the deprecated constructor easier to spot, and to
ensure that no new uses are introduced, rename it to
Address::deprecated().

While doing the rename, I've filled in element types in cases
where it was relatively obvious, but we're still left with 135
calls to the deprecated constructor.
2022-02-17 11:26:42 +01:00
Alexander Potapenko 05ee1f4af8 Revert "[asan] Add support for disable_sanitizer_instrumentation attribute"
This reverts commit dd145f953d.

https://reviews.llvm.org/D119726, like https://reviews.llvm.org/D114421,
still causes TSan to fail, see https://lab.llvm.org/buildbot/#/builders/70/builds/18020

Differential Revision: https://reviews.llvm.org/D119838
2022-02-15 15:04:53 +01:00
Alexander Potapenko dd145f953d [asan] Add support for disable_sanitizer_instrumentation attribute
For ASan this will effectively serve as a synonym for
__attribute__((no_sanitize("address")))

This is a reland of https://reviews.llvm.org/D114421

Reviewed By: melver, eugenis

Differential Revision: https://reviews.llvm.org/D119726
2022-02-15 14:06:12 +01:00
Bill Wendling deaf22bc0e [X86] Implement -fzero-call-used-regs option
The "-fzero-call-used-regs" option tells the compiler to zero out
certain registers before the function returns. It's also available as a
function attribute: zero_call_used_regs.

The two upper categories are:

  - "used": Zero out used registers.
  - "all": Zero out all registers, whether used or not.

The individual options are:

  - "skip": Don't zero out any registers. This is the default.
  - "used": Zero out all used registers.
  - "used-arg": Zero out used registers that are used for arguments.
  - "used-gpr": Zero out used registers that are GPRs.
  - "used-gpr-arg": Zero out used GPRs that are used as arguments.
  - "all": Zero out all registers.
  - "all-arg": Zero out all registers used for arguments.
  - "all-gpr": Zero out all GPRs.
  - "all-gpr-arg": Zero out all GPRs used for arguments.

This is used to help mitigate Return-Oriented Programming exploits.

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D110869
2022-02-08 17:42:54 -08:00
Alexandre Ganea 5af2433e17 [clang-cl] Support the /HOTPATCH flag
This patch adds support for the MSVC /HOTPATCH flag: https://docs.microsoft.com/sv-se/cpp/build/reference/hotpatch-create-hotpatchable-image?view=msvc-170&viewFallbackFrom=vs-2019

The flag is translated to a new -fms-hotpatch flag, which in turn adds a 'patchable-function' attribute for each function in the TU. This is then picked up by the PatchableFunction pass which would generate a TargetOpcode::PATCHABLE_OP of minsize = 2 (which means the target instruction must resolve to at least two bytes). TargetOpcode::PATCHABLE_OP is only implemented for x86/x64. When targetting ARM/ARM64, /HOTPATCH isn't required (instructions are always 2/4 bytes and suitable for hotpatching).

Additionally, when using /Z7, we generate a 'hot patchable' flag in the CodeView debug stream, in the S_COMPILE3 record. This flag is then picked up by LLD (or link.exe) and is used in conjunction with the linker /FUNCTIONPADMIN flag to generate extra space before each function, to accommodate for live patching long jumps. Please see: d703b92296/lld/COFF/Writer.cpp (L1298)

The outcome is that we can finally use Live++ or Recode along with clang-cl.

NOTE: It seems that MSVC cl.exe always enables /HOTPATCH on x64 by default, although if we did the same I thought we might generate sub-optimal code (if this flag was active by default). Additionally, MSVC always generates a .debug$S section and a S_COMPILE3 record, which Clang doesn't do without /Z7. Therefore, the following MSVC command-line "cl /c file.cpp" would have to be written with Clang such as "clang-cl /c file.cpp /HOTPATCH /Z7" in order to obtain the same result.

Depends on D43002, D80833 and D81301 for the full feature.

Differential Revision: https://reviews.llvm.org/D116511
2022-01-20 12:57:19 -05:00
Adam Magier b2715660ed [clang][CodeGen][UBSan] VLA size checking for unsigned integer parameter
The code generation for the UBSan VLA size check was qualified by a con-
dition that the parameter must be a signed integer, however the C spec
does not make any distinction that only signed integer parameters can be
used to declare a VLA, only qualifying that it must be greater than zero
if it is not a constant.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D116048
2022-01-12 01:11:52 +01:00
Nikita Popov acc39873b7 [CodeGen] Avoid deprecated Address constructor 2022-01-11 13:07:02 +01:00
Kazu Hirata 40446663c7 [clang] Use true/false instead of 1/0 (NFC)
Identified with modernize-use-bool-literals.
2022-01-09 00:19:47 -08:00
Kazu Hirata 298367ee6e [clang] Use nullptr instead of 0 or NULL (NFC)
Identified with modernize-use-nullptr.
2021-12-29 08:34:20 -08:00
Nikita Popov 09669e6c5f [CodeGen] Avoid pointer element type access when creating LValue
This required fixing two places that were passing the pointer type
rather than the expected pointee type to the method.
2021-12-23 10:53:15 +01:00
Nikita Popov e751d97863 [CodeGen] Avoid some pointer element type accesses
This avoids some pointer element type accesses when compiling
C++ code.
2021-12-21 14:16:28 +01:00
Sam McCall af27466c50 Reland "[AST] Add UsingType: a sugar type for types found via UsingDecl"
This reverts commit cc56c66f27.
Fixed a bad assertion, the target of a UsingShadowDecl must not have
*local* qualifiers, but it can be a typedef whose underlying type is qualified.
2021-12-20 18:03:15 +01:00
Sam McCall cc56c66f27 Revert "[AST] Add UsingType: a sugar type for types found via UsingDecl"
This reverts commit e1600db19d.

Breaks sanitizer tests, at least on windows:
https://lab.llvm.org/buildbot/#/builders/127/builds/21592/steps/4/logs/stdio
2021-12-20 17:53:56 +01:00
Sam McCall e1600db19d [AST] Add UsingType: a sugar type for types found via UsingDecl
Currently there's no way to find the UsingDecl that a typeloc found its
underlying type through. Compare to DeclRefExpr::getFoundDecl().

Design decisions:
- a sugar type, as there are many contexts this type of use may appear in
- UsingType is a leaf like TypedefType, the underlying type has no TypeLoc
- not unified with UnresolvedUsingType: a single name is appealing,
  but being sometimes-sugar is often fiddly.
- not unified with TypedefType: the UsingShadowDecl is not a TypedefNameDecl or
  even a TypeDecl, and users think of these differently.
- does not cover other rarer aliases like objc @compatibility_alias,
  in order to be have a concrete API that's easy to understand.
- implicitly desugared by the hasDeclaration ASTMatcher, to avoid
  breaking existing patterns and following the precedent of ElaboratedType.

Scope:
- This does not cover types associated with template names introduced by
  using declarations. A future patch should introduce a sugar TemplateName
  variant for this. (CTAD deduced types fall under this)
- There are enough AST matchers to fix the in-tree clang-tidy tests and
  probably any other matchers, though more may be useful later.

Caveats:
- This changes a fairly common pattern in the AST people may depend on matching.
  Previously, typeLoc(loc(recordType())) matched whether a struct was
  referred to by its original scope or introduced via using-decl.
  Now, the using-decl case is not matched, and needs a separate matcher.
  This is similar to the case of typedefs but nevertheless both adds
  complexity and breaks existing code.

Differential Revision: https://reviews.llvm.org/D114251
2021-12-20 17:15:38 +01:00
Nikita Popov 9e45146721 [CodeGen] Fix element type for sret argument
Fix a mistake in 9bf917394eba3ba4df77cc17690c6d04f4e9d57f: sret
arguments use ConvertType, not ConvertTypeForMem, see the handling
in CodeGenTypes::GetFunctionType().

This fixes fp-matrix-pragma.c on s390x.
2021-12-17 16:13:28 +01:00
Nikita Popov 9bf917394e [CodeGen] Avoid more pointer element type accesses 2021-12-17 12:11:50 +01:00
Mike Rice 2d0bf14397 [clang] Cleanup unneeded Function nullptr checks [NFC]
Add an assert and avoid unneeded checks of Fn in
CodeGenFunction::GenerateCode.

Differential Revision: https://reviews.llvm.org/D115817
2021-12-16 08:28:10 -08:00
Andrew Browne 7c004c2bc9 Revert "[asan] Add support for disable_sanitizer_instrumentation attribute"
This reverts commit 2b554920f1.

This change causes tsan test timeout on x86_64-linux-autoconf.

The timeout can be reproduced by:
  git clone https://github.com/llvm/llvm-zorg.git
  BUILDBOT_CLOBBER= BUILDBOT_REVISION=eef8f3f85679c5b1ae725bade1c23ab7bb6b924f llvm-zorg/zorg/buildbot/builders/sanitizers/buildbot_standard.sh
2021-12-10 14:33:38 -08:00
Alexander Potapenko 2b554920f1 [asan] Add support for disable_sanitizer_instrumentation attribute
For ASan this will effectively serve as a synonym for
__attribute__((no_sanitize("address")))

Differential Revision: https://reviews.llvm.org/D114421
2021-12-10 12:17:26 +01:00
Aaron Ballman 6c75ab5f66 Introduce _BitInt, deprecate _ExtInt
WG14 adopted the _ExtInt feature from Clang for C23, but renamed the
type to be _BitInt. This patch does the vast majority of the work to
rename _ExtInt to _BitInt, which accounts for most of its size. The new
type is exposed in older C modes and all C++ modes as a conforming
extension. However, there are functional changes worth calling out:

* Deprecates _ExtInt with a fix-it to help users migrate to _BitInt.
* Updates the mangling for the type.
* Updates the documentation and adds a release note to warn users what
is going on.
* Adds new diagnostics for use of _BitInt to call out when it's used as
a Clang extension or as a pre-C23 compatibility concern.
* Adds new tests for the new diagnostic behaviors.

I want to call out the ABI break specifically. We do not believe that
this break will cause a significant imposition for early adopters of
the feature, and so this is being done as a full break. If it turns out
there are critical uses where recompilation is not an option for some
reason, we can consider using ABI tags to ease the transition.
2021-12-06 12:52:01 -05:00
hsmahesha 3b9a85d10a [CFE][Codegen] Make sure to maintain the contiguity of all the static allocas
at the start of the entry block, which in turn would aid better code transformation/optimization.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D110257
2021-11-10 08:45:21 +05:30
serge-sans-paille 6bfc85c217 Fix inline builtin handling in case of redefinition
Basically, inline builtin definition are shadowed by externally visible
redefinition. This matches GCC behavior.

The implementation has to workaround the fact that:

1. inline builtin are renamed at callsite during codegen, but
2. they may be shadowed by a later external definition

As a consequence, during codegen, we need to walk redecls and eventually rewrite
some call sites, which is totally inelegant.

Differential Revision: https://reviews.llvm.org/D112059
2021-11-02 09:53:49 +01:00
Kazu Hirata dccfaddc6b [clang] Use StringRef::contains (NFC) 2021-10-21 08:58:19 -07:00
hsmahesha 0481682996 [CFE][Codegen][In-progress] Remove CodeGenFunction::InitTempAlloca()
CodeGenFunction::InitTempAlloca() inits the static alloca within the
entry block which may *not* necessarily be correct always.

For example, the current instruction insertion point (pointed by the
instruction builder) could be a program point which is hit multiple
times during the program execution, and it is expected that the static
alloca is initialized every time the program point is hit.

Hence remove CodeGenFunction::InitTempAlloca(), and initialize the
static alloca where the instruction insertion point is at the moment.

This patch, as a starting attempt, removes the calls to
CodeGenFunction::InitTempAlloca() which do not have any side effect on
the lit tests.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D111293
2021-10-09 09:23:14 +05:30
serge-sans-paille 0f0e31cf51 Update inline builtin handling to honor gnu inline attribute
Per the GCC info page:

    If the function is declared 'extern', then this definition of the
    function is used only for inlining.  In no case is the function
    compiled as a standalone function, not even if you take its address
    explicitly.  Such an address becomes an external reference, as if
    you had only declared the function, and had not defined it.

Respect that behavior for inline builtins: keep the original definition, and
generate a copy of the declaration suffixed by '.inline' that's only referenced
in direct call.

This fixes holes in c3717b6858.

Differential Revision: https://reviews.llvm.org/D111009
2021-10-04 22:26:25 +02:00
serge-sans-paille c3717b6858 Simplify handling of builtin with inline redefinition
(This is a recommit of 3d6f49a569 that should no longer break validation since
bd379915de).

It is a common practice in glibc header to provide an inline redefinition of an
existing function. It is especially the case for fortified function.

Clang currently has an imperfect approach to the problem, using a combination of
trivially recursive function detection and noinline attribute.

Simplify the logic by suffixing these functions by `.inline` during codegen, so
that they are not recognized as builtin by llvm.

After that patch, clang passes all tests from https://github.com/serge-sans-paille/fortify-test-suite

Differential Revision: https://reviews.llvm.org/D109967
2021-09-28 21:00:47 +02:00
Kevin Athey 0d76d4833d Revert "Simplify handling of builtin with inline redefinition"
This reverts commit 3d6f49a569.

Broke bot: https://lab.llvm.org/buildbot/#/builders/5/builds/12360
2021-09-28 11:30:37 -07:00
David Blaikie 85f612efeb DebugInfo: Use sugared function type when emitting function declarations for call sites
Otherwise we're losing type information for these functions.
2021-09-28 10:44:35 -07:00
serge-sans-paille 3d6f49a569 Simplify handling of builtin with inline redefinition
It is a common practice in glibc header to provide an inline redefinition of an
existing function. It is especially the case for fortified function.

Clang currently has an imperfect approach to the problem, using a combination of
trivially recursive function detection and noinline attribute.

Simplify the logic by suffixing these functions by `.inline` during codegen, so
that they are not recognized as builtin by llvm.

After that patch, clang passes all tests from https://github.com/serge-sans-paille/fortify-test-suite

Differential Revision: https://reviews.llvm.org/D109967
2021-09-28 13:24:25 +02:00
Erich Keane 42ae7eb581 Ensure field-annotations on pointers properly match the AS of the field.
Discovered in SYCL, the field annotations were always cast to an i8*,
which is an invalid bitcast for a pointer type with an address space.
This patch makes sure that we create an intrinsic that takes a pointer
to the correct address-space and properly do our casts.

Differential Revision: https://reviews.llvm.org/D109003
2021-09-01 06:12:24 -07:00
Yi Kong 5fc4828aa6 [clang] Don't generate warn-stack-size when the warning is ignored
8ace121305 introduced a regression for code that explicitly ignores the
-Wframe-larger-than= warning. Make sure we don't generate the
warn-stack-size attribute for that case.

Differential Revision: https://reviews.llvm.org/D108686
2021-08-25 14:58:45 +08:00
Alexander Potapenko b0391dfc73 [clang][Codegen] Introduce the disable_sanitizer_instrumentation attribute
The purpose of __attribute__((disable_sanitizer_instrumentation)) is to
prevent all kinds of sanitizer instrumentation applied to a certain
function, Objective-C method, or global variable.

The no_sanitize(...) attribute drops instrumentation checks, but may
still insert code preventing false positive reports. In some cases
though (e.g. when building Linux kernel with -fsanitize=kernel-memory
or -fsanitize=thread) the users may want to avoid any kind of
instrumentation.

Differential Revision: https://reviews.llvm.org/D108029
2021-08-20 14:01:06 +02:00
Dylan Fleming ef198cd99e [SVE] Remove usage of getMaxVScale for AArch64, in favour of IR Attribute
Removed AArch64 usage of the getMaxVScale interface, replacing it with
the vscale_range(min, max) IR Attribute.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D106277
2021-08-17 14:42:47 +01:00
Melanie Blower bc5b5ea037 [clang][patch][FPEnv] Make initialization of C++ globals strictfp aware
@kpn pointed out that the global variable initialization functions didn't
have the "strictfp" metadata set correctly, and @rjmccall said that there
was buggy code in SetFPModel and StartFunction, this patch is to solve
those problems. When Sema creates a FunctionDecl, it sets the
FunctionDeclBits.UsesFPIntrin to "true" if the lexical FP settings
(i.e. a combination of command line options and #pragma float_control
settings) correspond to ConstrainedFP mode. That bit is used when CodeGen
starts codegen for a llvm function, and it translates into the
"strictfp" function attribute. See bugs.llvm.org/show_bug.cgi?id=44571

Reviewed By: Aaron Ballman

Differential Revision: https://reviews.llvm.org/D102343
2021-07-29 12:02:37 -04:00
Melanie Blower ea864c9933 [clang][patch][NFC] Refactor calculation of FunctionDecl to avoid duplicate code 2021-07-20 11:01:22 -04:00
Nikita Popov 693251fb2f [CodeGen] Avoid CreateGEP with nullptr type (NFC)
In preparation for dropping support for it. I've replaced it with
a proper type where the correct type was obvious and left an
explicit getPointerElementType() where it wasn't.
2021-07-08 20:38:54 +02:00