Yes, i erroneously assumed that the "after" was meant,
but i was wrong:
> I really meant "performed before", for cases like 4u / -2,
> where -2 is implicitly converted to UINT_MAX - 2 before
> the computation. Conversions that are performed after
> a computation aren't part of the computation at all,
> so I think it's much clearer that they're not in scope
> for this sanitizer.
llvm-svn: 338306
Summary:
C and C++ are interesting languages. They are statically typed, but weakly.
The implicit conversions are allowed. This is nice, allows to write code
while balancing between getting drowned in everything being convertible,
and nothing being convertible. As usual, this comes with a price:
```
unsigned char store = 0;
bool consume(unsigned int val);
void test(unsigned long val) {
if (consume(val)) {
// the 'val' is `unsigned long`, but `consume()` takes `unsigned int`.
// If their bit widths are different on this platform, the implicit
// truncation happens. And if that `unsigned long` had a value bigger
// than UINT_MAX, then you may or may not have a bug.
// Similarly, integer addition happens on `int`s, so `store` will
// be promoted to an `int`, the sum calculated (0+768=768),
// and the result demoted to `unsigned char`, and stored to `store`.
// In this case, the `store` will still be 0. Again, not always intended.
store = store + 768; // before addition, 'store' was promoted to int.
}
// But yes, sometimes this is intentional.
// You can either make the conversion explicit
(void)consume((unsigned int)val);
// or mask the value so no bits will be *implicitly* lost.
(void)consume((~((unsigned int)0)) & val);
}
```
Yes, there is a `-Wconversion`` diagnostic group, but first, it is kinda
noisy, since it warns on everything (unlike sanitizers, warning on an
actual issues), and second, there are cases where it does **not** warn.
So a Sanitizer is needed. I don't have any motivational numbers, but i know
i had this kind of problem 10-20 times, and it was never easy to track down.
The logic to detect whether an truncation has happened is pretty simple
if you think about it - https://godbolt.org/g/NEzXbb - basically, just
extend (using the new, not original!, signedness) the 'truncated' value
back to it's original width, and equality-compare it with the original value.
The most non-trivial thing here is the logic to detect whether this
`ImplicitCastExpr` AST node is **actually** an implicit conversion, //or//
part of an explicit cast. Because the explicit casts are modeled as an outer
`ExplicitCastExpr` with some `ImplicitCastExpr`'s as **direct** children.
https://godbolt.org/g/eE1GkJ
Nowadays, we can just use the new `part_of_explicit_cast` flag, which is set
on all the implicitly-added `ImplicitCastExpr`'s of an `ExplicitCastExpr`.
So if that flag is **not** set, then it is an actual implicit conversion.
As you may have noted, this isn't just named `-fsanitize=implicit-integer-truncation`.
There are potentially some more implicit conversions to be warned about.
Namely, implicit conversions that result in sign change; implicit conversion
between different floating point types, or between fp and an integer,
when again, that conversion is lossy.
One thing i know isn't handled is bitfields.
This is a clang part.
The compiler-rt part is D48959.
Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=21530 | PR21530 ]], [[ https://bugs.llvm.org/show_bug.cgi?id=37552 | PR37552 ]], [[ https://bugs.llvm.org/show_bug.cgi?id=35409 | PR35409 ]].
Partially fixes [[ https://bugs.llvm.org/show_bug.cgi?id=9821 | PR9821 ]].
Fixes https://github.com/google/sanitizers/issues/940. (other than sign-changing implicit conversions)
Reviewers: rjmccall, rsmith, samsonov, pcc, vsk, eugenis, efriedma, kcc, erichkeane
Reviewed By: rsmith, vsk, erichkeane
Subscribers: erichkeane, klimek, #sanitizers, aaron.ballman, RKSimon, dtzWill, filcab, danielaustin, ygribov, dvyukov, milianw, mclow.lists, cfe-commits, regehr
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D48958
llvm-svn: 338288
ObjCIvarExpr is *not* a subclass of MemberExpr, and a separate matcher
is required to support it.
Adding a hasDeclaration support as well, as it's not very useful without
it.
Differential Revision: https://reviews.llvm.org/D49701
llvm-svn: 338137
Summary:
Extend the Clang-Format IncludeCategories documentation by adding a link to the supported regular expression standard (POSIX).
And extenting the example with a system header regex.
[[ https://bugs.llvm.org/show_bug.cgi?id=35041 | bug 35041]]
Contributed by WimLeflere!
Reviewers: krasimir, Typz
Reviewed By: krasimir
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D48827
llvm-svn: 337899
no-ops.
A non-escaping block on the stack will never be called after its
lifetime ends, so it doesn't have to be copied to the heap. To prevent
a non-escaping block from being copied to the heap, this patch sets
field 'isa' of the block object to NSConcreteGlobalBlock and sets the
BLOCK_IS_GLOBAL bit of field 'flags', which causes the runtime to treat
the block as if it were a global block (calling _Block_copy on the block
just returns the original block and calling _Block_release is a no-op).
Also, a new flag bit 'BLOCK_IS_NOESCAPE' is added, which allows the
runtime or tools to distinguish between true global blocks and
non-escaping blocks.
rdar://problem/39352313
Differential Revision: https://reviews.llvm.org/D49303
llvm-svn: 337580
Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.
More details : https://lkml.org/lkml/2018/4/4/601
GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.
-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.
This feature is implemented in as the function attribute
"null-pointer-is-valid"="true".
This CL only adds the attribute on the function.
It also strips "nonnull" attributes from function arguments but
keeps the related warnings unchanged.
Corresponding LLVM change rL336613 already updated the
optimizations to not treat null pointer dereferencing
as undefined if the attribute is present.
Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv
Reviewed By: jyknight
Subscribers: drinkcat, xbolva00, cfe-commits
Differential Revision: https://reviews.llvm.org/D47894
llvm-svn: 337433
which was reverted in r337336.
The problem that required a revert was fixed in r337338.
Also added a missing "REQUIRES: x86-registered-target" to one of
the tests.
Original commit message:
> Teach Clang to emit address-significance tables.
>
> By default, we emit an address-significance table on all ELF
> targets when the integrated assembler is enabled. The emission of an
> address-significance table can be controlled with the -faddrsig and
> -fno-addrsig flags.
>
> Differential Revision: https://reviews.llvm.org/D48155
llvm-svn: 337339
Causing multiple failures on sanitizer bots due to TLS symbol errors,
e.g.
/usr/bin/ld: __msan_origin_tls: TLS definition in /home/buildbots/ppc64be-clang-test/clang-ppc64be/stage1/lib/clang/7.0.0/lib/linux/libclang_rt.msan-powerpc64.a(msan.cc.o) section .tbss.__msan_origin_tls mismatches non-TLS reference in /tmp/lit_tmp_0a71tA/mallinfo-3ca75e.o
llvm-svn: 337336
By default, we emit an address-significance table on all ELF
targets when the integrated assembler is enabled. The emission of an
address-significance table can be controlled with the -faddrsig and
-fno-addrsig flags.
Differential Revision: https://reviews.llvm.org/D48155
llvm-svn: 337333
Summary:
Introduce built-ins to read the unsafe stack top and bottom. The unsafe
stack top is required to implement garbage collection scanning for
Oilpan. Currently there is already a built-in 'get_unsafe_stack_start'
to read the bottom of the unsafe stack, but I chose to duplicate this
API because 'start' is ambiguous (e.g. Oilpan uses WTF::GetStackStart to
read the safe stack top.)
Reviewers: pcc
Reviewed By: pcc
Subscribers: llvm-commits, kcc
Differential Revision: https://reviews.llvm.org/D49152
llvm-svn: 337037
Summary:
Setting UBSAN_OPTIONS=silence_unsigned_overflow=1 will silence all UIO
reports. This feature, combined with
-fsanitize-recover=unsigned-integer-overflow, is useful for providing
fuzzing signal without the excessive log output.
Helps with https://github.com/google/oss-fuzz/issues/910.
Reviewers: kcc, vsk
Reviewed By: vsk
Subscribers: vsk, kubamracek, Dor1s, llvm-commits
Differential Revision: https://reviews.llvm.org/D48660
llvm-svn: 335762
Similarly to CFI on virtual and indirect calls, this implementation
tries to use program type information to make the checks as precise
as possible. The basic way that it works is as follows, where `C`
is the name of the class being defined or the target of a call and
the function type is assumed to be `void()`.
For virtual calls:
- Attach type metadata to the addresses of function pointers in vtables
(not the functions themselves) of type `void (B::*)()` for each `B`
that is a recursive dynamic base class of `C`, including `C` itself.
This type metadata has an annotation that the type is for virtual
calls (to distinguish it from the non-virtual case).
- At the call site, check that the computed address of the function
pointer in the vtable has type `void (C::*)()`.
For non-virtual calls:
- Attach type metadata to each non-virtual member function whose address
can be taken with a member function pointer. The type of a function
in class `C` of type `void()` is each of the types `void (B::*)()`
where `B` is a most-base class of `C`. A most-base class of `C`
is defined as a recursive base class of `C`, including `C` itself,
that does not have any bases.
- At the call site, check that the function pointer has one of the types
`void (B::*)()` where `B` is a most-base class of `C`.
Differential Revision: https://reviews.llvm.org/D47567
llvm-svn: 335569
Summary: Mention that no_sanitize attribute can be used with globals.
Reviewers: alekseyshl
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D48390
llvm-svn: 335193
Summary:
It seems that the changes done to `ClangFormatStyleOptions.rst` @334408 are causing the generation of the documentation to fail, with the following error:
Warning, treated as error:
/llvm/tools/clang/docs/ClangFormatStyleOptions.rst:1060: WARNING: Definition list ends without a blank line; unexpected unindent.
This is due to missing indent in some code block, and fixed by this patch.
Reviewers: krasimir, djasper, klimek
Reviewed By: krasimir
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D48161
llvm-svn: 334709
WebKit C++ style for object initialization is as follows:
Foo foo { bar };
Yet using clang-format -style=webkit changes this to:
Foo foo{ bar };
As there is no existing combination of rules that will ensure a space
before a braced list in this fashion, this patch adds a new
SpaceBeforeCpp11BracedList rule.
Patch by Ross Kirsling!
Differential Revision: https://reviews.llvm.org/D46024
llvm-svn: 334692
Summary:
In many cases we can't devirtualize
because definition of vtable is not present. Most of the
time it is caused by inline virtual function not beeing
emitted. Forcing emitting of vtable adds a reference of these
inline virtual functions.
Note that GCC was always doing it.
Reviewers: rjmccall, rsmith, amharc, kuhar
Subscribers: llvm-commits, cfe-commits
Differential Revision: https://reviews.llvm.org/D47108
Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>
llvm-svn: 334600
Register x20 is a callee-saved register which may be used for other
purposes in certain contexts, for example to hold special variables
within the kernel. This change adds support for reserving this register
both to frontend and backend to make this register usable for these
purposes.
Differential Revision: https://reviews.llvm.org/D46552
llvm-svn: 334531
Summary:
This option replaces the BreakBeforeInheritanceComma option with an
enum, thus introducing a mode where the colon stays on the same line as
constructor declaration:
// When it fits on line:
class A : public B, public C {
...
};
// When it does not fit:
class A :
public B,
public C {
...
};
This matches the behavior of the `BreakConstructorInitializers` option,
introduced in https://reviews.llvm.org/D32479.
Reviewers: djasper, klimek
Reviewed By: djasper
Subscribers: mzeren-vmw, cfe-commits
Differential Revision: https://reviews.llvm.org/D43015
llvm-svn: 334408
Summary:
There are cases where the same string or select is repeated verbatim in a lot of diagnostics. This can be a pain to maintain and update. Tablegen provides no way stash the common text somewhere and reuse it in the diagnostics, until now!
This patch allows diagnostic texts to contain `%sub{<definition-name>}`, where `<definition-name>` names a Tablegen record of type `TextSubstitution`. These substitutions are done early, before the diagnostic string is otherwise processed. All `%sub` modifiers will be replaced before the diagnostic definitions are emitted.
The substitution must specify all arguments used by the substitution, and modifier indexes in the substitution are re-numbered accordingly. For example:
```
def select_ovl_candidate : TextSubstitution<"%select{function|constructor}0%select{| template| %2}1">;
```
when used as
```
"candidate `%sub{select_ovl_candidate}3,2,1 not viable"
```
will act as if we wrote:
```
"candidate %select{function|constructor}3%select{| template| %1}2 not viable"
```
Reviewers: rsmith, rjmccall, aaron.ballman, a.sidorin
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D46740
llvm-svn: 332799
in gcc by https://gcc.gnu.org/ml/gcc-cvs/2018-04/msg00534.html.
The -mibt feature flag is being removed, and the -fcf-protection
option now also defines a CET macro and causes errors when used
on non-X86 targets, while X86 targets no longer check for -mibt
and -mshstk to determine if -fcf-protection is supported. -mshstk
is now used only to determine availability of shadow stack intrinsics.
Comes with an LLVM patch (D46882).
Patch by mike.dvoretsky
Differential Revision: https://reviews.llvm.org/D46881
llvm-svn: 332704
Although not very well known, diagtool is an incredibly convenient
utility for dealing with diagnostics.
Particularly useful are the "tree" and "show-enabled" commands:
- The former prints the hierarchy of diagnostic (warning) flags and
which of them are enabled by default.
- The latter can be used to replace an invocation to clang and will
print which diagnostics are disabled, warnings or errors.
For instance: `diagtool show-enabled -Wall -Werror /tmp/test.c` will
print that -Wunused-variable (warn_unused_variable) will be treated as
an error.
This patch adds them to the install target so it gets shipped with the
LLVM release. It also adds a very basic man page and mentions this
change in the release notes.
Differential revision: https://reviews.llvm.org/D46694
llvm-svn: 332448
Summary:
Introduce `PenaltyBreakTemplateDeclaration` to control the penalty,
and change `AlwaysBreakTemplateDeclarations` to an enum with 3 modes:
* `No` for regular, penalty based, wrapping of template declaration
* `MultiLine` for always wrapping before multi-line declarations (e.g.
same as legacy behavior when `AlwaysBreakTemplateDeclarations=false`)
* `Yes` for always wrapping (e.g. same as legacy behavior when
`AlwaysBreakTemplateDeclarations=true`)
Reviewers: krasimir, djasper, klimek
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D42684
llvm-svn: 332436
These intrinsics work exactly as all other atomic_fetch_* intrinsics and allow to create *atomicrmw* with ordering.
Updated the clang-extensions document.
Differential Revision: https://reviews.llvm.org/D46386
llvm-svn: 332193
This is similar to the LLVM change https://reviews.llvm.org/D46290.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46320
llvm-svn: 331834
This implements the rule intended by the standard (see LWG 2358)
and the rule intended by the Itanium C++ ABI (see
https://github.com/itanium-cxx-abi/cxx-abi/pull/51), and makes
Clang match the behavior of GCC, ICC, and MSVC.
A pedantic reading of both the standard and the ABI indicate that Clang
is currently technically correct, but that's not worth much when it's
clear that the wording is wrong in both those places.
This is an ABI break for classes that derive from a class that is empty
other than one or more unnamed non-zero-length bit-fields. Such cases
are expected to be rare, but -fclang-abi-compat=6 restores the old
behavior just in case.
Differential Revision: https://reviews.llvm.org/D45174
llvm-svn: 331620
As suggested in the post-commit thread for rL331056, we should match these
clang options with the established vocabulary of the corresponding sanitizer
option. Also, the use of 'strict' is well-known for these kinds of knobs,
and we can improve the descriptive text in the docs.
So this intends to match the logic of D46135 but only change the words.
Matching LLVM commit to match this spelling of the attribute to follow shortly.
Differential Revision: https://reviews.llvm.org/D46236
llvm-svn: 331209
Clang incorrectly applied the packed attribute to base classes. Per GCC's
documentation and as can be observed from its behavior, packed only applies to
members, not base classes.
This change is conditioned behind -fclang-abi-compat so that an ABI break can
be avoided by users if desired.
Differential Revision: https://reviews.llvm.org/D46218
llvm-svn: 331136
As discussed in the post-commit thread for:
rL330437 ( http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20180423/545906.html )
We need a way to opt-out of a float-to-int-to-float cast optimization because too much
existing code relies on the platform-specific undefined result of those casts when the
float-to-int overflows.
The LLVM changes associated with adding this function attribute are here:
rL330947
rL330950
rL330951
Also as suggested, I changed the LLVM doc to mention the specific sanitizer flag that
catches this problem:
rL330958
Differential Revision: https://reviews.llvm.org/D46135
llvm-svn: 331041
Summary:
It seems there isn't much enthusiasm for `-wtest` D45685.
This is more conservative version, which i had in the very first
revision of D44883, but that 'erroneously' got removed because of the review.
**Based on some [irc] discussions, it must really be documented that
we want all the new diagnostics to have their own flags, to ease
rollouts, transitions, etc.**
Please do note that i'm only adding `-Wno-self-assign-overloaded`,
but not `-Wno-self-assign-field-overloaded`, because i'm honestly
not aware of any false-positives from the `-field` variant,
but i can just as easily add it if wanted.
https://reviews.llvm.org/D44883#1068561
Reviewers: dblaikie, aaron.ballman, thakis, rjmccall, rsmith
Reviewed By: dblaikie
Subscribers: Quuxplusone, chandlerc, cfe-commits
Differential Revision: https://reviews.llvm.org/D45766
llvm-svn: 330651
The WBNOINVD instruction writes back all modified
cache lines in the processor’s internal cache to main memory
but does not invalidate (flush) the internal caches.
Reviewers: craig.topper, zvi, ashlykov
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D43817
llvm-svn: 329848
Summary:
After a remark on a FreeBSD mailing list that the clang man page did
not have any list of possible values for the `-std=` flag, I have now
attempted to exhaustively list those, for each available language.
I also documented the default standard for each language, if there was
more than one choice.
Reviewers: rsmith, dexonsmith, sylvestre.ledru, mgorny
Reviewed By: rsmith
Subscribers: fhahn, emaste, cfe-commits, krytarowski
Differential Revision: https://reviews.llvm.org/D45406
llvm-svn: 329827
Currently we always include PTX into the fatbin along
with the GPU code.It about doubles the size of the GPU binary
we need to carry in the executable. These options allow control
inclusion of PTX into GPU binary.
This patch does not change the defaults, though we may consider
making no-PTX the default in the future.
Differential Revision: https://reviews.llvm.org/D45495
llvm-svn: 329737
Summary:
This has just bit me, so i though it would be nice to avoid that next time :)
Motivational case:
https://godbolt.org/g/cq9UNk
Basically, it's likely to happen if you don't like shadowing issues,
and use `-Wshadow` and friends. And it won't be diagnosed by clang.
The reason is, these self-assign diagnostics only work for builtin assignment
operators. Which makes sense, one could have a very special operator=,
that does something unusual in case of self-assignment,
so it may make sense to not warn on that.
But while it may be intentional in some cases, it may be a bug in other cases,
so it would be really great to have some diagnostic about it...
Reviewers: aaron.ballman, rsmith, rtrieu, nikola, rjmccall, dblaikie
Reviewed By: rjmccall
Subscribers: EricWF, lebedev.ri, thakis, Quuxplusone, cfe-commits
Differential Revision: https://reviews.llvm.org/D44883
llvm-svn: 329493
Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:
archtype
cas
classs
checkk
compres
definit
frome
iff
inteval
ith
lod
methode
nd
optin
ot
pres
statics
te
thru
Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)
Differential revision: https://reviews.llvm.org/D44188
llvm-svn: 329399
Summary:
`ASTPrinter` allows setting the ouput to any O-Stream, but that printer creates source-code-like syntax (and is also marked with a `FIXME`). The nice, colourful, mostly human-readable `ASTDumper` only works on the standard output, which is not feasible in case a user wants to see the AST of a file through a code navigation/comprehension tool.
This small addition of an overload solves generating a nice colourful AST block for the users of a tool I'm working on, [[ http://github.com/Ericsson/CodeCompass | CodeCompass ]], as opposed to having to duplicate the behaviour of definitions that only exist in the anonymous namespace of implementation TUs related to this module.
Reviewers: alexfh, klimek, rsmith
Reviewed By: alexfh
Subscribers: rnkovacs, dkrupp, gsd, xazax.hun, cfe-commits, #clang
Tags: #clang
Patch by Whisperity!
Differential Revision: https://reviews.llvm.org/D45096
llvm-svn: 329391
layout" rules.
The new rules say that a standard-layout struct has its first non-static
data member and all base classes at offset 0, and consider a class to
not be standard-layout if that would result in multiple subobjects of a
single type having the same address.
We track "is C++11 standard-layout class" separately from "is
standard-layout class" so that the ABIs that need this information can
still use it.
Differential Revision: https://reviews.llvm.org/D45176
llvm-svn: 329332
The implementation of shadow call stack on aarch64 is quite different to
the implementation on x86_64. Instead of reserving a segment register for
the shadow call stack, we reserve the platform register, x18. Any function
that spills lr to sp also spills it to the shadow call stack, a pointer to
which is stored in x18.
Differential Revision: https://reviews.llvm.org/D45239
llvm-svn: 329236
Summary:
Add support for the -fsanitize=shadow-call-stack flag which causes clang
to add ShadowCallStack attribute to functions compiled with that flag
enabled.
Reviewers: pcc, kcc
Reviewed By: pcc, kcc
Subscribers: cryptoad, cfe-commits, kcc
Differential Revision: https://reviews.llvm.org/D44801
llvm-svn: 329122
Summary:
As we are only doing X.0.Z releases (not using the minor version), there is no need to keep -X.Y in the version.
So, instead, I propose the following:
Instead of having clang-7.0 in bin/, we will have clang-7
Since also matches was gcc is doing.
Reviewers: tstellar, dlj, dim, hans
Reviewed By: dim, hans
Subscribers: dim, mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D41808
llvm-svn: 328769
Adding a matcher for BinaryOperator and cxxOperatorCallExpr to be able to
decide whether it is any kind of assignment operator or not. This would be
useful since allows us to easily detect assignments via matchers for static
analysis (Tidy, SA) purposes.
Differential Revision: https://reviews.llvm.org/D44893
llvm-svn: 328618
- Remove use of the opencl and amdopencl environment member of the target triple for the AMDGPU target.
- Use a function attribute to communicate to the AMDGPU backend.
Differential Revision: https://reviews.llvm.org/D43735
llvm-svn: 328347
I should have done it in rL327558 / D43162, but forgot..
I'm not 100% sure about the text, but i don't think
it warrants a whole new differential revision.
llvm-svn: 327725
Henry Wong