The constant is already reduced to 8-bits by the time we get here and the checks were just ensuring that it was 8 bits. Thus I don't think there's anyway for them to fail.
llvm-svn: 322244
Adding the new enumerator forced a bunch more changes into this patch than I
would have liked. The -Wtautological-compare warning was extended to properly
check the new comparison operator, clang-format needed updating because it uses
precedence levels as weights for determining where to break lines (and several
operators increased their precedence levels with this change), thread-safety
analysis needed changes to build its own IL properly for the new operator.
All "real" semantic checking for this operator has been deferred to a future
patch. For now, we use the relational comparison rules and arbitrarily give
the builtin form of the operator a return type of 'void'.
llvm-svn: 320707
and fold together into a single function.
In so doing, fix a handful of remaining bugs where we would report false
positives or false negatives if we promote a signed value to an unsigned type
for the comparison.
This re-commits r320122 and r320124, minus two changes:
* Comparisons between a constant and a non-constant expression of enumeration
type never warn, not even if the constant is out of range. We should be
warning about the creation of such a constant, not about its use.
* We do not use more precise bit-widths for comparisons against bit-fields.
The more precise diagnostics probably are the right thing, but we should
consider moving them under their own warning flag.
Other than the refactoring, this patch should only change the behavior for the
buggy cases (where the warnings didn't take into account that promotion from
signed to unsigned can leave a range of inaccessible values in the middle of
the promoted type).
llvm-svn: 320211
> Unify implementation of our two different flavours of -Wtautological-compare.
>
> In so doing, fix a handful of remaining bugs where we would report false
> positives or false negatives if we promote a signed value to an unsigned type
> for the comparison.
This caused a new warning in Chromium:
../../base/trace_event/trace_log.cc:1545:29: error: comparison of constant 64
with expression of type 'unsigned int' is always true
[-Werror,-Wtautological-constant-out-of-range-compare]
DCHECK(handle.event_index < TraceBufferChunk::kTraceBufferChunkSize);
~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The 'unsigned int' is really a 6-bit bitfield, which is why it's always
less than 64.
I thought we didn't use to warn (with out-of-range-compare) when comparing
against the boundaries of a type?
llvm-svn: 320162
This broke Chromium:
../../base/trace_event/trace_log.cc:1545:29: error: comparison of constant 64
with expression of type 'unsigned int' is always true
[-Werror,-Wtautological-constant-out-of-range-compare]
DCHECK(handle.event_index < TraceBufferChunk::kTraceBufferChunkSize);
~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The 'unsigned int' is really a 6-bit bitfield, which is why it's always
less than 63.
Did this use to fall under the "in-range" case before? I thought we
didn't use to warn when comparing against the boundaries of a type.
llvm-svn: 320133
In so doing, fix a handful of remaining bugs where we would report false
positives or false negatives if we promote a signed value to an unsigned type
for the comparison.
llvm-svn: 320122
This is a follow up of r302131, in which we forgot to add SemaChecking
tests. Adding these tests revealed two problems which have been fixed:
- added missing intrinsic __qdbl,
- properly range checking ssat16 and usat16.
Differential Revision: https://reviews.llvm.org/D40888
llvm-svn: 320019
This is a fix for PR35509 in which we crash because we attempt to compute the
alignment of an incomplete type.
Differential Revision: https://reviews.llvm.org/D40895
llvm-svn: 320017
codepath plus the new "minimum / maximum value of type" diagnostic to get the
same effect.
Move the warning for an in-range but tautological comparison of a constant (0
or 1) against a bool out of -Wtautological-constant-out-of-range-compare into
the more-appropriate -Wtautological-constant-compare.
llvm-svn: 319942
An enumeration with a fixed underlying type can have any value in its
underlying type, not just those spanned by the values of its enumerators.
llvm-svn: 319875
It seems this somehow made -Wempty-body fire in some macro cases where
it didn't before, e.g.
../../third_party/ffmpeg/libavcodec/bitstream.c(169,5): error: if statement has empty body [-Werror,-Wempty-body]
ff_dlog(NULL, "new table index=%d size=%d\n", table_index, table_size);
^
../../third_party/ffmpeg\libavutil/internal.h(276,80): note: expanded from macro 'ff_dlog'
# define ff_dlog(ctx, ...) do { if (0) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
^
../../third_party/ffmpeg/libavcodec/bitstream.c(169,5): note: put the
semicolon on a separate line to silence this warning
Reverting until this can be figured out.
> Do not show it when `if` or `else` come from macros.
> E.g.,
>
> #define USED(A) if (A); else
> #define SOME_IF(A) if (A)
>
> void test() {
> // No warnings are shown in those cases now.
> USED(0);
> SOME_IF(0);
> }
>
> Patch by Ilya Biryukov!
>
> Differential Revision: https://reviews.llvm.org/D40185
llvm-svn: 318665
Do not show it when `if` or `else` come from macros.
E.g.,
#define USED(A) if (A); else
#define SOME_IF(A) if (A)
void test() {
// No warnings are shown in those cases now.
USED(0);
SOME_IF(0);
}
Patch by Ilya Biryukov!
Differential Revision: https://reviews.llvm.org/D40185
llvm-svn: 318556
Summary:
As Mattias Eriksson has reported in PR35009, in C, for enums, the underlying type should
be used when checking for the tautological comparison, unlike C++, where the enumerator
values define the value range. So if not in CPlusPlus mode, use the enum underlying type.
Also, i have discovered a problem (a crash) when evaluating tautological-ness of the following comparison:
```
enum A { A_a = 0 };
if (a < 0) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
return 0;
```
This affects both the C and C++, but after the first fix, only C++ code was affected.
That was also fixed, while preserving (i think?) the proper diagnostic output.
And while there, attempt to enhance the test coverage.
Yes, some tests got moved around, sorry about that :)
Fixes PR35009
Reviewers: aaron.ballman, rsmith, rjmccall
Reviewed By: aaron.ballman
Subscribers: Rakete1111, efriedma, materi, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D39122
llvm-svn: 316268
Use the new helper methods to get the underlying type for NSUInteger,
NSInteger types. This avoids spreading the knowledge of the underlying
types in various sites. For non-LLP64 targets, this has no change.
llvm-svn: 316013
The first attempt, rL315614 was reverted because one libcxx
test broke, and i did not know at the time how to deal with it.
Summary:
Currently, clang only diagnoses completely out-of-range comparisons (e.g. `char` and constant `300`),
and comparisons of unsigned and `0`. But gcc also does diagnose the comparisons with the
`std::numeric_limits<>::max()` / `std::numeric_limits<>::min()` so to speak
Finally Fixes https://bugs.llvm.org/show_bug.cgi?id=34147
Continuation of https://reviews.llvm.org/D37565
Reviewers: rjmccall, rsmith, aaron.ballman
Reviewed By: rsmith
Subscribers: rtrieu, jroelofs, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D38101
llvm-svn: 315875
Summary:
Convert clang::LangAS to a strongly typed enum
Currently both clang AST address spaces and target specific address spaces
are represented as unsigned which can lead to subtle errors if the wrong
type is passed. It is especially confusing in the CodeGen files as it is
not possible to see what kind of address space should be passed to a
function without looking at the implementation.
I originally made this change for our LLVM fork for the CHERI architecture
where we make extensive use of address spaces to differentiate between
capabilities and pointers. When merging the upstream changes I usually
run into some test failures or runtime crashes because the wrong kind of
address space is passed to a function. By converting the LangAS enum to a
C++11 we can catch these errors at compile time. Additionally, it is now
obvious from the function signature which kind of address space it expects.
I found the following errors while writing this patch:
- ItaniumRecordLayoutBuilder::LayoutField was passing a clang AST address
space to TargetInfo::getPointer{Width,Align}()
- TypePrinter::printAttributedAfter() prints the numeric value of the
clang AST address space instead of the target address space.
However, this code is not used so I kept the current behaviour
- initializeForBlockHeader() in CGBlocks.cpp was passing
LangAS::opencl_generic to TargetInfo::getPointer{Width,Align}()
- CodeGenFunction::EmitBlockLiteral() was passing a AST address space to
TargetInfo::getPointerWidth()
- CGOpenMPRuntimeNVPTX::translateParameter() passed a target address space
to Qualifiers::addAddressSpace()
- CGOpenMPRuntimeNVPTX::getParameterAddress() was using
llvm::Type::getPointerTo() with a AST address space
- clang_getAddressSpace() returns either a LangAS or a target address
space. As this is exposed to C I have kept the current behaviour and
added a comment stating that it is probably not correct.
Other than this the patch should not cause any functional changes.
Reviewers: yaxunl, pcc, bader
Reviewed By: yaxunl, bader
Subscribers: jlebar, jholewinski, nhaehnle, Anastasia, cfe-commits
Differential Revision: https://reviews.llvm.org/D38816
llvm-svn: 315871
Currently Clang uses default address space (0) to represent private address space for OpenCL
in AST. There are two issues with this:
Multiple address spaces including private address space cannot be diagnosed.
There is no mangling for default address space. For example, if private int* is emitted as
i32 addrspace(5)* in IR. It is supposed to be mangled as PUAS5i but it is mangled as
Pi instead.
This patch attempts to represent OpenCL private address space explicitly in AST. It adds
a new enum LangAS::opencl_private and adds it to the variable types which are implicitly
private:
automatic variables without address space qualifier
function parameter
pointee type without address space qualifier (OpenCL 1.2 and below)
Differential Revision: https://reviews.llvm.org/D35082
llvm-svn: 315668
Summary:
Currently, clang only diagnoses completely out-of-range comparisons (e.g. `char` and constant `300`),
and comparisons of unsigned and `0`. But gcc also does diagnose the comparisons with the
`std::numeric_limits<>::max()` / `std::numeric_limits<>::min()` so to speak
Finally Fixes https://bugs.llvm.org/show_bug.cgi?id=34147
Continuation of https://reviews.llvm.org/D37565
Reviewers: rjmccall, rsmith, aaron.ballman
Reviewed By: rsmith
Subscribers: rtrieu, jroelofs, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D38101
llvm-svn: 315614
This function is used to perform semantic analysis on Microsoft style
`__va_start`. Rename it to make this more explicit. `__va_start` is
marked as `ALL_MS_LANGUAGES`, and requires Microsoft compatibility.
Other GNU targets will use `__builtin_va_start` instead. NFC.
Addresses post-commit review comments from David Majnemer.
llvm-svn: 314241
The `__va_start` intrinsic for Windows ARM does not account for const
correctness when performing a check. All local qualifiers are ignored
when validating the invocation. This was exposed by building the swift
stdlib against the Windows 10586 SDK for ARM. Simply expand out the
check for the two parameters and ignore the qualifiers for the check.
llvm-svn: 314226
For the triple thumbv7-apple-ios8.0.0 ssize_t is long and size_t is unsigned long,
while NSInteger is int and NSUinteger is unsigned int. Following
https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/Strings/Articles/formatSpecifiers.html
Clang catches it and insert a cast to long, for example
printf("%zd", getNSInteger())
will be replaced with
printf("%zd", (long)getNSInteger())
but since the underlying type of ssize_t is long the specifier "%zd" is not getting replaced.
This diff changes this behavior to enable replacing the specifier "%zd" with the correct one.
Differential revision: https://reviews.llvm.org/D38159
Test plan: make check-all
llvm-svn: 314011
As reported here: https://bugs.llvm.org/show_bug.cgi?id=34692
A non-defined enum with a backing type was always defaulting to
being treated as a signed type. IN the case where it IS defined,
the signed-ness of the actual items is used.
This patch uses the underlying type's signed-ness in the non-defined
case to test signed-comparision.
Differential Revision: https://reviews.llvm.org/D38145
llvm-svn: 313907
As Aaron Ballman has pointed out, that is not really correct.
So the key problem there is the invalidity of the testcase.
Revert r313747, and rework testcase in such a way, so these
details (platform-specific default enum sigdness) are
accounted for.
Also, add a C++-specific testcase.
llvm-svn: 313756
Hopefully fixes test-clang-msc-x64-on-i686-linux-RA build.
The underlying problem is that the enum is signed there.
Yet still, it is invalid for it to contain negative values,
so the comparison is always tautological in this case.
No differential, but related to https://reviews.llvm.org/D37629
llvm-svn: 313747
Recommit. Original commit was reverted because buildbots broke.
The error was only reproducible in the build with assertions.
The problem was that the diagnostic expected true/false as
bool, while it was provided as string "true"/"false".
Summary:
As requested by Sam McCall:
> Enums (not new I guess). Typical case: if (enum < 0 || enum > MAX)
> The warning strongly suggests that the enum < 0 check has no effect
> (for enums with nonnegative ranges).
> Clang doesn't seem to optimize such checks out though, and they seem
> likely to catch bugs in some cases. Yes, only if there's UB elsewhere,
> but I assume not optimizing out these checks indicates a deliberate
> decision to stay somewhat compatible with a technically-incorrect
> mental model.
> If this is the case, should we move these to a
> -Wtautological-compare-enum subcategory?
Reviewers: rjmccall, rsmith, aaron.ballman, sammccall, bkramer, djasper
Reviewed By: aaron.ballman
Subscribers: jroelofs, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D37629
llvm-svn: 313745
Summary:
As requested by Sam McCall:
> Enums (not new I guess). Typical case: if (enum < 0 || enum > MAX)
> The warning strongly suggests that the enum < 0 check has no effect
> (for enums with nonnegative ranges).
> Clang doesn't seem to optimize such checks out though, and they seem
> likely to catch bugs in some cases. Yes, only if there's UB elsewhere,
> but I assume not optimizing out these checks indicates a deliberate
> decision to stay somewhat compatible with a technically-incorrect
> mental model.
> If this is the case, should we move these to a
> -Wtautological-compare-enum subcategory?
Reviewers: rjmccall, rsmith, aaron.ballman, sammccall, bkramer, djasper
Reviewed By: aaron.ballman
Subscribers: jroelofs, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D37629
llvm-svn: 313677
Summary:
This is a first half(?) of a fix for the following bug:
https://bugs.llvm.org/show_bug.cgi?id=34147 (gcc -Wtype-limits)
GCC's -Wtype-limits does warn on comparison of unsigned value
with signed zero (as in, with 0), but clang only warns if the
zero is unsigned (i.e. 0U).
Also, be careful not to double-warn, or falsely warn on
comparison of signed/fp variable and signed 0.
Yes, all these testcases are needed.
Testing: $ ninja check-clang-sema check-clang-semacxx
Also, no new warnings for clang stage-2 build.
Reviewers: rjmccall, rsmith, aaron.ballman
Reviewed By: rjmccall
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D37565
llvm-svn: 312750
This patch adds support for __builtin_cpu_is. I've tried to match the strings supported to the latest version of gcc.
Differential Revision: https://reviews.llvm.org/D35449
llvm-svn: 310657
Converting a _Complex type to a real one simply discards the imaginary part.
This can easily lead to loss of information so for safety (and GCC
compatibility) this patch disallows that when the conversion would be implicit.
The one exception is bool, which actually compares both real and imaginary
parts and so is safe.
llvm-svn: 310427
OpenCL 2.0 atomic builtin functions have a scope argument which is ideally
represented as synchronization scope argument in LLVM atomic instructions.
Clang supports translating Clang atomic builtin functions to LLVM atomic
instructions. However it currently does not support synchronization scope
of LLVM atomic instructions. Without this, users have to use LLVM assembly
code to implement OpenCL atomic builtin functions.
This patch adds OpenCL 2.0 atomic builtin functions as Clang builtin
functions, which supports generating LLVM atomic instructions with
synchronization scope operand.
Currently only constant memory scope argument is supported. Support of
non-constant memory scope argument will be added later.
Differential Revision: https://reviews.llvm.org/D28691
llvm-svn: 310082
Move builtins from the x86 specific scope into the global
scope. Their use is still limited to x86_64 and aarch64 though.
This allows wine on aarch64 to properly handle variadic functions.
Differential Revision: https://reviews.llvm.org/D34475
llvm-svn: 308218
This patch series adds support for the IBM z14 processor. This part includes:
- Basic support for the new processor and its features.
- Support for low-level builtins mapped to new LLVM intrinsics.
Support for the -fzvector extension to vector float and the new
high-level vector intrinsics is provided by separate patches.
llvm-svn: 308197
Abderrazek Zaafrani