Summary:
Add new ``isa_and_nonnull<>`` operator that works just like
the ``isa<>`` operator, except that it allows for a null pointer as an
argument (which it then returns false).
Reviewers: lattner, aaron.ballman, greened
Reviewed By: lattner
Subscribers: hubert.reinterpretcast, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60291
llvm-svn: 357761
A fallible iterator is one whose increment or decrement operations may fail.
This would usually be supported by replacing the ++ and -- operators with
methods that return error:
class MyFallibleIterator {
public:
// ...
Error inc();
Errro dec();
// ...
};
The downside of this style is that it no longer conforms to the C++ iterator
concept, and can not make use of standard algorithms and features such as
range-based for loops.
The fallible_iterator wrapper takes an iterator written in the style above
and adapts it to (mostly) conform with the C++ iterator concept. It does this
by providing standard ++ and -- operator implementations, returning any errors
generated via a side channel (an Error reference passed into the wrapper at
construction time), and immediately jumping the iterator to a known 'end'
value upon error. It also marks the Error as checked any time an iterator is
compared with a known end value and found to be inequal, allowing early exit
from loops without redundant error checking*.
Usage looks like:
MyFallibleIterator I = ..., E = ...;
Error Err = Error::success();
for (auto &Elem : make_fallible_range(I, E, Err)) {
// Loop body is only entered when safe.
// Early exits from loop body permitted without checking Err.
if (SomeCondition)
return;
}
if (Err)
// Handle error.
* Since failure causes a fallible iterator to jump to end, testing that a
fallible iterator is not an end value implicitly verifies that the error is a
success value, and so is equivalent to an error check.
Reviewers: dblaikie, rupprecht
Subscribers: mgorny, dexonsmith, kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57618
llvm-svn: 353237
A while back, createStringError was added to provide easier construction
of StringError instances, especially with formatting options. Prior to
this patch, that the documentation only mentions the standard method of
using it. Since createStringError is slightly shorter to type, and also
provides the formatting options, this patch updates the Programmer's
Manual to use the new function in its examples, and to mention the
printf formatting options. It also fixes a small typo in one of the
examples and removes the unnecessary make_error_code call.
llvm-svn: 352846
Recommit r352791 after tweaking DerivedTypes.h slightly, so that gcc
doesn't choke on it, hopefully.
Original Message:
The FunctionCallee type is effectively a {FunctionType*,Value*} pair,
and is a useful convenience to enable code to continue passing the
result of getOrInsertFunction() through to EmitCall, even once pointer
types lose their pointee-type.
Then:
- update the CallInst/InvokeInst instruction creation functions to
take a Callee,
- modify getOrInsertFunction to return FunctionCallee, and
- update all callers appropriately.
One area of particular note is the change to the sanitizer
code. Previously, they had been casting the result of
`getOrInsertFunction` to a `Function*` via
`checkSanitizerInterfaceFunction`, and storing that. That would report
an error if someone had already inserted a function declaraction with
a mismatching signature.
However, in general, LLVM allows for such mismatches, as
`getOrInsertFunction` will automatically insert a bitcast if
needed. As part of this cleanup, cause the sanitizer code to do the
same. (It will call its functions using the expected signature,
however they may have been declared.)
Finally, in a small number of locations, callers of
`getOrInsertFunction` actually were expecting/requiring that a brand
new function was being created. In such cases, I've switched them to
Function::Create instead.
Differential Revision: https://reviews.llvm.org/D57315
llvm-svn: 352827
This reverts commit f47d6b38c7a61d50db4566b02719de05492dcef1 (r352791).
Seems to run into compilation failures with GCC (but not clang, where
I tested it). Reverting while I investigate.
llvm-svn: 352800
The FunctionCallee type is effectively a {FunctionType*,Value*} pair,
and is a useful convenience to enable code to continue passing the
result of getOrInsertFunction() through to EmitCall, even once pointer
types lose their pointee-type.
Then:
- update the CallInst/InvokeInst instruction creation functions to
take a Callee,
- modify getOrInsertFunction to return FunctionCallee, and
- update all callers appropriately.
One area of particular note is the change to the sanitizer
code. Previously, they had been casting the result of
`getOrInsertFunction` to a `Function*` via
`checkSanitizerInterfaceFunction`, and storing that. That would report
an error if someone had already inserted a function declaraction with
a mismatching signature.
However, in general, LLVM allows for such mismatches, as
`getOrInsertFunction` will automatically insert a bitcast if
needed. As part of this cleanup, cause the sanitizer code to do the
same. (It will call its functions using the expected signature,
however they may have been declared.)
Finally, in a small number of locations, callers of
`getOrInsertFunction` actually were expecting/requiring that a brand
new function was being created. In such cases, I've switched them to
Function::Create instead.
Differential Revision: https://reviews.llvm.org/D57315
llvm-svn: 352791
As noted in https://bugs.llvm.org/show_bug.cgi?id=36651, the specialization for
isPodLike<std::pair<...>> did not match the expectation of
std::is_trivially_copyable which makes the memcpy optimization invalid.
This patch renames the llvm::isPodLike trait into llvm::is_trivially_copyable.
Unfortunately std::is_trivially_copyable is not portable across compiler / STL
versions. So a portable version is provided too.
Note that the following specialization were invalid:
std::pair<T0, T1>
llvm::Optional<T>
Tests have been added to assert that former specialization are respected by the
standard usage of llvm::is_trivially_copyable, and that when a decent version
of std::is_trivially_copyable is available, llvm::is_trivially_copyable is
compared to std::is_trivially_copyable.
As of this patch, llvm::Optional is no longer considered trivially copyable,
even if T is. This is to be fixed in a later patch, as it has impact on a
long-running bug (see r347004)
Note that GCC warns about this UB, but this got silented by https://reviews.llvm.org/D50296.
Differential Revision: https://reviews.llvm.org/D54472
llvm-svn: 351701
This shortcut mechanism for creating types was added 10 years ago, but
has seen almost no uptake since then, neither internally nor in
external projects.
The very small number of characters saved by using it does not seem
worth the mental overhead of an additional type-creation API, so,
delete it.
Differential Revision: https://reviews.llvm.org/D56573
llvm-svn: 351020
In light of the recent changes to SmallVector in r335421, r337514, and
r337820, document its advantages over std::vector (see r175906 and
r266909).
Also add a release note.
https://reviews.llvm.org/D49748
llvm-svn: 338071
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
The examples in llvm/Support/Debug.h use `DEBUG(dbgs() << ...)` instead
of `errs()`, so the examples in the Programmer's Manual should match
that.
Patch by: Moritz Sichert <moritz.sichert@googlemail.com>
Differential revision: https://reviews.llvm.org/D41170
llvm-svn: 321444
Use text suggested by Justin Bogner in post-commit review of r311146
<http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20170814/479898.html>,
which makes it clear that report_fatal_error shouldn't be used when there is a
practicable alternative. Also make this clearer in CodingStandards.
llvm-svn: 311147
The current ProgrammersManual.rst document has a lot of well-written
documentation on error handling thanks to @lhames. It suggests errors can be
split cleanly into "programmatic" and "recoverable" errors. However, the
reality in current LLVM seems to be there are a number of cases where a
non-programmatic error is not easily recoverable. Therefore, add a note to
indicate the existence of report_fatal_error for these cases. I've also added
a reminder to CodingStandards.rst in the section on assertions, to indicate
that llvm_unreachable and assertions should not be relied upon to report
errors triggered by user input.
The ProgrammersManual is also silent on the use of LLVMContext::diagnose,
which is used in BPF+WebAssembly+AMDGPU to report some errors during
instruction selection. I don't address that in this patch, as it's not quite
clear how to fit in to the current error handling story
Differential Revision: https://reviews.llvm.org/D36826
llvm-svn: 311146
This make it consistent with STATISTIC which it will often appears near.
While there move one DEBUG_COUNTER instance out of an anonymous namespace. It's already declaring a static variable so the namespace is unnecessary.
llvm-svn: 310637
Commits were:
"Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts"
"Add a new WeakVH value handle; NFC"
"Rename WeakVH to WeakTrackingVH; NFC"
The changes assumed pointers are 8 byte aligned on all architectures.
llvm-svn: 301429
Summary:
I plan to use WeakVH to mean "nulls itself out on deletion, but does
not track RAUW" in a subsequent commit.
Reviewers: dblaikie, davide
Reviewed By: davide
Subscribers: arsenm, mehdi_amini, mcrosier, mzolotukhin, jfb, llvm-commits, nhaehnle
Differential Revision: https://reviews.llvm.org/D32266
llvm-svn: 301424
fallible functions.
Some fallible functions (those returning Error or Expected<T>) may only fail
for a subset of their inputs. For example, a "safe" square root function will
succeed for all finite positive inputs:
Expected<double> safeSqrt(double d) {
if (d < 0 && !isnan(d) && !isinf(d))
return make_error<...>("Cannot sqrt -ve values, nans or infs");
return sqrt(d);
}
At a safe callsite for such a function, checking the error return value is
redundant:
if (auto ValOrErr = safeSqrt(42.0)) {
// use *ValOrErr.
} else
llvm_unreachable("safeSqrt should always succeed for +ve values");
The cantFail function wraps this check and extracts the contained value,
simplifying control flow:
double Result = cantFail(safeSqrt(42.0));
This function should be used with care: it is a programmatic error to wrap a
call with cantFail if it can in fact fail. For debug builds this will
result in llvm_unreachable being called. For release builds the behavior is
undefined.
Use of this function is likely to be rare in library code, but more common
for tool and unit-test code where inputs and mock functions may be known to be
safe.
llvm-svn: 296384
Summary:
Fixed bunch of for loops to range based for loop
and bunch of rendundat types with auto.
Reviewers: echristo, silvas, chandlerc
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D30338
llvm-svn: 296251
Summary:
This replaces the format member search, which was quite complicated, with a more
direct approach to detecting whether a class should be formatted using the
format-member method. Instead we use a special type llvm::format_adapter, which
every adapter must inherit from. Then the search can be simply implemented with
the is_base_of type trait.
Aside from the simplification, I like this way more because it makes it more
explicit that you are supposed to use this type only for adapter-like
formattings, and the other approach (format_provider overloads) should be used
as a default (a mistake I made when first trying to use this library).
The only slight change in behaviour here is that now choose the format-adapter
branch even if the format member invocation will fail to compile (e.g. because it is a
non-const member function and we are passing a const adapter), whereas
previously we would have gone on to search for format_providers for the type.
However, I think that is actually a good thing, as it probably means the
programmer did something wrong.
Reviewers: zturner, inglorion
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27679
llvm-svn: 289795
Now that PointerType is no longer a SequentialType, all SequentialTypes
have an associated number of elements, so we can move that information to
the base class, allowing for a number of simplifications.
Differential Revision: https://reviews.llvm.org/D27122
llvm-svn: 288464
As proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/106640.html
This is for a couple of reasons:
- Values of type PointerType are unlike the other SequentialTypes (arrays
and vectors) in that they do not hold values of the element type. By moving
PointerType we can unify certain aspects of how the other SequentialTypes
are handled.
- PointerType will have no place in the SequentialType hierarchy once
pointee types are removed, so this is a necessary step towards removing
pointee types.
Differential Revision: https://reviews.llvm.org/D26595
llvm-svn: 288462
This introduces a new type-safe general purpose formatting
library. It provides compile-time type safety, does not require
a format specifier (since the type is deduced), and provides
mechanisms for extending the format capability to user defined
types, and overriding the formatting behavior for existing types.
This patch additionally adds documentation for the API to the
LLVM programmer's manual.
Mailing List Thread:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/105836.html
Differential Revision: https://reviews.llvm.org/D25587
llvm-svn: 286682
programmer's manual.
ExitOnError is often a better alternative to handleErrors for tool code. This
patch makes it easier to find the ExitOnError discussion when reading the
handleErrors section.
Thanks to Peter Collingbourne for the suggestion.
llvm-svn: 286167
