Looks like the only reason we use a unique_ptr here is so that we can
conditionally construct a LogicalErrorHandler. It's a small type, and
Optional can do the same thing with 100% fewer heap allocations.
llvm-svn: 338962
As documented here: https://software.intel.com/en-us/node/682969 and
https://software.intel.com/en-us/node/523346. cpu_dispatch multiversioning
is an ICC feature that provides for function multiversioning.
This feature is implemented with two attributes: First, cpu_specific,
which specifies the individual function versions. Second, cpu_dispatch,
which specifies the location of the resolver function and the list of
resolvable functions.
This is valuable since it provides a mechanism where the resolver's TU
can be specified in one location, and the individual implementions
each in their own translation units.
The goal of this patch is to be source-compatible with ICC, so this
implementation diverges from the ICC implementation in a few ways:
1- Linux x86/64 only: This implementation uses ifuncs in order to
properly dispatch functions. This is is a valuable performance benefit
over the ICC implementation. A future patch will be provided to enable
this feature on Windows, but it will obviously more closely fit ICC's
implementation.
2- CPU Identification functions: ICC uses a set of custom functions to identify
the feature list of the host processor. This patch uses the cpu_supports
functionality in order to better align with 'target' multiversioning.
1- cpu_dispatch function def/decl: ICC's cpu_dispatch requires that the function
marked cpu_dispatch be an empty definition. This patch supports that as well,
however declarations are also permitted, since the linker will solve the
issue of multiple emissions.
Differential Revision: https://reviews.llvm.org/D47474
llvm-svn: 337552
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
FunctionProtoType.
We previously re-evaluated the expression each time we wanted to know whether
the type is noexcept or not. We now evaluate the expression exactly once.
This is not quite "no functional change": it fixes a crasher bug during AST
deserialization where we would try to evaluate the noexcept specification in a
situation where we have not deserialized sufficient portions of the AST to
permit such evaluation.
llvm-svn: 331428
The diagnostic system for Clang can already handle many AST nodes. Instead
of converting them to strings first, just hand the AST node directly to
the diagnostic system and let it handle the output. Minor changes in some
diagnostic output.
llvm-svn: 328688
r327219 added wrappers to std::sort which randomly shuffle the container before
sorting. This will help in uncovering non-determinism caused due to undefined
sorting order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of
std::sort.
llvm-svn: 328636
Summary: Rewrites -Winfinite-recursion to remove the state dictionary and explore paths in loops - especially infinite loops. The new check now detects recursion in loop bodies dominated by a recursive call.
Reviewers: rsmith, rtrieu
Reviewed By: rtrieu
Subscribers: lebedev.ri, cfe-commits
Differential Revision: https://reviews.llvm.org/D43737
llvm-svn: 328173
This relands r326965.
There was a null dereference in typo correction that was triggered in
Sema/diagnose_if.c. We are not always in a function scope when doing
typo correction. The fix is to add a null check.
LLVM's optimizer made it hard to find this bug. I wrote it up in a
not-very-well-editted blog post here:
http://qinsb.blogspot.com/2018/03/ub-will-delete-your-null-checks.html
llvm-svn: 327334
This reverts r326965. It seems to have caused repeating test failures in
clang/test/Sema/diagnose_if.c on some buildbots.
I cannot reproduce the problem, and it's not immediately obvious what
the problem is, so let's revert to green.
llvm-svn: 326974
Summary:
Before this patch, Sema pre-allocated a FunctionScopeInfo and kept it in
the first, always present element of the FunctionScopes stack. This
meant that Sema::getCurFunction would return a pointer to this
pre-allocated object when parsing code outside a function body. This is
pretty much always a bug, so this patch moves the pre-allocated object
into a separate unique_ptr. This should make bugs like PR36536 a lot
more obvious.
As you can see from this patch, there were a number of places that
unconditionally assumed they were always called inside a function.
However, there are also many places that null checked the result of
getCurFunction(), so I think this is a reasonable direction.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D44039
llvm-svn: 326965
Reimplement the "noexcept function actually throws" warning to properly handle
nested try-blocks. In passing, change 'throw;' handling to treat any enclosing
try block as being sufficient to suppress the warning rather than requiring a
'catch (...)'; the warning is intended to be conservatively-correct.
llvm-svn: 325545
While here, fix up the myriad other ways in which Sema's two "can this handler
catch that exception?" implementations get things wrong and unify them.
llvm-svn: 322431
This saves some cycles when compiling with "-w".
(Also fix a potential crash on invalid code for tools that tries to recover from some
errors, because analysis might compute the CFG which crashes if the code contains
invalid declaration. This does not happen normally with because we also don't perform
these analysis if there was an error.)
Differential Revision: https://reviews.llvm.org/D40242
llvm-svn: 318900
I ran across an instance where the value was being loaded
out via back, then immediately popped. Since pop_back_val
is more efficient at this (it moves out), replace this
instance.
llvm-svn: 316015
Discovered that 'nothrow' (which is supposed to be an alias for noexcept)
was not warning with a throw inside of it. This patch corrects the behavior
previously created to add 'nothrow' to this list.
Differential Revision: https://reviews.llvm.org/D38203
llvm-svn: 314229
The implementation is in AnalysisDeclContext.cpp and the class is called
AnalysisDeclContext.
Making those match up has numerous benefits, including:
- Easier jump from header to/from implementation.
- Easily identify filename from class.
Differential Revision: https://reviews.llvm.org/D37500
llvm-svn: 312671
...as introduced with recent <https://reviews.llvm.org/D33333> "Emit warning
when throw exception in destruct or dealloc functions which has a (possible
implicit) noexcept specifier". (The equivalent of the goodReference case hit
when building LibreOffice.)
(These warnings are apparently only emitted when no errors have yet been
encountered, so it didn't work to add the test code to the end of the existing
clang/test/SemaCXX/exceptions.cpp.)
llvm-svn: 306715
(possible implicit) noexcept specifier
Throwing in the destructor is not good (C++11 change try to not allow see below).
But in reality, those codes are exist.
C++11 [class.dtor]p3:
A declaration of a destructor that does not have an exception-specification is
implicitly considered to have the same exception specification as an implicit
declaration.
With this change, the application worked before may now run into runtime
termination. My goal here is to emit a warning to provide only possible info to
where the code may need to be changed.
First there is no way, in compile time to identify the “throw” really throw out
of the function. Things like the call which throw out… To keep this simple,
when “throw” is seen, checking its enclosing function(only destructor and
dealloc functions) with noexcept(true) specifier emit warning.
Here is implementation detail:
A new member function CheckCXXThrowInNonThrowingFunc is added for class Sema
in Sema.h. It is used in the call to both BuildCXXThrow and
TransformCXXThrowExpr.
The function basic check if the enclosing function with non-throwing noexcept
specifer, if so emit warning for it.
The example of warning message like:
k1.cpp:18:3: warning: ''~dependent_warn'' has a (possible implicit) non-throwing
noexcept specifier. Throwing exception may cause termination.
[-Wthrow-in-dtor]
throw 1;
^
k1.cpp:43:30: note: in instantiation of member function
'dependent_warn<noexcept_fun>::~dependent_warn' requested here
dependent_warn<noexcept_fun> f; // cause warning
Differential Revision: https://reviews.llvm.org/D33333
llvm-svn: 306149
Summary:
This patch fixes a number of issues with the analysis warnings emitted when a coroutine may reach the end of the function w/o returning.
* Fix bug where coroutines with `return_value` are incorrectly diagnosed as missing `co_return`'s.
* Rework diagnostic message to no longer say "non-void coroutine", because that implies the coroutine doesn't have a void return type, which it might. In this case a non-void coroutine is one who's promise type does not contain `return_void()`
As a side-effect of this patch, coroutine bodies that contain an invalid coroutine promise objects are marked as invalid.
Reviewers: GorNishanov, rsmith, aaron.ballman, majnemer
Reviewed By: GorNishanov
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D33532
llvm-svn: 303831
Summary:
1. build declaration of the gro local variable that keeps the result of get_return_object.
2. build return statement returning the gro variable
3. emit them during CodeGen
4. sema and CodeGen tests updated
Reviewers: EricWF, rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D31646
llvm-svn: 303573
We don't know whether some other instantiation of the template might be able to
reach the annotation, so warning on it has a high chance of false positives.
Patch by Ahmed Asadi!
Differential Revision: https://reviews.llvm.org/D31069
llvm-svn: 298477
the same source range and use the unary operator fixit only when it
actually silences the warning.
rdar://24570531
Differential Revision: https://reviews.llvm.org/D28231
llvm-svn: 291757
Summary:
This patch adds semantic checking and building of the fall-through `co_return;` statement as well as the `p.set_exception(std::current_exception())` call for handling uncaught exceptions.
The fall-through statement is built and checked according to:
> [dcl.fct.def.coroutine]/4
> The unqualified-ids return_void and return_value are looked up in the scope of class P. If
> both are found, the program is ill-formed. If the unqualified-id return_void is found, flowing
> off the end of a coroutine is equivalent to a co_return with no operand. Otherwise, flowing off
> the end of a coroutine results in undefined behavior.
Similarly the `set_exception` call is only built when that unqualified-id is found in the scope of class P.
Additionally this patch adds fall-through warnings for non-void returning coroutines. Since it's surprising undefined behavior I thought it would be important to add the warning right away.
Reviewers: majnemer, GorNishanov, rsmith
Subscribers: mehdi_amini, cfe-commits
Differential Revision: https://reviews.llvm.org/D25349
llvm-svn: 285271
Revision r211132 was supposed to disable -Warc-repeated-use-of-weak for
Objective-C properties marked with the IBOutlet attribute. Those properties
are supposed to be weak but they are only accessed from the main thread
so there is no risk of asynchronous updates setting them to nil. That
combination makes -Warc-repeated-use-of-weak very noisy. The previous
change only handled one kind of access to weak IBOutlet properties.
Instead of trying to add checks for all the different kinds of property
accesses, this patch removes the previous special case check and adds a
check at the point where the diagnostic is reported. rdar://21366461
llvm-svn: 270665
Usually these parameters are used solely to initialize the field in the
initializer list, and there is no real shadowing confusion.
There is a new warning under -Wshadow called
-Wshadow-field-in-constructor-modified. It attempts to find
modifications of such constructor parameters that probably intended to
modify the field.
It has some false negatives, though, so there is another warning group,
-Wshadow-field-in-constructor, which always warns on this special case.
For users who just want the old behavior and don't care about these fine
grained groups, we have a new warning group called -Wshadow-all that
activates everything.
Fixes PR16088.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D18271
llvm-svn: 267957
exactly the same as clang's existing [[clang::fallthrough]] attribute, which
has been updated to have the same semantics. The one significant difference
is that [[fallthrough]] is ill-formed if it's not used immediately before a
switch label (even when -Wimplicit-fallthrough is disabled). To support that,
we now build a CFG of any function that uses a '[[fallthrough]];' statement
to check.
In passing, fix some bugs with our support for statement attributes -- in
particular, diagnose their use on declarations, rather than asserting.
llvm-svn: 262881
Previously, __weak was silently accepted and ignored in MRC mode.
That makes this a potentially source-breaking change that we have to
roll out cautiously. Accordingly, for the time being, actual support
for __weak references in MRC is experimental, and the compiler will
reject attempts to actually form such references. The intent is to
eventually enable the feature by default in all non-GC modes.
(It is, of course, incompatible with ObjC GC's interpretation of
__weak.)
If you like, you can enable this feature with
-Xclang -fobjc-weak
but like any -Xclang option, this option may be removed at any point,
e.g. if/when it is eventually enabled by default.
This patch also enables the use of the ARC __unsafe_unretained qualifier
in MRC. Unlike __weak, this is being enabled immediately. Since
variables are essentially __unsafe_unretained by default in MRC,
the only practical uses are (1) communication and (2) changing the
default behavior of by-value block capture.
As an implementation matter, this means that the ObjC ownership
qualifiers may appear in any ObjC language mode, and so this patch
removes a number of checks for getLangOpts().ObjCAutoRefCount
that were guarding the processing of these qualifiers. I don't
expect this to be a significant drain on performance; it may even
be faster to just check for these qualifiers directly on a type
(since it's probably in a register anyway) than to do N dependent
loads to grab the LangOptions.
rdar://9674298
llvm-svn: 251041
Now that -Winfinite-recursion no longer uses recursive calls to before path
analysis, several bits of the code can be improved. The main changes:
1) Early return when finding a path to the exit block without a recursive call
2) Moving the states vector into checkForRecursiveFunctionCall instead of
passing it in by reference
3) Change checkForRecursiveFunctionCall to return a bool when the warning
should be emitted.
4) Use the State vector instead of storing it in the Stack vector.
llvm-svn: 245666
In llvm commit r243581, a reverse range adapter was added which allows
us to change code such as
for (auto I = Fields.rbegin(), E = Fields.rend(); I != E; ++I) {
in to
for (const FieldDecl *I : llvm::reverse(Fields))
This commit changes a few of the places in clang which are eligible to use
this new adapter.
llvm-svn: 243663
Large CFGs cause `checkForFunctionCall()` to overflow its stack. Break
the recursion by manually managing the call stack instead.
Patch by Vedant Kumar!
llvm-svn: 243039
Split out `hasRecursiveCallInPath()` from `checkForFunctionCall()` to
flatten nesting and clarify the code. This also simplifies a follow-up
patch that refactors the other logic in `checkForFunctionCall()`.
Patch by Vedant Kumar!
llvm-svn: 243038
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.
llvm-svn: 240270
Summary:
This patch is part of http://llvm-reviews.chandlerc.com/D2181.
In-class initializers are appended to the CFG when CFGBuilder::addInitializer is called.
Reviewers: jordan_rose, rsmith
Reviewed By: jordan_rose
Subscribers: cfe-commits, klimek
Differential Revision: http://reviews.llvm.org/D2370
llvm-svn: 238913
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.
llvm-svn: 238601
These checks detect potential deadlocks caused by inconsistent lock
ordering. The checks are implemented under the -Wthread-safety-beta flag.
This patch also replaces calls to getAttrs() with calls to attrs() throughout
ThreadSafety.cpp, which fixes the earlier issue that cause assert failures.
llvm-svn: 228051
These checks detect potential deadlocks caused by inconsistent lock
ordering. The checks are implemented under the -Wthread-safety-beta flag.
llvm-svn: 227997
warns when a guarded variable is passed by reference as a function argument.
This is released as a separate warning flag, because it could potentially
break existing code that uses thread safety analysis.
llvm-svn: 218087
til::SExpr. This is a large patch, with many small changes to pretty printing
and expression lowering to make the new SExpr representation equivalent in
functionality to the old.
llvm-svn: 214089
The compilation pipeline doesn't actually need to know about the high-level
concept of diagnostic mappings, and hiding the final computed level presents
several simplifications and other potential benefits.
The only exceptions are opportunistic checks to see whether expensive code
paths can be avoided for diagnostics that are guaranteed to be ignored at a
certain SourceLocation.
This commit formalizes that invariant by introducing and using
DiagnosticsEngine::isIgnored() in place of individual level checks throughout
lex, parse and sema.
llvm-svn: 211005
which warns on compound conditionals that always evaluate to the same value.
For instance, (x > 5 && x < 3) will always be false since no value for x can
satisfy both conditions.
This patch also changes the CFG to use these tautological values for better
branch analysis. The test for -Wunreachable-code shows how this change catches
additional dead code.
Patch by Anders Rönnholm.
llvm-svn: 205665
Taking a hint from -Wparentheses, use an extra '()' as a sigil that
a dead condition is intentionally dead. For example:
if ((0)) { dead }
When this sigil is found, do not emit a dead code warning. When the
analysis sees:
if (0)
it suggests inserting '()' as a Fix-It.
llvm-svn: 205069
The exception is return statements that include control-flow,
which are clearly doing something "interesting".
99% of the cases I examined for -Wunreachable-code that fired
on return statements were not interesting enough to warrant
being in -Wunreachable-code by default. Thus the move to
include them in -Wunreachable-code-return.
This simplifies a bunch of logic, including removing the ad hoc
logic to look for std::string literals.
llvm-svn: 204307
Also relax unreachable 'break' and 'return' to not check for being
preceded by a call to 'noreturn'. That turns out to not be so
interesting in practice.
llvm-svn: 204000
Recent work on -Wunreachable-code has focused on suppressing uninteresting
unreachable code that center around "configuration values", but
there are still some set of cases that are sometimes interesting
or uninteresting depending on the codebase. For example, a dead
"break" statement may not be interesting for a particular codebase,
potentially because it is auto-generated or simply because code
is written defensively.
To address these workflow differences, -Wunreachable-code is now
broken into several diagnostic groups:
-Wunreachable-code: intended to be a reasonable "default" for
most users.
and then other groups that turn on more aggressive checking:
-Wunreachable-code-break: warn about dead break statements
-Wunreachable-code-trivial-return: warn about dead return statements
that return "trivial" values (e.g., return 0). Other return
statements that return non-trivial values are still reported
under -Wunreachable-code (this is an area subject to more refinement).
-Wunreachable-code-aggressive: supergroup that enables all these
groups.
The goal is to eventually make -Wunreachable-code good enough to
either be in -Wall or on-by-default, thus finessing these warnings
into different groups helps achieve maximum signal for more users.
TODO: the tests need to be updated to reflect this extra control
via diagnostic flags.
llvm-svn: 203994
This warning has a whole bunch of known false positives, much of them due
to code that is "sometimes unreachable". This can caused by code that
is conditionally generated by the preprocessor, branches that are defined
in terms of architecture-specific details (e.g., the size of a type), and
so on. While these are all good things to address one by one, the reality
is that this warning has received little love lately. By restricting
its purvue, we can focus on the top issues effecting main files, which
should be smaller, and then gradually widen the scope.
llvm-svn: 201607
A return type is the declared or deduced part of the function type specified in
the declaration.
A result type is the (potentially adjusted) type of the value of an expression
that calls the function.
Rule of thumb:
* Declarations have return types and parameters.
* Expressions have result types and arguments.
llvm-svn: 200082
In an expression like "new (a, b) Foo(x, y)", two things happen:
- Memory is allocated by calling a function named 'operator new'.
- The memory is initialized using the constructor for 'Foo'.
Currently the analyzer only models the second event, though it has special
cases for both the default and placement forms of operator new. This patch
is the first step towards properly modeling both events: it changes the CFG
so that the above expression now generates the following elements.
1. a
2. b
3. (CFGNewAllocator)
4. x
5. y
6. Foo::Foo
The analyzer currently ignores the CFGNewAllocator element, but the next
step is to treat that as a call like any other.
The CFGNewAllocator element is not added to the CFG for analysis-based
warnings, since none of them take advantage of it yet.
llvm-svn: 199123
This new warning detects when a function will recursively call itself on every
code path though that function. This catches simple recursive cases such as:
void foo() {
foo();
}
As well as more complex functions like:
void bar() {
if (test()) {
bar();
return;
} else {
bar();
}
return;
}
This warning uses the CFG. As with other CFG-based warnings, this is off
by default. Due to false positives, this warning is also disabled for
templated functions.
llvm-svn: 197853
to be treated as return values, and marked with the "returned_typestate"
attribute. Patch by chris.wailes@gmail.com; reviewed by delesley@google.com.
llvm-svn: 192932
marked all variables as "unknown" at the start of a loop. The new version
keeps the initial state of variables unchanged, but issues a warning if the
state at the end of the loop is different from the state at the beginning.
This patch will eventually be replaced with a more precise analysis.
Initial patch by chris.wailes@gmail.com. Reviewed and edited by
delesley@google.com.
llvm-svn: 192314
that a function can be called in. This reduced the total number of annotations
needed and makes writing more complicated behaviour less burdensome.
Patch by chriswails@gmail.com.
llvm-svn: 191983
_Bool in C, if the macro is defined. Also teach FixItUtils to look at whether
the macro was defined at the source location for which it is creating a fixit,
rather than looking at whether it's defined *now*. This is especially relevant
for analysis-based warnings which are delayed until end of TU.
llvm-svn: 191057
variable uninitialized every time we reach its (reachable) declaration, or
every time we call the surrounding function, promote the warning from
-Wmaybe-uninitialized to -Wsometimes-uninitialized.
This is still slightly weaker than desired: we should, in general, warn
if a use is uninitialized the first time it is evaluated.
llvm-svn: 190623
George Burgess IV