This patch replaces SmallSet<T *, N> with SmallPtrSet<T *, N>. Note
that SmallSet.h "redirects" SmallSet to SmallPtrSet for pointer
element types:
template <typename PointeeType, unsigned N>
class SmallSet<PointeeType*, N> : public SmallPtrSet<PointeeType*, N>
{};
We only have 10 instances that rely on this "redirection", with more
than half of them under clang-tools-extra/. Since the redirection
doesn't improve readability, this patch replaces SmallSet with
SmallPtrSet for pointer element types.
I'm planning to remove the redirection eventually.
This is a major change on how we represent nested name qualifications in
the AST.
* The nested name specifier itself and how it's stored is changed. The
prefixes for types are handled within the type hierarchy, which makes
canonicalization for them super cheap, no memory allocation required.
Also translating a type into nested name specifier form becomes a no-op.
An identifier is stored as a DependentNameType. The nested name
specifier gains a lightweight handle class, to be used instead of
passing around pointers, which is similar to what is implemented for
TemplateName. There is still one free bit available, and this handle can
be used within a PointerUnion and PointerIntPair, which should keep
bit-packing aficionados happy.
* The ElaboratedType node is removed, all type nodes in which it could
previously apply to can now store the elaborated keyword and name
qualifier, tail allocating when present.
* TagTypes can now point to the exact declaration found when producing
these, as opposed to the previous situation of there only existing one
TagType per entity. This increases the amount of type sugar retained,
and can have several applications, for example in tracking module
ownership, and other tools which care about source file origins, such as
IWYU. These TagTypes are lazily allocated, in order to limit the
increase in AST size.
This patch offers a great performance benefit.
It greatly improves compilation time for
[stdexec](https://github.com/NVIDIA/stdexec). For one datapoint, for
`test_on2.cpp` in that project, which is the slowest compiling test,
this patch improves `-c` compilation time by about 7.2%, with the
`-fsyntax-only` improvement being at ~12%.
This has great results on compile-time-tracker as well:
This patch also further enables other optimziations in the future, and
will reduce the performance impact of template specialization resugaring
when that lands.
It has some other miscelaneous drive-by fixes.
About the review: Yes the patch is huge, sorry about that. Part of the
reason is that I started by the nested name specifier part, before the
ElaboratedType part, but that had a huge performance downside, as
ElaboratedType is a big performance hog. I didn't have the steam to go
back and change the patch after the fact.
There is also a lot of internal API changes, and it made sense to remove
ElaboratedType in one go, versus removing it from one type at a time, as
that would present much more churn to the users. Also, the nested name
specifier having a different API avoids missing changes related to how
prefixes work now, which could make existing code compile but not work.
How to review: The important changes are all in
`clang/include/clang/AST` and `clang/lib/AST`, with also important
changes in `clang/lib/Sema/TreeTransform.h`.
The rest and bulk of the changes are mostly consequences of the changes
in API.
PS: TagType::getDecl is renamed to `getOriginalDecl` in this patch, just
for easier to rebasing. I plan to rename it back after this lands.
Fixes#136624
Fixes https://github.com/llvm/llvm-project/issues/43179
Fixes https://github.com/llvm/llvm-project/issues/68670
Fixes https://github.com/llvm/llvm-project/issues/92757
This patch implements a fix for the false-positive case described in
[issue #134840](https://github.com/llvm/llvm-project/issues/134840) for
the
[bugprone-tagged-union-member-count](https://clang.llvm.org/extra/clang-tidy/checks/bugprone/tagged-union-member-count.html)
clang-tidy check.
The example given in the linked issue was the following:
```C
#include <pthread.h>
typedef enum {
MYENUM_ONE,
MYENUM_TWO,
} myEnumT;
typedef struct {
pthread_mutex_t mtx;
myEnumT my_enum;
} myTypeT;
```
The
[bugprone-tagged-union-member-count](https://clang.llvm.org/extra/clang-tidy/checks/bugprone/tagged-union-member-count.html)
check emits the following a warning for this struct:
```
<source>:8:9: warning: tagged union has more data members (3) than tags (2)! [bugprone-tagged-union-member-count]
8 | typedef struct {
| ^
1 warning generated.
```
The issue is that `pthread_mutex_t` can be a union behind a typedef like
the following:
```C
typedef union
{
struct __pthread_mutex_s __data;
char __size[__SIZEOF_PTHREAD_MUTEX_T];
long int __align;
} pthread_mutex_t;
```
From the checker's point of view therefore `myTypeT` contains a data
member with an enum type and another data member with a union type and
starts analyzing it like a user-defined tagged union.
The proposed solution is that the types from system headers and the std
namespace are no longer candidates to be the enum part or the union part
of a user-defined tagged union. This filtering for enums and the std
namespace may not be strictly necessary in this example, however I added
it preemptively out of (perhaps unnecessary) caution.
Fixes https://github.com/llvm/llvm-project/issues/134840.
Let's consider the following code from the issue #139467:
```c
void test(int cond, char c) {
char ret = cond > 0 ? ':' : c;
}
```
Initializer of `ret` looks the following:
```
-ImplicitCastExpr 'char' <IntegralCast>
`-ConditionalOperator 'int'
|-BinaryOperator 'int' '>'
| |-ImplicitCastExpr 'int' <LValueToRValue>
| | `-DeclRefExpr 'int' lvalue ParmVar 'cond' 'int'
| `-IntegerLiteral 'int' 0
|-CharacterLiteral 'int' 58
`-ImplicitCastExpr 'int' <IntegralCast>
`-ImplicitCastExpr 'char' <LValueToRValue>
`-DeclRefExpr 'char' lvalue ParmVar 'c' 'char'
```
So it could be seen that `RHS` of the conditional operator is
`DeclRefExpr 'c'` which is casted to `int` and then the whole
conditional expression is casted to 'char'. But this last conversion is
not narrowing, because `RHS` was `char` _initially_. We should just
remove the cast from `char` to `int` before the narrowing conversion
check.
Fixes#139467
Ignore false positives on C23 enums which allows setting the fixed
underlying type to signed char.
The AST tree for C enums includes a ImplicitCastExp
(that was matched) but this is not the case for C++ enums.
Fixes#145651
---------
Signed-off-by: Björn Svensson <bjorn.a.svensson@est.tech>
This change enhances the `bugprone-unhandled-self-assignment` checker by
adding an additional matcher that generalizes the copy-and-swap idiom
pattern detection.
# What Changed
Added a new matcher that checks for:
- An instance of the current class being created in operator=
(regardless of constructor arguments)
- That instance being passed to a `swap` function call
# Problem Solved
This fix reduces false positives in PMR-like scenarios where "extended"
constructors are used (typically taking an additional allocator
argument). The checker now properly recognizes copy-and-swap
implementations that use extended copy/move constructors instead of
flagging them as unhandled self-assignment cases.
Fixes#146324
---------
Co-authored-by: Baranov Victor <bar.victor.2002@gmail.com>
Before this patch, this check only handles `VarDecl` as varaibles
declaration in statement, but this will ignore variables in structured
bindings (`BindingDecl` in AST), which leads to false positives.
Closes#138842.
Add `NamespaceBaseDecl` as common base class of `NamespaceDecl` and
`NamespaceAliasDecl`. This simplifies `NestedNameSpecifier` a bit.
Co-authored-by: Matheus Izvekov <mizvekov@gmail.com>
This PR add stacktrace of escaped exception to
`bugprone-exception-escape` check.
Changes:
1. Modified `ExceptionAnalyzer` and `ExceptionInfo` classes to hold
stacktrace of escaped exception in `llvm::MapVector`. `llvm::MapVector`
is needed to hold relative positions of functions in stack as well as
have fast lookup.
2. Added new diagnostics based of `misc-no-recursion` check.
Fixes https://github.com/llvm/llvm-project/issues/87422.
Added `.clang-tidy` config as discussed in
[RFC](https://discourse.llvm.org/t/rfc-create-hardened-clang-tidy-config-for-clang-tidy-directory/87247).
Added `bugprone`, `readability`, `modernize`, `performance` checks that
didn't create many warnings.
Fixed minor warnings to make `/clang-tidy` directory complaint with
`clang-tidy-20`.
Disabled checks will be enabled in future PRs after fixing their
warnings.
Some of these are even global mutable state — probably not what was
intended!
```cpp
static const char *AnalyzerCheckNamePrefix = "clang-analyzer-";
```
This fixes an issue compiling LLVM 20.1.7 on Ubuntu 22.04 with the
Ubuntu provided Clang 14 and C++20. That's probably happening due to
incomplete C++20 support in either Clang 14 or the GNU libstdc++ 12.
The actual error is:
```
[1/8] Building CXX object tools/clang/tools/extra/clang-tidy/bugprone/CMakeFiles/obj.clangTidyBugproneModule.dir/TaggedUnionMemberCountCheck.cpp.o
FAILED: tools/clang/tools/extra/clang-tidy/bugprone/CMakeFiles/obj.clangTidyBugproneModule.dir/TaggedUnionMemberCountCheck.cpp.o
/usr/lib/llvm-14/bin/clang++ -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/work/_build/tools/clang/tools/extra/clang-tidy/bugprone -I/work/llvm-project/clang-tools-extra/clang-tidy/bugprone -I/work/_build/tools/clang/tools/extra/clang-tidy -I/work/llvm-project/clang/include -I/work/_build/tools/clang/include -I/work/_build/include -I/work/llvm-project/llvm/include -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -Wno-nested-anon-types -O3 -DNDEBUG -std=c++20 -fno-exceptions -funwind-tables -fno-rtti -MD -MT tools/clang/tools/extra/clang-tidy/bugprone/CMakeFiles/obj.clangTidyBugproneModule.dir/TaggedUnionMemberCountCheck.cpp.o -MF tools/clang/tools/extra/clang-tidy/bugprone/CMakeFiles/obj.clangTidyBugproneModule.dir/TaggedUnionMemberCountCheck.cpp.o.d -o tools/clang/tools/extra/clang-tidy/bugprone/CMakeFiles/obj.clangTidyBugproneModule.dir/TaggedUnionMemberCountCheck.cpp.o -c /work/llvm-project/clang-tools-extra/clang-tidy/bugprone/TaggedUnionMemberCountCheck.cpp
/work/llvm-project/clang-tools-extra/clang-tidy/bugprone/TaggedUnionMemberCountCheck.cpp:148:39: error: use of overloaded operator '==' is ambiguous (with operand types 'llvm::APSInt' and 'unsigned long')
(LastEnumConstant->getInitVal() == (EnumValues.size() - 1))) {
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~
/work/llvm-project/llvm/include/llvm/ADT/APInt.h:2080:13: note: candidate function (with reversed parameter order)
inline bool operator==(uint64_t V1, const APInt &V2) { return V2 == V1; }
^
/work/llvm-project/llvm/include/llvm/ADT/APSInt.h:188:8: note: candidate function
bool operator==(int64_t RHS) const {
^
/work/llvm-project/llvm/include/llvm/ADT/APSInt.h:357:13: note: candidate function (with reversed parameter order)
inline bool operator==(int64_t V1, const APSInt &V2) { return V2 == V1; }
^
1 error generated.
```
I know that clang-14 in combination with the GNU libstdc++ 12 might not
be 100% C++20 compliant. But this is the only error we see when
compiling LLVM 20.1.7 and it looks very fixable
Thanks,
Gregor
---------
Signed-off-by: Gregor Jasny <gjasny@googlemail.com>
The static analyzer we use internally complains about potential
dereference of `nullptr` for `Found`. I think both `Found` and `Member`
can't be null here (please confirm). I have added assertions.
This patch fixes:
clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp:371:26:
error: variable 'E' set but not used
[-Werror,-Wunused-but-set-variable]
The sizeof operator misuses in loop conditionals can be a source of
bugs. The common misuse is attempting to retrieve the number of elements
in the array by using the sizeof expression and forgetting to divide the
value by the sizeof the array elements. This results in an incorrect
computation of the array length and requires a warning from the sizeof
checker.
Example:
```
int array[20];
void test_for_loop() {
// Needs warning.
for(int i = 0; i < sizeof(array); i++) {
array[i] = i;
}
}
void test_while_loop() {
int count = 0;
// Needs warning.
while(count < sizeof(array)) {
array[count] = 0;
count = count + 2;
}
}
```
rdar://151403083
---------
Co-authored-by: MalavikaSamak <malavika2@apple.com>
Run misc-use-internal-linkage check over clang-tidy code.
Also fixed a couple of other clang-tidy warnings.
Apart from issues in header files, all '.cpp' in
`clang-tools-extra/clang-tidy` must be clang-tidy clear now.
Sometimes a project may want to enable this check only in C++, and
disable it in C, since the patterns the check warns about are quite
common and idiomatic in C, and there are no better alternatives.
Fixes#140659
Co-authored-by: Carlos Gálvez <carlos.galvez@zenseact.com>
This matcher would never match anything, because all record types
as-written would be wrapped in an ElaboratedType.
Just fixing that leads to a matcher which has too many false positives
to be useful.
The warning message itself is not great either, it has a hard-coded type
name.
Fix false positives in `bugprone-crtp-constructor-accessibility` check
on deleted constructors that cannot be used to construct objects, even
if they have public or protected access.
Closes https://github.com/llvm/llvm-project/issues/131737.
These are identified by misc-include-cleaner. I've filtered out those
that break builds. Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
Add `AllowedTypes` options to support custom defined char like type.
treat `unsigned char` and `signed char` as char like type by default.
The allowed types only effect when the var decl or explicit cast to this
non-canonical type names.
Fixed: #133425
Improve `bugprone-capturing-this-in-member-variable` check:
Added support of `bind`-like functions that capture and store `this`
pointer in class member.
Closes https://github.com/llvm/llvm-project/issues/131220.
Report the range in diagnostics, in addition to the location
in case the range helps disambiguate a little in chained `->`
expressions.
```
b->a->f->x = 1;
^~~~~~~
```
instead of just:
```
b->a->f->x = 1;
^
```
As a followup we should probably also report the location/range
of an `->` if that operator is used. Like:
```
b->a->f->x = 1;
^~
```
Finds lambda captures that capture the ``this`` pointer and store it as
class
members without handle the copy and move constructors and the
assignments.
Capture this in a lambda and store it as a class member is dangerous
because the
lambda can outlive the object it captures. Especially when the object is
copied
or moved, the captured ``this`` pointer will be implicitly propagated to
the
new object. Most of the time, people will believe that the captured
``this``
pointer points to the new object, which will lead to bugs.
Fixes: #120863
---------
Co-authored-by: Baranov Victor <70346889+vbvictor@users.noreply.github.com>
Co-authored-by: Baranov Victor <bar.victor.2002@gmail.com>
The old `constructFrom` has hidden requirement which TypeMatcher must be used before ArgumentMatcher because there are bind inside.
Inlining this function to make it more intuitive.
It wants to find unintended character output from `uint8_t` and `int8_t`
to an ostream.
e.g.
```c++
uint8_t v = 9;
std::cout << v;
```
---------
Co-authored-by: whisperity <whisperity@gmail.com>
This PR add diagnostics for 3-parameter `std::basic_string(const char*
t, size_type pos, size_type count)` constructor in
bugprone-string-constructor check:
```cpp
std::string r1("test", 1, 0); // constructor creating an empty string
std::string r2("test", 0, -4); // negative value used as length parameter
// more examples in test file
```
Fixes false-positives reported in https://github.com/llvm/llvm-project/issues/123198.
Before, C++ member functions in the format of ``Class instance;
instance.memberfn();`` were unable to be matched.
This PR adds support for this type of call, and it is matched in exactly
the same format as other functions (eg. ``::Class::memberfn`` qualified
name).
This checks that classes/structs inheriting from
``std::enable_shared_from_this`` does so with public inheritance, so it
prevents crashes due to ``std::make_shared`` and ``shared_from_this()``
getting called when the internal weak pointer was not initialized (e.g.
due to private inheritance).
