Summary: This adds a new module to enforce standards specific to the llvm-libc project. This change also adds the first check which restricts user from including system libc headers accidentally which can lead to subtle bugs that would be a challenge to detect.
Reviewers: alexfh, hokein, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: juliehockett, arphaman, jfb, abrachet, sivachandra, Eugene.Zelenko, njames93, mgorny, xazax.hun, MaskRay, cfe-commits
Tags: #clang-tools-extra, #libc-project, #clang
Differential Revision: https://reviews.llvm.org/D75332
Summary:
Created a general check for restrict-system-includes under portability as recommend in the comments under D75332. I also fleshed out the user facing documentation to show examples for common use-cases such as allow-list, block-list, and wild carding.
Removed fuchsia's check as per phosek sugguestion.
Reviewers: aaron.ballman, phosek, alexfh, hokein, njames93
Reviewed By: phosek
Subscribers: Eugene.Zelenko, mgorny, xazax.hun, phosek, cfe-commits, MaskRay
Tags: #clang-tools-extra, #clang
Differential Revision: https://reviews.llvm.org/D75786
Summary:
Also use //check// in add_new_check.py for terminology consistency.
PS
My GitHub ID is [[ https://github.com/EugeneZelenko | EugeneZelenko ]], if it's necessary for attribution.
Reviewers: alexfh, hokein, aaron.ballman, njames93, MyDeveloperDay
Reviewed By: njames93
Subscribers: Andi, xazax.hun, cfe-commits
Tags: #clang-tools-extra, #clang
Differential Revision: https://reviews.llvm.org/D73580
Summary:
Recursion is a powerful tool, but like any tool
without care it can be dangerous. For example,
if the recursion is unbounded, you will
eventually run out of stack and crash.
You can of course track the recursion depth
but if it is hardcoded, there can always be some
other environment when that depth is too large,
so said magic number would need to be env-dependent.
But then your program's behavior is suddenly more env-dependent.
Also, recursion, while it does not outright stop optimization,
recursive calls are less great than normal calls,
for example they hinder inlining.
Recursion is banned in some coding guidelines:
* SEI CERT DCL56-CPP. Avoid cycles during initialization of static objects
* JPL 2.4 Do not use direct or indirect recursion.
* I'd say it is frowned upon in LLVM, although not banned
And is plain unsupported in some cases:
* OpenCL 1.2, 6.9 Restrictions: i. Recursion is not supported.
So there's clearly a lot of reasons why one might want to
avoid recursion, and replace it with worklist handling.
It would be great to have a enforcement for it though.
This implements such a check.
Here we detect both direct and indirect recursive calls,
although since clang-tidy (unlike clang static analyzer)
is CTU-unaware, if the recursion transcends a single standalone TU,
we will naturally not find it :/
The algorithm is pretty straight-forward:
1. Build call-graph for the entire TU.
For that, the existing `clang::CallGraph` is re-used,
although it had to be modified to also track the location of the call.
2. Then, the hard problem: how do we detect recursion?
Since we have a graph, let's just do the sane thing,
and look for Strongly Connected Function Declarations - widely known as `SCC`.
For that LLVM provides `llvm::scc_iterator`,
which is internally an Tarjan's DFS algorithm, and is used throught LLVM,
so this should be as performant as possible.
3. Now that we've got SCC's, we discard those that don't contain loops.
Note that there may be more than one loop in SCC!
4. For each loopy SCC, we call out each function, and print a single example
call graph that shows recursion -- it didn't seem worthwhile enumerating
every possible loop in SCC, although i suppose it could be implemented.
* To come up with that call graph cycle example, we start at first SCC node,
see which callee of the node is within SCC (and is thus known to be in cycle),
and recurse into it until we hit the callee that is already in call stack.
Reviewers: JonasToth, aaron.ballman, ffrankies, Eugene.Zelenko, erichkeane, NoQ
Reviewed By: aaron.ballman
Subscribers: Charusso, Naghasan, bader, riccibruno, mgorny, Anastasia, xazax.hun, cfe-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D72362
Summary: Such implementations may override the class's own implementation, and even be a danger in case someone later comes and adds one to the class itself. Most times this has been encountered have been a mistake.
Reviewers: stephanemoore, benhamilton, dmaclach
Reviewed By: stephanemoore, benhamilton, dmaclach
Subscribers: dmaclach, mgorny, cfe-commits
Tags: #clang-tools-extra, #clang
Differential Revision: https://reviews.llvm.org/D72876
Summary: Adds an option called `AddConstToQualified` to readability-qualified-auto to toggle adding const to the auto typed pointers and references. By default its enabled but in the LLVM module its disabled.
Reviewers: aaron.ballman, alexfh, JonasToth, hokein, sammccall
Reviewed By: aaron.ballman
Subscribers: Quuxplusone, merge_guards_bot, lebedev.ri, xazax.hun, cfe-commits
Tags: #clang, #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D73548
Summary:
I added subsubsections for typical Clang-tidy entries in Release Notes, so now scripts are aware of this changes.
I don't have GitHub commit access, so please commit changes.
Reviewers: aaron.ballman, alexfh, hokein
Reviewed By: alexfh
Subscribers: njames93, xazax.hun, cfe-commits
Tags: #clang-tools-extra, #clang
Differential Revision: https://reviews.llvm.org/D72527
Summary:
The original behaviour of this check only looked at VarDecls with strings that had an empty string initializer. This has been improved to check for FieldDecls with an in class initializer as well as constructor initializers.
Addresses [[ https://bugs.llvm.org/show_bug.cgi?id=44474 | clang-tidy "modernize-use-default-member-init"/"readability-redundant-string-init" and redundant initializer of std::string ]]
Reviewers: aaron.ballman, alexfh, hokein
Reviewed By: aaron.ballman
Subscribers: merge_guards_bot, mgorny, Eugene.Zelenko, xazax.hun, cfe-commits
Tags: #clang, #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D72448
Summary:
Typically most main functions have the signature:
```
int main(int argc, char *argv[])
```
To stick with convention when renaming parameters we should ignore the `argc` and `argv` names even if the parameter style says they should be renamed. This patch addresses this by checking all ParmVarDecls if they form part of a function with a signature that matches main `int name(int argc, char * argv[], (optional char *env[]))`
Reviewers: aaron.ballman, JonasToth, alexfh, hokein
Reviewed By: aaron.ballman
Subscribers: Mordante, merge_guards_bot, xazax.hun, kristof.beyls, cfe-commits
Tags: #clang, #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D73098
Finds cases where an integer expression is added to the result
of a memory allocation function instead of its argument.
Differential Revision: https://reviews.llvm.org/D71001
This patch adds bugprone-reserved-identifier, which flags uses of __names _Like
::_this, which are reserved for the implementation. The check can optionally be
inverted, i.e. configured to flag any names that are _not_ reserved, which may
be useful for e.g. standard library implementors.
Adds a check that detects any auto variables that are deduced to a pointer or
a const pointer then adds in the const and asterisk according. Will also
check auto L value references that could be written as const. This relates
to the coding standard
https://llvm.org/docs/CodingStandards.html#beware-unnecessary-copies-with-auto
Major changes are introduction of subsubsections to prevent people
putting new entries in wrong places. I also polished line length and
highlighting.
Patch by Eugene Zelenko!
Summary:
It now handles `typedef`s that include comma-separated multiple types, and handles embedded struct definitions, which previously could not be automatically converted.
For example, with this patch `modernize-use-using` now can convert:
typedef struct { int a; } R_t, *R_p;
to:
using R_t = struct { int a; };
using R_p = R_t*;
`-ast-dump` showed that the `CXXRecordDecl` definitions and multiple `TypedefDecl`s come consecutively in the tree, so `check()` stores information between calls to determine when it is receiving a second or additional `TypedefDecl` within a single `typedef`, or when the current `TypedefDecl` refers to an embedded `CXXRecordDecl` like a `struct`.
Reviewers: alexfh, aaron.ballman
Patch by: poelmanc
Subscribers: riccibruno, sammccall, cfe-commits, aaron.ballman
Tags: clang-tools-extra, clang
Differential Revision: https://reviews.llvm.org/D70270
Summary:
This check searches for signed char -> integer conversions which might
indicate programming error, because of the misinterpretation of char
values. A signed char might store the non-ASCII characters as negative
values. The human programmer probably expects that after an integer
conversion the converted value matches with the character code
(a value from [0..255]), however, the actual value is in
[-128..127] interval.
See also:
STR34-C. Cast characters to unsigned char before converting to larger integer sizes
<https://wiki.sei.cmu.edu/confluence/display/c/STR34-C.+Cast+characters+to+unsigned+char+before+converting+to+larger+integer+sizes>
By now this check is limited to assignment / variable declarations.
If we would catch all signed char -> integer conversion, then it would
produce a lot of findings and also false positives. So I added only
this use case now, but this check can be extended with additional
use cases later.
The CERT documentation mentions another use case when the char is
used for array subscript. Next to that a third use case can be
the signed char - unsigned char comparison, which also a use case
where things happen unexpectedly because of conversion to integer.
Reviewers: alexfh, hokein, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: sylvestre.ledru, whisperity, Eugene.Zelenko, mgorny, xazax.hun, cfe-commits
Tags: #clang, #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D71174
This represents largely a full re-write of modernize-avoid-bind, adding
significant new functionality in the process. In particular:
* Both boost::bind and std::bind are now supported
* Function objects are supported in addition to functions
* Member functions are supported
* Nested calls are supported using capture-init syntax
* std::ref() and boost::ref() are now recognized, and will capture by reference.
* Rather than capturing with a global =, we now build up an individual
capture list that is both necessary and sufficient for the call.
* Fixits are supported in a much larger variety of scenarios than before.
All previous tests pass under the re-write, but a large number of new
tests have been added as well.
Differential Revision: https://reviews.llvm.org/D70368
Summary:
`modernize-use-equals-default` replaces default constructors/destructors with `= default;`. When the optional semicolon after a member function is present, this results in two consecutive semicolons.
This patch checks to see if the next non-comment token after the code to be replaced is a semicolon, and if so offers a replacement of `= default` rather than `= default;`.
This patch adds trailing comments and semicolons to about 5 existing tests.
Reviewers: malcolm.parsons, angelgarcia, aaron.ballman, alexfh
Patch by: poelmanc
Subscribers: MyDeveloperDay, JonasToth, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D70144
Summary:
readability-redundant-member-init removes redundant / unnecessary member and base class initialization. Unfortunately for the specific case of a copy constructor's initialization of a base class, gcc at strict warning levels warns if "base class is not initialized in the copy constructor of a derived class".
This patch adds an option `IgnoreBaseInCopyConstructors` defaulting to 0 (thus maintaining current behavior by default) to skip the specific case of removal of redundant base class initialization in the copy constructor. Enabling this option enables the resulting code to continue to compile successfully under `gcc -Werror=extra`. New test cases `WithCopyConstructor1` and `WithCopyConstructor2` in clang-tools-extra/test/clang-tidy/readability-redundant-member-init.cpp show that it removes redundant members even from copy constructors.
Reviewers: malcolm.parsons, alexfh, hokein, aaron.ballman, lebedev.ri
Patch by: poelmanc
Subscribers: mgehre, lebedev.ri, cfe-commits
Tags: #clang, #clang-tools-extra
Differential revision: https://reviews.llvm.org/D69145
Summary:
In addition to adding `override` wherever possible, clang-tidy's `modernize-use-override` nicely removes `virtual` when `override` or `final` is specified, and further removes override when final is specified. While this is great default behavior, when code needs to be compiled with gcc at high warning levels that include `gcc -Wsuggest-override` or `gcc -Werror=suggest-override`, clang-tidy's removal of the redundant `override` keyword causes gcc to emit a warning or error. This discrepancy / conflict has been noted by others including a comment on Stack Overflow and by Mozilla's Firefox developers.
This patch adds an AllowOverrideAndFinal option defaulting to 0 - thus preserving current behavior - that when enabled allows both `override` and `final` to co-exist, while still fixing all other issues.
The patch includes a test file verifying all combinations of virtual/override/final, and mentions the new option in the release notes.
Reviewers: alexfh, djasper, JonasToth
Patch by: poelmanc
Subscribers: JonasToth, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D70165
Summary:
This patch adds a feature requested in https://reviews.llvm.org/D69238 to enable `readability-redundant-string-init` to take a list of strings to apply the fix to rather than hard-coding `basic_string`. It adds a `StringNames` option of semicolon-delimited names of string classes to which to apply this fix. Tests ensure this works with test class out::TestString as well as std::string and std::wstring as before. It should be applicable to llvm::StringRef, QString, etc.
Note: This commit was previously reverted due to a failing unit test. That test has been fixed in this version.
Reviewers: MyDeveloperDay, aaron.ballman, hokein, alexfh, JonasToth, gribozavr2
Patch by: poelmanc
Subscribers: gribozavr2, xazax.hun, Eugene.Zelenko, cfe-commits
Tags: #clang-tools-extra, #clang
Differential Revision: https://reviews.llvm.org/D69548
Summary:
`readability-redundant-string-init` was one of several clang-tidy checks documented as failing for C++17. (The failure mode in C++17 is that it changes `std::string Name = ""`; to `std::string Name = Name;`, which actually compiles but crashes at run-time.)
Analyzing the AST with `clang -Xclang -ast-dump` showed that the outer `CXXConstructExprs` that previously held the correct SourceRange were being elided in C++17/2a, but the containing `VarDecl` expressions still had all the relevant information. So this patch changes the fix to get its source ranges from `VarDecl`.
It adds one test `std::string g = "u", h = "", i = "uuu", j = "", k;` to confirm proper warnings and fixit replacements in a single `DeclStmt` where some strings require replacement and others don't. The readability-redundant-string-init.cpp and readability-redundant-string-init-msvc.cpp tests now pass for C++11/14/17/2a.
Reviewers: gribozavr, etienneb, alexfh, hokein, aaron.ballman, gribozavr2
Patch by: poelmanc
Subscribers: NoQ, MyDeveloperDay, Eugene.Zelenko, dylanmckay, cfe-commits
Tags: #clang, #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D69238
Summary:
This patch adds a feature requested in https://reviews.llvm.org/D69238 to enable `readability-redundant-string-init` to take a list of strings to apply the fix to rather than hard-coding `basic_string`. It adds a `StringNames` option of semicolon-delimited names of string classes to which to apply this fix. Tests ensure this works with test class out::TestString as well as std::string and std::wstring as before. It should be applicable to llvm::StringRef, QString, etc.
Reviewers: MyDeveloperDay, aaron.ballman, hokein, alexfh, JonasToth, gribozavr2
Patch by: poelmanc
Subscribers: gribozavr2, xazax.hun, Eugene.Zelenko, cfe-commits
Tags: #clang-tools-extra, #clang
Differential Revision: https://reviews.llvm.org/D69548
Summary:
Finds non-static member functions that can be made ``const``
because the functions don't use ``this`` in a non-const way.
The check conservatively tries to preserve logical costness in favor of
physical costness. See readability-make-member-function-const.rst for more
details.
Reviewers: aaron.ballman, gribozavr, hokein, alexfh
Subscribers: mgorny, xazax.hun, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D68074
Checks for types which can be made trivially-destructible by removing
out-of-line defaulted destructor declarations.
The check is motivated by the work on C++ garbage collector in Blink
(rendering engine for Chrome), which strives to minimize destructors and
improve runtime of sweeping phase.
In the entire chromium codebase the check hits over 2000 times.
Differential Revision: https://reviews.llvm.org/D69435
abelkocsis