[clang-tidy] implement new check 'misc-const-correctness' to add 'const' to unmodified variables

This patch connects the check for const-correctness with the new general
utility to add `const` to va

[clang-tidy] implement new check 'misc-const-correctness' to add 'const' to unmodified variables

This patch connects the check for const-correctness with the new general
utility to add `const` to variables.
The code-transformation is only done, if the detected variable for const-ness
is not part of a group-declaration.

The check allows to control multiple facets of adding `const`, e.g. if pointers themself should be
marked as `const` if they are not changed.

Reviewed By: njames93

Differential Revision: https://reviews.llvm.org/D54943

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Treat `std::move`, `forward`, etc. as builtins.

This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`,

Treat `std::move`, `forward`, etc. as builtins.

This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

This is a re-commit of
fc3090109643af8d2da9822d0f99c84742b9c877,
a571f82a50416b767fd3cce0fb5027bb5dfec58c,
64c045e25b8471bbb572bd29159c294a82a86a2, and
de6ddaeef3aaa8a9ae3663c12cdb57d9afc0f906,
and reverts aa643f455a5362de7189eac630050d2c8aefe8f2.
This change also includes a workaround for users using libc++ 3.1 and
earlier (!!), as apparently happens on AIX, where std::move sometimes
returns by value.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345

Revert "Fixup D123950 to address revert of D123345"

This reverts commit aa643f455a5362de7189eac630050d2c8aefe8f2.

show more ...

Revert "Treat `std::move`, `forward`, etc. as builtins."

This reverts commit b27430f9f46b88bcd54d992debc8d72e131e1bd0 as the
parent https://reviews.llvm.org/D123345 breaks the AIX CI:

https

Revert "Treat `std::move`, `forward`, etc. as builtins."

This reverts commit b27430f9f46b88bcd54d992debc8d72e131e1bd0 as the
parent https://reviews.llvm.org/D123345 breaks the AIX CI:

https://lab.llvm.org/buildbot/#/builders/214/builds/819

show more ...

Treat `std::move`, `forward`, etc. as builtins.

This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`,

Treat `std::move`, `forward`, etc. as builtins.

This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

This is a re-commit of
fc3090109643af8d2da9822d0f99c84742b9c877,
a571f82a50416b767fd3cce0fb5027bb5dfec58c, and
64c045e25b8471bbb572bd29159c294a82a86a25
which were reverted in
e75d8b70370435b0ad10388afba0df45fcf9bfcc
due to a crasher bug where CodeGen would emit a builtin glvalue as an
rvalue if it constant-folds.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345

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Revert "Treat `std::move`, `forward`, and `move_if_noexcept` as builtins."
Revert "Extend support for std::move etc to also cover std::as_const and"
Revert "Update test to handle opaque pointers flag

Revert "Treat `std::move`, `forward`, and `move_if_noexcept` as builtins."
Revert "Extend support for std::move etc to also cover std::as_const and"
Revert "Update test to handle opaque pointers flag flip."

It crashes on libcxx tests https://lab.llvm.org/buildbot/#/builders/85/builds/8174

This reverts commit fc3090109643af8d2da9822d0f99c84742b9c877.
This reverts commit a571f82a50416b767fd3cce0fb5027bb5dfec58c.
This reverts commit 64c045e25b8471bbb572bd29159c294a82a86a25.

show more ...

Extend support for std::move etc to also cover std::as_const and
std::addressof, plus the libstdc++-specific std::__addressof.

This brings us to parity with the corresponding GCC behavior.

Remove S

Extend support for std::move etc to also cover std::as_const and
std::addressof, plus the libstdc++-specific std::__addressof.

This brings us to parity with the corresponding GCC behavior.

Remove STDBUILTIN macro that ended up not being used.

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Bump googletest to 1.10.0

Remove references to the ast_type_traits namespace

Follow up to cd62511496938e33c061c90796dd23a5288ff843 /
https://reviews.llvm.org/D74499

Reviewed By: aaron.ballman

Differential Revision: https:/

Remove references to the ast_type_traits namespace

Follow up to cd62511496938e33c061c90796dd23a5288ff843 /
https://reviews.llvm.org/D74499

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D92994

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[clang] improve accuracy of ExprMutAnalyzer

This patch extracts the ExprMutAnalyzer changes from https://reviews.llvm.org/D54943
into its own revision for simpler review and more atomic changes.

Th

[clang] improve accuracy of ExprMutAnalyzer

This patch extracts the ExprMutAnalyzer changes from https://reviews.llvm.org/D54943
into its own revision for simpler review and more atomic changes.

The analysis results are improved. Nested expressions (e.g. conditional
operators) are now detected properly. Some edge cases, especially
template induced imprecisions are improved upon.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D88088

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Assignment and Inc/Dec operators wouldn't register as a mutation when Implicit Paren Casts were present

Add ignoringParenImpCasts to assignment and inc/dec mutation checks in ExprMutationAnalyzer to

Assignment and Inc/Dec operators wouldn't register as a mutation when Implicit Paren Casts were present

Add ignoringParenImpCasts to assignment and inc/dec mutation checks in ExprMutationAnalyzer to fix clang-tidy bug PR45490.
https://bugs.llvm.org/show_bug.cgi?id=45490

Reviewed By: njames93, aaron.ballman, gribozavr2

Differential Revision: https://reviews.llvm.org/D79912

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Set traversal explicitly where needed in tests

Reviewers: aaron.ballman, shafik

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72531

std::isspace -> llvm::isSpace (where locale should be ignored)

I've left out some cases where I wasn't totally sure this was right or
whether the include was ok (compiler-rt) or idiomatic (flang).

[ASTMatchers] StringRef'ify hasName

This was just inconvenient, and we make a copy anyways.

Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly m

Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.

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[NFC] format unittest for ExprMutAnalyzer

This formatting is a preparation for review in
https://reviews.llvm.org/D54943 to separate pure formatting changes from
actual testing changes.

Fix some clang analysis tests passing arguments incorrectly

llvm-svn: 355625

[analyzer] handle modification of vars inside an expr with comma operator

We should track mutation of a variable within a comma operator expression.
Current code in ExprMutationAnalyzer does not han

[analyzer] handle modification of vars inside an expr with comma operator

We should track mutation of a variable within a comma operator expression.
Current code in ExprMutationAnalyzer does not handle it.

This will handle cases like:

(a, b) ++ < == b is modified
(a, b) = c < == b is modifed


Patch by Djordje Todorovic.

Differential Revision: https://reviews.llvm.org/D58894

llvm-svn: 355605

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[clang] add tests to ExprMutAnalyzer that reproduced a crash in ASTMatchers

Summary:
This patch adds two unit-tests that are the result of reducing a crashing TU
when running ExprMutAnalyzer over it

[clang] add tests to ExprMutAnalyzer that reproduced a crash in ASTMatchers

Summary:
This patch adds two unit-tests that are the result of reducing a crashing TU
when running ExprMutAnalyzer over it. They are added only to ensure the regression
that has been fixed with https://reviews.llvm.org/D56444 don't creep back.

Reviewers: aaron.ballman, sammccall, rsmith, george.karpenkov

Reviewed By: sammccall

Subscribers: baloghadamsoftware, a.sidorin, Szelethus, donat.nagy, dkrupp, cfe-commits

Differential Revision: https://reviews.llvm.org/D56917

llvm-svn: 351743

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Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

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Fix use-after-free bug in Tooling.

Summary:
`buildASTFromCodeWithArgs()` was creating a memory buffer referencing a
stack-allocated string. This diff changes the implementation to copy the code
str

Fix use-after-free bug in Tooling.

Summary:
`buildASTFromCodeWithArgs()` was creating a memory buffer referencing a
stack-allocated string. This diff changes the implementation to copy the code
string into the memory buffer so that said buffer owns the memory.

Patch by Yitzhak Mandelbaum.

Reviewers: alexfh

Reviewed By: alexfh

Subscribers: cfe-commits, EricWF

Differential Revision: https://reviews.llvm.org/D55765

llvm-svn: 350638

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[NFC] Declare instead of define non-void functions in unit tests.

llvm-svn: 342586

[analyzer] Fix nullptr access when processing instantiated function in ExprMutationAnalyzer.

llvm-svn: 342562

[NFC] Fix uncompilable test cases of ExprMutationAnalyzer.

And ensure future test cases doesn't have compile errors.

llvm-svn: 342525

[analyzer] Treat std::{move,forward} as casts in ExprMutationAnalyzer.

Summary:
This is a follow up of D52008 and should make the analyzer being able to handle perfect forwardings in real world case

[analyzer] Treat std::{move,forward} as casts in ExprMutationAnalyzer.

Summary:
This is a follow up of D52008 and should make the analyzer being able to handle perfect forwardings in real world cases where forwardings are done through multiple layers of function calls with `std::forward`.

Fixes PR38891.

Reviewers: lebedev.ri, JonasToth, george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin, mikhail.ramalho, Szelethus, cfe-commits

Differential Revision: https://reviews.llvm.org/D52120

llvm-svn: 342409

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[analyzer] Handle forwarding reference better in ExprMutationAnalyzer.

Summary:
We used to treat an `Expr` mutated whenever it's passed as non-const
reference argument to a function. This results in

[analyzer] Handle forwarding reference better in ExprMutationAnalyzer.

Summary:
We used to treat an `Expr` mutated whenever it's passed as non-const
reference argument to a function. This results in false positives in
cases like this:
```
int x;
std::vector<int> v;
v.emplace_back(x); // `x` is passed as non-const reference to `emplace_back`
```
In theory the false positives can be suppressed with
`v.emplace_back(std::as_const(x))` but that's considered overly verbose,
inconsistent with existing code and spammy as diags.

This diff handles such cases by following into the function definition
and see whether the argument is mutated inside.

Reviewers: lebedev.ri, JonasToth, george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin, mikhail.ramalho, Szelethus, cfe-commits

Differential Revision: https://reviews.llvm.org/D52008

llvm-svn: 342271

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