18 Commits

Author SHA1 Message Date
Aaron Ballman
0f1c1be196 [clang] Remove rdar links; NFC
We have a new policy in place making links to private resources
something we try to avoid in source and test files. Normally, we'd
organically switch to the new policy rather than make a sweeping change
across a project. However, Clang is in a somewhat special circumstance
currently: recently, I've had several new contributors run into rdar
links around test code which their patch was changing the behavior of.
This turns out to be a surprisingly bad experience, especially for
newer folks, for a handful of reasons: not understanding what the link
is and feeling intimidated by it, wondering whether their changes are
actually breaking something important to a downstream in some way,
having to hunt down strangers not involved with the patch to impose on
them for help, accidental pressure from asking for potentially private
IP to be made public, etc. Because folks run into these links entirely
by chance (through fixing bugs or working on new features), there's not
really a set of problematic links to focus on -- all of the links have
basically the same potential for causing these problems. As a result,
this is an omnibus patch to remove all such links.

This was not a mechanical change; it was done by manually searching for
rdar, radar, radr, and other variants to find all the various
problematic links. From there, I tried to retain or reword the
surrounding comments so that we would lose as little context as
possible. However, because most links were just a plain link with no
supporting context, the majority of the changes are simple removals.

Differential Review: https://reviews.llvm.org/D158071
2023-08-28 12:13:42 -04:00
Mehdi Amini
e0ac46e69d Revert "Remove rdar links; NFC"
This reverts commit d618f1c3b12effd0c2bdb7d02108d3551f389d3d.
This commit wasn't reviewed ahead of time and significant concerns were
raised immediately after it landed. According to our developer policy
this warrants immediate revert of the commit.

https://llvm.org/docs/DeveloperPolicy.html#patch-reversion-policy

Differential Revision: https://reviews.llvm.org/D155509
2023-07-17 18:08:04 -07:00
Aaron Ballman
d618f1c3b1 Remove rdar links; NFC
This removes links to rdar, which is an internal bug tracker that the
community doesn't have visibility into.

See further discussion at:
https://discourse.llvm.org/t/code-review-reminder-about-links-in-code-commit-messages/71847
2023-07-07 08:41:11 -04:00
Aaron Ballman
199dfb4d0c Silence a false positive about an unevaluated expr w/side effects
If the operand to `sizeof` is an expression of VLA type, the operand is
still evaluated, so we should not issue a diagnostic about ignoring the
side effects in this case, as they're not actually ignored.

Fixes #48010
2022-05-05 12:12:30 -04:00
Aaron Ballman
22db4824b9 Use functions with prototypes when appropriate; NFC
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,

  void func();

becomes

  void func(void);

This is the third batch of tests being updated (there are a significant
number of other tests left to be updated).
2022-02-07 09:25:01 -05:00
Yuanfang Chen
27a972a699 Diagnose -Wunused-value based on CFG reachability
(This relands 59337263ab45d7657e and makes sure comma operator
 diagnostics are suppressed in a SFINAE context.)

While at it, add the diagnosis message "left operand of comma operator has no effect" (used by GCC) for comma operator.

This also makes Clang diagnose in the constant evaluation context which aligns with GCC/MSVC behavior. (https://godbolt.org/z/7zxb8Tx96)

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D103938
2021-09-28 10:00:15 -07:00
Yuanfang Chen
59337263ab Revert "Diagnose -Wunused-value based on CFG reachability"
This reverts commit cbbf2e8c8ae7730ff0121f4868de4a7d188feb65.
It seems causing diagnoses in SFINAE context.
2021-09-23 11:12:00 -07:00
Yuanfang Chen
cbbf2e8c8a Diagnose -Wunused-value based on CFG reachability
While at it, add the diagnosis message "left operand of comma operator has no effect" (used by GCC) for comma operator.

This also makes Clang diagnose in the constant evaluation context which aligns with GCC/MSVC behavior. (https://godbolt.org/z/7zxb8Tx96)

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D103938
2021-09-22 14:38:06 -07:00
Aaron Ballman
73a8bcd789 Revert "Diagnose -Wunused-value based on CFG reachability"
This reverts commit 63e0d038fc20c894a3d541effa1bc2b1fdea37b9.

It causes test failures:

http://lab.llvm.org:8011/#/builders/119/builds/5612
https://logs.chromium.org/logs/fuchsia/buildbucket/cr-buildbucket/8835548361443044001/+/u/clang/test/stdout
2021-09-21 12:25:13 -04:00
Yuanfang Chen
63e0d038fc Diagnose -Wunused-value based on CFG reachability
While at it, add the diagnosis message "left operand of comma operator has no effect" (used by GCC) for comma operator.

This also makes Clang diagnose in the constant evaluation context which aligns with GCC/MSVC behavior. (https://godbolt.org/z/7zxb8Tx96)

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D103938
2021-09-20 10:43:34 -07:00
Aaron Ballman
6c93b3e29c Adding a -Wunused-value warning for expressions with side effects used in an unevaluated expression context, such as sizeof(), or decltype(). Also adds a similar warning when the expression passed to typeid() *is* evaluated, since it is equally likely that the user would expect the expression operand to be unevaluated in that case.
llvm-svn: 224465
2014-12-17 21:57:17 +00:00
Ted Kremenek
e96dad9544 Don't warn about unused values in ternary ?: expressions unless both the LHS and RHS are "unused" (side-effect free).
Patch by Justin Bogner!  Fixes PR 8282.

llvm-svn: 126779
2011-03-01 20:34:48 +00:00
Argyrios Kyrtzidis
72664df103 Implement -Wunused-label.
llvm-svn: 114315
2010-09-19 21:21:25 +00:00
Argyrios Kyrtzidis
9096341310 Warn when an expression result in a LabelStmt is unused.
llvm-svn: 114314
2010-09-19 21:21:10 +00:00
Argyrios Kyrtzidis
639ffb0c07 Fix rdar://8139785 "implement warning on dead expression in comma operator"
As a bonus, fix the warning for || and && operators; it was emitted even if one of the operands had side effects, e.g:

x || test_logical_foo1();

emitted a bogus "expression result unused" for 'x'.

llvm-svn: 107274
2010-06-30 10:53:14 +00:00
Ted Kremenek
a1de6fc575 Include all warnings under '-Wunused' in '-Wmost' and '-Wall'.
llvm-svn: 100786
2010-04-08 17:54:28 +00:00
Ted Kremenek
43a9c9626f Don't emit an 'unused expression' warning for '||' and '&&' expressions that contain assignments
or similar side-effects.

llvm-svn: 100676
2010-04-07 18:49:21 +00:00
John McCall
c493a73240 Improve the unused-value check to look into comma expressions and filter out
voids in sub-expressions.  Patch by Mike M!

Fixes PR4806.

llvm-svn: 98335
2010-03-12 07:11:26 +00:00