The driver enables -fdiagnostics-show-option by default, so flip the CC1
default to reduce the lengths of common CC1 command lines.
This change also makes ParseDiagnosticArgs() consistently enable
-fdiagnostics-show-option by default.
Summary:
The -Wparentheses warnings are enabled by default in clang but they are under
-Wall in gcc (gcc/c-family/c.opt). Some of the operator precedence warnings are
oftentimes criticized as noise (clang: default; gcc: -Wall). If a warning is
very controversial, it is probably not a good idea to enable it by default.
This patch disables the rather annoying ones:
-Wbitwise-op-parentheses, e.g. i & i | i
-Wlogical-op-parentheses, e.g. i && i || i
After this change:
```
* = enabled by default
-Wall
-Wparentheses
-Wlogical-op-parentheses
-Wlogical-not-parentheses*
-Wbitwise-op-parentheses
-Wshift-op-parentheses*
-Woverloaded-shift-op-parentheses*
-Wparentheses-equality*
-Wdangling-else*
```
-Woverloaded-shift-op-parentheses is typically followed by overload
resolution failure. We can instead improve the error message, and
probably delete -Woverloaded-shift-op-parentheses in the future. Keep it
for now because it gives some diagnostics.
Reviewers: akyrtzi, jyknight, rtrieu, rsmith, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: dexonsmith, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D65192
llvm-svn: 367690
These run lines originally tested that the fix-its were properly applied.
Originally, the fixits were attached to warnings and were applied by -fixit.
Now, the fixits are attached to notes, so nothing happens. These run lines
still manage to pass since Clang will produce an empty output which gets piped
back to Clang. Then Clang produces no error on an empty input.
llvm-svn: 179131
pretty. In particular this makes it much easier for me to read messages
such as:
x.cc:42: ?: has lower ...
Where I'm inclined to associate the third ':' with a missing column
number, but in fact column numbers have been turned off. Similar
punctuation collisions happened elsewhere as well.
llvm-svn: 133121
Warn in cases such as "x + someCondition ? 42 : 0;",
where the condition expression looks arithmetic, and has
a right-hand side that looks boolean.
This (partly) addresses http://llvm.org/bugs/show_bug.cgi?id=9969
llvm-svn: 132565
assert(a || b && "bad");
since this is safe. This way we avoid a big source of such warnings which in this case are practically useless.
Note that we don't handle *all* cases where precedence wouldn't matter because of constants since
this is a bit costly to check, and IMO clarifying precedence with parentheses is good for
readability in general.
llvm-svn: 119533
that adds parentheses from the main diagnostic down to a new
note. This way, when the fix-it represents a choice between two
options, each of the options is associted with a note. There is no
default option in such cases. For example:
/Users/dgregor/t.c:2:9: warning: & has lower precedence than ==; ==
will be
evaluated first [-Wparentheses]
if (x & y == 0) {
^~~~~~~~
/Users/dgregor/t.c:2:9: note: place parentheses around the &
expression to
evaluate it first
if (x & y == 0) {
^
( )
/Users/dgregor/t.c:2:9: note: place parentheses around the ==
expression to
silence this warning
if (x & y == 0) {
^
( )
llvm-svn: 101249
suggestions follow recovery. Additionally, add a note to these
diagnostics which suggests a fix-it for changing the behavior to what
the user probably meant. Examples:
t.cpp:2:9: warning: & has lower precedence than ==; == will be evaluated first
[-Wparentheses]
if (i & j == k) {
^~~~~~~~
( )
t.cpp:2:9: note: place parentheses around the & expression to evaluate it first
if (i & j == k) {
^
( )
t.cpp:14:9: warning: using the result of an assignment as a condition
without
parentheses [-Wparentheses]
if (i = f()) {
~~^~~~~
( )
t.cpp:14:9: note: use '==' to turn this assignment into an equality
comparison
if (i = f()) {
^
==
llvm-svn: 92975
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
Fangrui Song