maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[Sema] Disable -Wbitwise-op-parentheses and -Wlogical-op-parentheses 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
This commit is contained in:
Fangrui Song 2019-08-02 16:31:38 +00:00
parent 89683e9dd7
commit e93341f7c8
5 changed files with 103 additions and 55 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
clang/include/clang/Basic/DiagnosticSemaKinds.td
View File

@ -5642,10 +5642,10 @@ def note_logical_instead_of_bitwise_remove_constant : Note<
"remove constant to silence this warning">;
def warn_bitwise_op_in_bitwise_op : Warning<
"'%0' within '%1'">, InGroup<BitwiseOpParentheses>;
"'%0' within '%1'">, InGroup<BitwiseOpParentheses>, DefaultIgnore;
def warn_logical_and_in_logical_or : Warning<
"'&&' within '||'">, InGroup<LogicalOpParentheses>;
"'&&' within '||'">, InGroup<LogicalOpParentheses>, DefaultIgnore;
def warn_overloaded_shift_in_comparison :Warning<
"overloaded operator %select{>>|<<}0 has higher precedence than "

58
clang/test/Sema/bitwise-op-parentheses.c Normal file
View File

@ -0,0 +1,58 @@
// RUN: %clang_cc1 -fsyntax-only -verify %s -DSILENCE
// RUN: %clang_cc1 -fsyntax-only -verify %s -Wbitwise-op-parentheses
// RUN: %clang_cc1 -fsyntax-only -verify %s -Wparentheses
// RUN: %clang_cc1 -fsyntax-only -fdiagnostics-parseable-fixits %s -Wbitwise-op-parentheses 2>&1 | FileCheck %s
#ifdef SILENCE
// expected-no-diagnostics
#endif
void bitwise_op_parentheses(unsigned i) {
(void)(i & i | i);
#ifndef SILENCE
// expected-warning@-2 {{'&' within '|'}}
// expected-note@-3 {{place parentheses around the '&' expression to silence this warning}}
#endif
// CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:10-[[@LINE-5]]:10}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:15-[[@LINE-6]]:15}:")"
(void)(i | i & i);
#ifndef SILENCE
// expected-warning@-2 {{'&' within '|'}}
// expected-note@-3 {{place parentheses around the '&' expression to silence this warning}}
#endif
// CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:19-[[@LINE-6]]:19}:")"
(void)(i ^ i | i);
#ifndef SILENCE
// expected-warning@-2 {{'^' within '|'}}
// expected-note@-3 {{place parentheses around the '^' expression to silence this warning}}
#endif
// CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:10-[[@LINE-5]]:10}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:15-[[@LINE-6]]:15}:")"
(void)(i | i ^ i);
#ifndef SILENCE
// expected-warning@-2 {{'^' within '|'}}
// expected-note@-3 {{place parentheses around the '^' expression to silence this warning}}
#endif
// CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:19-[[@LINE-6]]:19}:")"
(void)(i & i ^ i);
#ifndef SILENCE
// expected-warning@-2 {{'&' within '^'}}
// expected-note@-3 {{place parentheses around the '&' expression to silence this warning}}
#endif
// CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:10-[[@LINE-5]]:10}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:15-[[@LINE-6]]:15}:")"
(void)(i ^ i & i);
#ifndef SILENCE
// expected-warning@-2 {{'&' within '^'}}
// expected-note@-3 {{place parentheses around the '&' expression to silence this warning}}
#endif
// CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:19-[[@LINE-6]]:19}:")"
}

41
clang/test/Sema/logical-op-parentheses.c Normal file
View File

@ -0,0 +1,41 @@
// RUN: %clang_cc1 -fsyntax-only -verify %s -DSILENCE
// RUN: %clang_cc1 -fsyntax-only -verify %s -Wlogical-op-parentheses
// RUN: %clang_cc1 -fsyntax-only -verify %s -Wparentheses
// RUN: %clang_cc1 -fsyntax-only -fdiagnostics-parseable-fixits %s -Wlogical-op-parentheses 2>&1 | FileCheck %s
#ifdef SILENCE
// expected-no-diagnostics
#endif
void logical_op_parentheses(unsigned i) {
(void)(i ||
i && i);
#ifndef SILENCE
// expected-warning@-2 {{'&&' within '||'}}
// expected-note@-3 {{place parentheses around the '&&' expression to silence this warning}}
#endif
// CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:20-[[@LINE-6]]:20}:")"
(void)(i || i && "w00t");
(void)("w00t" && i || i);
(void)(i || i && "w00t" || i);
#ifndef SILENCE
// expected-warning@-2 {{'&&' within '||'}}
// expected-note@-3 {{place parentheses around the '&&' expression to silence this warning}}
#endif
// CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:15-[[@LINE-5]]:15}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:26-[[@LINE-6]]:26}:")"
(void)(i || "w00t" && i || i);
#ifndef SILENCE
// expected-warning@-2 {{'&&' within '||'}}
// expected-note@-3 {{place parentheses around the '&&' expression to silence this warning}}
#endif
// CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:15-[[@LINE-5]]:15}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:26-[[@LINE-6]]:26}:")"
(void)(i && i || 0);
(void)(0 || i && i);
}

53
clang/test/Sema/parentheses.c
View File

@ -1,3 +1,4 @@
// RUN: %clang_cc1 -fsyntax-only -verify %s
// RUN: %clang_cc1 -Wparentheses -fsyntax-only -verify %s
// RUN: %clang_cc1 -Wparentheses -fsyntax-only -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
@ -44,58 +45,6 @@ void bitwise_rel(unsigned i) {
// Eager logical op
(void)(i == 1 | i == 2 | i == 3);
(void)(i != 1 & i != 2 & i != 3);
(void)(i & i | i); // expected-warning {{'&' within '|'}} \
// expected-note {{place parentheses around the '&' expression to silence this warning}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:10-[[@LINE-2]]:10}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:15-[[@LINE-3]]:15}:")"
(void)(i | i & i); // expected-warning {{'&' within '|'}} \
// expected-note {{place parentheses around the '&' expression to silence this warning}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:14-[[@LINE-2]]:14}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:19-[[@LINE-3]]:19}:")"
(void)(i ^ i | i); // expected-warning {{'^' within '|'}} \
// expected-note {{place parentheses around the '^' expression to silence this warning}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:10-[[@LINE-2]]:10}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:15-[[@LINE-3]]:15}:")"
(void)(i | i ^ i); // expected-warning {{'^' within '|'}} \
// expected-note {{place parentheses around the '^' expression to silence this warning}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:14-[[@LINE-2]]:14}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:19-[[@LINE-3]]:19}:")"
(void)(i & i ^ i); // expected-warning {{'&' within '^'}} \
// expected-note {{place parentheses around the '&' expression to silence this warning}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:10-[[@LINE-2]]:10}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:15-[[@LINE-3]]:15}:")"
(void)(i ^ i & i); // expected-warning {{'&' within '^'}} \
// expected-note {{place parentheses around the '&' expression to silence this warning}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:14-[[@LINE-2]]:14}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:19-[[@LINE-3]]:19}:")"
(void)(i ||
i && i); // expected-warning {{'&&' within '||'}} \
// expected-note {{place parentheses around the '&&' expression to silence this warning}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:14-[[@LINE-2]]:14}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:20-[[@LINE-3]]:20}:")"
(void)(i || i && "w00t"); // no warning.
(void)("w00t" && i || i); // no warning.
(void)(i || i && "w00t" || i); // expected-warning {{'&&' within '||'}} \
// expected-note {{place parentheses around the '&&' expression to silence this warning}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:15-[[@LINE-2]]:15}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:26-[[@LINE-3]]:26}:")"
(void)(i || "w00t" && i || i); // expected-warning {{'&&' within '||'}} \
// expected-note {{place parentheses around the '&&' expression to silence this warning}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:15-[[@LINE-2]]:15}:"("
// CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:26-[[@LINE-3]]:26}:")"
(void)(i && i || 0); // no warning.
(void)(0 || i && i); // no warning.
}
_Bool someConditionFunc();

2
clang/test/SemaCXX/parentheses.cpp
View File

@ -1,4 +1,4 @@
// RUN: %clang_cc1 -verify %s
// RUN: %clang_cc1 -verify -Wlogical-op-parentheses %s
// PR16930, PR16727:
template<class Foo>