[C++ PATCH] Fix -Wlogical-not-parentheses (PR c++/62199)
Marek Polacek
polacek@redhat.com
Fri Aug 22 18:45:00 GMT 2014
On Fri, Aug 22, 2014 at 12:52:51PM -0400, Jason Merrill wrote:
> On 08/22/2014 12:33 PM, Marek Polacek wrote:
> >On Fri, Aug 22, 2014 at 12:24:16PM -0400, Jason Merrill wrote:
> >>Sorry to nitpick, but now that we aren't checking the lhs for BOOLEAN_TYPE,
> >>do we need to look at it at all?
> >
> >I believe so: if the LHS is an INTEGER_CST, we can't use TREE_OPERAND
> >on it. Happens e.g. for if (!5 > a).
>
> Yes, but why do we want to use TREE_OPERAND on it?
Oh yeah, seems that we don't need that. Actually, I think we can take
this one step further: since we can't use unary ! on a vector, we can
drop the VECTOR_TYPE checks, meaning that we don't need the lhs
parameter at all! What do you say?
Bootstrapped/regtested on x86_64-linux.
2014-08-22 Marek Polacek <polacek@redhat.com>
PR c++/62199
* doc/invoke.texi: Update -Wlogical-not-parentheses description.
c-family/
* c-common.c (warn_logical_not_parentheses): Don't check LHS. Don't
check for vector types. Drop LHS argument.
* c-common.h (warn_logical_not_parentheses): Adjust.
c/
* c-typeck.c (parser_build_binary_op): Adjust call to
warn_logical_not_parentheses.
cp/
* parser.c (cp_parser_binary_expression): Check each LHS if it's
preceded with logical not. Adjust call to
warn_logical_not_parentheses.
testsuite/
* c-c++-common/pr62199.c: New test.
* c-c++-common/pr62199-2.c: New test.
* g++.dg/warn/Wparentheses-25.C: Drop XFAILs.
diff --git gcc/c-family/c-common.c gcc/c-family/c-common.c
index c5eb2a7..58b9763 100644
--- gcc/c-family/c-common.c
+++ gcc/c-family/c-common.c
@@ -1727,21 +1727,15 @@ warn_logical_operator (location_t location, enum tree_code code, tree type,
/* Warn about logical not used on the left hand side operand of a comparison.
This function assumes that the LHS is inside of TRUTH_NOT_EXPR.
- Do not warn if the LHS or RHS is of a boolean or a vector type. */
+ Do not warn if RHS is of a boolean type. */
void
warn_logical_not_parentheses (location_t location, enum tree_code code,
- tree lhs, tree rhs)
+ tree rhs)
{
- if (TREE_CODE_CLASS (code) != tcc_comparison)
- return;
- if (TREE_TYPE (lhs) == NULL_TREE
- || TREE_TYPE (rhs) == NULL_TREE)
- ;
- else if (TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE
- || TREE_CODE (TREE_TYPE (rhs)) == BOOLEAN_TYPE
- || VECTOR_TYPE_P (TREE_TYPE (lhs))
- || VECTOR_TYPE_P (TREE_TYPE (rhs)))
+ if (TREE_CODE_CLASS (code) != tcc_comparison
+ || TREE_TYPE (rhs) == NULL_TREE
+ || TREE_CODE (TREE_TYPE (rhs)) == BOOLEAN_TYPE)
return;
warning_at (location, OPT_Wlogical_not_parentheses,
diff --git gcc/c-family/c-common.h gcc/c-family/c-common.h
index 995bc8c..20b65e9 100644
--- gcc/c-family/c-common.h
+++ gcc/c-family/c-common.h
@@ -780,8 +780,7 @@ extern void overflow_warning (location_t, tree);
extern bool warn_if_unused_value (const_tree, location_t);
extern void warn_logical_operator (location_t, enum tree_code, tree,
enum tree_code, tree, enum tree_code, tree);
-extern void warn_logical_not_parentheses (location_t, enum tree_code, tree,
- tree);
+extern void warn_logical_not_parentheses (location_t, enum tree_code, tree);
extern void check_main_parameter_types (tree decl);
extern bool c_determine_visibility (tree);
extern bool vector_types_compatible_elements_p (tree, tree);
diff --git gcc/c/c-typeck.c gcc/c/c-typeck.c
index d6d96cf..a7de8f3 100644
--- gcc/c/c-typeck.c
+++ gcc/c/c-typeck.c
@@ -3414,7 +3414,7 @@ parser_build_binary_op (location_t location, enum tree_code code,
if (warn_logical_not_paren
&& code1 == TRUTH_NOT_EXPR
&& code2 != TRUTH_NOT_EXPR)
- warn_logical_not_parentheses (location, code, arg1.value, arg2.value);
+ warn_logical_not_parentheses (location, code, arg2.value);
/* Warn about comparisons against string literals, with the exception
of testing for equality or inequality of a string literal with NULL. */
diff --git gcc/cp/parser.c gcc/cp/parser.c
index 9053bfa..4dc7c33 100644
--- gcc/cp/parser.c
+++ gcc/cp/parser.c
@@ -8020,13 +8020,12 @@ cp_parser_binary_expression (cp_parser* parser, bool cast_p,
enum tree_code rhs_type;
enum cp_parser_prec new_prec, lookahead_prec;
tree overload;
- bool parenthesized_not_lhs_warn
- = cp_lexer_next_token_is (parser->lexer, CPP_NOT);
/* Parse the first expression. */
+ current.lhs_type = (cp_lexer_next_token_is (parser->lexer, CPP_NOT)
+ ? TRUTH_NOT_EXPR : ERROR_MARK);
current.lhs = cp_parser_cast_expression (parser, /*address_p=*/false,
cast_p, decltype_p, pidk);
- current.lhs_type = ERROR_MARK;
current.prec = prec;
if (cp_parser_error_occurred (parser))
@@ -8081,8 +8080,9 @@ cp_parser_binary_expression (cp_parser* parser, bool cast_p,
/* Extract another operand. It may be the RHS of this expression
or the LHS of a new, higher priority expression. */
+ rhs_type = (cp_lexer_next_token_is (parser->lexer, CPP_NOT)
+ ? TRUTH_NOT_EXPR : ERROR_MARK);
rhs = cp_parser_simple_cast_expression (parser);
- rhs_type = ERROR_MARK;
/* Get another operator token. Look up its precedence to avoid
building a useless (immediately popped) stack entry for common
@@ -8125,9 +8125,8 @@ cp_parser_binary_expression (cp_parser* parser, bool cast_p,
c_inhibit_evaluation_warnings -= current.lhs == truthvalue_true_node;
if (warn_logical_not_paren
- && parenthesized_not_lhs_warn)
- warn_logical_not_parentheses (current.loc, current.tree_type,
- TREE_OPERAND (current.lhs, 0), rhs);
+ && current.lhs_type == TRUTH_NOT_EXPR)
+ warn_logical_not_parentheses (current.loc, current.tree_type, rhs);
overload = NULL;
/* ??? Currently we pass lhs_type == ERROR_MARK and rhs_type ==
diff --git gcc/doc/invoke.texi gcc/doc/invoke.texi
index f8499bc..dda8e91 100644
--- gcc/doc/invoke.texi
+++ gcc/doc/invoke.texi
@@ -4776,8 +4776,8 @@ bit-wise operator is likely to be expected.
@opindex Wlogical-not-parentheses
@opindex Wno-logical-not-parentheses
Warn about logical not used on the left hand side operand of a comparison.
-This option does not warn if the LHS or RHS operand is of a boolean or
-a vector type. Its purpose is to detect suspicious code like the following:
+This option does not warn if the RHS operand is of a boolean type. Its
+purpose is to detect suspicious code like the following:
@smallexample
int a;
@dots{}
diff --git gcc/testsuite/c-c++-common/pr62199-2.c gcc/testsuite/c-c++-common/pr62199-2.c
index e69de29..7647f16 100644
--- gcc/testsuite/c-c++-common/pr62199-2.c
+++ gcc/testsuite/c-c++-common/pr62199-2.c
@@ -0,0 +1,20 @@
+/* PR c++/62199 */
+/* { dg-do compile } */
+/* { dg-options "-Wlogical-not-parentheses" } */
+
+#ifndef __cplusplus
+# define bool _Bool
+#endif
+
+bool r;
+
+void
+foo (bool b)
+{
+ r = !b == 1; /* { dg-warning "logical not is only applied to the left hand side of comparison" } */
+ r = !b != 1; /* { dg-warning "logical not is only applied to the left hand side of comparison" } */
+ r = !b > 1; /* { dg-warning "logical not is only applied to the left hand side of comparison" } */
+ r = !b >= 1; /* { dg-warning "logical not is only applied to the left hand side of comparison" } */
+ r = !b < 1; /* { dg-warning "logical not is only applied to the left hand side of comparison" } */
+ r = !b <= 1; /* { dg-warning "logical not is only applied to the left hand side of comparison" } */
+}
diff --git gcc/testsuite/c-c++-common/pr62199.c gcc/testsuite/c-c++-common/pr62199.c
index e69de29..51078c8 100644
--- gcc/testsuite/c-c++-common/pr62199.c
+++ gcc/testsuite/c-c++-common/pr62199.c
@@ -0,0 +1,22 @@
+/* PR c++/62199 */
+/* { dg-do compile } */
+/* { dg-options "-Wlogical-not-parentheses" } */
+
+int r;
+void
+foo (int a)
+{
+ r = a > 0 || !a >= 2; /* { dg-warning "19:logical not is only applied to the left hand side of comparison" } */
+ r = !a || a == 10;
+ r = !a && !a < 4; /* { dg-warning "16:logical not is only applied to the left hand side of comparison" } */
+ r = !a > 0 && a < 6; /* { dg-warning "10:logical not is only applied to the left hand side of comparison" } */
+ r = a + (!a < 12); /* { dg-warning "15:logical not is only applied to the left hand side of comparison" } */
+ r = a == 7 || !a < 12; /* { dg-warning "20:logical not is only applied to the left hand side of comparison" } */
+ r = (a == 7 * a > 0) || !a < 2; /* { dg-warning "30:logical not is only applied to the left hand side of comparison" } */
+ r = (1 > !a) || (!42 > a); /* { dg-warning "24:logical not is only applied to the left hand side of comparison" } */
+ r = (!5 > a); /* { dg-warning "11:logical not is only applied to the left hand side of comparison" } */
+ r = (!0 > a); /* { dg-warning "11:logical not is only applied to the left hand side of comparison" } */
+ r = (!-5 > a); /* { dg-warning "12:logical not is only applied to the left hand side of comparison" } */
+ r = (!(5 + 3) > a); /* { dg-warning "17:logical not is only applied to the left hand side of comparison" } */
+ r = (!(5 - a) > a); /* { dg-warning "17:logical not is only applied to the left hand side of comparison" } */
+}
diff --git gcc/testsuite/g++.dg/warn/Wparentheses-25.C gcc/testsuite/g++.dg/warn/Wparentheses-25.C
index ab00c25..d9951a4 100644
--- gcc/testsuite/g++.dg/warn/Wparentheses-25.C
+++ gcc/testsuite/g++.dg/warn/Wparentheses-25.C
@@ -8,7 +8,7 @@ int foo (int);
int
bar (int a, int b, int c)
{
- foo (!a & b); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
+ foo (!a & b); /* { dg-warning "parentheses" "correct warning" } */
foo (!a & (b < c));
foo (!a & (b > c));
foo (!a & (b == c));
@@ -20,7 +20,7 @@ bar (int a, int b, int c)
foo (!a & !b);
foo (!(a & b));
foo ((!a) & b);
- foo (!a & 2); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
+ foo (!a & 2); /* { dg-warning "parentheses" "correct warning" } */
foo (!a & (2 < c));
foo (!a & (2 > c));
foo (!a & (2 == c));
@@ -32,7 +32,7 @@ bar (int a, int b, int c)
foo (!a & !2);
foo (!(a & 2));
foo ((!a) & 2);
- foo (!1 & 2); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
+ foo (!1 & 2); /* { dg-warning "parentheses" "correct warning" } */
foo (!1 & (2 < c));
foo (!1 & (2 > c));
foo (!1 & (2 == c));
@@ -44,7 +44,7 @@ bar (int a, int b, int c)
foo (!1 & !2);
foo (!(1 & 2));
- foo (!a | b); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
+ foo (!a | b); /* { dg-warning "parentheses" "correct warning" } */
foo (!a | (b < c));
foo (!a | (b > c));
foo (!a | (b == c));
@@ -56,7 +56,7 @@ bar (int a, int b, int c)
foo (!a | !b);
foo (!(a | b));
foo ((!a) | b);
- foo (!a | 2); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
+ foo (!a | 2); /* { dg-warning "parentheses" "correct warning" } */
foo (!a | (2 < c));
foo (!a | (2 > c));
foo (!a | (2 == c));
@@ -68,7 +68,7 @@ bar (int a, int b, int c)
foo (!a | !2);
foo (!(a | 2));
foo ((!a) | 2);
- foo (!1 | 2); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
+ foo (!1 | 2); /* { dg-warning "parentheses" "correct warning" } */
foo (!1 | (2 < c));
foo (!1 | (2 > c));
foo (!1 | (2 == c));
@@ -159,55 +159,55 @@ bar (int a, int b, int c)
int
baz (int a, int b, int c)
{
- foo (!a & (b << c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (b >> c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (b + c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (b - c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (b = c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & ~b); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (b & c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (b | c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & 2); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (2 << c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (2 >> c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (2 + c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (2 - c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (c = 2)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & ~2); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (2 & c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a & (2 | c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 & (2 << c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 & (2 >> c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 & (2 + c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 & (2 - c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 & (c = 2)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 & ~2); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 & (2 & c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 & (2 | c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (b << c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (b >> c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (b + c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (b - c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (b = c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | ~b); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (b & c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (b | c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (2 << c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (2 >> c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (2 + c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (2 - c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (c = 2)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | ~2); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (2 & c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!a | (2 | c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 | (2 << c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 | (2 >> c));/* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 | (2 + c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 | (2 - c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 | (c = 2)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 | ~2); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 | (2 & c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
- foo (!1 | (2 | c)); /* { dg-warning "parentheses" "correct warning" { xfail *-*-* } } */
+ foo (!a & (b << c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (b >> c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (b + c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (b - c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (b = c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & ~b); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (b & c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (b | c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & 2); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (2 << c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (2 >> c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (2 + c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (2 - c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (c = 2)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & ~2); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (2 & c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a & (2 | c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 & (2 << c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 & (2 >> c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 & (2 + c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 & (2 - c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 & (c = 2)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 & ~2); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 & (2 & c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 & (2 | c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (b << c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (b >> c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (b + c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (b - c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (b = c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | ~b); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (b & c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (b | c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (2 << c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (2 >> c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (2 + c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (2 - c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (c = 2)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | ~2); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (2 & c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!a | (2 | c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 | (2 << c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 | (2 >> c));/* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 | (2 + c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 | (2 - c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 | (c = 2)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 | ~2); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 | (2 & c)); /* { dg-warning "parentheses" "correct warning" } */
+ foo (!1 | (2 | c)); /* { dg-warning "parentheses" "correct warning" } */
foo ((b << c) & !a);
foo ((b >> c) & !a);
foo ((b + c) & !a);
Marek
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