From f834806177042ee269333855dee99fda84bc7c26 Mon Sep 17 00:00:00 2001 From: Bernd Edlinger Date: Mon, 24 Oct 2016 17:14:41 +0000 Subject: [PATCH] c-common.c (c_common_truthvalue_conversion): Warn for multiplications in boolean context. 2016-10-24 Bernd Edlinger * c-common.c (c_common_truthvalue_conversion): Warn for multiplications in boolean context. Fix the quoting of '<<' and '<' in the shift warning. gcc: 2016-10-24 Bernd Edlinger * doc/invoke.text (Wint-in-bool-context): Update documentation. * value-prof.c (stringop_block_profile): Fix a warning. testsuite: 2016-10-24 Bernd Edlinger * c-c++-common/Wint-in-bool-context-3.c: New test. From-SVN: r241490 --- gcc/ChangeLog | 5 +++++ gcc/c-family/ChangeLog | 6 ++++++ gcc/c-family/c-common.c | 7 ++++++- gcc/doc/invoke.texi | 5 +++-- gcc/testsuite/ChangeLog | 4 ++++ .../c-c++-common/Wint-in-bool-context-3.c | 15 +++++++++++++++ gcc/value-prof.c | 4 ++-- 7 files changed, 41 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/c-c++-common/Wint-in-bool-context-3.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a8528b91c41..1f6712e6144 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2016-10-24 Bernd Edlinger + + * doc/invoke.text (Wint-in-bool-context): Update documentation. + * value-prof.c (stringop_block_profile): Fix a warning. + 2016-10-24 Martin Sebor PR middle-end/77735 diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index b16b1c1fac4..6a6dba28593 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,9 @@ +2016-10-24 Bernd Edlinger + + * c-common.c (c_common_truthvalue_conversion): Warn for + multiplications in boolean context. Fix the quoting of '<<' and '<' + in the shift warning. + 2016-10-20 Bernd Edlinger * c-common.c (c_common_truthvalue_conversion): Fix the comment. diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index abc07402640..c0dafc08652 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -3327,6 +3327,11 @@ c_common_truthvalue_conversion (location_t location, tree expr) return c_common_truthvalue_conversion (location, TREE_OPERAND (expr, 0)); + case MULT_EXPR: + warning_at (EXPR_LOCATION (expr), OPT_Wint_in_bool_context, + "%<*%> in boolean context, suggest %<&&%> instead"); + break; + case LSHIFT_EXPR: /* We will only warn on signed shifts here, because the majority of false positive warnings happen in code where unsigned arithmetic @@ -3336,7 +3341,7 @@ c_common_truthvalue_conversion (location_t location, tree expr) if (TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE && !TYPE_UNSIGNED (TREE_TYPE (expr))) warning_at (EXPR_LOCATION (expr), OPT_Wint_in_bool_context, - "<< in boolean context, did you mean '<' ?"); + "%<<<%> in boolean context, did you mean %<<%> ?"); break; case COND_EXPR: diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 9f57d52d516..5ccd4244ef3 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -6169,8 +6169,9 @@ of the C++ standard. @opindex Wno-int-in-bool-context Warn for suspicious use of integer values where boolean values are expected, such as conditional expressions (?:) using non-boolean integer constants in -boolean context, like @code{if (a <= b ? 2 : 3)}. Or left shifting in -boolean context, like @code{for (a = 0; 1 << a; a++);}. +boolean context, like @code{if (a <= b ? 2 : 3)}. Or left shifting of signed +integers in boolean context, like @code{for (a = 0; 1 << a; a++);}. Likewise +for all kinds of multiplications regardless of the data type. This warning is enabled by @option{-Wall}. @item -Wno-int-to-pointer-cast diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 28c755036d8..5b83f4de125 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2016-10-24 Bernd Edlinger + + * c-c++-common/Wint-in-bool-context-3.c: New test. + 2016-10-24 Martin Sebor PR middle-end/77735 diff --git a/gcc/testsuite/c-c++-common/Wint-in-bool-context-3.c b/gcc/testsuite/c-c++-common/Wint-in-bool-context-3.c new file mode 100644 index 00000000000..869132a90c3 --- /dev/null +++ b/gcc/testsuite/c-c++-common/Wint-in-bool-context-3.c @@ -0,0 +1,15 @@ +/* { dg-options "-Wint-in-bool-context" } */ +/* { dg-do compile } */ + +#define BITS_PER_UNIT 8 + +int foo (int count) +{ + int alignment; + + alignment = 1; + while (!(count & alignment) + && (alignment * 2 * BITS_PER_UNIT)) /* { dg-warning "boolean context" } */ + alignment <<= 1; + return alignment * BITS_PER_UNIT; +} diff --git a/gcc/value-prof.c b/gcc/value-prof.c index e794e6d5aef..dc570692fbf 100644 --- a/gcc/value-prof.c +++ b/gcc/value-prof.c @@ -1878,12 +1878,12 @@ stringop_block_profile (gimple *stmt, unsigned int *expected_align, else { gcov_type count; - int alignment; + unsigned int alignment; count = histogram->hvalue.counters[0]; alignment = 1; while (!(count & alignment) - && (alignment * 2 * BITS_PER_UNIT)) + && (alignment <= UINT_MAX / 2 / BITS_PER_UNIT)) alignment <<= 1; *expected_align = alignment * BITS_PER_UNIT; gimple_remove_histogram_value (cfun, stmt, histogram); -- 2.30.2