diff options
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/c-family/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/c-family/c-common.c | 43 | ||||
| -rw-r--r-- | gcc/c-family/c-common.h | 1 | ||||
| -rw-r--r-- | gcc/c-family/c.opt | 4 | ||||
| -rw-r--r-- | gcc/c/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/c/c-parser.c | 17 | ||||
| -rw-r--r-- | gcc/cp/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/cp/parser.c | 25 | ||||
| -rw-r--r-- | gcc/doc/invoke.texi | 12 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/testsuite/c-c++-common/memset-array.c | 36 |
12 files changed, 139 insertions, 24 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1e28a4b521f..2ddc3df12bd 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2016-04-27 Bernd Schmidt <bschmidt@redhat.com> + + * doc/invoke.texi (Warning Options): Add -Wmemset-elt-size. + (-Wmemset-elt-size): New item. + 2016-04-27 Eric Botcazou <ebotcazou@adacore.com> PR ada/70759 diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index af601678982..1d87d9dd815 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,9 @@ +2016-04-27 Bernd Schmidt <bschmidt@redhat.com> + + * c.opt (Wmemset-elt-size): New option. + * c-common.c (warn_for_memset): New function. + * c-common.h (warn_for_memset): Declare. + 2016-04-25 Jason Merrill <jason@redhat.com> * c-common.c (handle_unused_attribute): Accept CONST_DECL. diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 1edc0bc65bb..1f0d76aa15b 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -11767,6 +11767,49 @@ warn_for_div_by_zero (location_t loc, tree divisor) warning_at (loc, OPT_Wdiv_by_zero, "division by zero"); } +/* Warn for patterns where memset appears to be used incorrectly. The + warning location should be LOC. ARG0, and ARG2 are the first and + last arguments to the call, while LITERAL_ZERO_MASK has a 1 bit for + each argument that was a literal zero. */ + +void +warn_for_memset (location_t loc, tree arg0, tree arg2, + int literal_zero_mask) +{ + if (warn_memset_transposed_args + && integer_zerop (arg2) + && (literal_zero_mask & (1 << 2)) != 0 + && (literal_zero_mask & (1 << 1)) == 0) + warning_at (loc, OPT_Wmemset_transposed_args, + "%<memset%> used with constant zero length " + "parameter; this could be due to transposed " + "parameters"); + + if (warn_memset_elt_size && TREE_CODE (arg2) == INTEGER_CST) + { + STRIP_NOPS (arg0); + if (TREE_CODE (arg0) == ADDR_EXPR) + arg0 = TREE_OPERAND (arg0, 0); + tree type = TREE_TYPE (arg0); + if (TREE_CODE (type) == ARRAY_TYPE) + { + tree elt_type = TREE_TYPE (type); + tree domain = TYPE_DOMAIN (type); + if (!integer_onep (TYPE_SIZE_UNIT (elt_type)) + && TYPE_MAXVAL (domain) + && TYPE_MINVAL (domain) + && integer_zerop (TYPE_MINVAL (domain)) + && integer_onep (fold_build2 (MINUS_EXPR, domain, + arg2, + TYPE_MAXVAL (domain)))) + warning_at (loc, OPT_Wmemset_elt_size, + "%<memset%> used with length equal to " + "number of elements without multiplication " + "by element size"); + } + } +} + /* Subroutine of build_binary_op. Give warnings for comparisons between signed and unsigned quantities that may fail. Do the checking based on the original operand trees ORIG_OP0 and ORIG_OP1, diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h index 4c43a354fef..b631e7d1af5 100644 --- a/gcc/c-family/c-common.h +++ b/gcc/c-family/c-common.h @@ -903,6 +903,7 @@ extern void c_parse_file (void); extern void c_parse_final_cleanups (void); extern void warn_for_omitted_condop (location_t, tree); +extern void warn_for_memset (location_t, tree, tree, int); /* These macros provide convenient access to the various _STMT nodes. */ diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt index 4f86876c533..05bfa7cbc6f 100644 --- a/gcc/c-family/c.opt +++ b/gcc/c-family/c.opt @@ -565,6 +565,10 @@ Wmemset-transposed-args C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not. +Wmemset-elt-size +C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) +Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size. + Wmisleading-indentation C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall) Warn when the indentation of the code does not reflect the block structure. diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog index b59d69092c9..a641721bece 100644 --- a/gcc/c/ChangeLog +++ b/gcc/c/ChangeLog @@ -1,3 +1,8 @@ +2016-04-27 Bernd Schmidt <bschmidt@redhat.com> + + * c-parser.c (c_parser_postfix_expression_after_primary): Call + warn_for_memset instead of warning directly here. + 2016-04-26 Marek Polacek <polacek@redhat.com> PR c/67784 diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c index 74423a6b233..36c44ab5b56 100644 --- a/gcc/c/c-parser.c +++ b/gcc/c/c-parser.c @@ -8291,18 +8291,15 @@ c_parser_postfix_expression_after_primary (c_parser *parser, expr.value, exprlist, sizeof_arg, sizeof_ptr_memacc_comptypes); - if (warn_memset_transposed_args - && TREE_CODE (expr.value) == FUNCTION_DECL + if (TREE_CODE (expr.value) == FUNCTION_DECL && DECL_BUILT_IN_CLASS (expr.value) == BUILT_IN_NORMAL && DECL_FUNCTION_CODE (expr.value) == BUILT_IN_MEMSET - && vec_safe_length (exprlist) == 3 - && integer_zerop ((*exprlist)[2]) - && (literal_zero_mask & (1 << 2)) != 0 - && (!integer_zerop ((*exprlist)[1]) - || (literal_zero_mask & (1 << 1)) == 0)) - warning_at (expr_loc, OPT_Wmemset_transposed_args, - "%<memset%> used with constant zero length parameter; " - "this could be due to transposed parameters"); + && vec_safe_length (exprlist) == 3) + { + tree arg0 = (*exprlist)[0]; + tree arg2 = (*exprlist)[2]; + warn_for_memset (expr_loc, arg0, arg2, literal_zero_mask); + } start = expr.get_start (); finish = parser->tokens_buf[0].get_finish (); diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index b2185df76ae..6fc42bc030d 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,8 @@ +2016-04-27 Bernd Schmidt <bschmidt@redhat.com> + + * parser.c (cp_parser_postfix_expression): Call + warn_for_memset instead of warning directly here. + 2016-04-26 Patrick Palka <ppalka@gcc.gnu.org> PR c++/70241 diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 2dcb766a995..98a0cd42fea 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -6829,20 +6829,19 @@ cp_parser_postfix_expression (cp_parser *parser, bool address_p, bool cast_p, } } - if (warn_memset_transposed_args) + if (TREE_CODE (postfix_expression) == FUNCTION_DECL + && DECL_BUILT_IN_CLASS (postfix_expression) == BUILT_IN_NORMAL + && DECL_FUNCTION_CODE (postfix_expression) == BUILT_IN_MEMSET + && vec_safe_length (args) == 3) { - if (TREE_CODE (postfix_expression) == FUNCTION_DECL - && DECL_BUILT_IN_CLASS (postfix_expression) == BUILT_IN_NORMAL - && DECL_FUNCTION_CODE (postfix_expression) == BUILT_IN_MEMSET - && vec_safe_length (args) == 3 - && TREE_CODE ((*args)[2]) == INTEGER_CST - && integer_zerop ((*args)[2]) - && !(TREE_CODE ((*args)[1]) == INTEGER_CST - && integer_zerop ((*args)[1]))) - warning (OPT_Wmemset_transposed_args, - "%<memset%> used with constant zero length " - "parameter; this could be due to transposed " - "parameters"); + tree arg0 = (*args)[0]; + tree arg1 = (*args)[1]; + tree arg2 = (*args)[2]; + int literal_mask = ((!!integer_zerop (arg1) << 1) + | (!!integer_zerop (arg2) << 2)); + if (TREE_CODE (arg2) == CONST_DECL) + arg2 = DECL_INITIAL (arg2); + warn_for_memset (input_location, arg0, arg2, literal_mask); } if (TREE_CODE (postfix_expression) == COMPONENT_REF) diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 2617cb458ba..67760b5b455 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -273,7 +273,7 @@ Objective-C and Objective-C++ Dialects}. -Wno-int-to-pointer-cast -Winvalid-memory-model -Wno-invalid-offsetof @gol -Winvalid-pch -Wlarger-than=@var{len} @gol -Wlogical-op -Wlogical-not-parentheses -Wlong-long @gol --Wmain -Wmaybe-uninitialized -Wmemset-transposed-args @gol +-Wmain -Wmaybe-uninitialized -Wmemset-elt-size -Wmemset-transposed-args @gol -Wmisleading-indentation -Wmissing-braces @gol -Wmissing-field-initializers -Wmissing-include-dirs @gol -Wno-multichar -Wnonnull -Wnonnull-compare @gol @@ -3548,6 +3548,7 @@ Options} and @ref{Objective-C and Objective-C++ Dialect Options}. -Wlogical-not-parentheses -Wmain @r{(only for C/ObjC and unless} @option{-ffreestanding}@r{)} @gol -Wmaybe-uninitialized @gol +-Wmemset-elt-size @gol -Wmemset-transposed-args @gol -Wmisleading-indentation @r{(only for C/C++)} @gol -Wmissing-braces @r{(only for C/ObjC)} @gol @@ -5257,6 +5258,15 @@ Warn when the @code{sizeof} operator is applied to a parameter that is declared as an array in a function definition. This warning is enabled by default for C and C++ programs. +@item -Wmemset-elt-size +@opindex Wmemset-elt-size +@opindex Wno-memset-elt-size +Warn for suspicious calls to the @code{memset} built-in function, if the +first argument references an array, and the third argument is a number +equal to the number of elements, but not equal to the size of the array +in memory. This indicates that the user has omitted a multiplication by +the element size. This warning is enabled by @option{-Wall}. + @item -Wmemset-transposed-args @opindex Wmemset-transposed-args @opindex Wno-memset-transposed-args diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ecd3fa9519f..77f8b0dd24a 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2016-04-27 Bernd Schmidt <bschmidt@redhat.com> + + * c-c++-common/memset-array.c: New test. + 2016-04-26 Martin Sebor <msebor@redhat.com> PR c++/66639 diff --git a/gcc/testsuite/c-c++-common/memset-array.c b/gcc/testsuite/c-c++-common/memset-array.c new file mode 100644 index 00000000000..0346a210bb0 --- /dev/null +++ b/gcc/testsuite/c-c++-common/memset-array.c @@ -0,0 +1,36 @@ +/* { dg-do compile } */ +/* { dg-options "-Wmemset-elt-size" } */ +enum a { + a_1, + a_2, + a_n +}; +int t1[20]; +int t2[a_n]; + +struct s +{ + int t[20]; +}; + +void foo (struct s *s) +{ + __builtin_memset (t1, 0, 20); /* { dg-warning "element size" } */ + __builtin_memset (t2, 0, a_n); /* { dg-warning "element size" } */ + __builtin_memset (s->t, 0, 20); /* { dg-warning "element size" } */ +} + +char u1[20]; +char u2[a_n]; + +struct s2 +{ + char u[20]; +}; + +void bar (struct s2 *s) +{ + __builtin_memset (u1, 0, 20); + __builtin_memset (u2, 0, a_n); + __builtin_memset (s->u, 0, 20); +} |