diff options
Diffstat (limited to 'gcc/c-family/c-warn.c')
| -rw-r--r-- | gcc/c-family/c-warn.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c index 84ad663..99cde4a 100644 --- a/gcc/c-family/c-warn.c +++ b/gcc/c-family/c-warn.c @@ -3726,3 +3726,35 @@ maybe_warn_sizeof_array_div (location_t loc, tree arr, tree arr_type, } } } + +/* Warn about C++20 [depr.array.comp] array comparisons: "Equality + and relational comparisons between two operands of array type are + deprecated." We also warn in C and earlier C++ standards. CODE is + the code for this comparison, OP0 and OP1 are the operands. */ + +void +do_warn_array_compare (location_t location, tree_code code, tree op0, tree op1) +{ + STRIP_NOPS (op0); + STRIP_NOPS (op1); + if (TREE_CODE (op0) == ADDR_EXPR) + op0 = TREE_OPERAND (op0, 0); + if (TREE_CODE (op1) == ADDR_EXPR) + op1 = TREE_OPERAND (op1, 0); + + auto_diagnostic_group d; + if (warning_at (location, OPT_Warray_compare, + (c_dialect_cxx () && cxx_dialect >= cxx20) + ? G_("comparison between two arrays is deprecated in C++20") + : G_("comparison between two arrays"))) + { + /* C doesn't allow +arr. */ + if (c_dialect_cxx ()) + inform (location, "use unary %<+%> which decays operands to pointers " + "or %<&%D[0] %s &%D[0]%> to compare the addresses", + op0, op_symbol_code (code), op1); + else + inform (location, "use %<&%D[0] %s &%D[0]%> to compare the addresses", + op0, op_symbol_code (code), op1); + } +} |