Assuming you applied this as svn 267273, it causes bootstrap failure
on powerpc64le-unknown-linux-gnu. Stage 2 fails with multiple instances
of this error:
../../trunk-base/gcc/c-family/c-pragma.c: In function ‘void
handle_pragma_scalar_storage_order(cpp_reader*)’:
../../trunk-base/gcc/c-family/c-pragma.c:417:24: error: self-comparison always
evaluates to false [-Werror=tautological-compare]
417 | if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN)
| ^~
../../trunk-base/gcc/c-family/c-attribs.c: In function ‘tree_node*
handle_scalar_storage_order_attribute(tree_node**, tree, tree, int, bool*)’:
../../trunk-base/gcc/c-family/c-attribs.c:1401:24: error: self-comparison
always evaluates to false [-Werror=tautological-compare]
1401 | if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN)
| ^~
../../trunk-base/gcc/builtins.c: In function ‘rtx_def* c_readstr(const char*,
scalar_int_mode)’:
../../trunk-base/gcc/builtins.c:830:28: error: self-comparison always evaluates
to false [-Werror=tautological-compare]
830 | if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN
| ^~
../../trunk-base/gcc/combine.c: In function ‘int
rtx_equal_for_field_assignment_p(rtx, rtx, bool)’:
../../trunk-base/gcc/combine.c:9668:28: error: self-comparison always evaluates
to false [-Werror=tautological-compare]
9668 | if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN)
| ^~
Aaron
On 12/12/18 2:42 PM, Jason Merrill wrote:
> On 12/4/18 5:35 PM, David Malcolm wrote:
>> The v1 patch:
>> https://gcc.gnu.org/ml/gcc-patches/2018-11/msg00303.html
>> has bitrotten somewhat, so here's v2 of the patch, updated relative
>> to r266740.
>>
>> Blurb from v1 patch follows:
>>
>> The C frontend is able (where expression locations are available) to print
>> problems with binary operators in 3-location form, labelling the types of
>> the expressions:
>>
>> arg_0 op arg_1
>> ~~~~~ ^~ ~~~~~
>> | |
>> | arg1 type
>> arg0 type
>>
>> The C++ frontend currently just shows the combined location:
>>
>> arg_0 op arg_1
>> ~~~~~~^~~~~~~~
>>
>> and fails to highlight where the subexpressions are, or their types.
>>
>> This patch introduces a op_location_t struct for handling the above
>> operator-location vs combined-location split, and a new
>> class binary_op_rich_location for displaying the above, so that the
>> C++ frontend is able to use the more detailed 3-location form for
>> type mismatches in binary operators, and for -Wtautological-compare
>> (where types are not displayed). Both forms can be seen in this
>> example:
>>
>> bad-binary-ops.C:69:20: error: no match for 'operator&&' (operand types are
>> 's' and 't')
>> 69 | return ns_4::foo && ns_4::inner::bar;
>> | ~~~~~~~~~ ^~ ~~~~~~~~~~~~~~~~
>> | | |
>> | s t
>> bad-binary-ops.C:69:20: note: candidate: 'operator&&(bool, bool)' <built-in>
>> 69 | return ns_4::foo && ns_4::inner::bar;
>> | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
>>
>> The patch also allows from some uses of macros in
>> -Wtautological-compare, where both sides of the comparison have
>> been spelled the same way, e.g.:
>>
>> Wtautological-compare-ranges.c:23:11: warning: self-comparison always
>> evaluates to true [-Wtautological-compare]
>> 23 | if (FOO == FOO);
>> | ^~
>>
>> Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu, in
>> conjunction with the previous patch.
>>
>> OK for trunk?
>> Dave
>>
>> gcc/c-family/ChangeLog:
>> PR c++/87504
>> * c-common.h (warn_tautological_cmp): Convert 1st param from
>> location_t to const op_location_t &.
>> * c-warn.c (find_array_ref_with_const_idx_r): Strip location
>> wrapper when testing for INTEGER_CST.
>> (warn_tautological_bitwise_comparison): Convert 1st param from
>> location_t to const op_location_t &; use it to build a
>> binary_op_rich_location, and use this.
>> (spelled_the_same_p): New function.
>> (warn_tautological_cmp): Convert 1st param from location_t to
>> const op_location_t &. Warn for macro expansions if
>> spelled_the_same_p. Use binary_op_rich_location.
>>
>> gcc/c/ChangeLog:
>> PR c++/87504
>> * c-typeck.c (class maybe_range_label_for_tree_type_mismatch):
>> Move from here to gcc-rich-location.h and gcc-rich-location.c.
>> (build_binary_op): Use struct op_location_t and
>> class binary_op_rich_location.
>>
>> gcc/cp/ChangeLog:
>> PR c++/87504
>> * call.c (op_error): Convert 1st param from location_t to
>> const op_location_t &. Use binary_op_rich_location for binary
>> ops.
>> (build_conditional_expr_1): Convert 1st param from location_t to
>> const op_location_t &.
>> (build_conditional_expr): Likewise.
>> (build_new_op_1): Likewise.
>> (build_new_op): Likewise.
>> * cp-tree.h (build_conditional_expr): Likewise.
>> (build_new_op): Likewise.
>> (build_x_binary_op): Likewise.
>> (cp_build_binary_op): Likewise.
>> * parser.c (cp_parser_primary_expression): Build a location
>> for id-expression nodes.
>> (cp_parser_binary_expression): Use an op_location_t when
>> calling build_x_binary_op.
>> (cp_parser_operator): Build a location for user-defined literals.
>> * typeck.c (build_x_binary_op): Convert 1st param from location_t
>> to const op_location_t &.
>> (cp_build_binary_op): Likewise. Use binary_op_rich_location.
>>
>> gcc/ChangeLog:
>> PR c++/87504
>> * gcc-rich-location.c
>> (maybe_range_label_for_tree_type_mismatch::get_text): Move here from
>> c/c-typeck.c.
>> (binary_op_rich_location::binary_op_rich_location): New ctor.
>> (binary_op_rich_location::use_operator_loc_p): New function.
>> * gcc-rich-location.h
>> (class maybe_range_label_for_tree_type_mismatch)): Move here from
>> c/c-typeck.c.
>> (struct op_location_t): New forward decl.
>> (class binary_op_rich_location): New class.
>> * tree.h (struct op_location_t): New struct.
>>
>> gcc/testsuite/ChangeLog:
>> * c-c++-common/Wtautological-compare-ranges.c: New test.
>> * g++.dg/cpp0x/pr51420.C: Add -fdiagnostics-show-caret and update
>> expected output.
>> * g++.dg/diagnostic/bad-binary-ops.C: Update expected output from
>> 1-location form to 3-location form, with labelling of ranges with
>> types. Add examples of id-expression nodes with namespaces.
>> * g++.dg/diagnostic/param-type-mismatch-2.C: Likewise.
>>
>> This is the 2nd commit message:
>>
>> FIXME: column and multiline fixes to * g++.dg/cpp0x/pr51420.C
>> ---
>> gcc/c-family/c-common.h | 3 +-
>> gcc/c-family/c-warn.c | 57 +++++++++++---
>> gcc/c/c-typeck.c | 41 +---------
>> gcc/cp/call.c | 28 ++++---
>> gcc/cp/cp-tree.h | 10 ++-
>> gcc/cp/parser.c | 32 ++++++--
>> gcc/cp/typeck.c | 14 ++--
>> gcc/gcc-rich-location.c | 89
>> ++++++++++++++++++++++
>> gcc/gcc-rich-location.h | 57 ++++++++++++++
>> .../c-c++-common/Wtautological-compare-ranges.c | 42 ++++++++++
>> gcc/testsuite/g++.dg/cpp0x/pr51420.C | 10 +++
>> gcc/testsuite/g++.dg/diagnostic/bad-binary-ops.C | 57 +++++++++++++-
>> .../g++.dg/diagnostic/param-type-mismatch-2.C | 4 +-
>> gcc/tree.h | 49 ++++++++++++
>> 14 files changed, 417 insertions(+), 76 deletions(-)
>> create mode 100644
>> gcc/testsuite/c-c++-common/Wtautological-compare-ranges.c
>>
>> diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
>> index 4187343..0b9ddf6 100644
>> --- a/gcc/c-family/c-common.h
>> +++ b/gcc/c-family/c-common.h
>> @@ -1268,7 +1268,8 @@ extern void constant_expression_error (tree);
>> extern void overflow_warning (location_t, tree, tree = NULL_TREE);
>> extern void warn_logical_operator (location_t, enum tree_code, tree,
>> enum tree_code, tree, enum tree_code, tree);
>> -extern void warn_tautological_cmp (location_t, enum tree_code, tree, tree);
>> +extern void warn_tautological_cmp (const op_location_t &, enum tree_code,
>> + tree, tree);
>> extern void warn_logical_not_parentheses (location_t, enum tree_code, tree,
>> tree);
>> extern bool warn_if_unused_value (const_tree, location_t);
>> diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c
>> index fc7f87c..fce9d84 100644
>> --- a/gcc/c-family/c-warn.c
>> +++ b/gcc/c-family/c-warn.c
>> @@ -322,7 +322,8 @@ find_array_ref_with_const_idx_r (tree *expr_p, int *,
>> void *)
>> if ((TREE_CODE (expr) == ARRAY_REF
>> || TREE_CODE (expr) == ARRAY_RANGE_REF)
>> - && TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST)
>> + && (TREE_CODE (tree_strip_any_location_wrapper (TREE_OPERAND (expr,
>> 1)))
>> + == INTEGER_CST))
>> return integer_type_node;
>
> I think we want fold_for_warn here. OK with that change (assuming it passes).
>
> Jason
>
--
Aaron Sawdey, Ph.D. acsaw...@linux.vnet.ibm.com
050-2/C113 (507) 253-7520 home: 507/263-0782
IBM Linux Technology Center - PPC Toolchain
