PR c/64249
* c-common.c (warn_duplicated_cond_add_or_warn): New function.
* c-common.h (warn_duplicated_cond_add_or_warn): Declare.
* c.opt (Wduplicated-cond): New option.
* c-parser.c (c_parser_statement_after_labels): Add CHAIN parameter
and pass it down to c_parser_if_statement.
(c_parser_else_body): Add CHAIN parameter and pass it down to
c_parser_statement_after_labels.
(c_parser_if_statement): Add CHAIN parameter. Add code to warn about
duplicated if-else-if conditions.
* parser.c (cp_parser_statement): Add CHAIN parameter and pass it
down to cp_parser_selection_statement.
(cp_parser_selection_statement): Add CHAIN parameter. Add code to
warn about duplicated if-else-if conditions.
(cp_parser_implicitly_scoped_statement): Add CHAIN parameter and pass
it down to cp_parser_statement.
* doc/invoke.texi: Document -Wduplicated-cond.
* Makefile.in (insn-latencytab.o): Use -Wno-duplicated-cond.
(insn-dfatab.o): Likewise.
* genemit.c (gen_exp): Rewrite condition to avoid -Wduplicated-cond
warning.
* c-c++-common/Wduplicated-cond-1.c: New test.
* c-c++-common/Wduplicated-cond-2.c: New test.
* c-c++-common/Wduplicated-cond-3.c: New test.
* c-c++-common/Wduplicated-cond-4.c: New test.
* c-c++-common/Wmisleading-indentation.c (fn_37): Avoid
-Wduplicated-cond warning.
From-SVN: r228388
