From 10ef8f287e92cad2f6963a9ee25d954c87567629 Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Fri, 23 Jan 2015 11:57:43 +0000 Subject: re PR preprocessor/60570 (expression in 'elif' directive mis-diagnosed as error when group will be skipped) DR#412 PR preprocessor/60570 * directives.c (do_elif): Don't evaluate #elif conditionals when they don't need to be. * gcc.dg/cpp/pr36320.c: Turn dg-error into dg-bogus. * gcc.dg/cpp/pr60570.c: New test. From-SVN: r220035 --- libcpp/directives.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) (limited to 'libcpp/directives.c') diff --git a/libcpp/directives.c b/libcpp/directives.c index ab4f15c..37cd109 100644 --- a/libcpp/directives.c +++ b/libcpp/directives.c @@ -2036,23 +2036,16 @@ do_elif (cpp_reader *pfile) } ifs->type = T_ELIF; - if (! ifs->was_skipping) + /* See DR#412: "Only the first group whose control condition + evaluates to true (nonzero) is processed; any following groups + are skipped and their controlling directives are processed as + if they were in a group that is skipped." */ + if (ifs->skip_elses) + pfile->state.skipping = 1; + else { - bool value; - /* The standard mandates that the expression be parsed even - if we are skipping elses at this point -- the lexical - restrictions on #elif only apply to skipped groups, but - this group is not being skipped. Temporarily set - skipping to false to get lexer warnings. */ - pfile->state.skipping = 0; - value = _cpp_parse_expr (pfile, false); - if (ifs->skip_elses) - pfile->state.skipping = 1; - else - { - pfile->state.skipping = ! value; - ifs->skip_elses = value; - } + pfile->state.skipping = ! _cpp_parse_expr (pfile, false); + ifs->skip_elses = ! pfile->state.skipping; } /* Invalidate any controlling macro. */ -- cgit v1.1