From b24d8acbfffe30f40e280f11f23adac81b1e7f0c Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 29 Apr 2021 19:50:47 +0000 Subject: preprocessor: Handle digit separators in #line [PR82359] As reported in bug 82359, the preprocessor does not allow C++ digit separators in the line number in a #line directive, despite the standard syntax for that directive using digit-sequence which allows digit separators. There is some confusion in that bug about whether C++ is meant to allow digit separators there or not, but the last comment there suggests they are meant to be allowed, and the version of digit separators accepted for C2X at the March meeting explicitly mentions digit separators in the #line specification to avoid any ambiguity there. This patch thus adds code to handle digit separators in the line number in #line, as part of the preparation for enabling digit separators in C2X mode. The code changed does not contain any conditionals for whether digit separators are supported in the chosen language version, because that was handled earlier in pp-number lexing and if they aren't supported they won't appear in the string passed to that function. It does however make sure not to allow adjacent digit separators because those are only handled at a later stage of lexing at present. (Problems with how certain source character sequences involving digit separators that don't actually match the pp-number syntax get lexed as a pp-number and only diagnosed later, if at all, are bugs 83873 and 97604, to be addressed separately.) Making the change in this location will have the effect of allowing digit separators in the "# " form of directive as well as #line; I don't think that's a problem. Bootstrapped with no regressions for x86_64-pc-linux-gnu. libcpp/ PR preprocessor/82359 * directives.c (strtolinenum): Handle digit separators. gcc/testsuite/ PR preprocessor/82359 * g++.dg/cpp1y/digit-sep-line.C, g++.dg/cpp1y/digit-sep-line-neg.C: New tests. --- libcpp/directives.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'libcpp') diff --git a/libcpp/directives.c b/libcpp/directives.c index f4aa17d..795f93e 100644 --- a/libcpp/directives.c +++ b/libcpp/directives.c @@ -922,12 +922,19 @@ strtolinenum (const uchar *str, size_t len, linenum_type *nump, bool *wrapped) linenum_type reg = 0; uchar c; + bool seen_digit_sep = false; *wrapped = false; while (len--) { c = *str++; + if (!seen_digit_sep && c == '\'' && len) + { + seen_digit_sep = true; + continue; + } if (!ISDIGIT (c)) return true; + seen_digit_sep = false; if (reg > ((linenum_type) -1) / 10) *wrapped = true; reg *= 10; -- cgit v1.1