[Bug preprocessor/82359] #line does not allow C++14 quotes in number
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82359 Joseph S. Myers changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED Resolution|--- |FIXED Target Milestone|--- |12.0 --- Comment #5 from Joseph S. Myers --- Fixed for GCC 12.
[Bug preprocessor/82359] #line does not allow C++14 quotes in number
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82359 --- Comment #4 from CVS Commits --- The master branch has been updated by Joseph Myers : https://gcc.gnu.org/g:b24d8acbfffe30f40e280f11f23adac81b1e7f0c commit r12-302-gb24d8acbfffe30f40e280f11f23adac81b1e7f0c Author: Joseph Myers Date: Thu Apr 29 19:50:47 2021 + 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.
[Bug preprocessor/82359] #line does not allow C++14 quotes in number
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82359 Aaron Ballman changed: What|Removed |Added CC||aaron at aaronballman dot com --- Comment #3 from Aaron Ballman --- (In reply to Jonathan Wakely from comment #1) > (In reply to Andrew Schepler from comment #0) > > In C++14 and later, any integer literal may contain single quote characters > > (aka apostrophe, ASCII 0x27). > > That's a standard defect (and has already been raised as such on the > committee reflector). I'm working on a proposal to add support for digit separators in C and came across this bug as part of that effort. FWIW, I looked around for a defect on this and could not find one, nor any reflector discussion on it. So I reached out to Core to ask their opinion and the position seems to be that there's no reason to disallow digit separators in #line directives. They observed that digit separators are permitted in digit sequences in general (for example, in preprocessor constant expressions), so treating #line as a special case would seem like an arbitrary inconsistency. https://lists.isocpp.org/core/2020/10/10086.php There is implementation divergence on it: GCC and EDG reject digit separators in #line; Clang and MSVC accept. I'm hoping to avoid accidentally diverging C and C++ here, so my intent is to propose to accept digit separators in C as well. Is there a reason GCC needs to reject that Core perhaps isn't aware of?
[Bug preprocessor/82359] #line does not allow C++14 quotes in number
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82359 --- Comment #2 from Jonathan Wakely --- Oops, that wasn't very clear. Digit-separators are not a defect (although that depends who you ask). But the fact that the #line directive allows them is a defect.
[Bug preprocessor/82359] #line does not allow C++14 quotes in number
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82359 --- Comment #1 from Jonathan Wakely --- (In reply to Andrew Schepler from comment #0) > In C++14 and later, any integer literal may contain single quote characters > (aka apostrophe, ASCII 0x27). That's a standard defect (and has already been raised as such on the committee reflector).
