Subject: 25.2; c++ angle bracket incorrect mismatch

From: "Tanis, Craig" <[email-masked]>
Date: Mon, 11 Sep 2017 14:49:57 +0000

The opening angle bracket from the stream insertion operator (<<)
becomes misclassified as an opening delimiter if a later string literal in the
file contains >>

See the following sample file.  Notice that you must type in the string
as indicated because the act of typing triggers the misclassification.
When the error occurs, the closing bracket matches the '<' right before "nice". 

I suggest pasting this into a new file and then manipulating the first string.

//---------------------------
int main(int argc, char *argv[])
{
  std::cout << "nice"; // <-- manually type in this string
  return 0;
}

void subroutine()
{
    char* foo= "a >> b";
    return;
}

//---------------------------

In GNU Emacs 25.2.1 (x86_64-apple-darwin13.4.0, NS appkit-1265.21 Version 10.9.5 (Build 13F1911))
of 2017-04-21 built on builder10-9.porkrind.org
Windowing system distributor 'Apple', version 10.3.1504
Configured using:
'configure --with-ns '--enable-locallisppath=/Library/Application
Support/Emacs/${version}/site-lisp:/Library/Application
Support/Emacs/site-lisp' --with-modules'

Configured features:
NOTIFY ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS NS MODULES

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: C++/l

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
up-list: Scan error: "Unbalanced parentheses", 34, 1
Saving file /Users/ctanis/Desktop/foo.cpp...
Wrote /Users/ctanis/Desktop/foo.cpp
user-error: The mark is not set now, so there is no region
Undo!

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message dired format-spec rfc822 mml
mml-sec password-cache epg epg-config gnus-util mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail
rfc2047 rfc2045 ietf-drums mm-util help-fns mail-prsvr mail-utils
cl-extra help-mode cc-mode cc-fonts easymenu cc-guess cc-menus cc-cmds
cc-styles cc-align cc-engine cc-vars cc-defs cl-loaddefs pcase cl-lib
time-date mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel ns-win ucs-normalize term/common-win tool-bar dnd
fontset image regexp-opt fringe tabulated-list newcomment elisp-mode
lisp-mode prog-mode register page menu-bar rfn-eshadow timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core frame
cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai
tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian
slovak czech european ethiopic indian cyrillic chinese charscript
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote kqueue cocoa ns
multi-tty make-network-process emacs)

Memory information:
((conses 16 215382 7642)
(symbols 48 21583 0)
(miscs 40 52 152)
(strings 32 20302 6885)
(string-bytes 1 698238)
(vectors 16 35302)
(vector-slots 8 678284 5012)
(floats 8 162 29)
(intervals 56 258 9)
(buffers 976 18))

----
Craig Tanis, PhD
UTC Computer Science and Engineering
[email-masked]