[groff] 10/26: [refer]: Refactor diagnostic message reporting.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit be87fd2c03f6fca0109db6ea9469c63db22b7f43
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Thu May 5 17:31:35 2022 -0500

    [refer]: Refactor diagnostic message reporting.
    
    * src/preproc/refer/command.cpp (process_commands): Begin migration to
      use existing global variables for location reports in diagnostic
      messages.  Save current file name and line number before calling
      `command_loop()` and restore them afterward.  Also decrement line
      counter before entering that loop because it would be too far advanced
      by one due to the final newline on a parsed input line.
---
 ChangeLog                     | 10 ++++++++++
 src/preproc/refer/command.cpp |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 4a5acce0..774456e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2022-05-05  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       * src/preproc/refer/command.cpp (process_commands): Begin
+       migration to use existing global variables for location reports
+       in diagnostic messages.  Save current file name and line number
+       before calling `command_loop()` and restore them afterward.
+       Also decrement line counter before entering that loop because it
+       would be too far advanced by one due to the final newline on a
+       parsed input line.
+
 2022-05-05  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * src/preproc/refer/refer.cpp (main): Report system error on
diff --git a/src/preproc/refer/command.cpp b/src/preproc/refer/command.cpp
index c7014b62..c2076d9b 100644
--- a/src/preproc/refer/command.cpp
+++ b/src/preproc/refer/command.cpp
@@ -795,9 +795,16 @@ static void command_loop()
 
 void process_commands(string &s, const char *file, int lineno)
 {
+  const char *saved_filename = current_filename;
+  int saved_lineno = current_lineno;
   input_stack::init();
+  current_filename = file;
+  // Report diagnostics with respect to line _before_ last newline seen.
+  current_lineno = lineno - 1;
   input_stack::push_string(s, file, lineno);
   command_loop();
+  current_filename = saved_filename;
+  current_lineno = saved_lineno;
 }
 
 // Local Variables: