[groff] 25/25: Slow our roll on withdrawal of AT&T font support.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 5011cd1d5a647d977f74ccaad21e5abe004fe30e
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Mon Oct 28 18:16:40 2024 -0500

    Slow our roll on withdrawal of AT&T font support.
    
    Deprecate rather than withdrawing support for AT&T font names, on "pdf"
    and "ps" devices only.
    
    * tmac/ps.tmac: Restore font translations to groff font names.
    
    * src/roff/troff/env.cpp: New global vector
      `deprecated_font_identifiers` stores deprecated AT&T font names.  Add
      external declaration of `is_device_ps_or_pdf`.
    
      (warn_if_font_name_deprecated): New function searches vector for given
      symbol `nm` (a font name); if found, throws a warning in category
      "font" and deletes the name from the vector.
    
      (environment::set_font): If `is_device_ps_or_pdf`, call
      `warn_if_font_name_deprecated()`.
    
      (init_env_requests): Populate new vector.
    
    * src/roff/troff/input.cpp: New global Boolean tracks whether the output
      device is named "pdf" or "ps".  We need this because "CW" is a valid,
      non-deprecated font name on the "dvi" device.
    
      (main): Once the name of the output device is determined, update
      `is_device_ps_or_pdf` if necessary.
    
    * NEWS: Revise item.
    
    Thanks to Deri James for the discussion; see
    <https://lists.gnu.org/archive/html/groff/2024-10/msg00066.html> and
    follow-ups.
---
 ChangeLog                | 29 +++++++++++++++++++++++++++++
 NEWS                     | 41 +++++++++++++++++++++++++----------------
 src/roff/troff/env.cpp   | 44 ++++++++++++++++++++++++++++++++++++++++++++
 src/roff/troff/input.cpp |  4 ++++
 tmac/ps.tmac             | 22 ++++++++++++++++++++++
 5 files changed, 124 insertions(+), 16 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 16ff148ce..15b1496b8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,32 @@
+2024-10-28  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       Deprecate rather than withdrawing support for AT&T font names,
+       on "pdf" and "ps" devices only.
+
+       * tmac/ps.tmac: Restore font translations to groff font names.
+
+       * src/roff/troff/env.cpp: New global vector
+       `deprecated_font_identifiers` stores deprecated AT&T font names.
+       Add external declaration of `is_device_ps_or_pdf`.
+       (warn_if_font_name_deprecated): New function searches vector for
+       given symbol `nm` (a font name); if found, throws a warning in
+       category "font" and deletes the name from the vector.
+       (environment::set_font): If `is_device_ps_or_pdf`, call
+       `warn_if_font_name_deprecated()`.
+       (init_env_requests): Populate new vector.
+
+       * src/roff/troff/input.cpp: New global Boolean tracks whether
+       the output device is named "pdf" or "ps".  We need this because
+       "CW" is a valid, non-deprecated font name on the "dvi" device.
+       (main): Once the name of the output device is determined, update
+       `is_device_ps_or_pdf` if necessary.
+
+       * NEWS: Revise item.
+
+       Thanks to Deri James for the discussion; see
+       <https://lists.gnu.org/archive/html/groff/2024-10/msg00066.html>
+       and follow-ups.
+
 2024-10-23  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * src/roff/troff/env.cpp (environment::print_env): Rearrange
diff --git a/NEWS b/NEWS
index 59a70a7f7..8f16e6239 100644
--- a/NEWS
+++ b/NEWS
@@ -185,22 +185,31 @@ Macro packages
    multi-line headings.  Thanks to Peter Schaffter.
 
 *  The device-specific macro files loaded by "troffrc" automatically on
-   startup, such as "ps.tmac" and "html.tmac", no longer perform font
-   translations for font names used by varieties of AT&T troff ('C',
-   'Hb', 'HX', and many others).  These names are not portable: in AT&T
-   troff, the font repertoire, like the special character repertoire,
-   was device-dependent.  Since groff 1.23.0, GNU troff diagnoses
-   attempts to use nonexistent font names.  We recommend addressing such
-   portability issues wherever suits you: (1) in a document, perhaps by
-   using `ie` and `el` requests and the `.g` register to test whether
-   the formatter claims support for groff extensions, then `ie` and `el`
-   again with the `F` groff conditional expression operator to check for
-   font availability, and performing font remappings with the groff
-   `ftr` request as desired; (2) doing so in your "troffrc" file; or (3)
-   by modifying these macro files similarly.  Users of the "dvi" and
-   "lbp" output devices should be aware that these devices don't supply
-   full families of monospaced fonts (and never have).  See grodvi(1)
-   and grolbp(1).
+   startup, such as "html.tmac", no longer perform font translations for
+   font names used by varieties of AT&T troff ('C', 'Hb', 'HX', and
+   several others).
+
+   These names are not portable: in AT&T troff, the font repertoire,
+   like the special character repertoire, was device-dependent.  Since
+   groff 1.23.0, GNU troff diagnoses attempts to use nonexistent font
+   names.  We recommend addressing such portability issues wherever
+   suits you: (1) in a document, perhaps by using `ie` and `el` requests
+   and the `.g` register to test whether the formatter claims support
+   for groff extensions, then `ie` and `el` again with the `F` groff
+   conditional expression operator to check for font availability, and
+   performing font remappings with the groff `ftr` request as desired;
+   (2) doing so in your "troffrc" file; or (3) by modifying these macro
+   files similarly.  Users of the "dvi" and "lbp" output devices should
+   be aware that these devices don't supply full families of monospaced
+   fonts (and never have).  See grodvi(1) and grolbp(1) for lists of
+   font names supported by each device.
+
+   The legacy names are retained for the "pdf" and "ps" devices for this
+   release; however, use of them prompts one warning in the "font"
+   category from the formatter per deprecated name.  We expect to
+   withdraw support for the names completely in the next groff release.
+   See gropdf(1) and grops(1) for lists of font names supported by each
+   device.
 
 *  Hyperlink support is now enabled by default on PDF and terminal
    devices for an (man) and doc (mdoc) documents.  Instructions and
diff --git a/src/roff/troff/env.cpp b/src/roff/troff/env.cpp
index c3c341e21..33f51d10e 100644
--- a/src/roff/troff/env.cpp
+++ b/src/roff/troff/env.cpp
@@ -39,6 +39,9 @@ along with this program.  If not, see 
<http://www.gnu.org/licenses/>. */
 #include <errno.h> // errno
 #include <math.h> // ceil()
 
+#include <vector>
+#include <algorithm> // find()
+
 symbol default_family("T");
 
 enum { ADJUST_LEFT = 0,
@@ -556,12 +559,32 @@ static node *configure_space_underlining(bool b)
   return new device_extension_node(m, 1);
 }
 
+// TODO: Kill this off in groff 1.25.
+std::vector<string> deprecated_font_identifiers;
+extern bool is_device_ps_or_pdf; // See input.cpp.
+
+static void warn_if_font_name_deprecated(symbol nm)
+{
+  const char *name = nm.contents();
+  std::vector<string>::iterator it
+    = find(deprecated_font_identifiers.begin(),
+          deprecated_font_identifiers.end(), name);
+  if (it != deprecated_font_identifiers.end()) {
+    warning(WARN_FONT, "font name '%1' is deprecated", name);
+    // Warn only once for each name.
+    deprecated_font_identifiers.erase(it);
+  }
+}
+
 bool environment::set_font(symbol nm)
 {
   if (line_interrupted) {
     warning(WARN_FONT, "ignoring font selection on interrupted line");
     return true; // "no operation" is successful
   }
+  // TODO: Kill off in groff 1.25.
+  if (is_device_ps_or_pdf)
+    warn_if_font_name_deprecated(nm);
   if (nm == symbol("P") || nm.is_empty()) {
     if (family->make_definite(prev_fontno) < 0)
       return false;
@@ -4302,6 +4325,27 @@ void init_env_requests()
   register_dictionary.define("skw", new variable_reg(&skw_reg_contents));
   register_dictionary.define("ssc", new variable_reg(&ssc_reg_contents));
   register_dictionary.define("st", new variable_reg(&st_reg_contents));
+  // TODO: Kill the following off in groff 1.25.
+  deprecated_font_identifiers.push_back("AX");
+  deprecated_font_identifiers.push_back("KR");
+  deprecated_font_identifiers.push_back("KI");
+  deprecated_font_identifiers.push_back("KB");
+  deprecated_font_identifiers.push_back("KX");
+  deprecated_font_identifiers.push_back("CW");
+  deprecated_font_identifiers.push_back("C");
+  deprecated_font_identifiers.push_back("CO");
+  deprecated_font_identifiers.push_back("CX");
+  deprecated_font_identifiers.push_back("H");
+  deprecated_font_identifiers.push_back("HO");
+  deprecated_font_identifiers.push_back("HX");
+  deprecated_font_identifiers.push_back("Hr");
+  deprecated_font_identifiers.push_back("Hi");
+  deprecated_font_identifiers.push_back("Hb");
+  deprecated_font_identifiers.push_back("Hx");
+  deprecated_font_identifiers.push_back("PA");
+  deprecated_font_identifiers.push_back("PX");
+  deprecated_font_identifiers.push_back("NX");
+  deprecated_font_identifiers.push_back("ZI");
 }
 
 // Appendix H of _The TeXbook_ is useful background for the following.
diff --git a/src/roff/troff/input.cpp b/src/roff/troff/input.cpp
index ddb5db681..cdfeb2f77 100644
--- a/src/roff/troff/input.cpp
+++ b/src/roff/troff/input.cpp
@@ -112,6 +112,7 @@ bool is_writing_html = false;
 static int suppression_level = 0;      // depth of nested \O escapes
 
 bool in_nroff_mode = false;
+bool is_device_ps_or_pdf = false;
 
 // Keep track of whether \f, \F, \D'F...', \H, \m, \M, \O[345], \R, \s,
 // or \S has been processed in token::next().
@@ -9034,6 +9035,9 @@ int main(int argc, char **argv)
   if (want_unsafe_requests)
     mac_path = &macro_path;
   set_string(".T", device);
+  // TODO: Kill this off in groff 1.25.  See env.cpp.
+  if ((strcmp("pdf", device) == 0) || strcmp("ps", device) == 0)
+    is_device_ps_or_pdf = true;
   init_charset_table();
   init_hpf_code_table();
   if (0 /* nullptr */ == font::load_desc())
diff --git a/tmac/ps.tmac b/tmac/ps.tmac
index 5ddc45aca..f77a827ff 100644
--- a/tmac/ps.tmac
+++ b/tmac/ps.tmac
@@ -3,6 +3,28 @@
 .do nr *groff_ps_tmac_C \n[.cp]
 .cp 0
 .
+.\" These font translations will be withdrawn in groff 1.25.
+.ftr AX ABI
+.ftr KR BMR
+.ftr KI BMI
+.ftr KB BMB
+.ftr KX BMBI
+.ftr CW CR
+.ftr CO CI
+.ftr CX CBI
+.ftr H HR
+.ftr HO HI
+.ftr HX HBI
+.ftr Hr HNR
+.ftr Hi HNI
+.ftr Hb HNB
+.ftr Hx HNBI
+.ftr NX NBI
+.ftr PA PR
+.ftr PX PBI
+.ftr ZI ZCMI
+.ftr C CR
+.
 .cflags 8 \[an]
 .
 .char \[radicalex] \h'-\w'\[sr]'u'\[radicalex]\h'\w'\[sr]'u'