Split tagging into a validation part including prioritization

in tag.{h,c} and {mdoc,man}_validate.c
and into a formatting part including command line argument checking
in term_tag.{h,c}, html.c, and {mdoc|man}_{term|html}.c.

Immediate functional benefits include:
* Improved prioritization of automatic tags for .Em and .Sy.
* Avoiding bogus automatic tags when .Em, .Fn, or .Sy are explicitly tagged.
* Explicit tagging of .Er and .Fl now works in HTML output.
* Automatic tagging of .IP and .TP now works in HTML output.
But mainly, this patch provides clean earth to build further improvements on.

Technical changes:
* Main program: Write a tag file for ASCII and UTF-8 output only.
* All formatters: There is no more need to delay writing the tags.
* mdoc(7)+man(7) formatters: No more need for elaborate syntax tree inspection.
* HTML formatter: If available, use the "string" attribute as the tag.
* HTML formatter: New function to write permalinks, to reduce code duplication.

Style cleanup in the vicinity while here:
* mdoc(7) terminal formatter: To set up bold font for children,
defer to termp_bold_pre() rather than calling term_fontpush() manually.
* mdoc(7) terminal formatter: Garbage collect some duplicate functions.
* mdoc(7) HTML formatter: Unify <code> handling, delete redundant functions.
* Where possible, use switch statements rather than if cascades.
* Get rid of some more Yoda notation.

The necessity for such changes was first discussed with kn@, but i didn't
bother him with a request to review the resulting -673/+782 line patch.

1 files changed, 8 insertions, 7 deletions

diff --git a/Makefile.depend b/Makefile.depend
index 3540aeda..eb8606d5 100644
--- a/Makefile.depend
+++ b/Makefile.depend
@@ -33,12 +33,12 @@ eqn_html.o: eqn_html.c config.h mandoc.h roff.h eqn.h out.h html.h
 eqn_term.o: eqn_term.c config.h eqn.h out.h term.h
 html.o: html.c config.h mandoc_aux.h mandoc_ohash.h compat_ohash.h mandoc.h roff.h out.h html.h manconf.h main.h
 lib.o: lib.c config.h roff.h libmdoc.h lib.in
-main.o: main.c config.h mandoc_aux.h mandoc.h mandoc_xr.h roff.h mdoc.h man.h mandoc_parse.h tag.h main.h manconf.h mansearch.h
+main.o: main.c config.h mandoc_aux.h mandoc.h mandoc_xr.h roff.h mdoc.h man.h mandoc_parse.h term_tag.h main.h manconf.h mansearch.h
 man.o: man.c config.h mandoc_aux.h mandoc.h roff.h man.h libmandoc.h roff_int.h libman.h
 man_html.o: man_html.c config.h mandoc_aux.h mandoc.h roff.h man.h out.h html.h main.h
 man_macro.o: man_macro.c config.h mandoc.h roff.h man.h libmandoc.h roff_int.h libman.h
-man_term.o: man_term.c config.h mandoc_aux.h mandoc.h roff.h man.h out.h term.h tag.h main.h
-man_validate.o: man_validate.c config.h mandoc_aux.h mandoc.h roff.h man.h libmandoc.h roff_int.h libman.h
+man_term.o: man_term.c config.h mandoc_aux.h mandoc.h roff.h man.h out.h term.h term_tag.h main.h
+man_validate.o: man_validate.c config.h mandoc_aux.h mandoc.h roff.h tag.h man.h libmandoc.h roff_int.h libman.h
 mandoc.o: mandoc.c config.h mandoc_aux.h mandoc.h roff.h libmandoc.h roff_int.h
 mandoc_aux.o: mandoc_aux.c config.h mandoc.h mandoc_aux.h
 mandoc_msg.o: mandoc_msg.c config.h mandoc.h
@@ -55,19 +55,19 @@ mdoc_macro.o: mdoc_macro.c config.h mandoc.h roff.h mdoc.h libmandoc.h roff_int.
 mdoc_man.o: mdoc_man.c config.h mandoc_aux.h mandoc.h roff.h mdoc.h man.h out.h main.h
 mdoc_markdown.o: mdoc_markdown.c mandoc_aux.h mandoc.h roff.h mdoc.h main.h
 mdoc_state.o: mdoc_state.c mandoc.h roff.h mdoc.h libmandoc.h roff_int.h libmdoc.h
-mdoc_term.o: mdoc_term.c config.h mandoc_aux.h roff.h mdoc.h out.h term.h tag.h main.h
-mdoc_validate.o: mdoc_validate.c config.h mandoc_aux.h mandoc.h mandoc_xr.h roff.h mdoc.h libmandoc.h roff_int.h libmdoc.h
+mdoc_term.o: mdoc_term.c config.h mandoc_aux.h roff.h mdoc.h out.h term.h term_tag.h main.h
+mdoc_validate.o: mdoc_validate.c config.h mandoc_aux.h mandoc.h mandoc_xr.h roff.h tag.h mdoc.h libmandoc.h roff_int.h libmdoc.h
 msec.o: msec.c config.h mandoc.h libmandoc.h msec.in
 out.o: out.c config.h mandoc_aux.h tbl.h out.h
 preconv.o: preconv.c config.h mandoc.h roff.h mandoc_parse.h libmandoc.h
-read.o: read.c config.h mandoc_aux.h mandoc.h roff.h mdoc.h man.h mandoc_parse.h libmandoc.h roff_int.h
+read.o: read.c config.h mandoc_aux.h mandoc.h roff.h tag.h mdoc.h man.h mandoc_parse.h libmandoc.h roff_int.h
 roff.o: roff.c config.h mandoc_aux.h mandoc_ohash.h compat_ohash.h mandoc.h roff.h mandoc_parse.h libmandoc.h roff_int.h tbl_parse.h eqn_parse.h predefs.in
 roff_html.o: roff_html.c mandoc.h roff.h out.h html.h
 roff_term.o: roff_term.c mandoc.h roff.h out.h term.h
 roff_validate.o: roff_validate.c mandoc.h roff.h libmandoc.h roff_int.h
 soelim.o: soelim.c config.h compat_stringlist.h
 st.o: st.c config.h mandoc.h roff.h libmdoc.h
-tag.o: tag.c config.h mandoc_aux.h mandoc_ohash.h compat_ohash.h mandoc.h tag.h
+tag.o: tag.c config.h mandoc_aux.h mandoc_ohash.h compat_ohash.h roff.h tag.h
 tbl.o: tbl.c config.h mandoc_aux.h mandoc.h tbl.h libmandoc.h tbl_parse.h tbl_int.h
 tbl_data.o: tbl_data.c config.h mandoc_aux.h mandoc.h tbl.h libmandoc.h tbl_int.h
 tbl_html.o: tbl_html.c config.h mandoc.h roff.h tbl.h out.h html.h
@@ -78,4 +78,5 @@ term.o: term.c config.h mandoc.h mandoc_aux.h out.h term.h main.h
 term_ascii.o: term_ascii.c config.h mandoc.h mandoc_aux.h out.h term.h manconf.h main.h
 term_ps.o: term_ps.c config.h mandoc_aux.h out.h term.h manconf.h main.h
 term_tab.o: term_tab.c mandoc_aux.h out.h term.h
+term_tag.o: term_tag.c config.h mandoc.h roff.h tag.h term_tag.h
 tree.o: tree.c config.h mandoc.h roff.h mdoc.h man.h tbl.h eqn.h main.h