opts: add logic to generate options-urls.cc

Changed in v2:
- split out from the code that uses this
- now handles lang-specific URLs, as well as generic URLs
- the generated options-urls.cc now contains a function with a
  switch statement, rather than an array, to support
  lang-specific URLs:

const char *
get_opt_url_suffix (int option_index, unsigned lang_mask)
{
  switch (option_index)
    {
     [...snip...]
     case OPT_B:
       if (lang_mask & CL_D)
         return "gdc/Directory-Options.html#index-B";
       return "gcc/Directory-Options.html#index-B";
    [...snip...]
  return nullptr;
}

gcc/ChangeLog:
	* Makefile.in (ALL_OPT_URL_FILES): New.
	(GCC_OBJS): Add options-urls.o.
	(OBJS): Likewise.
	(OBJS-libcommon): Likewise.
	(s-options): Depend on $(ALL_OPT_URL_FILES), and add this to
	inputs to opt-gather.awk.
	(options-urls.cc): New Makefile target.
	* opt-functions.awk (url_suffix): New function.
	(lang_url_suffix): New function.
	* options-urls-cc-gen.awk: New file.
	* opts.h (get_opt_url_suffix): New decl.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

gcc/Makefile.in

@@ -1273,6 +1273,8 @@ FLAGS_TO_PASS = \
 # All option source files
 ALL_OPT_FILES=$(lang_opt_files) $(extra_opt_files)
 
+ALL_OPT_URL_FILES=$(patsubst %, %.urls, $(ALL_OPT_FILES))
+
 # Target specific, C specific object file
 C_TARGET_OBJS=@c_target_objs@
 
@@ -1289,7 +1291,7 @@ FORTRAN_TARGET_OBJS=@fortran_target_objs@
 RUST_TARGET_OBJS=@rust_target_objs@
 
 # Object files for gcc many-languages driver.
-GCC_OBJS = gcc.o gcc-main.o ggc-none.o gcc-urlifier.o
+GCC_OBJS = gcc.o gcc-main.o ggc-none.o gcc-urlifier.o options-urls.o
 
 c-family-warn = $(STRICT_WARN)
 
@@ -1612,6 +1614,7 @@ OBJS = \
 	optinfo.o \
 	optinfo-emit-json.o \
 	options-save.o \
+	options-urls.o \
 	opts-global.o \
 	ordered-hash-map-tests.o \
 	passes.o \
@@ -1838,7 +1841,8 @@ OBJS-libcommon = diagnostic-spec.o diagnostic.o diagnostic-color.o \
 # compiler and containing target-dependent code.
 OBJS-libcommon-target = $(common_out_object_file) prefix.o \
 	opts.o opts-common.o options.o vec.o hooks.o common/common-targhooks.o \
-	hash-table.o file-find.o spellcheck.o selftest.o opt-suggestions.o
+	hash-table.o file-find.o spellcheck.o selftest.o opt-suggestions.o \
+	options-urls.o
 
 # This lists all host objects for the front ends.
 ALL_HOST_FRONTEND_OBJS = $(foreach v,$(CONFIG_LANGUAGES),$($(v)_OBJS))
@@ -2441,9 +2445,9 @@ s-specs : Makefile
 	$(STAMP) s-specs
 
 optionlist: s-options ; @true
-s-options: $(ALL_OPT_FILES) Makefile $(srcdir)/opt-gather.awk
+s-options: $(ALL_OPT_FILES) $(ALL_OPT_URL_FILES) Makefile $(srcdir)/opt-gather.awk
 	LC_ALL=C ; export LC_ALL ; \
-	$(AWK) -f $(srcdir)/opt-gather.awk $(ALL_OPT_FILES) > tmp-optionlist
+	$(AWK) -f $(srcdir)/opt-gather.awk $(ALL_OPT_FILES) $(ALL_OPT_URL_FILES) > tmp-optionlist
 	$(SHELL) $(srcdir)/../move-if-change tmp-optionlist optionlist
 	$(STAMP) s-options
 
@@ -2459,6 +2463,12 @@ options-save.cc: optionlist $(srcdir)/opt-functions.awk $(srcdir)/opt-read.awk \
 	       -f $(srcdir)/optc-save-gen.awk \
 	       -v header_name="config.h system.h coretypes.h tm.h" < $< > $@
 
+options-urls.cc: optionlist $(srcdir)/opt-functions.awk $(srcdir)/opt-read.awk \
+    $(srcdir)/options-urls-cc-gen.awk
+	$(AWK) -f $(srcdir)/opt-functions.awk -f $(srcdir)/opt-read.awk \
+	       -f $(srcdir)/options-urls-cc-gen.awk \
+	       -v header_name="config.h system.h coretypes.h tm.h" < $< > $@
+
 options.h: s-options-h ; @true
 s-options-h: optionlist $(srcdir)/opt-functions.awk $(srcdir)/opt-read.awk \
     $(srcdir)/opth-gen.awk

gcc/opt-functions.awk

@@ -193,6 +193,21 @@ function var_name(flags)
 	return nth_arg(0, opt_args("Var", flags))
 }
 
+# If FLAGS includes a UrlSuffix flag, return the value it specifies.
+# Return the empty string otherwise.
+function url_suffix(flags)
+{
+	return nth_arg(0, opt_args("UrlSuffix", flags))
+}
+
+# If FLAGS includes a LangUrlSuffix_LANG flag, return the
+# value it specifies.
+# Return the empty string otherwise.
+function lang_url_suffix(flags, lang)
+{
+	return nth_arg(0, opt_args("LangUrlSuffix_" lang, flags))
+}
+
 # Return the name of the variable if FLAGS has a HOST_WIDE_INT variable. 
 # Return the empty string otherwise.
 function host_wide_int_var_name(flags)

gcc/options-urls-cc-gen.awk

@@ -0,0 +1,105 @@
+#  Copyright (C) 2023 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 3, or (at your option) any
+# later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# This Awk script reads in the option records generated from 
+# opt-gather.awk, and generates a C++ file containing an array
+# of URL suffixes (possibly NULL), one per option.
+
+# This program uses functions from opt-functions.awk and code from
+# opt-read.awk.
+#
+# Usage: awk -f opt-functions.awk -f opt-read.awk -f options-urls-cc-gen.awk \
+#            [-v header_name=header.h] < inputfile > options-urls.cc
+
+END {
+
+
+print "/* This file is auto-generated by options-urls-cc-gen.awk.  */"
+print ""
+n_headers = split(header_name, headers, " ")
+for (i = 1; i <= n_headers; i++)
+	print "#include " quote headers[i] quote
+print "#include " quote "opts.h" quote
+print "#include " quote "intl.h" quote
+print "#include " quote "insn-attr-common.h" quote
+print ""
+
+if (n_extra_c_includes > 0) {
+	for (i = 0; i < n_extra_c_includes; i++) {
+		print "#include " quote extra_c_includes[i] quote
+	}
+	print ""
+}
+
+print "const char *"
+print "get_opt_url_suffix (int option_index, unsigned lang_mask)"
+print "{"
+print "  switch (option_index)"
+print "    {"
+
+
+optindex = 0
+for (i = 0; i < n_opts; i++) {
+	# Combine the flags of identical switches.  Switches
+	# appear many times if they are handled by many front
+	# ends, for example.
+	while( i + 1 != n_opts && opts[i] == opts[i + 1] ) {
+		flags[i + 1] = flags[i] " " flags[i + 1];
+		i++;
+	}
+
+	len = length (opts[i]);
+	enum = opt_enum(opts[i])
+
+	# Aliases do not get enumeration names.
+	if ((flag_set_p("Alias.*", flags[i]) \
+	     && !flag_set_p("SeparateAlias", flags[i])) \
+	    || flag_set_p("Ignore", flags[i])) {
+	    show_case = 0;
+	} else {
+	    show_case = 1;
+	}
+
+	if (show_case) {
+	    printf("     case %s:\n", opt_enum(opts[i]))
+
+	    # Handle any lang-specific LangUrlSuffix directives:
+	    for (lang_idx = 0; lang_idx < n_langs; lang_idx++) {
+		lang_name = lang_sanitized_name(langs[lang_idx])
+		u = lang_url_suffix(flags[i], lang_name)
+		if (u != "") {
+		    printf("       if (lang_mask & CL_%s)\n", lang_name)
+		    printf("         return \"%s\";\n", u)
+		}
+	    }
+
+	    # Use any language-independent UrlSuffix directive:
+	    u = url_suffix(flags[i])
+	    if (u != "") {
+		printf("       return \"%s\";\n", u)
+	    } else {
+		printf("       break;\n")
+	    }
+	}
+
+	# Bump up the informational option index.
+	++optindex
+ }
+
+print "    }"
+print "  return nullptr;"
+print "}"
+}

gcc/opts.h

@@ -152,6 +152,10 @@ struct cl_option_state {
 
 extern const struct cl_option cl_options[];
 extern const unsigned int cl_options_count;
+
+extern const char *
+get_opt_url_suffix (int option_index, unsigned lang_mask);
+
 #ifdef ENABLE_PLUGIN
 extern const struct cl_var cl_vars[];
 #endif