TOML,Cargo: disable the parsers temporarily

See #4096.

The TOML parser is broken. I replaced '|' in ABNF with '/' in PEG without
enough consideration when importing the ABNF definition
from https://github.com/toml-lang/toml/blob/main/toml.abnf.

I kept the code because many test cases depend on the TOML parser.
In addition, the design of the kind definition of the parser is
still valuable

The Cargo subparser is also disabled.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

Author: masatake

Units/parser-cargo.r/simple.d/args.ctags

@@ -1,4 +1,6 @@
 --languages=-TOML
+--languages=+Cargo
+
 --map-Cargo=.cargo
 --sort=no
 --fields=+lK

Units/parser-markdown.r/packcc-parser-running-within-code-block-with-bom.d/args.ctags

@@ -1 +1,3 @@
+--languages=+TOML
+
 --extras=+g

Units/parser-markdown.r/packcc-parser-running-within-code-block.d/args.ctags

@@ -1 +1,3 @@
+--languages=+TOML
+
 --extras=+g

Units/parser-sh.r/sh-heredoc-run-guest-parser-with-packcc-with-bom.d/args.ctags

@@ -1,3 +1,5 @@
+--languages=+TOML
+
 --extras=+g
 --sort=no
 --fields=+lne

Units/parser-sh.r/sh-heredoc-run-guest-parser-with-packcc.d/args.ctags

@@ -1,3 +1,5 @@
+--languages=+TOML
+
 --extras=+g
 --sort=no
 --fields=+lne

Units/parser-toml.r/run-as-guest-with-bom.d/args.ctags

@@ -1,3 +1,5 @@
+--languages=+TOML
+
 --sort=no
 --fields=+ne
 --extras=+g

Units/parser-toml.r/run-as-guest.d/args.ctags

@@ -1,3 +1,5 @@
+--languages=+TOML
+
 --sort=no
 --fields=+ne
 --extras=+g

Units/parser-toml.r/simple.d/args.ctags

@@ -1,2 +1,4 @@
+--languages=+TOML
+
 --sort=no
 --fields=+K{nth}{end}{line}

docs/news/HEAD.rst

@@ -40,12 +40,17 @@ Parser related changes
 New parsers
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-* TOML *peg/packcc*
-* Cargo *TOML based subparser*
 * SELinuxIntefae *M4 based subparser*
 * SELinuxTypeEnforcement *optlib*
 * PythonEntryPoints *subparser*
 
+.. note:: We added a TOML as a new parser in this version. However,
+		  after adding it, we learned its implementation didn't work
+		  entirely. So we deleted the TOML parser, and Cargo subparser
+		  runs on the TOML parser from this "New parsers" list.
+		  See `TOML: infinite loop <https://github.com/universal-ctags/ctags/issues/4096>`__
+		  about how it doesn't work.
+
 Changes about parser specific kinds, roles, fields, and extras
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

main/parse.c

@@ -1813,6 +1813,22 @@ extern void enableLanguage (const langType language, const bool state)
 {
 	Assert (0 <= language  &&  language < (int) LanguageCount);
 	LanguageTable [language].def->enabled = state;
+
+	static bool warned_toml;
+	static bool warned_cargo;
+
+	/* See #4096 */
+	if (!warned_toml && strcmp (LanguageTable [language].def->name, "TOML") == 0)
+	{
+		warned_toml = true;
+		error (WARNING, "The current implementation of the TOML parser is broken.");
+	}
+
+	if (!warned_cargo && strcmp (LanguageTable [language].def->name, "Cargo") == 0)
+	{
+		warned_cargo = true;
+		error (WARNING, "Enabling Cargo subparser may enable TOML parser.");
+	}
 }
 
 #ifdef DO_TRACING

parsers/cargo.c

@@ -136,5 +136,8 @@ extern parserDefinition* CargoParser (void)
 	def->patterns   = patterns;
 	def->parser     = findCargoTags;
 	def->useCork    = CORK_QUEUE;
+
+	def->enabled = false;		/* The base parser, TOML parser doesn't work well. */
+
 	return def;
 }

peg/toml_post.h

@@ -243,7 +243,9 @@ extern parserDefinition* TomlParser (void)
 	def->extensions = extensions;
 	def->parser     = findTomlTags;
 	def->useCork    = true;
-	def->enabled    = true;
 	def->requestAutomaticFQTag = false;
+
+	def->enabled    = false;	/* This parser is broken. */
+
 	return def;
 }