ITcl: introduce "forceUse" parameter

The original code expects the pattern `namespace import itcl' in input.
The pattern is used for detecting whether Itcl is used in the input file.
However, there can be a case that the pattern is not appeared though
the input file uses Itcl:

   package require Itcl
   namespace import itcl::*
   source input.tcl

To allow users to handle the none-self-contained case manually, this
change introduces the parameter `--param-Itcl.forceUse=1`.  If the
parameter is set, the parser runs as if 'namespace import itcl::*' is
specified at the head of input files.

Suggested-by: @bigfaceworm
Signed-off-by: Masatake YAMATO <[email protected]>

Author: masatake

Tmain/list-params.d/stdout-expected.txt

@@ -5,6 +5,7 @@ CPreProcessor  define   define replacement for an identifier (name(params,...)=d
 CPreProcessor  if0      examine code within "#if 0" branch (true or [false])
 CPreProcessor  ignore   a token to be specially handled
 Fypp           guest    parser run after Fypp parser parses the original input ("NONE" or a parser name [Fortran])
+ITcl           forceUse enable the parser even when `itcl' namespace is not specified in the input (true or [false])
 TclOO          forceUse enable the parser even when `oo' namespace is not specified in the input (true or [false])
 
 # ALL MACHINABLE
@@ -14,6 +15,7 @@ CPreProcessor	define	define replacement for an identifier (name(params,...)=defi
 CPreProcessor	if0	examine code within "#if 0" branch (true or [false])
 CPreProcessor	ignore	a token to be specially handled
 Fypp	guest	parser run after Fypp parser parses the original input ("NONE" or a parser name [Fortran])
+ITcl	forceUse	enable the parser even when `itcl' namespace is not specified in the input (true or [false])
 TclOO	forceUse	enable the parser even when `oo' namespace is not specified in the input (true or [false])
 
 # ALL MACHINABLE NOHEADER
@@ -22,6 +24,7 @@ CPreProcessor	define	define replacement for an identifier (name(params,...)=defi
 CPreProcessor	if0	examine code within "#if 0" branch (true or [false])
 CPreProcessor	ignore	a token to be specially handled
 Fypp	guest	parser run after Fypp parser parses the original input ("NONE" or a parser name [Fortran])
+ITcl	forceUse	enable the parser even when `itcl' namespace is not specified in the input (true or [false])
 TclOO	forceUse	enable the parser even when `oo' namespace is not specified in the input (true or [false])
 
 # CPP

Units/parser-itcl.r/force-use.d/args.ctags

@@ -0,0 +1,3 @@
+--sort=no
+--param-ITcl.forceUse=1
+--fields=+{language}

Units/parser-itcl.r/force-use.d/expected.tags

@@ -0,0 +1,2 @@
+MyClass	input.tcl	/^class MyClass {$/;"	c	language:ITcl
+foo	input.tcl	/^    public method foo {} {$/;"	m	language:ITcl	class:MyClass

Units/parser-itcl.r/force-use.d/input.tcl

@@ -0,0 +1,14 @@
+# Assume this source file is loaded from
+# another source file:
+# 
+#   package require Itcl
+#   namespace import itcl::*
+#   source input.tcl
+#
+class MyClass {
+    public method foo {} {
+    }
+}
+
+body MyClass::foo {} {
+}

parsers/itcl.c

@@ -9,6 +9,7 @@
 #include "general.h"  /* must always come first */
 #include "tcl.h"
 #include "entry.h"
+#include "param.h"
 #include "parse.h"
 #include "read.h"
 #include "keyword.h"
@@ -70,6 +71,8 @@ static const keywordTable ITclKeywordTable[] = {
 	{ "proc",			KEYWORD_PROC		},
 };
 
+static bool itclForceUse;
+
 static keywordId resolveKeyword (vString *string)
 {
 	char *s = vStringValue (string);
@@ -277,7 +280,7 @@ static void inputStart (subparser *s)
 {
 	struct itclSubparser *itcl = (struct itclSubparser *)s;
 
-	itcl->foundITclNamespaceImported = false;
+	itcl->foundITclNamespaceImported = itclForceUse;
 }
 
 struct itclSubparser itclSubparser = {
@@ -296,6 +299,19 @@ static void findITclTags(void)
 	scheduleRunningBaseparser (RUN_DEFAULT_SUBPARSERS);
 }
 
+static void itclForceUseParamHandler (const langType language CTAGS_ATTR_UNUSED,
+									  const char *name, const char *arg)
+{
+	itclForceUse = paramParserBool (arg, itclForceUse, name, "parameter");
+}
+
+static parameterHandlerTable ItclParameterHandlerTable [] = {
+	{ .name = "forceUse",
+	  .desc = "enable the parser even when `itcl' namespace is not specified in the input (true or [false])" ,
+	  .handleParameter = itclForceUseParamHandler,
+	},
+};
+
 extern parserDefinition* ITclParser (void)
 {
 	static const char *const extensions [] = { "itcl", NULL };
@@ -319,5 +335,8 @@ extern parserDefinition* ITclParser (void)
 	def->keywordTable = ITclKeywordTable;
 	def->keywordCount = ARRAY_SIZE (ITclKeywordTable);
 
+	def->parameterHandlerTable = ItclParameterHandlerTable;
+	def->parameterHandlerCount = ARRAY_SIZE(ItclParameterHandlerTable);
+
 	return def;
 }