Implement the current_filename and current_line keywords

fixes #10243

doc/18-language-reference.md

@@ -859,6 +859,15 @@ supports:
 Additional documentation on type methods is available in the
 [library reference](19-library-reference.md#library-reference).
 
+## <a id="location-information"></a> Location Information
+
+The location of the currently executing script can be obtained using the
+`current_filename` and `current_line` keywords.
+
+Example:
+
+    log("Hello from '" + current_filename + "' in line " + current_line)
+
 ## <a id="reserved-keywords"></a> Reserved Keywords
 
 These keywords are reserved and must not be used as constants or custom attributes.
@@ -867,6 +876,7 @@ These keywords are reserved and must not be used as constants or custom attribut
     template
     include
     include_recursive
+    ignore_on_error
     library
     null
     true
@@ -887,6 +897,8 @@ These keywords are reserved and must not be used as constants or custom attribut
     if
     else
     in
+    current_filename
+    current_line
 
 You can escape reserved keywords using the `@` character. The following example
 tries to set `vars.include` which references a reserved keyword and generates

lib/base/configwriter.cpp

@@ -232,6 +232,8 @@ const std::vector<String>& ConfigWriter::GetKeywords(void)
 		keywords.push_back("locals");
 		keywords.push_back("use");
 		keywords.push_back("ignore_on_error");
+		keywords.push_back("current_filename");
+		keywords.push_back("current_line");
 		keywords.push_back("apply");
 		keywords.push_back("to");
 		keywords.push_back("where");

lib/config/config_lexer.ll

@@ -196,6 +196,8 @@ else				return T_ELSE;
 while				return T_WHILE;
 throw				return T_THROW;
 ignore_on_error			return T_IGNORE_ON_ERROR;
+current_filename		return T_CURRENT_FILENAME;
+current_line			return T_CURRENT_LINE;
 =\>				return T_FOLLOWS;
 \<\<				return T_SHIFT_LEFT;
 \>\>				return T_SHIFT_RIGHT;

lib/config/config_parser.yy

@@ -144,6 +144,8 @@ static void MakeRBinaryOp(Expression** result, Expression *left, Expression *rig
 %token T_LOCALS "locals (T_LOCALS)"
 %token T_CONST "const (T_CONST)"
 %token T_IGNORE_ON_ERROR "ignore_on_error (T_IGNORE_ON_ERROR)"
+%token T_CURRENT_FILENAME "current_filename (T_CURRENT_FILENAME)"
+%token T_CURRENT_LINE "current_line (T_CURRENT_LINE)"
 %token T_USE "use (T_USE)"
 %token T_OBJECT "object (T_OBJECT)"
 %token T_TEMPLATE "template (T_TEMPLATE)"
@@ -799,6 +801,14 @@ rterm_no_side_effect: T_STRING
 	{
 		$$ = new GetScopeExpression(ScopeLocal);
 	}
+	| T_CURRENT_FILENAME
+	{
+		$$ = MakeLiteral(@$.Path);
+	}
+	| T_CURRENT_LINE
+	{
+		$$ = MakeLiteral(@$.FirstLine);
+	}
 	| rterm_array
 	| rterm_scope_require_side_effect
 	{