fbc: automatically restart fbc/parser at first executable statement i…

…f required

- some #cmdline directive will initiate a request to restart fbc/parser
- track the stage within the parser (0=preprocessor only, 1=executable statements or preprocessor)
- show a warning on #cmdline statements if they occur after the point in parsing preprocessor only

changelog.txt

@@ -14,6 +14,7 @@ Version 1.10.0
 - sf.net #953: fbc: improve compile time error messages for LINE INPUT [#] statements giving better positional information
 - sf.net #826: fbc: booleans are ranked against integer types to determine closest match in type resolution
 - sf.net #455: fbc: Allow &nnn... octal literals in source (like VALINT and friends)
+- fbc: automatically restart fbc/parser at first executable statement if required
 
 [added]
 - gas64: '.cif_sections' and '.cif_' directives for stack unwinding (adeyblue)

src/compiler/parser-toplevel.bas

@@ -31,6 +31,7 @@ declare sub parserLetEnd( )
 '':::::
 sub parserSetCtx( )
 
+	parser.stage = 0 '' start in preprocessor stage
 	parser.scope = FB_MAINSCOPE
 
 	parser.currproc = NULL
@@ -116,9 +117,16 @@ sub cProgram()
 		end if
 	#endmacro
 
+	#macro maybeRestartParser()
+		if( fbShouldRestart() ) then
+			exit sub
+		elseif( fbShouldContinue() = FALSE ) then
+			exit sub
+		end if
+	#endmacro
+
 	'' For each line...
 	do
-
 		'' parse the empty lines and comments and process directives, but
 		'' don't write to the ASM output.  Clear the output buffer for
 		'' the current line instead of calling hEmitCurrentLineText( )
@@ -138,7 +146,7 @@ sub cProgram()
 			lexSkipToken( )
 			'' need to check for exit here because directives may have been
 			'' invoked or errors occur in ppCheck() calls in lexSkipToken()
-			maybeExitParser()
+			maybeRestartParser()
 
 			'' must increment statement count after EOL's
 			parser.stmt.cnt += 1
@@ -149,14 +157,21 @@ sub cProgram()
 		'' statements in the current file scope.  if #include is
 		'' invoked, then should be handled by new include scope
 		if( cComment() ) then
-			maybeExitParser()
+			maybeRestartParser()
 			continue do
 		end if
 
-		maybeExitParser()
+		maybeRestartParser()
 
 		'' if it wasn't an empty line, comment, or directive then
 		'' we should expect a statement next requiring debug nodes
+		'' i.e. even on first entry to CProgram(), if execution makes
+		'' it to this point then next statement is expected to be something
+		'' executable.  And if the parser or fbc needed to be restarted,
+		'' it would have happened already in maybeExitParser() above
+
+		'' set parser executable code stage
+		parser.stage = 1
 
 		'' line begin
 		astAdd( astNewDBG( AST_OP_DBG_LINEINI, lexLineNum( ), env.inf.incfile ) )

src/compiler/parser.bi

@@ -174,6 +174,7 @@ type PARSERCTX
 	nsprefix        as FBSYMCHAIN ptr           '' used by cTypeOrExpression() & cIdentifier()
 
 	'' globals
+	stage           as uinteger                 '' current stage (0=preprocessor, 1=executable)
 	scope           as uinteger                 '' current scope (0=main module)
 
 	mangling        as FB_MANGLING              '' current EXTERN's mangling

src/compiler/pp.bas

@@ -10,10 +10,10 @@
 #include once "pp.bi"
 
 #define LEX_FLAGS (LEXCHECK_NOWHITESPC or _
-				   LEXCHECK_NOSUFFIX or _
-				   LEXCHECK_NODEFINE or _
-				   LEXCHECK_NOQUOTES or _
-				   LEXCHECK_NOSYMBOL)
+	LEXCHECK_NOSUFFIX or _
+	LEXCHECK_NODEFINE or _
+	LEXCHECK_NOQUOTES or _
+	LEXCHECK_NOSYMBOL)
 
 type SYMBKWD
 	name            as const zstring ptr
@@ -94,9 +94,9 @@ sub ppInit( )
 		end if
 
 		kwdTb(i).sym = symbAddKeyword( kwdTb(i).name, _
-									   kwdTb(i).id, _
-									   FB_TKCLASS_KEYWORD, _
-									   @pp.kwdns.nspc.ns.hashtb )
+			kwdTb(i).id, _
+			FB_TKCLASS_KEYWORD, _
+			@pp.kwdns.nspc.ns.hashtb )
 		if( kwdTb(i).sym = NULL ) then
 			exit sub
 		end if
@@ -871,6 +871,14 @@ declare sub fbcParseArgsFromString _
 private sub ppCmdline( )
 	dim as zstring ptr args = any
 
+	'' Prepocessor is done parsing? warn that statement is ignored
+	if( parser.stage > 0 ) then
+		errReportWarn( FB_WARNINGMSG_CMDLINEIGNORED )
+		'' error recovery: skip
+		lexSkipToken( )
+		exit sub
+	end if
+
 	if( lexGetClass( ) <> FB_TKCLASS_STRLITERAL ) then
 		errReport( FB_ERRMSG_SYNTAXERROR )
 		'' error recovery: skip