compiler: blank ident error fixes + other small cflag / parser fixes (#2418)

* merge master
* fix blank ident & add cflag error
* undo cflag changes
* fix gen_js
* undo gen_js changes
* fix
* fix

vlib/compiler/cflags.v

@@ -93,7 +93,7 @@ fn (table mut Table) parse_cflag(cflag string, mod string) {
 		if flag[0] == `-` {
 			for f in allowed_flags {
 				i := 1+f.len
-				if i < flag.len && f == flag.substr(1,i) {
+				if i <= flag.len && f == flag.substr(1,i) {
 					name = flag.left(i).trim_space()
 					flag = flag.right(i).trim_space()
 					break
@@ -137,6 +137,7 @@ fn (table mut Table) parse_cflag(cflag string, mod string) {
 			break
 		}
 	}
+	return
 }
 
 //TODO: implement msvc specific c_options_before_target and c_options_after_target ...

vlib/compiler/comptime.v

@@ -179,12 +179,14 @@ fn (p mut Parser) chash() {
 	// println('chsh() file=$p.file  hash="$hash"')
 	p.next()
 	if hash.starts_with('flag ') {
-		mut flag := hash.right(5)
-		// expand `@VROOT` `@VMOD` to absolute path
-		flag = flag.replace('@VROOT', p.vroot)
-		flag = flag.replace('@VMOD', v_modules_path)
-		//p.log('adding flag "$flag"')
-		p.table.parse_cflag(flag, p.mod)
+		p.first_pass() {
+			mut flag := hash.right(5)
+			// expand `@VROOT` `@VMOD` to absolute path
+			flag = flag.replace('@VROOT', p.vroot)
+			flag = flag.replace('@VMOD', v_modules_path)
+			//p.log('adding flag "$flag"')
+			p.table.parse_cflag(flag, p.mod)
+		}
 		return
 	}
 	if hash.starts_with('include') {

vlib/compiler/gen_c.v

@@ -92,14 +92,23 @@ fn (p mut Parser) gen_blank_identifier_assign() {
 	assign_error_tok_idx := p.token_idx
 	p.check_name()
 	p.check_space(.assign)
-	expr := p.lit
 	is_indexer := p.peek() == .lsbr
-	is_fn_call := p.peek() == .lpar || (p.peek() == .dot && p.tokens[p.token_idx+2].tok == .lpar)
-	if !is_indexer && !is_fn_call {
-		p.error_with_token_index('assigning `$expr` to `_` is redundant', assign_error_tok_idx)
+	mut expr := p.lit
+	mut is_fn_call := p.peek() == .lpar 
+	if !is_fn_call {
+		mut i := p.token_idx+1
+		for (p.tokens[i].tok == .dot || p.tokens[i].tok == .name) &&
+			p.tokens[i].lit != '_' {
+			expr += if p.tokens[i].tok == .dot { '.' } else { p.tokens[i].lit }
+			i++
+		}
+		is_fn_call = p.tokens[i].tok == .lpar
 	}
 	pos := p.cgen.add_placeholder()
 	mut typ := p.bool_expression()
+	if !is_indexer && !is_fn_call {
+		p.error_with_token_index('assigning `$expr` to `_` is redundant', assign_error_tok_idx)
+	}
 	tmp := p.get_tmp()
 	// handle or
 	if p.tok == .key_orelse {

vlib/compiler/gen_js.v

@@ -38,13 +38,22 @@ fn (p mut Parser) gen_blank_identifier_assign() {
 	assign_error_tok_idx := p.token_idx
 	p.check_name()
 	p.check_space(.assign)
-	expr := p.lit
 	is_indexer := p.peek() == .lsbr
-	is_fn_call := p.peek() == .lpar || (p.peek() == .dot && p.tokens[p.token_idx+2].tok == .lpar)
+	mut expr := p.lit
+	mut is_fn_call := p.peek() == .lpar 
+	if !is_fn_call {
+		mut i := p.token_idx+1
+		for (p.tokens[i].tok == .dot || p.tokens[i].tok == .name) &&
+			p.tokens[i].lit != '_' {
+			expr += if p.tokens[i].tok == .dot { '.' } else { p.tokens[i].lit }
+			i++
+		}
+		is_fn_call = p.tokens[i].tok == .lpar
+	}
+	p.bool_expression()
 	if !is_indexer && !is_fn_call {
 		p.error_with_token_index('assigning `$expr` to `_` is redundant', assign_error_tok_idx)
 	}
-	p.bool_expression()
 	or_else := p.tok == .key_orelse
 	//tmp := p.get_tmp()
 	if or_else {