ww+wcc: emit and lex // MODULE: <name> directive in combined.ww

selfhost/cmd/wcc/lex.ww

@@ -25,6 +25,7 @@ type lex = struct {
 	col:    i32,
 	a:      *arena,
 	errs:   i32,
+	module: str,	// current module from `// MODULE: foo` directive; "" if none
 };
 
 export fn lexinit(l: *lex, a: *arena, file: str, src: *u8, len: u64) void = {
@@ -36,6 +37,10 @@ export fn lexinit(l: *lex, a: *arena, file: str, src: *u8, len: u64) void = {
 	l.col = 1;
 	l.a = a;
 	l.errs = 0;
+	let empty: str;
+	empty.ptr = nil;
+	empty.len = 0;
+	l.module = empty;
 };
 
 // srcb — byte at offset; helper that lifts the cast out of indexing.
@@ -113,6 +118,32 @@ fn skipws(l: *lex) bool = {
 		if (c == 47) {	// '/'
 			let c2: i32 = lpeek(l, 1u64);
 			if (c2 == 47) {
+				lget(l); lget(l);	// consume '//'
+				// Driver injects `// MODULE: foo` before each
+				// source file's contents; capture so cgen can
+				// mangle private symbols by module.
+				if (lpeek(l, 0u64) == 32) {	// ' '
+				if (lpeek(l, 1u64) == 77) {	// 'M'
+				if (lpeek(l, 2u64) == 79) {	// 'O'
+				if (lpeek(l, 3u64) == 68) {	// 'D'
+				if (lpeek(l, 4u64) == 85) {	// 'U'
+				if (lpeek(l, 5u64) == 76) {	// 'L'
+				if (lpeek(l, 6u64) == 69) {	// 'E'
+				if (lpeek(l, 7u64) == 58) {	// ':'
+				if (lpeek(l, 8u64) == 32) {	// ' '
+					let i: i32 = 0;
+					for (i < 9) { lget(l); i += 1; };
+					let start: u64 = l.lpos;
+					for (true) {
+						let cx: i32 = lpeek(l, 0u64);
+						if (cx < 0) { break; };
+						if (cx == 10) { break; };
+						if (cx == 13) { break; };
+						lget(l);
+					};
+					let n: u64 = l.lpos - start;
+					l.module = astrndup(l.a, l.src + start, n);
+				};};};};};};};};};
 				for (true) {
 					let cx: i32 = lpeek(l, 0u64);
 					if (cx < 0) { return false; };