ww: import toolchain — C bootstrap + ww-side self-host (phases 0-10)

C bootstrap (phases 0-9):
  cmd/wwc, cmd/6c, cmd/6a, cmd/6l, cmd/ww, rt, lib/*.

ww-side self-host (phase 10):
  selfhost/cmd/wwc — ww-cgen frontend; bootstrap fixed point.
  selfhost/cmd/6a  — assembler; byte-identical to C 6a (test 991).
  selfhost/cmd/6l  — linker w/ archive (.a) support; byte-identical
                     to C 6l (test 992).
  selfhost/cmd/ww  — driver (build/run/version); byte-identical to
                     C ww (test 993).

make test: 15/15. make bootstrap: ww2.s == ww3.s, ww2.o == ww3.o,
ww2 == ww3 byte-identical, with the full ww-tooled chain.

cmd/6c/main.c

@@ -0,0 +1,93 @@
+/*
+ * 6c — amd64 compiler driver. Reads a .ww source file, runs the
+ * libwwc frontend (lex → parse → check), then walks the typed AST
+ * via cgen.c and writes Plan 9-flavoured amd64 asm to stdout (or
+ * the file given by -o).
+ */
+#include "gc.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int
+slurp(const char *path, char **outbuf, u64 *outlen)
+{
+	FILE *f = fopen(path, "rb");
+	if (f == NULL) return -1;
+	fseek(f, 0, SEEK_END);
+	long n = ftell(f);
+	fseek(f, 0, SEEK_SET);
+	if (n < 0) { fclose(f); return -1; }
+	char *b = malloc((size_t)n + 1);
+	if (b == NULL) { fclose(f); return -1; }
+	if (fread(b, 1, (size_t)n, f) != (size_t)n) { free(b); fclose(f); return -1; }
+	b[n] = '\0';
+	fclose(f);
+	*outbuf = b;
+	*outlen = (u64)n;
+	return 0;
+}
+
+int
+main(int argc, char **argv)
+{
+	const char *src = NULL;
+	const char *out = NULL;
+	for (int i = 1; i < argc; i++) {
+		const char *a = argv[i];
+		if (strcmp(a, "-o") == 0 && i + 1 < argc) {
+			out = argv[++i];
+		} else if (a[0] == '-') {
+			fprintf(stderr, "6c: unknown flag %s\n", a);
+			return 2;
+		} else if (src == NULL) {
+			src = a;
+		} else {
+			fprintf(stderr, "6c: only one input supported\n");
+			return 2;
+		}
+	}
+	if (src == NULL) {
+		fputs("usage: 6c [-o out.s] file.ww\n", stderr);
+		return 2;
+	}
+
+	char *buf;
+	u64 len;
+	if (slurp(src, &buf, &len) < 0) {
+		fprintf(stderr, "6c: %s: cannot read\n", src);
+		return 1;
+	}
+
+	Arena *a = newarena();
+	Lex l;
+	Parser p;
+	Checker c;
+	Cg cg;
+
+	lexinit(&l, a, src, buf, len);
+	parserinit(&p, a, &l);
+	Node *file = parsefile(&p);
+	if (l.errs || p.errs) return 1;
+
+	check_init(&c, a);
+	check_file(&c, file);
+	if (c.errs) return 1;
+
+	FILE *of = stdout;
+	if (out) {
+		of = fopen(out, "wb");
+		if (of == NULL) {
+			fprintf(stderr, "6c: cannot open %s\n", out);
+			return 1;
+		}
+	}
+
+	cg_init(&cg, a);
+	cg_file(&cg, of, file);
+
+	if (of != stdout) fclose(of);
+	freearena(a);
+	free(buf);
+	return 0;
+}