Add 'stage0/' from commit 'b3d106ec971300a9c745f4681fab3df7518c4346'

git-subtree-dir: stage0
git-subtree-mainline: 3db960767d
git-subtree-split: b3d106ec97

stage0/zig0.c

@@ -0,0 +1,59 @@
+#include "common.h"
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+// API:
+// - code = 0: program successfully terminated.
+// - code = 1: panicked, panic message in msg. Caller should free msg.
+// - code = 2: interpreter error, error in msg. Caller should free msg.
+static int zig0Run(const char* program, char** msg) {
+    (void)program;
+    (void)msg;
+    return 0;
+}
+
+// API: run and:
+// code = 3: abnormal error, expect something in stderr.
+int zig0RunFile(const char* fname, char** msg) {
+    FILE* f = fopen(fname, "r");
+    if (f == NULL) {
+        perror("fopen");
+        return 3;
+    }
+    fseek(f, 0, SEEK_END);
+    long fsizel = ftell(f);
+    if (fsizel == -1) {
+        perror("ftell");
+        fclose(f);
+        return 3;
+    }
+    unsigned long fsize = (unsigned long)fsizel;
+    fseek(f, 0, SEEK_SET);
+
+    char* program = malloc(fsize + 1);
+    if (program == NULL) {
+        perror("malloc");
+        fclose(f);
+        return 3;
+    }
+
+    size_t bytes_read = fread(program, 1, fsize, f);
+    if (bytes_read < fsize) {
+        if (ferror(f)) {
+            perror("fread");
+        } else {
+            fprintf(stderr, "Unexpected end of file\n");
+        }
+        free(program);
+        fclose(f);
+        return 3;
+    }
+    fclose(f);
+    program[fsize] = 0;
+
+    int code = zig0Run(program, msg);
+    free(program);
+    return code;
+}