Add integration test framework

v0/integration_tests/simple/expected.c

@@ -0,0 +1 @@
+Hello, world

v0/integration_tests/simple/input.c2

@@ -0,0 +1,2 @@
+module simple;
+u32 x = 123;

v0/test_integration.c

@@ -0,0 +1,63 @@
+#define _DEFAULT_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+
+int run_test(const char* dir_name) {
+    char cmd[2048];
+    char input_path[1024];
+    char expected_path[1024];
+    
+    snprintf(input_path, sizeof(input_path), "v0/integration_tests/%s/input.c2", dir_name);
+    snprintf(expected_path, sizeof(expected_path), "v0/integration_tests/%s/expected.c", dir_name);
+    
+    if (snprintf(cmd, sizeof(cmd), "./v0/bin/c2 %s > actual.c", input_path) >= sizeof(cmd)) {
+        printf("Command buffer too small for %s\n", dir_name);
+        return 1;
+    }
+    
+    if (system(cmd) != 0) {
+        printf("Failed to run compiler for %s\n", dir_name);
+        return 1;
+    }
+    
+    if (snprintf(cmd, sizeof(cmd), "diff -u %s actual.c", expected_path) >= sizeof(cmd)) {
+        printf("Command buffer too small for %s\n", dir_name);
+        return 1;
+    }
+    
+    if (system(cmd) != 0) {
+        printf("Test %s failed: Output mismatch\n", dir_name);
+        return 1;
+    }
+    
+    printf("Test %s passed\n", dir_name);
+    return 0;
+}
+
+int main() {
+    DIR* d = opendir("v0/integration_tests");
+    if (!d) {
+        perror("opendir");
+        return 1;
+    }
+    
+    struct dirent* dir;
+    int passed = 0;
+    int failed = 0;
+    
+    while ((dir = readdir(d)) != NULL) {
+        if (dir->d_type == DT_DIR && strcmp(dir->d_name, ".") != 0 && strcmp(dir->d_name, "..") != 0) {
+            if (run_test(dir->d_name) == 0) {
+                passed++;
+            } else {
+                failed++;
+            }
+        }
+    }
+    closedir(d);
+    
+    printf("\nTotal tests: %d, Passed: %d, Failed: %d\n", passed + failed, passed, failed);
+    return failed > 0 ? 1 : 0;
+}