1 files changed, 86 insertions, 0 deletions
diff --git a/src/path.c b/src/path.c
index be2b347..930fbb7 100644
--- a/src/path.c
+++ b/src/path.c
@@ -114,6 +114,92 @@ char *ecex_path_normalize(const char *path) {
     return joined;
 }
 
+static int ecex_project_root_has_marker(const char *dir) {
+    static const char *const markers[] = {
+        ".git",
+        "compile_commands.json",
+        "compile_flags.txt",
+        ".ecex-project",
+    };
+
+    for (size_t i = 0; i < sizeof(markers) / sizeof(markers[0]); i++) {
+        char *path = ecex_path_join(dir, markers[i]);
+        if (!path) continue;
+        int found = ecex_path_exists(path);
+        free(path);
+        if (found) return 1;
+    }
+
+    return 0;
+}
+
+static char *ecex_path_parent_dup(const char *path) {
+    if (!path || !path[0]) return NULL;
+
+    char *parent = ecex_strdup(path);
+    if (!parent) return NULL;
+
+    size_t len = strlen(parent);
+    while (len > 1 && parent[len - 1] == '/') parent[--len] = '\0';
+    if (strcmp(parent, "/") == 0) return parent;
+
+    char *slash = strrchr(parent, '/');
+    if (!slash) {
+        free(parent);
+        return NULL;
+    }
+
+    if (slash == parent) parent[1] = '\0';
+    else *slash = '\0';
+    return parent;
+}
+
+char *ecex_project_root_for_file(const char *path) {
+    char *start = NULL;
+
+    if (path && path[0]) {
+        if (ecex_path_is_dir(path)) {
+            start = ecex_path_normalize(path);
+        } else {
+            char *dir = ecex_path_dirname(path);
+            if (dir) {
+                start = ecex_path_normalize(dir);
+                free(dir);
+            }
+        }
+    } else {
+        char cwd[4096];
+        if (ecex_path_cwd(cwd, sizeof(cwd)) == 0) start = ecex_path_normalize(cwd);
+    }
+
+    if (!start) return NULL;
+    char *fallback = ecex_strdup(start);
+    if (!fallback) {
+        free(start);
+        return NULL;
+    }
+
+    char *dir = start;
+    while (dir && dir[0]) {
+        if (ecex_project_root_has_marker(dir)) {
+            free(fallback);
+            return dir;
+        }
+
+        char *parent = ecex_path_parent_dup(dir);
+        if (!parent || strcmp(parent, dir) == 0) {
+            free(parent);
+            break;
+        }
+
+        free(dir);
+        dir = parent;
+    }
+
+    free(dir);
+    return fallback;
+}
+
 int ecex_path_exists(const char *path) {
     if (!path) return 0;
     char *expanded = ecex_path_expand_user(path);