stage1: add linux XDG Base Directory support

- define zig global cache based on XDG spec:

    if env XDG_CACHE_HOME {
        "$XDG_CACHE_HOME/zig"
    } else {
        "$HOME/.cache/zig"
    }

- old definition "$HOME/.local/share/zig" is retired
- closes #3573

1 files changed, 25 insertions, 14 deletions

diff --git a/src/os.cpp b/src/os.cpp
index 908c3b47d9..da1f4ecfb0 100644
--- a/src/os.cpp
+++ b/src/os.cpp
@@ -1748,7 +1748,7 @@ static void utf16le_ptr_to_utf8(Buf *out, WCHAR *utf16le) {
 #endif
 
 // Ported from std.os.getAppDataDir
-Error os_get_app_data_dir(Buf *out_path, const char *appname) {
+Error os_get_cache_dir(Buf *out_path, const char *appname) {
 #if defined(ZIG_OS_WINDOWS)
     WCHAR *dir_path_ptr;
     switch (SHGetKnownFolderPath(FOLDERID_LocalAppData, KF_FLAG_CREATE, nullptr, &dir_path_ptr)) {
@@ -1774,24 +1774,35 @@ Error os_get_app_data_dir(Buf *out_path, const char *appname) {
     buf_appendf(out_path, "%s/Library/Application Support/%s", home_dir, appname);
     return ErrorNone;
 #elif defined(ZIG_OS_POSIX)
-    const char *home_dir = getenv("HOME");
-    if (home_dir == nullptr) {
-        // TODO use /etc/passwd
-        return ErrorFileNotFound;
-    }
-    if (home_dir[0] == 0) {
-        return ErrorFileNotFound;
-    }
-    buf_init_from_str(out_path, home_dir);
-    if (buf_ptr(out_path)[buf_len(out_path) - 1] != '/') {
-        buf_append_char(out_path, '/');
+    const char *cache_dir = getenv("XDG_CACHE_HOME");
+    if (cache_dir == nullptr) {
+        cache_dir = getenv("HOME");
+        if (cache_dir == nullptr) {
+            // TODO use /etc/passwd
+            return ErrorFileNotFound;
+        }
+        if (cache_dir[0] == 0) {
+            return ErrorFileNotFound;
+        }
+        buf_init_from_str(out_path, cache_dir);
+        if (buf_ptr(out_path)[buf_len(out_path) - 1] != '/') {
+            buf_append_char(out_path, '/');
+        }
+        buf_appendf(out_path, ".cache/%s", appname);
+    } else {
+        if (cache_dir[0] == 0) {
+            return ErrorFileNotFound;
+        }
+        buf_init_from_str(out_path, cache_dir);
+        if (buf_ptr(out_path)[buf_len(out_path) - 1] != '/') {
+            buf_append_char(out_path, '/');
+        }
+        buf_appendf(out_path, "%s", appname);
     }
-    buf_appendf(out_path, ".local/share/%s", appname);
     return ErrorNone;
 #endif
 }
 
-
 #if defined(ZIG_OS_LINUX) || defined(ZIG_OS_FREEBSD) || defined(ZIG_OS_NETBSD) || defined(ZIG_OS_DRAGONFLY)
 static int self_exe_shared_libs_callback(struct dl_phdr_info *info, size_t size, void *data) {
     ZigList<Buf *> *libs = reinterpret_cast< ZigList<Buf *> *>(data);