Add environment overrides for default RMLVO

You can now set default values in the environment, as well as a context
option to ignore the environment, e.g. for tests.

Signed-off-by: Daniel Stone <daniel@fooishbar.org>

configure.ac

@@ -114,6 +114,26 @@ AC_ARG_WITH([default_layout],
 AC_DEFINE_UNQUOTED([DEFAULT_XKB_LAYOUT], ["$DEFAULT_XKB_LAYOUT"],
                    [Default XKB layout])
 
+AC_ARG_WITH([default_variant],
+    [AS_HELP_STRING([--with-default-variant=<path>],
+        [Default XKB variant (default: (none))])],
+    [DEFAULT_XKB_VARIANT="$withval"],
+    [DEFAULT_XKB_VARAINT=])
+if ! test "x$DEFAULT_XKB_VARIANT" = x; then
+    AC_DEFINE_UNQUOTED([DEFAULT_XKB_VARIANT], ["$DEFAULT_XKB_VARIANT"],
+                       [Default XKB variant])
+fi
+
+AC_ARG_WITH([default_options],
+    [AS_HELP_STRING([--with-default-options=<path>],
+        [Default XKB options (default: (none))])],
+    [DEFAULT_XKB_OPTIONS="$withval"],
+    [DEFAULT_XKB_OPTIONS=])
+if ! test "x$DEFAULT_XKB_OPTIONS" = x; then
+    AC_DEFINE_UNQUOTED([DEFAULT_XKB_OPTIONS], ["$DEFAULT_XKB_OPTIONS"],
+                       [Default XKB options])
+fi
+
 AC_CONFIG_FILES([
     Makefile
     xkbcommon-uninstalled.pc

src/context.c

@@ -44,6 +44,8 @@ struct xkb_context {
     int log_verbosity;
     void *user_data;
 
+    struct xkb_rule_names names_dflt;
+
     darray(char *) includes;
     darray(char *) failed_includes;
 
@@ -52,6 +54,8 @@ struct xkb_context {
     /* Buffer for the *Text() functions. */
     char text_buffer[2048];
     size_t text_next;
+
+    unsigned int use_environment_names : 1;
 };
 
 /**
@@ -271,6 +275,14 @@ log_verbosity(const char *verbosity) {
     return 0;
 }
 
+#ifndef DEFAULT_XKB_VARIANT
+#define DEFAULT_XKB_VARIANT NULL
+#endif
+
+#ifndef DEFAULT_XKB_OPTIONS
+#define DEFAULT_XKB_OPTIONS NULL
+#endif
+
 /**
  * Create a new context.
  */
@@ -305,6 +317,8 @@ xkb_context_new(enum xkb_context_flags flags)
         return NULL;
     }
 
+    ctx->use_environment_names = !(flags & XKB_CONTEXT_NO_ENVIRONMENT_NAMES);
+
     ctx->atom_table = atom_table_new();
     if (!ctx->atom_table) {
         xkb_context_unref(ctx);
@@ -418,3 +432,61 @@ xkb_context_get_buffer(struct xkb_context *ctx, size_t size)
 
     return rtrn;
 }
+
+const char *
+xkb_context_get_default_rules(struct xkb_context *ctx)
+{
+    const char *env = NULL;
+
+    if (ctx->use_environment_names)
+        env = getenv("XKB_DEFAULT_RULES");
+
+    return env ? env : DEFAULT_XKB_RULES;
+}
+
+const char *
+xkb_context_get_default_model(struct xkb_context *ctx)
+{
+    const char *env = NULL;
+
+    if (ctx->use_environment_names)
+        env = getenv("XKB_DEFAULT_MODEL");
+
+    return env ? env : DEFAULT_XKB_MODEL;
+}
+
+const char *
+xkb_context_get_default_layout(struct xkb_context *ctx)
+{
+    const char *env = NULL;
+
+    if (ctx->use_environment_names)
+        env = getenv("XKB_DEFAULT_LAYOUT");
+
+    return env ? env : DEFAULT_XKB_LAYOUT;
+}
+
+const char *
+xkb_context_get_default_variant(struct xkb_context *ctx)
+{
+    const char *env = NULL;
+    const char *layout = getenv("XKB_DEFAULT_VARIANT");
+
+    /* We don't want to inherit the variant if they haven't also set a
+     * layout, since they're so closely paired. */
+    if (layout && ctx->use_environment_names)
+        env = getenv("XKB_DEFAULT_VARIANT");
+
+    return env ? env : DEFAULT_XKB_VARIANT;
+}
+
+const char *
+xkb_context_get_default_options(struct xkb_context *ctx)
+{
+    const char *env = NULL;
+
+    if (ctx->use_environment_names)
+        env = getenv("XKB_DEFAULT_OPTIONS");
+
+    return env ? env : DEFAULT_XKB_OPTIONS;
+}

src/context.h

@@ -77,6 +77,21 @@ xkb_log(struct xkb_context *ctx, enum xkb_log_level level,
     xkb_log_cond_level((ctx), (level), __VA_ARGS__); \
 } while (0)
 
+const char *
+xkb_context_get_default_rules(struct xkb_context *ctx);
+
+const char *
+xkb_context_get_default_model(struct xkb_context *ctx);
+
+const char *
+xkb_context_get_default_layout(struct xkb_context *ctx);
+
+const char *
+xkb_context_get_default_variant(struct xkb_context *ctx);
+
+const char *
+xkb_context_get_default_options(struct xkb_context *ctx);
+
 /*
  * The format is not part of the argument list in order to avoid the
  * "ISO C99 requires rest arguments to be used" warning when only the

src/keymap.c

@@ -153,13 +153,24 @@ xkb_keymap_new_from_names(struct xkb_context *ctx,
         return NULL;
     }
 
-    rmlvo = *rmlvo_in;
+    if (rmlvo_in)
+        rmlvo = *rmlvo_in;
+    else
+        memset(&rmlvo, 0, sizeof(rmlvo));
+
     if (isempty(rmlvo.rules))
-        rmlvo.rules = DEFAULT_XKB_RULES;
+        rmlvo.rules = xkb_context_get_default_rules(ctx);
     if (isempty(rmlvo.model))
-        rmlvo.model = DEFAULT_XKB_MODEL;
-    if (isempty(rmlvo.layout))
-        rmlvo.layout = DEFAULT_XKB_LAYOUT;
+        rmlvo.model = xkb_context_get_default_model(ctx);
+    /* Layout and variant are tied together, so don't try to use one from
+     * the caller and one from the environment. */
+    if (isempty(rmlvo.layout)) {
+        rmlvo.layout = xkb_context_get_default_layout(ctx);
+        rmlvo.variant = xkb_context_get_default_variant(ctx);
+    }
+    /* Options can be empty, so respect that if passed in. */
+    if (rmlvo.options == NULL)
+        rmlvo.options = xkb_context_get_default_options(ctx);
 
     keymap = xkb_keymap_new(ctx, format, flags);
     if (!keymap)

test/rmlvo-to-kccgst.c

@@ -61,13 +61,6 @@ main(int argc, char *argv[])
         }
     }
 
-    if (isempty(rmlvo.rules))
-        rmlvo.rules = DEFAULT_XKB_RULES;
-    if (isempty(rmlvo.model))
-        rmlvo.model = DEFAULT_XKB_MODEL;
-    if (isempty(rmlvo.layout))
-        rmlvo.layout = DEFAULT_XKB_LAYOUT;
-
     ctx = test_get_context(0);
     if (!ctx) {
         fprintf(stderr, "Failed to get xkb context\n");

xkbcommon/xkbcommon.h

@@ -417,7 +417,9 @@ xkb_keysym_to_utf32(xkb_keysym_t keysym);
 /** Flags for context creation. */
 enum xkb_context_flags {
     /** Create this context with an empty include path. */
-    XKB_CONTEXT_NO_DEFAULT_INCLUDES = (1 << 0)
+    XKB_CONTEXT_NO_DEFAULT_INCLUDES = (1 << 0),
+    /** Don't take RMLVO names from the environment. */
+    XKB_CONTEXT_NO_ENVIRONMENT_NAMES = (1 << 1),
 };
 
 /**