Implement 'rsource' statement ('source' with relative path)

The 'rsource' statement works like 'source', but looks relative to the
Kconfig file that has the 'rsource' rather than relative to the base
Kconfig file. Using 'rsource' makes it possible to move subtrees with
Kconfig files around without breaking references to other Kconfig files.

So far, this is a Kconfiglib-exclusive feature.

1 files changed, 49 insertions, 1 deletions

diff --git a/kconfiglib.py b/kconfiglib.py
index fda12c6..c246cdc 100644
--- a/kconfiglib.py
+++ b/kconfiglib.py
@@ -300,6 +300,40 @@ If a condition is missing (e.g., <cond> when the 'if <cond>' is removed from
 functions just avoid printing 'if y' conditions to give cleaner output.
 
 
+'source' with relative path
+===========================
+
+The library implements a custom 'rsource' statement that allows to import
+Kconfig file by specifying path relative to directory of the currently parsed
+file, instead of path relative to project root.
+This extension is not supported by Linux kernel tools (yet).
+
+Consider following directory tree:
+
+  Project
+  +--Kconfig
+  |
+  +--src
+     +--Kconfig
+     |
+     +--SubSystem1
+        +--Kconfig
+        |
+        +--ModuleA
+           +--Kconfig
+
+In above example, src/SubSystem1/Kconfig imports Kconfig for ModuleA.
+With default 'source' it looks like:
+
+  source "src/SubSystem1/ModuleA/Kconfig"
+
+Using 'rsource' it can be rewritten as:
+
+  rsource "ModuleA/Kconfig"
+
+If absolute path is given to 'rsource' then it follows behavior of 'source'.
+
+
 Feedback
 ========
 
@@ -1572,6 +1606,17 @@ class Kconfig(object):
                                               prev_node)
                 self._leave_file()
 
+            elif t0 == _T_RSOURCE:
+                self._enter_file(os.path.join(
+                    os.path.dirname(self._filename),
+                    self._expand_syms(self._expect_str_and_eol())
+                ))
+                prev_node = self._parse_block(None,            # end_token
+                                              parent,
+                                              visible_if_deps,
+                                              prev_node)
+                self._leave_file()
+
             elif t0 == end_token:
                 # We have reached the end of the block. Terminate the final
                 # node and return it.
@@ -4450,13 +4495,14 @@ STR_TO_TRI = {
     _T_OR,
     _T_PROMPT,
     _T_RANGE,
+    _T_RSOURCE,
     _T_SELECT,
     _T_SOURCE,
     _T_STRING,
     _T_TRISTATE,
     _T_UNEQUAL,
     _T_VISIBLE,
-) = range(44)
+) = range(45)
 
 # Keyword to token map, with the get() method assigned directly as a small
 # optimization
@@ -4490,6 +4536,7 @@ _get_keyword = {
     "optional":       _T_OPTIONAL,
     "prompt":         _T_PROMPT,
     "range":          _T_RANGE,
+    "rsource":        _T_RSOURCE,
     "select":         _T_SELECT,
     "source":         _T_SOURCE,
     "string":         _T_STRING,
@@ -4513,6 +4560,7 @@ _STRING_LEX = frozenset((
     _T_MAINMENU,
     _T_MENU,
     _T_PROMPT,
+    _T_RSOURCE,
     _T_SOURCE,
     _T_STRING,
     _T_TRISTATE,