Implement clean-path
We shouldn't give non-clean paths to tools -- if a/b/../file was
specified, we can simplify that path to a/file, and not need to create
a/b just to make the path name work.
The testcases come from golang's filepath.Clean tests, this should be
compatible with that implementation.
Bug: 37716307
Test: TEST_MAKE_clean_path=true m -j blueprint_tools
Change-Id: I290a02b0a1e4a7c2b9255bca3c881589b521c402
diff --git a/core/definitions.mk b/core/definitions.mk
index 10d26c4..64bdfe6 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -3238,6 +3238,141 @@
endef
###########################################################
+## Path Cleaning
+###########################################################
+
+# Remove "dir .." combinations (but keep ".. ..")
+#
+# $(1): The expanded path, where / is converted to ' ' to work with $(word)
+define _clean-path-strip-dotdot
+$(strip \
+ $(if $(word 2,$(1)),
+ $(if $(call streq,$(word 2,$(1)),..),
+ $(if $(call streq,$(word 1,$(1)),..),
+ $(word 1,$(1)) $(call _clean-path-strip-dotdot,$(wordlist 2,$(words $(1)),$(1)))
+ ,
+ $(call _clean-path-strip-dotdot,$(wordlist 3,$(words $(1)),$(1)))
+ )
+ ,
+ $(word 1,$(1)) $(call _clean-path-strip-dotdot,$(wordlist 2,$(words $(1)),$(1)))
+ )
+ ,
+ $(1)
+ )
+)
+endef
+
+# Remove any leading .. from the path (in case of /..)
+#
+# Should only be called if the original path started with /
+# $(1): The expanded path, where / is converted to ' ' to work with $(word)
+define _clean-path-strip-root-dotdots
+$(strip $(if $(call streq,$(firstword $(1)),..),
+ $(call _clean-path-strip-root-dotdots,$(wordlist 2,$(words $(1)),$(1))),
+ $(1)))
+endef
+
+# Call _clean-path-strip-dotdot until the path stops changing
+# $(1): Non-empty if this path started with a /
+# $(2): The expanded path, where / is converted to ' ' to work with $(word)
+define _clean-path-expanded
+$(strip \
+ $(eval _ep := $(call _clean-path-strip-dotdot,$(2)))
+ $(if $(1),$(eval _ep := $(call _clean-path-strip-root-dotdots,$(_ep))))
+ $(if $(call streq,$(2),$(_ep)),
+ $(_ep),
+ $(call _clean-path-expanded,$(1),$(_ep))))
+endef
+
+# Clean the file path -- remove //, dir/.., extra .
+#
+# This should be the same semantics as golang's filepath.Clean
+#
+# $(1): The file path to clean
+define clean-path
+$(strip \
+ $(if $(call streq,$(words $(1)),1),
+ $(eval _rooted := $(filter /%,$(1)))
+ $(eval _expanded_path := $(filter-out .,$(subst /,$(space),$(1))))
+ $(eval _path := $(if $(_rooted),/)$(subst $(space),/,$(call _clean-path-expanded,$(_rooted),$(_expanded_path))))
+ $(if $(_path),
+ $(_path),
+ .
+ )
+ ,
+ $(if $(call streq,$(words $(1)),0),
+ .,
+ $(error Call clean-path with only one path (without spaces))
+ )
+ )
+)
+endef
+
+ifeq ($(TEST_MAKE_clean_path),true)
+ define my_test
+ $(if $(call streq,$(call clean-path,$(1)),$(2)),,
+ $(eval my_failed := true)
+ $(warning clean-path test '$(1)': expected '$(2)', got '$(call clean-path,$(1))'))
+ endef
+ my_failed :=
+
+ # Already clean
+ $(call my_test,abc,abc)
+ $(call my_test,abc/def,abc/def)
+ $(call my_test,a/b/c,a/b/c)
+ $(call my_test,.,.)
+ $(call my_test,..,..)
+ $(call my_test,../..,../..)
+ $(call my_test,../../abc,../../abc)
+ $(call my_test,/abc,/abc)
+ $(call my_test,/,/)
+
+ # Empty is current dir
+ $(call my_test,,.)
+
+ # Remove trailing slash
+ $(call my_test,abc/,abc)
+ $(call my_test,abc/def/,abc/def)
+ $(call my_test,a/b/c/,a/b/c)
+ $(call my_test,./,.)
+ $(call my_test,../,..)
+ $(call my_test,../../,../..)
+ $(call my_test,/abc/,/abc)
+
+ # Remove doubled slash
+ $(call my_test,abc//def//ghi,abc/def/ghi)
+ $(call my_test,//abc,/abc)
+ $(call my_test,///abc,/abc)
+ $(call my_test,//abc//,/abc)
+ $(call my_test,abc//,abc)
+
+ # Remove . elements
+ $(call my_test,abc/./def,abc/def)
+ $(call my_test,/./abc/def,/abc/def)
+ $(call my_test,abc/.,abc)
+
+ # Remove .. elements
+ $(call my_test,abc/def/ghi/../jkl,abc/def/jkl)
+ $(call my_test,abc/def/../ghi/../jkl,abc/jkl)
+ $(call my_test,abc/def/..,abc)
+ $(call my_test,abc/def/../..,.)
+ $(call my_test,/abc/def/../..,/)
+ $(call my_test,abc/def/../../..,..)
+ $(call my_test,/abc/def/../../..,/)
+ $(call my_test,abc/def/../../../ghi/jkl/../../../mno,../../mno)
+ $(call my_test,/../abc,/abc)
+
+ # Combinations
+ $(call my_test,abc/./../def,def)
+ $(call my_test,abc//./../def,def)
+ $(call my_test,abc/../../././../def,../../def)
+
+ ifdef my_failed
+ $(error failed clean-path test)
+ endif
+endif
+
+###########################################################
## Other includes
###########################################################
