[PATCH v3 1/2] meta: Add support for FILESEXTRAPATHS

[vijaikumar.kanagarajan@gmail.com]

From: Vijai Kumar K <Vijaikumar_Kanagarajan@mentor.com>

OE-core provides FILESEXTRAPATHS to extend the search path for
files and patches. This is particularly useful when you want to
add more files or replace existing files using bbappend.

Bring in support for FILESEXTRAPATHS from OE-core.

Signed-off-by: Vijai Kumar K <Vijaikumar_Kanagarajan@mentor.com>
---
 RECIPE-API-CHANGELOG.md   | 10 ++++++++++
 doc/user_manual.md        |  2 ++
 meta/classes/base.bbclass | 19 +++++++++++++++++++
 meta/conf/bitbake.conf    |  3 ++-
 4 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/RECIPE-API-CHANGELOG.md b/RECIPE-API-CHANGELOG.md
index bbef1a3..e9072d7 100644
--- a/RECIPE-API-CHANGELOG.md
+++ b/RECIPE-API-CHANGELOG.md
@@ -176,3 +176,13 @@ Otherwise set a encrypted root password like this:
 USERS += "root"
 USER_root[password] = "$6$rounds=10000$RXeWrnFmkY$DtuS/OmsAS2cCEDo0BF5qQsizIrq6jPgXnwv3PHqREJeKd1sXdHX/ayQtuQWVDHe0KIO0/sVH8dvQm1KthF0d/"
 ```
+### Use FILESEXTRAPATHS to add custom paths to FILESPATH
+
+Direct modification of FILESPATH variable is discouraged. Use FILESEXTRAPATHS
+instead to add a custom search path for files and patches. This makes overriding
+files and patches using bbappend a lot easier.
+
+For example:
+```
+FILESEXTRAPATHS_prepend := "$THISDIR/files:"
+```
diff --git a/doc/user_manual.md b/doc/user_manual.md
index c2657da..e096c24 100644
--- a/doc/user_manual.md
+++ b/doc/user_manual.md
@@ -321,6 +321,8 @@ Some other variables include:
  - `HOST_DISTRO_BOOTSTRAP_KEYS` - Analogously to DISTRO_BOOTSTRAP_KEYS: List of gpg key URIs used to verify apt bootstrap repo for the host.
  - `DISTRO_APT_PREMIRRORS` - The preferred mirror (append it to the default URI in the format `ftp.debian.org my.preferred.mirror`. This variable is optional.
  - `THIRD_PARTY_APT_KEYS` - List of gpg key URIs used to verify apt repos for apt installation after bootstrapping
+ - `FILESEXTRAPATHS` - The default directories BitBake uses when it processes recipes are initially defined by the FILESPATH variable. You can extend FILESPATH variable by using FILESEXTRAPATHS.
+ - `FILESOVERRIDES` - A subset of OVERRIDES used by the build system for creating FILESPATH. The FILESOVERRIDES variable uses overrides to automatically extend the FILESPATH variable.
 
 ---
 
diff --git a/meta/classes/base.bbclass b/meta/classes/base.bbclass
index 8c7b021..0670430 100644
--- a/meta/classes/base.bbclass
+++ b/meta/classes/base.bbclass
@@ -19,6 +19,7 @@
 # OTHER DEALINGS IN THE SOFTWARE.
 
 THISDIR = "${@os.path.dirname(d.getVar('FILE', True))}"
+FILESPATH = "${@base_set_filespath(["${FILE_DIRNAME}/${PF}","${FILE_DIRNAME}/${P}:${FILE_DIRNAME}/${PN}", "${FILE_DIRNAME}/files","${FILE_DIRNAME}"], d)}"
 
 def get_deb_host_arch():
     import subprocess
@@ -222,3 +223,21 @@ python do_cleanall() {
     except bb.fetch2.BBFetchException as e:
         bb.fatal(str(e))
 }
+
+# Derived from OpenEmbedded Core: meta/classes/utils.bbclass
+def base_set_filespath(path, d):
+    filespath = []
+    extrapaths = (d.getVar("FILESEXTRAPATHS") or "")
+    # Remove default flag which was used for checking
+    extrapaths = extrapaths.replace("__default:", "")
+    # Don't prepend empty strings to the path list
+    if extrapaths != "":
+        path = extrapaths.split(":") + path
+    # The ":" ensures we have an 'empty' override
+    overrides = (":" + (d.getVar("FILESOVERRIDES") or "")).split(":")
+    overrides.reverse()
+    for o in overrides:
+        for p in path:
+            if p != "":
+                filespath.append(os.path.join(p, o))
+    return ":".join(filespath)
diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index bca1114..1f20c98 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -23,8 +23,8 @@ B = "${S}"
 CVSDIR = "${DL_DIR}/cvs"
 DEPENDS = ""
 DEPLOY_DIR = "${TMPDIR}/deploy"
-FILESPATH = "${FILE_DIRNAME}/${PF}:${FILE_DIRNAME}/${P}:${FILE_DIRNAME}/${PN}:${FILE_DIRNAME}/files:${FILE_DIRNAME}"
 FILE_DIRNAME = "${@os.path.dirname(d.getVar('FILE', False))}"
+FILESEXTRAPATHS ?= "__default:"
 GITDIR = "${DL_DIR}/git"
 P = "${PN}-${PV}"
 PF = "${PN}-${PV}-${PR}"
@@ -58,6 +58,7 @@ SDKCHROOT_DIR = "${DEPLOY_DIR_SDKCHROOT}/${DISTRO}-${DISTRO_ARCH}"
 CACHE = "${TMPDIR}/cache"
 
 OVERRIDES = "${DISTRO_ARCH}:${MACHINE}:${DISTRO}:forcevariable"
+FILESOVERRIDES = "${DISTRO_ARCH}:${MACHINE}"
 
 # Setting default QEMU_ARCH variables for different DISTRO_ARCH:
 QEMU_ARCH_amd64 = "x86_64"
-- 
2.17.1