[Buildroot] [PATCH 0/4 v2] BR2_EXTERNAL, O: misc fixes and docs

[Buildroot] [PATCH 0/4 v2] BR2_EXTERNAL, O: misc fixes and docs

[Yann E. MORIN]

From: "Yann E. MORIN" <yann.morin.1998@free.fr>

Hello All!

Here is a small series that fixes use of relative paths in BR2_EXTERNAL
and documents the limitations in the manual for BR2_EXTERNAL and O.


Changes v1 -> v2:
  - don't discourage relative paths, just properly document them  (Thomas,
    Arnout)
  - fix overriding BR2_EXTERNAL  (J?r?my)
  - simplify error message when BR2_EXTERNAL is not found  (Arnout)
  - document that $(O) is created


Regards,
Yann E. MORIN.


----------------------------------------------------------------
Yann E. MORIN (4):
      manual: $(BR2_EXTERNAL)/{Config.in,external.mk} are mandatory
      Makefile: internally use absolute paths to BR2_EXTERNAL
      manual: switch BR2_EXTERNAL examples to use absolute paths
      manual: add explanations on limitations about using O=...

 Makefile                             |  5 +++++
 docs/manual/common-usage.txt         | 12 +++++++++---
 docs/manual/customize-outside-br.txt | 11 ++++++-----
 3 files changed, 20 insertions(+), 8 deletions(-)

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[Buildroot] [PATCH 1/4] manual: $(BR2_EXTERNAL)/{Config.in, external.mk} are mandatory

[Yann E. MORIN]

From: "Yann E. MORIN" <yann.morin.1998@free.fr>

The manual is a bit vague about whether Config.in and external.mk
are mandatory or optional.

Make it explicit in the manual that they are mandatory.

Reported-by: J?r?my Rosen <jeremy.rosen@openwide.fr>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
---
 docs/manual/customize-outside-br.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/manual/customize-outside-br.txt b/docs/manual/customize-outside-br.txt
index 19257e6..585eedf 100644
--- a/docs/manual/customize-outside-br.txt
+++ b/docs/manual/customize-outside-br.txt
@@ -83,6 +83,7 @@ Or disable the usage of external definitions:
    logic. Buildroot automatically includes +BR2_EXTERNAL/Config.in+ to
    make it appear in the top-level configuration menu, and includes
    +BR2_EXTERNAL/external.mk+ with the rest of the makefile logic.
+   Providing those two files is mandatory, but they can be empty.
 +
 The main usage of this is to store package recipes. The recommended
    way to do this is to write a +BR2_EXTERNAL/Config.in+ that looks
-- 
1.8.1.2

[Buildroot] [PATCH 2/4] Makefile: internally use absolute paths to BR2_EXTERNAL

[Yann E. MORIN]

From: "Yann E. MORIN" <yann.morin.1998@free.fr>

Using a relative path for BR2_EXTERNAL, and using an external defconfig,
such as in (from a Buildroot top-dir):
    make O=.. BR2_EXTERNAL=.. foo_defconfig

is broken. It is unclear why the %_defconfig rule recurses in that case.

This patch internaly makes BR2_EXTERNAL canonical (ie. makes it an absolute
path), and checks the directory exists.

Reported-by: J?r?my Rosen <jeremy.rosen@openwide.fr>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Peter Korsgaard <jacmet@uclibc.org>
Cc: Romain Naour <romain.naour@openwide.fr>
Cc: Arnout Vandecappelle <arnout@mind.be>

---
Changes v1->v2:
  - fix override BR2_EXTERNAL  (J?r?my)
  - only one error message  (Arnout)
---
 Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Makefile b/Makefile
index fceb2e8..142c78f 100644
--- a/Makefile
+++ b/Makefile
@@ -118,6 +118,11 @@ ifeq ($(BR2_EXTERNAL),)
   override BR2_EXTERNAL = support/dummy-external
   $(shell rm -f $(BR2_EXTERNAL_FILE))
 else
+  _BR2_EXTERNAL = $(shell cd $(BR2_EXTERNAL) >/dev/null 2>&1 && pwd)
+  ifeq ($(_BR2_EXTERNAL),)
+    $(error BR2_EXTERNAL='$(BR2_EXTERNAL)' does not exist, relatively to $(TOPDIR))
+  endif
+  override BR2_EXTERNAL := $(_BR2_EXTERNAL)
   $(shell echo BR2_EXTERNAL ?= $(BR2_EXTERNAL) > $(BR2_EXTERNAL_FILE))
 endif
 
-- 
1.8.1.2

[Buildroot] [PATCH 3/4] manual: switch BR2_EXTERNAL examples to use absolute paths

[Yann E. MORIN]

From: "Yann E. MORIN" <yann.morin.1998@free.fr>

Although it is possible to use relative paths, there are a few pitfalls
whith doing so. To avoid confusion for a (newcoming) user, use absolute
paths in the manual, since it is guaranteed to be working without corner
cases.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

---
Note: we only change our examples in the manual; using relative paths is
still possible. There is no additional blurb in the manual that would
favour using relative or absolute paths.
---
 docs/manual/customize-outside-br.txt | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/docs/manual/customize-outside-br.txt b/docs/manual/customize-outside-br.txt
index 585eedf..134ed64 100644
--- a/docs/manual/customize-outside-br.txt
+++ b/docs/manual/customize-outside-br.txt
@@ -30,18 +30,18 @@ there is no need to pass +BR2_EXTERNAL+ at every +make+ invocation. It
 can however be changed at any time by passing a new value, and can be
 removed by passing an empty value.
 
-The +BR2_EXTERNAL+ path can be either an absolute or a relative path,
+*Note:* the +BR2_EXTERNAL+ path can be either an absolute or a relative path,
 but if it's passed as a relative path, it is important to note that it
-is interpreted relatively to the main Buildroot source directory, not
+is interpreted relatively to the main Buildroot source directory, *not*
 the Buildroot output directory.
 
 Some examples:
 
 -----
- buildroot/ $ make BR2_EXTERNAL=../foobar menuconfig
+ buildroot/ $ make BR2_EXTERNAL=/path/to/foobar menuconfig
 -----
 
-Starting from now on, external definitions from the +../foobar+
+Starting from now on, external definitions from the +/path/to/foobar+
 directory will be used:
 
 -----
@@ -52,7 +52,7 @@ directory will be used:
 We can switch to another external definitions directory at any time:
 
 -----
- buildroot/ $ make BR2_EXTERNAL=../barfoo xconfig
+ buildroot/ $ make BR2_EXTERNAL=/where/we/have/barfoo xconfig
 -----
 
 Or disable the usage of external definitions:
-- 
1.8.1.2

[Buildroot] [PATCH 4/4] manual: add explanations on limitations about using O=...

[Yann E. MORIN]

From: "Yann E. MORIN" <yann.morin.1998@free.fr>

Using a relative path for O=... has limitations, since it is interpreted
relative to the Buildroot tree, and thus may lead to unexpected results.

For example, running this:
    make -C buildroot O=my-O

will not create my-O in the current working directory, but as a
sub-directory of the Buildroot tree, here in buildroot/my-O

Explain this in the manual (as is similarly done for BR2_EXTERNAL).
Also add a note that $(O) will be created if missing.

Also change O=.. and -C .. to O=<...> and -C <...> to make it explicit
this is an ellipse, not a relative path.

Reported-by: J?r?my Rosen <jeremy.rosen@openwide.fr>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
---
 docs/manual/common-usage.txt | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/docs/manual/common-usage.txt b/docs/manual/common-usage.txt
index 1d15c05..5e3d71d 100644
--- a/docs/manual/common-usage.txt
+++ b/docs/manual/common-usage.txt
@@ -40,7 +40,13 @@ Or:
  $ cd /tmp/build; make O=$PWD -C path/to/buildroot
 --------------------
 
-All the output files will be located under +/tmp/build+.
+All the output files will be located under +/tmp/build+. If the +O+
+path does not exist, Buildroot will create it.
+
+*Note:* the +O+ path can be either an absolute or a relative path, but if it's
+passed as a relative path, it is important to note that it is interpreted
+relative to the main Buildroot source directory, *not* the current working
+directory.
 
 When using out-of-tree builds, the Buildroot +.config+ and temporary
 files are also stored in the output directory. This means that you can
@@ -48,8 +54,8 @@ safely run multiple builds in parallel using the same source tree as
 long as they use unique output directories.
 
 For ease of use, Buildroot generates a Makefile wrapper in the output
-directory - so after the first run, you no longer need to pass +O=..+
-and +-C ..+, simply run (in the output directory):
+directory - so after the first run, you no longer need to pass +O=<...>+
+and +-C <...>+, simply run (in the output directory):
 
 --------------------
  $ make <target>
-- 
1.8.1.2

[Buildroot] [PATCH 1/4] manual: $(BR2_EXTERNAL)/{Config.in, external.mk} are mandatory

[Peter Korsgaard]

>>>>> "Yann" == Yann E MORIN <yann.morin.1998@free.fr> writes:

 > From: "Yann E. MORIN" <yann.morin.1998@free.fr>
 > The manual is a bit vague about whether Config.in and external.mk
 > are mandatory or optional.

 > Make it explicit in the manual that they are mandatory.

 > Reported-by: J?r?my Rosen <jeremy.rosen@openwide.fr>
 > Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

Committed, thanks.

-- 
Bye, Peter Korsgaard