Patchwork [v3,1/2] dependencies: build a host python2 if no suitable one cane be found

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Submitter Samuel Martin
Date June 2, 2012, 10:08 p.m.
Message ID <1338674897-1810-1-git-send-email-s.martin49@gmail.com>
Download mbox | patch
Permalink /patch/162456/
State Superseded
Headers show

Comments

Samuel Martin - June 2, 2012, 10:08 p.m.
Some distros choose to change the /usr/bin/python binary, make it pointed to
python3 instead of python2.

This may have some bad consequences for packages that uses some
non-python3-compliant python scripts in their build system (eg. in install or
post-install scripts).

This patch checks for a suitable python2 version (2.6 or 2.7) on the host
system, and declares the following variables:
- PYTHON2: pointing to the host python2 binary;
- NEED_PYTHON2: sets to "host-python" if no python2 binary has been found.

This way, a package using some python2 scripts must:
- adds $(NEED_PYTHON2) to its dependency list;
- sets $(PYTHON2) as the python binary to be used.

A side effect of this patch is getting rid of any host python. Buildroot can
runs on a host without python, or with a too old python2 version, or with only
python3.

Changes since v2:
- misc. fixes and cleanup

Changes since v1:
- use support/dependency infrastructure
- rename some symbols

Signed-off-by: Samuel Martin <s.martin49@gmail.com>

 create mode 100644 support/dependencies/check-host-python2.mk
 create mode 100755 support/dependencies/check-host-python2.sh

--
1.7.10.3
Samuel Martin - June 28, 2012, 8:58 p.m.
ping?
Arnout Vandecappelle - July 15, 2012, 11:50 a.m.
On 06/03/12 00:08, Samuel Martin wrote:
> Some distros choose to change the /usr/bin/python binary, make it pointed to
> python3 instead of python2.
>
> This may have some bad consequences for packages that uses some
> non-python3-compliant python scripts in their build system (eg. in install or
> post-install scripts).
>
> This patch checks for a suitable python2 version (2.6 or 2.7) on the host
> system, and declares the following variables:
> - PYTHON2: pointing to the host python2 binary;
> - NEED_PYTHON2: sets to "host-python" if no python2 binary has been found.
>
> This way, a package using some python2 scripts must:
> - adds $(NEED_PYTHON2) to its dependency list;
> - sets $(PYTHON2) as the python binary to be used.
>
> A side effect of this patch is getting rid of any host python. Buildroot can
> runs on a host without python, or with a too old python2 version, or with only
> python3.
>
> Changes since v2:
> - misc. fixes and cleanup
>
> Changes since v1:
> - use support/dependency infrastructure
> - rename some symbols

  The patch changelog should go under the Signed-off-by line, separated with
---

>
> Signed-off-by: Samuel Martin<s.martin49@gmail.com>

Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>


>
>   create mode 100644 support/dependencies/check-host-python2.mk
>   create mode 100755 support/dependencies/check-host-python2.sh
>
> diff --git a/support/dependencies/check-host-python2.mk b/support/dependencies/check-host-python2.mk
> new file mode 100644
> index 0000000..3b66ffc
> --- /dev/null
> +++ b/support/dependencies/check-host-python2.mk
> @@ -0,0 +1,6 @@
> +PYTHON2 = $(call suitable-host-package,python2)
> +
> +ifeq (,$(PYTHON2))

  Minor nit: we always write ifeq ($(PYTHON2),)


  Regards,
  Arnout

Patch

diff --git a/support/dependencies/check-host-python2.mk b/support/dependencies/check-host-python2.mk
new file mode 100644
index 0000000..3b66ffc
--- /dev/null
+++ b/support/dependencies/check-host-python2.mk
@@ -0,0 +1,6 @@ 
+PYTHON2 = $(call suitable-host-package,python2)
+
+ifeq (,$(PYTHON2))
+  NEED_PYTHON2 = host-python
+  PYTHON2 = $(HOST_DIR)/usr/bin/python
+endif
diff --git a/support/dependencies/check-host-python2.sh b/support/dependencies/check-host-python2.sh
new file mode 100755
index 0000000..6ad4b3a
--- /dev/null
+++ b/support/dependencies/check-host-python2.sh
@@ -0,0 +1,13 @@ 
+#!/bin/sh
+
+candidates="python python2"
+
+for candidate in ${candidates} ; do
+  which ${candidate} &>/dev/null || continue
+  # restrict version of python2 to 2.6 or 2.7
+  if ${candidate} --version 2>&1 | grep -q 'Python 2\.[6-7].*' ; then
+    # found a valid candidate, so quit now
+    echo $(which ${candidate})
+    exit
+  fi
+done