diff mbox

[v3] Fix for GIT cross-compilation.

Message ID 1463950732-28803-1-git-send-email-mc5686@mclink.it
State Changes Requested
Headers show

Commit Message

Mauro Condarelli May 22, 2016, 8:58 p.m. UTC 
GIT configuration partially relies on system parameters retrieved
using 'uname -?' directlly at make time.
This does not mix well with cross compilation.

This patch allows to feed canned uname results directly from git.mk.

---
Changes v2 -> v3
  - Use BR2_TOOLCHAIN_HEADERS_AT_LEAST instead of BR2_LINUX_KERNEL_VERSION
                                                (suggested by T.Petazzoni)
  - Use $(call qstrip,...) to strip quotes      (suggested by T.Petazzoni)
  - Correctly spell "Buildroot"                 (suggested by T.Petazzoni)

Signed-off-by: Mauro Condarelli <mc5686@mclink.it>
---
 ...nfig.mak.uname-to-allow-cross-compilation.patch | 47 ++++++++++++++++++++++
 package/git/git.mk                                 | 10 +++++
 2 files changed, 57 insertions(+)
 create mode 100644 package/git/0001-Fix-config.mak.uname-to-allow-cross-compilation.patch

Comments

Thomas Petazzoni May 31, 2016, 7:55 p.m. UTC | #1 
Hello,

On Sun, 22 May 2016 22:58:52 +0200, Mauro Condarelli wrote:
> GIT configuration partially relies on system parameters retrieved
> using 'uname -?' directlly at make time.
> This does not mix well with cross compilation.
> 
> This patch allows to feed canned uname results directly from git.mk.
> 

Your Signed-off-by line should be here, and not after the "---",
otherwise it gets stripped when applying your patch.

Also, the commit title should always follow this convention:

	<package>: <description>

So in your case, something like:

	git: fix for build environment leak into the target

or something similar.

> Changes v2 -> v3
>   - Use BR2_TOOLCHAIN_HEADERS_AT_LEAST instead of BR2_LINUX_KERNEL_VERSION
>                                                 (suggested by T.Petazzoni)
>   - Use $(call qstrip,...) to strip quotes      (suggested by T.Petazzoni)
>   - Correctly spell "Buildroot"                 (suggested by T.Petazzoni)
> 
> Signed-off-by: Mauro Condarelli <mc5686@mclink.it>
> ---
>  ...nfig.mak.uname-to-allow-cross-compilation.patch | 47 ++++++++++++++++++++++
>  package/git/git.mk                                 | 10 +++++
>  2 files changed, 57 insertions(+)
>  create mode 100644 package/git/0001-Fix-config.mak.uname-to-allow-cross-compilation.patch

Unfortunately, your change causes a rather annoying regression: git now
gets built twice, once during the "build step" and once again during
the "install target step". I've tested with your patch, and git is only
build once, during the "build step".

Without your patch:

  http://code.bulix.org/h0xlwt-99879?raw

With your patch:

  http://code.bulix.org/msebii-99878?raw

Maybe you need to pass all the uname_<XYZ> variables during the install
step as well, so that it doesn't think it needs to rebuild the whole
thing again?

Could you have a look at this issue?

Thanks,

Thomas
diff mbox

Patch

diff --git a/package/git/0001-Fix-config.mak.uname-to-allow-cross-compilation.patch b/package/git/0001-Fix-config.mak.uname-to-allow-cross-compilation.patch
new file mode 100644
index 0000000..0305b67
--- /dev/null
+++ b/package/git/0001-Fix-config.mak.uname-to-allow-cross-compilation.patch
@@ -0,0 +1,47 @@ 
+From 9dcf7e679c441b877b63ff8e6dfc3865af6c6720 Mon Sep 17 00:00:00 2001
+From: Mauro Condarelli <mc5686@mclink.it>
+Date: Sun, 22 May 2016 20:44:26 +0200
+Subject: [PATCH 1/1] Fix config.mak.uname to allow cross-compilation
+
+Current implementation imperatively sets variables from "uname" output.
+This breaks cross-compilation because uname is run on host while target
+configuration may be different.
+
+Make current behavior a non-imperative default, so it's possible to
+force different values setting make variables.
+
+To cross-compile it will be necessary to explicitly set the various
+uname_X variables to values compatible with target.
+No change is needed with normal host compilation.
+Patch is trivial.
+
+Signed-off-by: Mauro Condarelli <mc5686@mclink.it>
+---
+ config.mak.uname | 12 ++++++------
+ 1 file changed, 6 insertions(+), 6 deletions(-)
+
+diff --git a/config.mak.uname b/config.mak.uname
+index 40d6b29..d933b23 100644
+--- a/config.mak.uname
++++ b/config.mak.uname
+@@ -1,11 +1,11 @@
+ # Platform specific Makefile tweaks based on uname detection
+ 
+-uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo not')
+-uname_M := $(shell sh -c 'uname -m 2>/dev/null || echo not')
+-uname_O := $(shell sh -c 'uname -o 2>/dev/null || echo not')
+-uname_R := $(shell sh -c 'uname -r 2>/dev/null || echo not')
+-uname_P := $(shell sh -c 'uname -p 2>/dev/null || echo not')
+-uname_V := $(shell sh -c 'uname -v 2>/dev/null || echo not')
++uname_S ?= $(shell sh -c 'uname -s 2>/dev/null || echo not')
++uname_M ?= $(shell sh -c 'uname -m 2>/dev/null || echo not')
++uname_O ?= $(shell sh -c 'uname -o 2>/dev/null || echo not')
++uname_R ?= $(shell sh -c 'uname -r 2>/dev/null || echo not')
++uname_P ?= $(shell sh -c 'uname -p 2>/dev/null || echo not')
++uname_V ?= $(shell sh -c 'uname -v 2>/dev/null || echo not')
+ 
+ ifdef MSVC
+ 	# avoid the MingW and Cygwin configuration sections
+-- 
+2.1.4
+
diff --git a/package/git/git.mk b/package/git/git.mk
index db26036..105f3fa 100644
--- a/package/git/git.mk
+++ b/package/git/git.mk
@@ -63,4 +63,14 @@  GIT_CONF_ENV += \
 	ac_cv_fread_reads_directories=yes \
 	ac_cv_snprintf_returns_bogus=yes LIBS='$(GIT_CONF_ENV_LIBS)'
 
+# git has make-time configuration based on uname; pass over specific
+# values to be used in config.mak.uname unstead of `uname -#` output
+GIT_MAKE_OPTS += \
+	uname_S="Linux" \
+	uname_M=$(BR2_ARCH) \
+	uname_O="GNU/Linux" \
+	uname_R=$(BR2_TOOLCHAIN_HEADERS_AT_LEAST) \
+	uname_P="unknown" \
+	uname_V="Buildroot Linux $(call qstrip,$(BR2_TOOLCHAIN_HEADERS_AT_LEAST))"
+
 $(eval $(autotools-package))