pkg-infra: add <pkg>_CONFIG_FIXUP to fix *-config files

This patch will add <pkg>_CONFIG_FIXUP variable to buildroot infra.

It's purpose is to inform buildroot that the package in question
contains some $(STAGING_DIR)/usr/bin/*-config files and that we
want to automatically fix prefixes of such files.

It is often the case that many packages call these
files during their configuration step to determine 3rd party
library package locations and any flags needed to link against them.

For example:
Some package might try to check the existense and linking flags
of NSPR package by calling $(STAGING_DIR)/usr/bin/nspr-config --prefix.
Without this fix. NSPR would return /usr/ as it's prefix which is
wrong when cross-compiling.
Correct would be $(STAGING_DIR)/usr.

All packages that have <pkg>_INSTALL_STAGING = YES defined and
also install some config file(s) into $(STAGING_DIR)/usr/bin must
hereafter also define <pkg>_CONFIG_FIXUP with the correspondig
filename(s).

For example:

DIVINE_CONFIG_FIXUP = divine-config

or for multiple files:

IMAGEMAGICK_CONFIG_FIXUP = Magick-config Wand-config

Signed-off-by: Stefan Fröberg <stefan.froberg@petroprogram.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

docs/manual/adding-packages-generic.txt

@@ -25,32 +25,33 @@ system is based on hand-written Makefiles or shell scripts.
 09: LIBFOO_LICENSE = GPLv3+
 10: LIBFOO_LICENSE_FILES = COPYING
 11: LIBFOO_INSTALL_STAGING = YES
-12: LIBFOO_DEPENDENCIES = host-libaaa libbbb
-13:
-14: define LIBFOO_BUILD_CMDS
-15:	$(MAKE) CC="$(TARGET_CC)" LD="$(TARGET_LD)" -C $(@D) all
-16: endef
-17:
-18: define LIBFOO_INSTALL_STAGING_CMDS
-19:	$(INSTALL) -D -m 0755 $(@D)/libfoo.a $(STAGING_DIR)/usr/lib/libfoo.a
-20:	$(INSTALL) -D -m 0644 $(@D)/foo.h $(STAGING_DIR)/usr/include/foo.h
-21:	$(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(STAGING_DIR)/usr/lib
-22: endef
-23:
-24: define LIBFOO_INSTALL_TARGET_CMDS
-25:	$(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(TARGET_DIR)/usr/lib
-26:	$(INSTALL) -d -m 0755 $(TARGET_DIR)/etc/foo.d
-27: endef
-28:
-29: define LIBFOO_DEVICES
-30:	/dev/foo  c  666  0  0	42  0  -  -  -
-31: endef
-32:
-33: define LIBFOO_PERMISSIONS
-34:	/bin/foo  f  4755  0  0	 -  -  -  -  -
-35: endef
-36:
-37: $(eval $(generic-package))
+12: LIBFOO_CONFIG_FIXUP = libfoo-config
+13: LIBFOO_DEPENDENCIES = host-libaaa libbbb
+14:
+15: define LIBFOO_BUILD_CMDS
+16:	$(MAKE) CC="$(TARGET_CC)" LD="$(TARGET_LD)" -C $(@D) all
+17: endef
+18:
+19: define LIBFOO_INSTALL_STAGING_CMDS
+20:	$(INSTALL) -D -m 0755 $(@D)/libfoo.a $(STAGING_DIR)/usr/lib/libfoo.a
+21:	$(INSTALL) -D -m 0644 $(@D)/foo.h $(STAGING_DIR)/usr/include/foo.h
+22:	$(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(STAGING_DIR)/usr/lib
+23: endef
+24:
+25: define LIBFOO_INSTALL_TARGET_CMDS
+26:	$(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(TARGET_DIR)/usr/lib
+27:	$(INSTALL) -d -m 0755 $(TARGET_DIR)/etc/foo.d
+28: endef
+29:
+30: define LIBFOO_DEVICES
+31:	/dev/foo  c  666  0  0	42  0  -  -  -
+32: endef
+33:
+34: define LIBFOO_PERMISSIONS
+35:	/bin/foo  f  4755  0  0	 -  -  -  -  -
+36: endef
+37:
+38: $(eval $(generic-package))
 --------------------------------
 
 The Makefile begins on line 6 to 10 with metadata information: the
@@ -69,7 +70,45 @@ install header files and other development files in the staging space.
 This will ensure that the commands listed in the
 +LIBFOO_INSTALL_STAGING_CMDS+ variable will be executed.
 
-On line 12, we specify the list of dependencies this package relies
+On line 12, we specify that there is some fixing to be done to some
+of the 'libfoo-config' files that were installed during
++LIBFOO_INSTALL_STAGING_CMDS+ phase.
+These *-config files are executable shell script files that are
+located in '$(STAGING_DIR)/usr/bin' directory and are executed
+by other 3rd party packages to find out the location and the linking
+flags of this particular package.
+
+The problem is that all these *-config files by default give wrong,
+host system linking flags that are unsuitable for cross-compiling.
+
+For example:	'-I/usr/include' instead of '-I$(STAGING_DIR)/usr/include'
+or:		'-L/usr/lib' instead of '-L$(STAGING_DIR)/usr/lib'
+
+So some sed magic is done to these scripts to make them give correct
+flags.
+The argument to be given to +LIBFOO_CONFIG_FIXUP+ is the file name(s)
+of the shell script(s) needing fixing. All these names are relative to
+'$(STAGING_DIR)/usr/bin' and if needed multiple names can be given.
+
+Example 1:
+
+Package divine installs shell script '$(STAGING_DIR)/usr/bin/divine-config'.
+
+So it's fixup would be:
+
+DIVINE_CONFIG = divine-config
+
+Example 2:
+
+Package imagemagick installs the following scripts:
+'$(STAGING_DIR)/usr/bin/{Magick,Magick++,MagickCore,MagickWand,Wand}-config'
+
+So it's fixup would be:
+
+IMAGEMAGICK_CONFIG_FIXUP = Magick-config Magick++-config \
+			   MagickCore-config MagickWand-config Wand-config
+
+On line 13, we specify the list of dependencies this package relies
 on. These dependencies are listed in terms of lower-case package names,
 which can be packages for the target (without the +host-+
 prefix) or packages for the host (with the +host-+) prefix).
@@ -245,6 +284,11 @@ information is (assuming the package name is +libfoo+) :
   variables are executed to install the package into the target
   directory.
 
+* +LIBFOO_CONFIG_FIXUP+ lists the names of the files in
+  '$(STAGING_DIR)/usr/bin' that need some special fixing to make them
+  cross-compiling friendly. Multiple file names separated by space can be
+  given and all are relative to '$(STAGING_DIR)/usr/bin'.
+
 * +LIBFOO_DEVICES+ lists the device files to be created by Buildroot
   when using the static device table. The syntax to use is the
   makedevs one. You can find some documentation for this syntax in the

package/pkg-generic.mk

@@ -128,6 +128,13 @@ $(BUILD_DIR)/%/.stamp_staging_installed:
 	@$(call MESSAGE,"Installing to staging directory")
 	$($(PKG)_INSTALL_STAGING_CMDS)
 	$(foreach hook,$($(PKG)_POST_INSTALL_STAGING_HOOKS),$(call $(hook))$(sep))
+	$(Q)if test -n "$($(PKG)_CONFIG_FIXUP)" ; then \
+		$(call MESSAGE,"Fixing package configuration files") ;\
+			$(SED)  "s,^\(exec_\)\?prefix=.*,\1prefix=$(STAGING_DIR)/usr,g" \
+				-e "s,-I/usr/,-I$(STAGING_DIR)/usr/,g" \
+				-e "s,-L/usr/,-L$(STAGING_DIR)/usr/,g" \
+				$(addprefix $(STAGING_DIR)/usr/bin/,$($(PKG)_CONFIG_FIXUP)) ;\
+	fi
 	$(Q)touch $@
 
 # Install to images dir