Re: [PATCH v3] config: Allow kernel installation packaging to override pkg-config

[Nicolas Schier <nicolas@fjasle.eu>]

On Fri, Mar 04, 2022 at 04:14:51AM +0000 Chun-Tse Shao wrote:
> [ Resending as a separate thread ]
> 
> Add HOSTPKG_CONFIG to allow tooling that builds the kernel to override
> what pkg-config and parameters are used.
> 
> Signed-off-by: Chun-Tse Shao <ctshao@google.com>
> ---
> Changes from v2: https://lore.kernel.org/all/20220302193638.11034-1-ctshao@google.com/
>   - Fix more open coded instance of pkg-config in scripts and certs
>   - Tested with make allmodconfig
> 
> Changes from v1: https://lore.kernel.org/all/20220301230629.1892828-1-ctshao@google.com/
>   - Make the commit message more clearer.
> ---
> 
>  Makefile                     |  3 ++-
>  certs/Makefile               |  4 ++--
>  scripts/Makefile             |  4 ++--
>  scripts/dtc/Makefile         |  6 +++---
>  scripts/kconfig/gconf-cfg.sh | 10 +++++-----
>  scripts/kconfig/mconf-cfg.sh | 14 +++++++-------
>  scripts/kconfig/nconf-cfg.sh | 14 +++++++-------
>  scripts/kconfig/qconf-cfg.sh | 14 +++++++-------
>  tools/objtool/Makefile       |  4 ++--
>  9 files changed, 37 insertions(+), 36 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index daeb5c88b50b..f6c5bef7e141 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -430,6 +430,7 @@ else
>  HOSTCC	= gcc
>  HOSTCXX	= g++
>  endif
> +HOSTPKG_CONFIG	= pkg-config
> 
>  export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
>  			      -O2 -fomit-frame-pointer -std=gnu89
> @@ -525,7 +526,7 @@ KBUILD_LDFLAGS_MODULE :=
>  KBUILD_LDFLAGS :=
>  CLANG_FLAGS :=
> 
> -export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
> +export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
>  export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
>  export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
>  export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
> diff --git a/certs/Makefile b/certs/Makefile
> index 3ea7fe60823f..fa540d14ef2d 100644
> --- a/certs/Makefile
> +++ b/certs/Makefile
> @@ -89,5 +89,5 @@ targets += x509_revocation_list
> 
>  hostprogs := extract-cert
> 
> -HOSTCFLAGS_extract-cert.o = $(shell pkg-config --cflags libcrypto 2> /dev/null)
> -HOSTLDLIBS_extract-cert = $(shell pkg-config --libs libcrypto 2> /dev/null || echo -lcrypto)
> +HOSTCFLAGS_extract-cert.o = $(shell $(HOSTPKG_CONFIG) --cflags libcrypto 2> /dev/null)
> +HOSTLDLIBS_extract-cert = $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)
> diff --git a/scripts/Makefile b/scripts/Makefile
> index ce5aa9030b74..f084f08ed176 100644
> --- a/scripts/Makefile
> +++ b/scripts/Makefile
> @@ -14,8 +14,8 @@ hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE)	+= insert-sys-cert
>  HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include
>  HOSTLDLIBS_sorttable = -lpthread
>  HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
> -HOSTCFLAGS_sign-file.o = $(shell pkg-config --cflags libcrypto 2> /dev/null)
> -HOSTLDLIBS_sign-file = $(shell pkg-config --libs libcrypto 2> /dev/null || echo -lcrypto)
> +HOSTCFLAGS_sign-file.o = $(shell $(HOSTPKG_CONFIG) --cflags libcrypto 2> /dev/null)
> +HOSTLDLIBS_sign-file = $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)
> 
>  ifdef CONFIG_UNWINDER_ORC
>  ifeq ($(ARCH),x86_64)
> diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile
> index 95aaf7431bff..743fc08827ea 100644
> --- a/scripts/dtc/Makefile
> +++ b/scripts/dtc/Makefile
> @@ -18,7 +18,7 @@ fdtoverlay-objs	:= $(libfdt) fdtoverlay.o util.o
>  # Source files need to get at the userspace version of libfdt_env.h to compile
>  HOST_EXTRACFLAGS += -I $(srctree)/$(src)/libfdt
> 
> -ifeq ($(shell pkg-config --exists yaml-0.1 2>/dev/null && echo yes),)
> +ifeq ($(shell $(HOSTPKG_CONFIG) --exists yaml-0.1 2>/dev/null && echo yes),)
>  ifneq ($(CHECK_DT_BINDING)$(CHECK_DTBS),)
>  $(error dtc needs libyaml for DT schema validation support. \
>  	Install the necessary libyaml development package.)
> @@ -27,9 +27,9 @@ HOST_EXTRACFLAGS += -DNO_YAML
>  else
>  dtc-objs	+= yamltree.o
>  # To include <yaml.h> installed in a non-default path
> -HOSTCFLAGS_yamltree.o := $(shell pkg-config --cflags yaml-0.1)
> +HOSTCFLAGS_yamltree.o := $(shell $(HOSTPKG_CONFIG) --cflags yaml-0.1)
>  # To link libyaml installed in a non-default path
> -HOSTLDLIBS_dtc	:= $(shell pkg-config yaml-0.1 --libs)
> +HOSTLDLIBS_dtc	:= $(shell $(HOSTPKG_CONFIG) yaml-0.1 --libs)
>  endif
> 
>  # Generated files need one more search path to include headers in source tree
> diff --git a/scripts/kconfig/gconf-cfg.sh b/scripts/kconfig/gconf-cfg.sh
> index 480ecd8b9f41..267ef6012203 100755
> --- a/scripts/kconfig/gconf-cfg.sh
> +++ b/scripts/kconfig/gconf-cfg.sh
> @@ -3,14 +3,14 @@
> 
>  PKG="gtk+-2.0 gmodule-2.0 libglade-2.0"
> 
> -if [ -z "$(command -v pkg-config)" ]; then
> +if [ -z "$(command -v $(HOSTPKG_CONFIG))" ]; then

Dereferencing variables in shell scripts has to be done by using "${var}" or
"$var".  "$(var)" starts a sub-shell and executes "var", which is not your
intention.  Thus, better try something like:

    if [ -z "$(command -v "${HOSTPKG_CONFIG}")" ]; then

(and all other shell script replacements in need to be revised, too.)

Kind regards,
Nicolas