[PATCH] Makefile: fix overriding of make command line arguments.

[Stefan Tauner]

Command line arguments given when executing make should not stop us
from setting commonly user-configurable variables like CPPFLAGS or
LDFLAGS.
Without this patch 'make CPPFLAGS="-Ifail"' would fail to find
libusb1 headers and abort.
Add override statements where we append mandatory options to
these variables to make (Debian) packagers more happy.

Also, r1920 introduced some explicit calls to pkg-config instead of
$(PKG_CONFIG). This patch corrects that as well.

Signed-off-by: Stefan Tauner 
---
 Makefile | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/Makefile b/Makefile
index 11888d5..4d6b40f 100644
--- a/Makefile
+++ b/Makefile
@@ -67,14 +67,14 @@ CFLAGS += -Werror
 endif

ifdef LIBS_BASE
-CPPFLAGS += -I$(LIBS_BASE)/include
-LDFLAGS += -L$(LIBS_BASE)/lib -Wl,-rpath -Wl,$(LIBS_BASE)/lib
 PKG_CONFIG_LIBDIR ?= $(LIBS_BASE)/lib/pkgconfig
+override CPPFLAGS += -I$(LIBS_BASE)/include
+override LDFLAGS += -L$(LIBS_BASE)/lib -Wl,-rpath -Wl,$(LIBS_BASE)/lib
 endif

ifeq ($(CONFIG_STATIC),yes)
-PKG_CONFIG += --static
-LDFLAGS += -static
+override PKG_CONFIG += --static
+override LDFLAGS += -static
 endif

# Set LC_ALL=C to minimize influences of the locale.
@@ -112,28 +112,28 @@ endif
 override TARGET_OS := $(strip $(call debug_shell,$(CC) $(CPPFLAGS) -E os.h 2>/dev/null | grep -v '^#' | grep '"' | cut -f 2 -d'"'))

ifeq ($(TARGET_OS), Darwin)
-CPPFLAGS += -I/opt/local/include -I/usr/local/include
-LDFLAGS += -L/opt/local/lib -L/usr/local/lib
+override CPPFLAGS += -I/opt/local/include -I/usr/local/include
+override LDFLAGS += -L/opt/local/lib -L/usr/local/lib
 endif

ifeq ($(TARGET_OS), FreeBSD)
-CPPFLAGS += -I/usr/local/include
-LDFLAGS += -L/usr/local/lib
+override CPPFLAGS += -I/usr/local/include
+override LDFLAGS += -L/usr/local/lib
 endif

ifeq ($(TARGET_OS), OpenBSD)
-CPPFLAGS += -I/usr/local/include
-LDFLAGS += -L/usr/local/lib
+override CPPFLAGS += -I/usr/local/include
+override LDFLAGS += -L/usr/local/lib
 endif

ifeq ($(TARGET_OS), NetBSD)
-CPPFLAGS += -I/usr/pkg/include
-LDFLAGS += -L/usr/pkg/lib
+override CPPFLAGS += -I/usr/pkg/include
+override LDFLAGS += -L/usr/pkg/lib
 endif

ifeq ($(TARGET_OS), DragonFlyBSD)
-CPPFLAGS += -I/usr/local/include
-LDFLAGS += -L/usr/local/lib
+override CPPFLAGS += -I/usr/local/include
+override LDFLAGS += -L/usr/local/lib
 endif

ifeq ($(TARGET_OS), DOS)
@@ -821,11 +821,11 @@ ifeq ($(TARGET_OS),$(filter $(TARGET_OS),FreeBSD DragonFlyBSD))
 USB1LIBS += -lusb
 else
 ifeq ($(TARGET_OS),NetBSD)
-CPPFLAGS += -I/usr/pkg/include/libusb-1.0
+override CPPFLAGS += -I/usr/pkg/include/libusb-1.0
 USB1LIBS += -lusb-1.0
 else
-USB1LIBS += $(call debug_shell,[ -n "$(PKG_CONFIG_LIBDIR)" ] && export PKG_CONFIG_LIBDIR="$(PKG_CONFIG_LIBDIR)"; pkg-config --libs libusb-1.0  || printf "%s" "-lusb-1.0")
-CPPFLAGS += $(call debug_shell,[ -n "$(PKG_CONFIG_LIBDIR)" ] && export PKG_CONFIG_LIBDIR="$(PKG_CONFIG_LIBDIR)"; pkg-config --cflags-only-I libusb-1.0  || printf "%s" "-I/usr/include/libusb-1.0")
+USB1LIBS += $(call debug_shell,[ -n "$(PKG_CONFIG_LIBDIR)" ] && export PKG_CONFIG_LIBDIR="$(PKG_CONFIG_LIBDIR)"; $(PKG_CONFIG) --libs libusb-1.0  || printf "%s" "-lusb-1.0")
+override CPPFLAGS += $(call debug_shell,[ -n "$(PKG_CONFIG_LIBDIR)" ] && export PKG_CONFIG_LIBDIR="$(PKG_CONFIG_LIBDIR)"; $(PKG_CONFIG) --cflags-only-I libusb-1.0  || printf "%s" "-I/usr/include/libusb-1.0")
 endif
 endif
 endif