build: respect environment options more (#1392)

* build: update m4/ax_pthread.m4 from serial 23 -> serial 31

Update ax_pthread.m4 to the latest version from the autoconf-archive
project.

Signed-off-by: Sam James <sam@gentoo.org>

* build: properly detect AR, CC, RANLIB

It's necessary to be able to override choice of AR/CC/RANLIB and other toolchain
variables/tools for cross-compilation, testing with other toolchains, and
to ensure the compiler chosen by the user is actually used for the build.

Previously, GNU_PREFIX was kind-of used for this but this isn't a standard
variable (at all) and it wasn't applied consistently anyway.

We now use the standard autoconf mechanisms for finding these tools.

(RANLIB is already covered by LT_INIT.)

Signed-off-by: Sam James <sam@gentoo.org>

* build: use $(MAKE)

This ensures that parallel make works correctly, as otherwise, a fresh
make job will be started without the jobserver fd, and hence
not know about its parent, forcing -j1.

* build: respect CPPFLAGS, LDFLAGS

- CPPFLAGS is for the C preprocessor (usually for setting defines)
- LDFLAGS should be placed before objects for certain flags to work
  (e.g. -Wl,--as-needed)

Signed-off-by: Sam James <sam@gentoo.org>

Co-authored-by: Luca Deri <lucaderi@users.noreply.github.com>

1 files changed, 12 insertions, 10 deletions

diff --git a/example/Makefile.in b/example/Makefile.in
index 11c30ad5c..bd4353997 100644
--- a/example/Makefile.in
+++ b/example/Makefile.in
@@ -1,11 +1,13 @@
+AR=@AR@
 CC=@CC@
 CXX=@CXX@
 BUILD_MINGW=@BUILD_MINGW@
 BUILD_MINGW_X64=@BUILD_MINGW_X64@
 SRCHOME=../src
 CFLAGS=-g -fPIC -DPIC -I$(SRCHOME)/include @PCAP_INC@ @CFLAGS@
+LDFLAGS=@LDFLAGS@
 LIBNDPI=$(SRCHOME)/lib/libndpi.a
-LDFLAGS=$(LIBNDPI) @PCAP_LIB@ @LIBS@ @ADDITIONAL_LIBS@ @LDFLAGS@
+LIBS=$(LIBNDPI) @PCAP_LIB@ @LIBS@ @ADDITIONAL_LIBS@
 HEADERS=intrusion_detection.h reader_util.h $(SRCHOME)/include/ndpi_api.h \
         $(SRCHOME)/include/ndpi_typedefs.h $(SRCHOME)/include/ndpi_protocol_ids.h
 OBJS=ndpiReader.o reader_util.o intrusion_detection.o
@@ -14,17 +16,17 @@ PREFIX?=@prefix@
 ifneq ($(BUILD_MINGW),)
 SUFFIX:=.exe
 CFLAGS+=-I@srcdir@/../windows/WpdPack/Include -I@srcdir@/../windows/WpdPack/Include/pcap
-LDFLAGS+=-Wl,-Bstatic -lpthread -Wl,-Bdynamic
+LIBS+=-Wl,-Bstatic -lpthread -Wl,-Bdynamic
 
 ifneq ($(BUILD_MINGW_X64),)
-LDFLAGS+=@srcdir@/../windows/WpdPack/Lib/x64/wpcap.lib
+LIBS+=@srcdir@/../windows/WpdPack/Lib/x64/wpcap.lib
 else
-LDFLAGS+=@srcdir@/../windows/WpdPack/Lib/wpcap.lib
+LIBS+=@srcdir@/../windows/WpdPack/Lib/wpcap.lib
 endif
 
 else
 
-LDFLAGS+=-lpthread
+LIBS+=-lpthread
 
 endif
 
@@ -34,16 +36,16 @@ EXECUTABLE_SOURCES := ndpiReader.c ndpiSimpleIntegration.c
 COMMON_SOURCES := $(filter-out $(EXECUTABLE_SOURCES),$(wildcard *.c ))
 
 libndpiReader.a: $(COMMON_SOURCES:%.c=%.o) $(LIBNDPI)
-	ar rsv libndpiReader.a $(COMMON_SOURCES:%.c=%.o)
+	$(AR) rsv libndpiReader.a $(COMMON_SOURCES:%.c=%.o)
 
 ndpiReader$(SUFFIX): libndpiReader.a $(LIBNDPI) ndpiReader.o
-	$(CC) $(CFLAGS) ndpiReader.o libndpiReader.a -o $@ $(LDFLAGS)
+	$(CC) $(CFLAGS) $(LDFLAGS) ndpiReader.o libndpiReader.a $(LIBS) -o $@
 
 ndpiSimpleIntegration$(SUFFIX): ndpiSimpleIntegration.o
-	$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
+	$(CC) $(CFLAGS) $(LDFLAGS) $< $(LIBS) -o $@
 
 %.o: %.c $(HEADERS) Makefile
-	$(CC) $(CFLAGS) -c $< -o $@
+	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@
 
 install: ndpiReader$(SUFFIX)
 	mkdir -p $(DESTDIR)$(PREFIX)/bin/
@@ -56,7 +58,7 @@ install: ndpiReader$(SUFFIX)
 	[ -f ndpiReader.dpdk ] && cp ndpiReader.dpdk $(DESTDIR)$(PREFIX)/bin/ || true
 
 dpdk:
-	make -f Makefile.dpdk
+	$(MAKE) -f Makefile.dpdk
 
 check:
 	 cppcheck --template='{file}:{line}:{severity}:{message}' --quiet --enable=all --force -I$(SRCHOME)/include *.c