[lttng-dev] [PATCH lttng-ust v2] Move include directive from CFLAGS to LOCAL_CPPFLAGS in examples' Makefiles

[Mathieu Desnoyers]

* Jérémie Galarneau (jeremie.galarneau at efficios.com) wrote:
> The use of LOCAL_* flags and override directives ensures that the build
> succeeds even if the user explicitly overrides CFLAGS/CPPFLAGS/LDFLAGS.

why use LOCAL_CPPFLAGS on one hand, but "override LDFLAGS" on the other?
What's the difference ? Why should it differ ?

Thanks,

Mathieu

> 
> Fixes #537
> 
> Signed-off-by: Jérémie Galarneau <jeremie.galarneau at efficios.com>
> ---
>  doc/examples/demo/Makefile             | 14 +++++++-------
>  doc/examples/easy-ust/Makefile         | 10 +++++-----
>  doc/examples/hello-static-lib/Makefile | 10 +++++-----
>  3 files changed, 17 insertions(+), 17 deletions(-)
> 
> diff --git a/doc/examples/demo/Makefile b/doc/examples/demo/Makefile
> index bbc8ccb..27ca92b 100644
> --- a/doc/examples/demo/Makefile
> +++ b/doc/examples/demo/Makefile
> @@ -15,14 +15,14 @@
>  CC = gcc
>  LIBS = -ldl	# On Linux
>  #LIBS = -lc	# On BSD
> -CFLAGS += -I.
> +LOCAL_CPPFLAGS += -I.
>  
>  # Only necessary when building from the source tree and lttng-ust is not
>  # installed
>  ifdef BUILD_EXAMPLES_FROM_TREE
> -CFLAGS += -I../../../include/
> +LOCAL_CPPFLAGS += -I../../../include/
>  LIBLTTNG_UST_PATH = ../../../liblttng-ust/.libs/
> -LDFLAGS += -L$(LIBLTTNG_UST_PATH) -Wl,-rpath='$$ORIGIN/$(LIBLTTNG_UST_PATH)'
> +override LDFLAGS += -L$(LIBLTTNG_UST_PATH) -Wl,-rpath='$$ORIGIN/$(LIBLTTNG_UST_PATH)'
>  
>  # Third-party Makefiles have to define these targets to integrate with an
>  # automake project
> @@ -37,22 +37,22 @@ endif
>  all: demo lttng-ust-provider-ust-tests-demo.so lttng-ust-provider-ust-tests-demo3.so
>  
>  tp.o: tp.c ust_tests_demo.h
> -	$(CC) $(CPPFLAGS) $(CFLAGS) -fpic -c -o $@ $<
> +	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -fpic -c -o $@ $<
>  
>  tp2.o: tp2.c ust_tests_demo2.h
> -	$(CC) $(CPPFLAGS) $(CFLAGS) -fpic -c -o $@ $<
> +	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -fpic -c -o $@ $<
>  
>  lttng-ust-provider-ust-tests-demo.so: tp.o tp2.o
>  	$(CC) -shared -o $@ $(LDFLAGS) -llttng-ust $^
>  
>  tp3.o: tp3.c ust_tests_demo3.h
> -	$(CC) $(CPPFLAGS) $(CFLAGS) -fpic -c -o $@ $<
> +	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -fpic -c -o $@ $<
>  
>  lttng-ust-provider-ust-tests-demo3.so: tp3.o
>  	$(CC) -shared -o $@ $(LDFLAGS) -llttng-ust $^
>  
>  demo.o: demo.c
> -	$(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
> +	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -c -o $@ $<
>  
>  demo: demo.o
>  	$(CC) -o $@ $^ $(LIBS)
> diff --git a/doc/examples/easy-ust/Makefile b/doc/examples/easy-ust/Makefile
> index e20e53a..e3546e1 100644
> --- a/doc/examples/easy-ust/Makefile
> +++ b/doc/examples/easy-ust/Makefile
> @@ -17,14 +17,14 @@
>  CC = gcc
>  LIBS = -ldl -llttng-ust		# On Linux
>  #LIBS = -lc -llttng-ust		# On BSD
> -CFLAGS += -I.
> +LOCAL_CPPFLAGS += -I.
>  
>  # Only necessary when building from the source tree and lttng-ust is not
>  # installed
>  ifdef BUILD_EXAMPLES_FROM_TREE
> -CFLAGS += -I../../../include/
> +LOCAL_CPPFLAGS += -I../../../include/
>  LIBLTTNG_UST_PATH = ../../../liblttng-ust/.libs/
> -LDFLAGS += -L$(LIBLTTNG_UST_PATH) -Wl,-rpath='$$ORIGIN/$(LIBLTTNG_UST_PATH)'
> +override LDFLAGS += -L$(LIBLTTNG_UST_PATH) -Wl,-rpath='$$ORIGIN/$(LIBLTTNG_UST_PATH)'
>  
>  # Third-party Makefiles have to define these targets to integrate with an
>  # automake project
> @@ -42,10 +42,10 @@ sample: sample.o tp.o
>  	$(CC) -o $@ $^ $(LDFLAGS) $(LIBS)
>  
>  sample.o: sample.c sample_component_provider.h
> -	$(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
> +	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -c -o $@ $<
>  
>  tp.o: tp.c sample_component_provider.h
> -	$(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
> +	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -c -o $@ $<
>  
>  html: sample_component_provider.html sample.html tp.html
>  
> diff --git a/doc/examples/hello-static-lib/Makefile b/doc/examples/hello-static-lib/Makefile
> index dd246f7..85c64c1 100644
> --- a/doc/examples/hello-static-lib/Makefile
> +++ b/doc/examples/hello-static-lib/Makefile
> @@ -13,16 +13,16 @@
>  # a program with tracepoint provider probes compiled as static libraries.
>  
>  CC = gcc
> -CFLAGS += -I.
> +LOCAL_CPPFLAGS += -I.
>  LIBS = -ldl -llttng-ust	# On Linux
>  #LIBS = -lc -llttng-ust	# On BSD
>  
>  # Only necessary when building from the source tree and lttng-ust is not
>  # installed
>  ifdef BUILD_EXAMPLES_FROM_TREE
> -CFLAGS += -I../../../include/
> +LOCAL_CPPFLAGS += -I../../../include/
>  LIBLTTNG_UST_PATH = ../../../liblttng-ust/.libs/
> -LDFLAGS += -L$(LIBLTTNG_UST_PATH) -Wl,-rpath='$$ORIGIN/$(LIBLTTNG_UST_PATH)'
> +override LDFLAGS += -L$(LIBLTTNG_UST_PATH) -Wl,-rpath='$$ORIGIN/$(LIBLTTNG_UST_PATH)'
>  
>  # Third-party Makefiles have to define these targets to integrate with an
>  # automake project
> @@ -37,13 +37,13 @@ endif
>  all: hello
>  
>  lttng-ust-provider-hello.o: tp.c ust_tests_hello.h
> -	$(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
> +	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -c -o $@ $<
>  
>  lttng-ust-provider-hello.a: lttng-ust-provider-hello.o
>  	ar -rc $@ $^
>  
>  hello.o: hello.c
> -	$(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
> +	$(CC) $(CPPFLAGS) $(LOCAL_CPPFLAGS) $(CFLAGS) -c -o $@ $<
>  
>  hello: hello.o lttng-ust-provider-hello.a
>  	$(CC) -o $@ $(LDFLAGS) $^ $(LIBS)
> -- 
> 1.8.2.3
> 
> 
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-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com