Re: [Qemu-devel] [PATCH] build: Use separate makefile for "trace/"

[Paolo Bonzini]

Il 11/12/2012 22:44, Lluís Vilanova ha scritto:
> Signed-off-by: Lluís Vilanova <address@hidden>
> ---
>  .gitignore                          |    6 +--
>  Makefile                            |    8 ++-
>  Makefile.objs                       |   64 +---------------------------
>  scripts/tracetool/backend/dtrace.py |    2 -
>  trace/Makefile.objs                 |   81 
> +++++++++++++++++++++++++++++++++++
>  5 files changed, 92 insertions(+), 69 deletions(-)
>  create mode 100644 trace/Makefile.objs
> 
> diff --git a/.gitignore b/.gitignore
> index bd6ba1c..b67a37e 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -3,9 +3,9 @@ config-all-devices.*
>  config-host.*
>  config-target.*
>  trace.h
> -trace.c
> -trace-dtrace.h
> -trace-dtrace.dtrace
> +trace/generated.c
> +trace/generated-dtrace.h
> +trace/generated-dtrace.dtrace
>  *-timestamp
>  *-softmmu
>  *-darwin-user
> diff --git a/Makefile b/Makefile
> index e9d6848..9dbcca3 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -33,10 +33,10 @@ endif
>  
>  GENERATED_HEADERS = config-host.h trace.h qemu-options.def
>  ifeq ($(TRACE_BACKEND),dtrace)
> -GENERATED_HEADERS += trace-dtrace.h
> +GENERATED_HEADERS += trace/generated-dtrace.h
>  endif
>  GENERATED_HEADERS += qmp-commands.h qapi-types.h qapi-visit.h
> -GENERATED_SOURCES += qmp-marshal.c qapi-types.c qapi-visit.c trace.c
> +GENERATED_SOURCES += qmp-marshal.c qapi-types.c qapi-visit.c 
> trace/generated.c
>  
>  # Don't try to regenerate Makefile or configure
>  # We don't generate any of them
> @@ -252,9 +252,9 @@ clean:
>       rm -f *.a *.lo $(TOOLS) $(HELPERS-y) qemu-ga TAGS cscope.* *.pod *~ */*~
>       rm -Rf .libs
>       rm -f qemu-img-cmds.h
> -     rm -f trace-dtrace.dtrace trace-dtrace.dtrace-timestamp
>       @# May not be present in GENERATED_HEADERS
> -     rm -f trace-dtrace.h trace-dtrace.h-timestamp
> +     rm -f trace/generated-dtrace.dtrace 
> trace/generated-dtrace.dtrace-timestamp
> +     rm -f trace/generated-dtrace.h trace/generated-dtrace.h-timestamp
>       rm -f $(foreach f,$(GENERATED_HEADERS),$(f) $(f)-timestamp)
>       rm -f $(foreach f,$(GENERATED_SOURCES),$(f) $(f)-timestamp)
>       rm -rf qapi-generated
> diff --git a/Makefile.objs b/Makefile.objs
> index 3c7abca..24832a2 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -147,66 +147,7 @@ libdis-$(CONFIG_LM32_DIS) += lm32-dis.o
>  ######################################################################
>  # trace
>  
> -ifeq ($(TRACE_BACKEND),dtrace)
> -TRACE_H_EXTRA_DEPS=trace-dtrace.h
> -endif
> -trace.h: trace.h-timestamp $(TRACE_H_EXTRA_DEPS)
> -trace.h-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak
> -     $(call quiet-command,$(TRACETOOL) \
> -             --format=h \
> -             --backend=$(TRACE_BACKEND) \
> -             < $< > $@,"  GEN   trace.h")
> -     @cmp -s $@ trace.h || cp $@ trace.h
> -
> -trace.c: trace.c-timestamp
> -trace.c-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak
> -     $(call quiet-command,$(TRACETOOL) \
> -             --format=c \
> -             --backend=$(TRACE_BACKEND) \
> -             < $< > $@,"  GEN   trace.c")
> -     @cmp -s $@ trace.c || cp $@ trace.c
> -
> -trace.o: trace.c $(GENERATED_HEADERS)
> -
> -trace-dtrace.h: trace-dtrace.dtrace
> -     $(call quiet-command,dtrace -o $@ -h -s $<, "  GEN   trace-dtrace.h")
> -
> -# Normal practice is to name DTrace probe file with a '.d' extension
> -# but that gets picked up by QEMU's Makefile as an external dependency
> -# rule file. So we use '.dtrace' instead
> -trace-dtrace.dtrace: trace-dtrace.dtrace-timestamp
> -trace-dtrace.dtrace-timestamp: $(SRC_PATH)/trace-events 
> $(BUILD_DIR)/config-host.mak
> -     $(call quiet-command,$(TRACETOOL) \
> -             --format=d \
> -             --backend=$(TRACE_BACKEND) \
> -             < $< > $@,"  GEN   trace-dtrace.dtrace")
> -     @cmp -s $@ trace-dtrace.dtrace || cp $@ trace-dtrace.dtrace
> -
> -trace-dtrace.o: trace-dtrace.dtrace $(GENERATED_HEADERS)
> -     $(call quiet-command,dtrace -o $@ -G -s $<, "  GEN   trace-dtrace.o")
> -
> -ifeq ($(LIBTOOL),)
> -trace-dtrace.lo: trace-dtrace.dtrace
> -     @echo "missing libtool. please install and rerun configure."; exit 1
> -else
> -trace-dtrace.lo: trace-dtrace.dtrace
> -     $(call quiet-command,$(LIBTOOL) --mode=compile --tag=CC dtrace -o $@ -G 
> -s $<, "  lt GEN trace-dtrace.o")
> -endif
> -
> -trace/simple.o: trace/simple.c $(GENERATED_HEADERS)
> -
> -trace-obj-$(CONFIG_TRACE_DTRACE) += trace-dtrace.o
> -ifneq ($(TRACE_BACKEND),dtrace)
> -trace-obj-y = trace.o
> -endif
> -
> -trace-obj-$(CONFIG_TRACE_DEFAULT) += trace/default.o
> -trace-obj-$(CONFIG_TRACE_SIMPLE) += trace/simple.o
> -trace-obj-$(CONFIG_TRACE_SIMPLE) += qemu-timer-common.o
> -trace-obj-$(CONFIG_TRACE_STDERR) += trace/stderr.o
> -trace-obj-y += trace/control.o
> -
> -$(trace-obj-y): $(GENERATED_HEADERS)
> +trace-obj-y += trace/

Please just put it into oslib-obj-y.

>  ######################################################################
>  # smartcard
> @@ -250,5 +191,6 @@ nested-vars += \
>       block-obj-y \
>       user-obj-y \
>       common-obj-y \
> -     extra-obj-y
> +     extra-obj-y \
> +     trace-obj-y
>  dummy := $(call unnest-vars)
> diff --git a/scripts/tracetool/backend/dtrace.py 
> b/scripts/tracetool/backend/dtrace.py
> index 23c43e2..0cbc68a 100644
> --- a/scripts/tracetool/backend/dtrace.py
> +++ b/scripts/tracetool/backend/dtrace.py
> @@ -37,7 +37,7 @@ def c(events):
>  
>  
>  def h(events):
> -    out('#include "trace-dtrace.h"',
> +    out('#include "trace/generated-dtrace.h"',
>          '')
>  
>      for e in events:
> diff --git a/trace/Makefile.objs b/trace/Makefile.objs
> new file mode 100644
> index 0000000..d7e8cdf
> --- /dev/null
> +++ b/trace/Makefile.objs
> @@ -0,0 +1,81 @@
> +# -*- mode: makefile -*-
> +
> +trace/simple.o: trace/simple.c $(GENERATED_HEADERS)
> +
> +trace-obj-$(CONFIG_TRACE_DEFAULT) += default.o
> +trace-obj-$(CONFIG_TRACE_SIMPLE) += simple.o
> +trace-obj-$(CONFIG_TRACE_SIMPLE) += ../qemu-timer-common.o

Is this line needed?  (Actually, it is obviously unneeded if you use
oslib-obj-y).  I am also worried that it causes duplicate symbols when
you link in both qemu-timer-common.o and trace/../qemu-timer-common.o.
The $(sort) invocation in the LINK macro of rules.mak will not treat
these two paths as duplicate.

> +trace-obj-$(CONFIG_TRACE_STDERR) += stderr.o
> +trace-obj-y += control.o
> +
> +
> +######################################################################
> +# Auto-generated tracing routines
> +
> +# NOTE: "trace.h" is kept in the top-level dir to shorten common include path

Ok, I'll take care of moving it to trace/ later when I do the same for
all other includes.

> +ifeq ($(TRACE_BACKEND),dtrace)
> +TRACE_H_EXTRA_DEPS=trace/generated-dtrace.h
> +endif
> +trace.h: trace.h-timestamp $(TRACE_H_EXTRA_DEPS)
> +trace.h-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak
> +     $(call quiet-command,$(TRACETOOL) \
> +             --format=h \
> +             --backend=$(TRACE_BACKEND) \
> +             < $< > $@,"  GEN   trace.h")
> +     @cmp -s $@ trace.h || cp $@ trace.h
> +
> +
> +trace/generated.c: trace/generated.c-timestamp

Please use $(obj)/generated.c, and similarly for everything else.

> +trace/generated.c-timestamp: $(SRC_PATH)/trace-events 
> $(BUILD_DIR)/config-host.mak
> +     $(call quiet-command,$(TRACETOOL) \
> +             --format=c \
> +             --backend=$(TRACE_BACKEND) \
> +             < $< > $@,"  GEN   trace/generated.c")
> +     @cmp -s $@ trace/generated.c || cp $@ trace/generated.c
> +
> +trace/generated.o: trace/generated.c trace.h
> +
> +
> +ifneq ($(TRACE_BACKEND),dtrace)
> +trace-obj-y += generated.o
> +endif
> +
> +
> +######################################################################
> +# Auto-generated DTrace code
> +
> +# Normal practice is to name DTrace probe file with a '.d' extension
> +# but that gets picked up by QEMU's Makefile as an external dependency
> +# rule file. So we use '.dtrace' instead
> +trace/generated-dtrace.dtrace: trace/generated-dtrace.dtrace-timestamp
> +trace/generated-dtrace.dtrace-timestamp: $(SRC_PATH)/trace-events 
> $(BUILD_DIR)/config-host.mak
> +     $(call quiet-command,$(TRACETOOL) \
> +             --format=d \
> +             --backend=$(TRACE_BACKEND) \
> +             < $< > $@,"  GEN   trace/generated-dtrace.dtrace")
> +     @cmp -s $@ trace/generated-dtrace.dtrace || cp $@ 
> trace/generated-dtrace.dtrace
> +
> +
> +trace/generated-dtrace.h: trace/generated-dtrace.dtrace
> +     $(call quiet-command,dtrace -o $@ -h -s $<, "  GEN   
> trace/generated-dtrace.h")
> +
> +trace/generated-dtrace.o: trace/generated-dtrace.dtrace $(GENERATED_HEADERS)
> +     $(call quiet-command,dtrace -o $@ -G -s $<, "  GEN   
> trace/generated-dtrace.o")
> +
> +
> +ifeq ($(LIBTOOL),)
> +trace/generated-dtrace.lo: trace/generated-dtrace.dtrace
> +     @echo "missing libtool. please install and rerun configure."; exit 1
> +else
> +trace/generated-dtrace.lo: trace/generated-dtrace.dtrace
> +     $(call quiet-command,$(LIBTOOL) --mode=compile --tag=CC dtrace -o $@ -G 
> -s $<, "  lt GEN trace/generated-dtrace.lo")
> +endif
> +
> +
> +trace-obj-$(CONFIG_TRACE_DTRACE) += generated-dtrace.o
> +
> +
> +######################################################################
> +# Keep at bottom
> +
> +$(trace-obj-y): $(GENERATED_HEADERS)

This does not do what you think, because trace-obj-y includes a relative
path.  It can be simply

trace/%.o: $(GENERATED_HEADERS)

but it is actually unnecessary because of this in the toplevel:

# Add a dependency on the generated files, so that they are always
# rebuilt before other object files
ifneq ($(filter-out %clean,$(MAKECMDGOALS)),$(if $(MAKECMDGOALS),,fail))
Makefile: $(GENERATED_HEADERS)
endif

Paolo