> -----Original Message-----
> From: softworkz <ffmpegag...@gmail.com>
> Sent: Sonntag, 18. Mai 2025 08:31
> To: ffmpeg-devel@ffmpeg.org
> Cc: softworkz <softwo...@hotmail.com>; softworkz <softwo...@hotmail.com>
> Subject: [PATCH v2] ffbuild/commonmak: Fix rebuild check with implicit rule
> chains
>
> From: softworkz <softwo...@hotmail.com>
>
> When there's a chain of implicit rules, make treats files generated
> inside that chain as intermediate files. Those intermediate files are
> removed after completion of make. When make is run again, it normally
> determines the need for a rebuild by comparing the timestamps of the
> original source file and the final output of the chain and if still
> up-to-date, it doesn't rebuild, even when the intermediate files are
> not present. That makes sense of course - why would it delete them
> otherwise, it would end up in builds being never up-to-date.
> But this original by-the-book logic appeared to be broken and has been
> worked around by adding all intermediate files to the .SECONDARY
> special target, which required extra logic and issues with make clean.
>
> What broke the up-to-date checking is the dependency file generation.
> For the .c files generated by BIN2C the compile target created a .d
> file which indicated that the .ptx.o file has a dependency on the
> ptx.c file. And that dependency broke the normal make behavior with
> intermediate files.
>
> This patch compiles the BIN2C generated .c files without generating
> .d files. In turn the files do not longer need to be added to the
> .SECONDARY target in common.mak.
>
> When interested in those files for debugging, a line can be added to
> the corresponding Makefile like
>
> .SECONDARY: %.ptx.c %.ptx.gz
>
> Signed-off-by: softworkz <softwo...@hotmail.com>
> ---
> ffbuild/commonmak: Fix rebuild check with implicit rule chains
>
> When there's a chain of implicit rules, make treats files generated
> inside that chain as intermediate files. Those intermediate files are
> removed after completion of make. When make is run again, it normally
> determines the need for a rebuild by comparing the timestamps of the
> original source file and the final output of the chain and if still
> up-to-date, it doesn't rebuild, even when the intermediate files are not
> present. That makes sense of course - why would it delete them
> otherwise, it would end up in builds being never up-to-date. But this
> original by-the-book logic appeared to be broken and has been worked
> around by adding all intermediate files to the .SECONDARY special
> target, which required extra logic and issues with make clean.
>
> What broke the up-to-date checking is the dependency file generation.
> For the .c files generated by BIN2C the compile target created a .d file
> which indicated that the .ptx.o file has a dependency on the ptx.c file.
> And that dependency broke the normal make behavior with intermediate
> files.
>
> This patch compiles the BIN2C generated .c files without generating .d
> files. In turn the files do not longer need to be added to the
> .SECONDARY target in common.mak.
>
> When interested in those files for debugging, a line can be added to the
> corresponding Makefile like
>
> .SECONDARY: %.ptx.c %.ptx.gz
>
>
> V2
> ==
>
> * Fix MSVC build
> (use the universal command pattern)
>
> Published-As: https://github.com/ffstaging/FFmpeg/releases/tag/pr-ffstaging-
> 80%2Fsoftworkz%2Fsubmit_commonmak-v2
> Fetch-It-Via: git fetch https://github.com/ffstaging/FFmpeg pr-ffstaging-
> 80/softworkz/submit_commonmak-v2
> Pull-Request: https://github.com/ffstaging/FFmpeg/pull/80
>
> Range-diff vs v1:
>
> 1: e276f54ffc ! 1: f468ea2431 ffbuild/commonmak: Fix rebuild check with
> implicit rule chains
> @@ ffbuild/common.mak: else
> endif
>
> +%.ptx.o: %.ptx.c
> -+ $(CC) $(CCFLAGS) -x c -c -o $@ $<
> ++ $(CC) $(CCFLAGS) $(CC_C) $(CC_O) $(patsubst
> $(SRC_PATH)/%,$(SRC_LINK)/%,$<)
> +
> +
> # 1) Preprocess CSS to a minified version
> @@ ffbuild/common.mak: else # NO COMPRESSION
> endif
>
> +%.html.o: %.html.c
> -+ $(CC) $(CCFLAGS) -x c -c -o $@ $<
> ++ $(CC) $(CCFLAGS) $(CC_C) $(CC_O) $(patsubst
> $(SRC_PATH)/%,$(SRC_LINK)/%,$<)
> +
> +%.css.o: %.css.c
> -+ $(CC) $(CCFLAGS) -x c -c -o $@ $<
> ++ $(CC) $(CCFLAGS) $(CC_C) $(CC_O) $(patsubst
> $(SRC_PATH)/%,$(SRC_LINK)/%,$<)
> +
> +
> clean::
>
>
> ffbuild/common.mak | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/ffbuild/common.mak b/ffbuild/common.mak
> index 0e1eb1f62b..d9462271d5 100644
> --- a/ffbuild/common.mak
> +++ b/ffbuild/common.mak
> @@ -139,6 +139,10 @@ else
> $(BIN2C) $(patsubst $(SRC_PATH)/%,$(SRC_LINK)/%,$<) $@ $(subst
> .,_,$(basename $(notdir $@)))
> endif
>
> +%.ptx.o: %.ptx.c
> + $(CC) $(CCFLAGS) $(CC_C) $(CC_O) $(patsubst
> $(SRC_PATH)/%,$(SRC_LINK)/%,$<)
> +
> +
> # 1) Preprocess CSS to a minified version
> %.css.min: %.css
> # Must start with a tab in the real Makefile
> @@ -177,6 +181,13 @@ else # NO COMPRESSION
> $(BIN2C) $< $@ $(subst .,_,$(basename $(notdir $@)))
> endif
>
> +%.html.o: %.html.c
> + $(CC) $(CCFLAGS) $(CC_C) $(CC_O) $(patsubst
> $(SRC_PATH)/%,$(SRC_LINK)/%,$<)
> +
> +%.css.o: %.css.c
> + $(CC) $(CCFLAGS) $(CC_C) $(CC_O) $(patsubst
> $(SRC_PATH)/%,$(SRC_LINK)/%,$<)
> +
> +
> clean::
> $(RM) $(BIN2CEXE) $(CLEANSUFFIXES:%=ffbuild/%)
>
> @@ -228,11 +239,9 @@ ALLHEADERS := $(subst $(SRC_DIR)/,$(SUBDIR),$(wildcard
> $(SRC_DIR)/*.h $(SRC_DIR)
> SKIPHEADERS += $(ARCH_HEADERS:%=$(ARCH)/%) $(SKIPHEADERS-)
> SKIPHEADERS := $(SKIPHEADERS:%=$(SUBDIR)%)
> HOBJS = $(filter-out $(SKIPHEADERS:.h=.h.o),$(ALLHEADERS:.h=.h.o))
> -PTXOBJS = $(filter %.ptx.o,$(OBJS))
> -RESOURCEOBJS = $(filter %.css.o %.html.o,$(OBJS))
> $(HOBJS): CCFLAGS += $(CFLAGS_HEADERS)
> checkheaders: $(HOBJS)
> -.SECONDARY: $(HOBJS:.o=.c) $(PTXOBJS:.o=.c) $(PTXOBJS:.o=.gz)
> $(PTXOBJS:.o=) $(RESOURCEOBJS:.o=.c) $(RESOURCEOBJS:%.css.o=%.css.min)
> $(RESOURCEOBJS:%.css.o=%.css.min.gz) $(RESOURCEOBJS:%.html.o=%.html.gz)
> $(RESOURCEOBJS:.o=)
> +.SECONDARY: $(HOBJS:.o=.c)
>
> alltools: $(TOOLS)
>
>
> base-commit: eb6dc952cbd479bf43673af9ca0bc83f37f8f329
> --
I just realized that I forgot to mention the specific problem that this
is addressing: Andreas and James had discovered that the up-to-date check
doesn't work properly - in a way that when you run make after make again,
it wants to rebuild the .o files from the BIN2C-generated .c files.
This patch fixes this by making it work in the way it is intended by make.
(https://www.gnu.org/software/make/manual/html_node/Chained-Rules.html)
sw
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