[DTrace-devel] [PATCH 1/5] build: overridable configuration variables
Eugene Loh
eugene.loh at oracle.com
Tue Dec 12 23:30:18 UTC 2023
Reviewed-by: Eugene Loh <eugene.loh at oracle.com>
subject to comments below. (And, this whole stuff is pretty foreign to me.)
On 11/29/23 11:08, Nick Alcock via DTrace-devel wrote:
> The Makeconfig checks are purely compile-time, so should always work: but if
> they don't, it is sometimes desirable to be able to override them.
I'm really puzzled by this text. "Should always work", but if the
impossible happens...? Is there a clearer way to state the case for
this patch?
> This change causes every check-* invocation in Makeconfig to respond to
> HAVE_* make variables set on the command line, and also to produce a line in
> 'make help' of the general form
>
> HAVE_LIBSYSTEMD=[yes/no] Override check for presence of sd_notify in libsystemd
>
> etc.
>
> (The escaping in make-override-help to figure out how many tabs to insert to
> properly align the help will make your eyes bleed. One $ for every nested
> $(eval $(call ...)): thank goodness they're all at the same level!)
>
> Signed-off-by: Nick Alcock <nick.alcock at oracle.com>
> ---
> Makeconfig | 101 +++++++++++++++++++++++++++++++++++++++-------------
> Makeoptions | 13 ++++---
> 2 files changed, 83 insertions(+), 31 deletions(-)
>
> diff --git a/Makeconfig b/Makeconfig
> index 08cb48101f9a..f6a28d8f79f5 100644
> --- a/Makeconfig
> +++ b/Makeconfig
> @@ -10,6 +10,23 @@
> CONFIG_H = $(objdir)/config.h
> CONFIG_MK = $(objdir)/config.mk
>
> +# Emit a help rule for an override.
> +#
> +# Syntax: $(call make-overrride-help,var,help-string)
s/rrr/rr/
> +define make-override-help
> +help::
Patch 4 introduces help-overrides. I don't understand the big picture
here, but might it not make sense to do the help-overrides stuff here in
patch 1 rather than introducing stuff that will be changed a few patches
later?
> + width=$$$$(printf '$(1)=[yes/no]' | wc -c); \
> + tabs=""; \
Why isn't the default \t\t\t\t? Arguably, it shouldn't matter since
that case might never come up, but it'd be more straightforward that way.
> + if [[ $$$${width} -gt 31 ]]; then \
> + tabs=' '; \
> + elif [[ $$$${width} -gt 23 ]]; then \
> + tabs='\t'; \
> + elif [[ $$$${width} -gt 15 ]]; then \
> + tabs='\t\t'; \
> + fi; \
> + printf "$(1)=[yes/no]$$$${tabs}Override check for$(2)\n" >&2
> +endef
> +
> # Generate a makefile rule to check for the presence of FUNCTION
> # in HEADER and emit an appropriate header file fragment into a
> # file under $(objdir)/.config.
> @@ -20,14 +37,24 @@ CONFIG_MK = $(objdir)/config.mk
> # Syntax: $(call check-header-rule,name,function,header)
> define check-header-rule
> $(objdir)/.config/config.$(1).h $(objdir)/.config/config.$(1).mk: $(objdir)/.config/.dir.stamp
> - if printf '#include <%s.h>\nint main(void) { %s; }' "$(3)" "$(2)" | \
> - $(CC) $(filter-out --coverage,$(CFLAGS) $(LDFLAGS)) -D_GNU_SOURCE -Werror=implicit-function-declaration -c -o /dev/null -x c - >/dev/null 2>&1; then \
> - echo '#define HAVE_$(1) 1' > $(objdir)/.config/config.$(1).h; \
> - echo 'HAVE_$(1)=y' > $(objdir)/.config/config.$(1).mk; \
> - else \
> - echo '/* #undef HAVE_$(1) */' > $(objdir)/.config/config.$(1).h; \
> - echo '# HAVE_$(1) undefined' > $(objdir)/.config/config.$(1).mk; \
> - fi
> + case x$(HAVE_$(1)) in \
> + xyes) echo '#define HAVE_$(1) 1' > $(objdir)/.config/config.$(1).h; \
> + echo 'HAVE_$(1)=y' > $(objdir)/.config/config.$(1).mk;; \
> + xno) echo '/* #undef HAVE_$(1) */' > $(objdir)/.config/config.$(1).h; \
> + echo '# HAVE_$(1) undefined' > $(objdir)/.config/config.$(1).mk;; \
> + *) if printf '#include <%s.h>\nint main(void) { %s; }' "$(3)" "$(2)" | \
Should this case be x) rather than *)?
> + $(CC) $(filter-out --coverage,$(CFLAGS) $(LDFLAGS)) -D_GNU_SOURCE -Werror=implicit-function-declaration -c -o /dev/null -x c - >/dev/null 2>&1; then \
> + echo '#define HAVE_$(1) 1' > $(objdir)/.config/config.$(1).h; \
> + echo 'HAVE_$(1)=y' > $(objdir)/.config/config.$(1).mk; \
> + else \
> + echo '/* #undef HAVE_$(1) */' > $(objdir)/.config/config.$(1).h; \
> + echo '# HAVE_$(1) undefined' > $(objdir)/.config/config.$(1).mk; \
> + fi;; \
> + *) echo "HAVE_$(1) must be yes or no, not $(HAVE_$(1))" >&2; \
> + false;; \
> + esac
> +
> +$(eval $(call make-override-help,HAVE_$(1), presence of $(2) in $(3).h))
>
> $(CONFIG_H): $(objdir)/.config/config.$(1).h
> $(CONFIG_MK): $(objdir)/.config/config.$(1).mk
> @@ -43,14 +70,24 @@ endef
> # Syntax: $(call check-symbol,name,symbol,library)
> define check-symbol-rule
> $(objdir)/.config/config.$(1).h $(objdir)/.config/config.$(1).mk: $(objdir)/.config/.dir.stamp
> - if echo 'void $(2)(); int main(void) { $(2)(); }' | \
> - $(CC) $(filter-out --coverage,$(CFLAGS) $(LDFLAGS)) -o /dev/null -x c - -l$(3) >/dev/null 2>&1; then \
> - echo '#define HAVE_$(1) 1' > $(objdir)/.config/config.$(1).h; \
> - echo 'HAVE_$(1)=y' > $(objdir)/.config/config.$(1).mk; \
> - else \
> - echo '/* #undef HAVE_$(1) */' > $(objdir)/.config/config.$(1).h; \
> - echo '# HAVE_$(1) undefined' > $(objdir)/.config/config.$(1).mk; \
> - fi
> + case x$(HAVE_$(1)) in \
> + xyes) echo '#define HAVE_$(1) 1' > $(objdir)/.config/config.$(1).h; \
> + echo 'HAVE_$(1)=y' > $(objdir)/.config/config.$(1).mk;; \
> + xno) echo '/* #undef HAVE_$(1) */' > $(objdir)/.config/config.$(1).h; \
> + echo '# HAVE_$(1) undefined' > $(objdir)/.config/config.$(1).mk;; \
> + x) if echo 'void $(2)(); int main(void) { $(2)(); }' | \
> + $(CC) $(filter-out --coverage,$(CFLAGS) $(LDFLAGS)) -o /dev/null -x c - -l$(3) >/dev/null 2>&1; then \
> + echo '#define HAVE_$(1) 1' > $(objdir)/.config/config.$(1).h; \
> + echo 'HAVE_$(1)=y' > $(objdir)/.config/config.$(1).mk; \
> + else \
> + echo '/* #undef HAVE_$(1) */' > $(objdir)/.config/config.$(1).h; \
> + echo '# HAVE_$(1) undefined' > $(objdir)/.config/config.$(1).mk; \
> + fi;; \
> + *) echo "HAVE_$(1) must be yes or no, not $(HAVE_$(1))" >&2; \
> + false;; \
> + esac
> +
> +$(eval $(call make-override-help,HAVE_$(1), presence of $(2) in lib$(3)))
>
> $(CONFIG_H): $(objdir)/.config/config.$(1).h
> $(CONFIG_MK): $(objdir)/.config/config.$(1).mk
> @@ -66,14 +103,24 @@ endef
> # Syntax: $(call check-header-symbol-rule,name,symbol,library,header)
> define check-header-symbol-rule
> $(objdir)/.config/config.$(1).h $(objdir)/.config/config.$(1).mk: $(objdir)/.config/.dir.stamp
> - if printf '#include <%s.h>\nint main(void) { %s; }' "$(4)" "$(2)" | \
> - $(CC) $(filter-out --coverage,$(CFLAGS) $(LDFLAGS)) -D_GNU_SOURCE -Werror=implicit-function-declaration -o /dev/null -x c - -l$(3) >/dev/null 2>&1; then \
> - echo '#define HAVE_$(1) 1' > $(objdir)/.config/config.$(1).h; \
> - echo 'HAVE_$(1)=y' > $(objdir)/.config/config.$(1).mk; \
> - else \
> - echo '/* #undef HAVE_$(1) */' > $(objdir)/.config/config.$(1).h; \
> - echo '# HAVE_$(1) undefined' > $(objdir)/.config/config.$(1).mk; \
> - fi
> + case x$(HAVE_$(1)) in \
> + xyes) echo '#define HAVE_$(1) 1' > $(objdir)/.config/config.$(1).h; \
> + echo 'HAVE_$(1)=y' > $(objdir)/.config/config.$(1).mk;; \
> + xno) echo '/* #undef HAVE_$(1) */' > $(objdir)/.config/config.$(1).h; \
> + echo '# HAVE_$(1) undefined' > $(objdir)/.config/config.$(1).mk;; \
> + *) if printf '#include <%s.h>\nint main(void) { %s; }' "$(4)" "$(2)" | \
Should this case be x) rather than *)?
> + $(CC) $(filter-out --coverage,$(CFLAGS) $(LDFLAGS)) -D_GNU_SOURCE -Werror=implicit-function-declaration -o /dev/null -x c - -l$(3) >/dev/null 2>&1; then \
> + echo '#define HAVE_$(1) 1' > $(objdir)/.config/config.$(1).h; \
> + echo 'HAVE_$(1)=y' > $(objdir)/.config/config.$(1).mk; \
> + else \
> + echo '/* #undef HAVE_$(1) */' > $(objdir)/.config/config.$(1).h; \
> + echo '# HAVE_$(1) undefined' > $(objdir)/.config/config.$(1).mk; \
> + fi;; \
> + *) echo "HAVE_$(1) must be yes or no, not $(HAVE_$(1))" >&2; \
> + false;; \
> + esac
> +
> +$(eval $(call make-override-help,HAVE_$(1), presence of $(2) in lib$(3) and $(4).h))
>
> $(CONFIG_H): $(objdir)/.config/config.$(1).h
> $(CONFIG_MK): $(objdir)/.config/config.$(1).mk
> @@ -92,6 +139,9 @@ $(CONFIG_MK):
> echo 'CONFIGURED := yes' >> $(objdir)/config.mk
> cat $(objdir)/.config/*.mk >> $(objdir)/config.mk 2>/dev/null || true
>
> +help::
> + printf "Overrides for library and symbol searches:\n\n" >&2
> +
> $(eval $(call check-symbol-rule,ELF_GETSHDRSTRNDX,elf_getshdrstrndx,elf))
> $(eval $(call check-symbol-rule,LIBCTF,ctf_open,ctf))
> $(eval $(call check-symbol-rule,STRRSTR,strrstr,c))
> @@ -103,3 +153,6 @@ endif
> $(eval $(call check-header-rule,FUSE_NUMA,fuse_set_numa,fuse/fuse_lowlevel))
> $(eval $(call check-header-symbol-rule,CLOSE_RANGE,close_range(3,~0U,0),c,unistd))
> $(eval $(call check-header-rule,GETTID,gettid,unistd))
> +
> +help::
> + printf "\n" >&2
> diff --git a/Makeoptions b/Makeoptions
Okay though Makeoptions might as well be a separate patch. In favor of
separate patch: it's unrelated to this patch. In favor of leaving as
is: it's not a big deal one way or the other.
> index cec68a0af2bc..25234092c6dd 100644
> --- a/Makeoptions
> +++ b/Makeoptions
> @@ -1,7 +1,7 @@
> # The implementation of the configurable make options.
> #
> # Oracle Linux DTrace.
> -# Copyright (c) 2011, 2022, Oracle and/or its affiliates. All rights reserved.
> +# Copyright (c) 2011, 2023, Oracle and/or its affiliates. All rights reserved.
> # Licensed under the Universal Permissive License v 1.0 as shown at
> # http://oss.oracle.com/licenses/upl.
>
> @@ -13,13 +13,12 @@ libfuse2 ?= no
>
> help::
> @printf "Options:\n\n" >&2
> - @printf "make debugging=yes [targets] Disable optimization to make debugger use easier\n" >&2
> - @printf "make coverage=yes [targets] Turn on coverage support in the testsuite\n" >&2
> - @printf "make verbose=yes [target] Enable verbose building\n" >&2
> - @printf "make dof_dbg=yes [targets] Turn on especially noisy DOF parser debugging\n\n" >&2
> + @printf "make debugging=yes [targets]\tDisable optimization to make debugger use easier\n" >&2
> + @printf "make coverage=yes [targets]\tTurn on coverage support in the testsuite\n" >&2
> + @printf "make verbose=yes [target]\tEnable verbose building\n" >&2
> + @printf "make dof_dbg=yes [targets]\tTurn on especially noisy DOF parser debugging\n\n" >&2
> @printf "Dependencies:\n\n" >&2
> - @printf "make libfuse2=yes [targets] Build against libfuse 2 even if libfuse 3 is found\n" >&2
> - @printf "\n" >&2
> + @printf "make libfuse2=yes [targets]\tBuild against libfuse 2 even if libfuse 3 is found\n\n" >&2
>
> ifneq ($(debugging),no)
> override CFLAGS += -O0 -g
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