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  3. [PATCH v3 0/3] objtool build improvements
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[PATCH v3 1/3] objtool: Install libsubcmd in build

Ian Rogers posted 3 patches 2 years, 8 months ago
There is a newer version of this series
[PATCH v3 1/3] objtool: Install libsubcmd in build
Posted by Ian Rogers 2 years, 8 months ago 
Including from tools/lib can create inadvertent dependencies. Install
libsubcmd in the objtool build and then include the headers from
there.

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
---
 tools/objtool/Build    |  2 --
 tools/objtool/Makefile | 33 +++++++++++++++++++++++++--------
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/tools/objtool/Build b/tools/objtool/Build
index 33f2ee5a46d3..a3cdf8af6635 100644
--- a/tools/objtool/Build
+++ b/tools/objtool/Build
@@ -16,8 +16,6 @@ objtool-y += libctype.o
 objtool-y += str_error_r.o
 objtool-y += librbtree.o
 
-CFLAGS += -I$(srctree)/tools/lib
-
 $(OUTPUT)libstring.o: ../lib/string.c FORCE
 	$(call rule_mkdir)
 	$(call if_changed_dep,cc_o_c)
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index a3a9cc24e0e3..fd9b3e3113c6 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -12,9 +12,15 @@ srctree := $(patsubst %/,%,$(dir $(CURDIR)))
 srctree := $(patsubst %/,%,$(dir $(srctree)))
 endif
 
-SUBCMD_SRCDIR		= $(srctree)/tools/lib/subcmd/
-LIBSUBCMD_OUTPUT	= $(or $(OUTPUT),$(CURDIR)/)
-LIBSUBCMD		= $(LIBSUBCMD_OUTPUT)libsubcmd.a
+LIBSUBCMD_DIR = $(srctree)/tools/lib/subcmd/
+ifneq ($(OUTPUT),)
+  LIBSUBCMD_OUTPUT = $(abspath $(OUTPUT))/libsubcmd
+else
+  LIBSUBCMD_OUTPUT = $(CURDIR)/libsubcmd
+endif
+LIBSUBCMD_DESTDIR = $(LIBSUBCMD_OUTPUT)
+LIBSUBCMD = $(LIBSUBCMD_OUTPUT)/libsubcmd.a
+CFLAGS += -I$(LIBSUBCMD_OUTPUT)/include
 
 OBJTOOL    := $(OUTPUT)objtool
 OBJTOOL_IN := $(OBJTOOL)-in.o
@@ -28,7 +34,8 @@ INCLUDES := -I$(srctree)/tools/include \
 	    -I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
 	    -I$(srctree)/tools/arch/$(SRCARCH)/include	\
 	    -I$(srctree)/tools/objtool/include \
-	    -I$(srctree)/tools/objtool/arch/$(SRCARCH)/include
+	    -I$(srctree)/tools/objtool/arch/$(SRCARCH)/include \
+	    -I$(LIBSUBCMD_OUTPUT)/include
 WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed -Wno-nested-externs
 CFLAGS   := -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES) $(LIBELF_FLAGS)
 LDFLAGS  += $(LIBELF_LIBS) $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
@@ -38,6 +45,7 @@ elfshdr := $(shell echo '$(pound)include <libelf.h>' | $(CC) $(CFLAGS) -x c -E -
 CFLAGS += $(if $(elfshdr),,-DLIBELF_USE_DEPRECATED)
 
 AWK = awk
+MKDIR = mkdir
 
 BUILD_ORC := n
 
@@ -57,13 +65,22 @@ $(OBJTOOL): $(LIBSUBCMD) $(OBJTOOL_IN)
 	$(QUIET_LINK)$(CC) $(OBJTOOL_IN) $(LDFLAGS) -o $@
 
 
-$(LIBSUBCMD): fixdep FORCE
-	$(Q)$(MAKE) -C $(SUBCMD_SRCDIR) OUTPUT=$(LIBSUBCMD_OUTPUT)
+$(LIBSUBCMD_OUTPUT):
+	@$(MKDIR) -p $@
+
+$(LIBSUBCMD): fixdep FORCE $(LIBSUBCMD_OUTPUT)
+	@$(MAKE) -C $(LIBSUBCMD_DIR) O=$(LIBSUBCMD_OUTPUT) \
+		DESTDIR=$(LIBSUBCMD_DESTDIR) prefix= subdir= \
+		$@ install_headers
+
+$(LIBSUBCMD)-clean:
+	$(call QUIET_CLEAN, libsubcmd)
+	$(Q)$(RM) -r -- $(LIBSUBCMD_OUTPUT)
 
-clean:
+clean: $(LIBSUBCMD)-clean
 	$(call QUIET_CLEAN, objtool) $(RM) $(OBJTOOL)
 	$(Q)find $(OUTPUT) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete
-	$(Q)$(RM) $(OUTPUT)arch/x86/lib/inat-tables.c $(OUTPUT)fixdep $(LIBSUBCMD)
+	$(Q)$(RM) $(OUTPUT)arch/x86/lib/inat-tables.c $(OUTPUT)fixdep
 
 FORCE:
 
-- 
2.39.0.314.g84b9a713c41-goog
Re: [PATCH v3 1/3] objtool: Install libsubcmd in build
Posted by Josh Poimboeuf 2 years, 7 months ago 
On Thu, Jan 05, 2023 at 01:01:53AM -0800, Ian Rogers wrote:
> Including from tools/lib can create inadvertent dependencies. Install
> libsubcmd in the objtool build and then include the headers from
> there.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Tested-by: Nick Desaulniers <ndesaulniers@google.com>

After a make, "git status" shows:

Untracked files:
  (use "git add <file>..." to include in what will be committed)
	tools/objtool/libsubcmd/

So tools/objtool/.gitignore needs an update.

> --- a/tools/objtool/Makefile
> +++ b/tools/objtool/Makefile
> @@ -12,9 +12,15 @@ srctree := $(patsubst %/,%,$(dir $(CURDIR)))
>  srctree := $(patsubst %/,%,$(dir $(srctree)))
>  endif
>  
> -SUBCMD_SRCDIR		= $(srctree)/tools/lib/subcmd/
> -LIBSUBCMD_OUTPUT	= $(or $(OUTPUT),$(CURDIR)/)
> -LIBSUBCMD		= $(LIBSUBCMD_OUTPUT)libsubcmd.a
> +LIBSUBCMD_DIR = $(srctree)/tools/lib/subcmd/
> +ifneq ($(OUTPUT),)
> +  LIBSUBCMD_OUTPUT = $(abspath $(OUTPUT))/libsubcmd
> +else
> +  LIBSUBCMD_OUTPUT = $(CURDIR)/libsubcmd
> +endif
> +LIBSUBCMD_DESTDIR = $(LIBSUBCMD_OUTPUT)

Similar to Nicolas' comment, it's confusing to have two variables with
the same value.  Please s/LIBSUBCMD_DESTDIR/LIBSUBCMD_OUTPUT/

> +LIBSUBCMD = $(LIBSUBCMD_OUTPUT)/libsubcmd.a
> +CFLAGS += -I$(LIBSUBCMD_OUTPUT)/include

As far as I can tell, this CFLAGS addition is both ineffective (it's
overwritten later) and unnecessary (it's made redundant by the same
addition to the INCLUDES variable).

-- 
Josh
Re: [PATCH v3 1/3] objtool: Install libsubcmd in build
Posted by Ian Rogers 2 years, 7 months ago 
On Wed, Jan 25, 2023 at 5:46 PM Josh Poimboeuf <jpoimboe@kernel.org> wrote:
>
> On Thu, Jan 05, 2023 at 01:01:53AM -0800, Ian Rogers wrote:
> > Including from tools/lib can create inadvertent dependencies. Install
> > libsubcmd in the objtool build and then include the headers from
> > there.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > Tested-by: Nick Desaulniers <ndesaulniers@google.com>
>
> After a make, "git status" shows:
>
> Untracked files:
>   (use "git add <file>..." to include in what will be committed)
>         tools/objtool/libsubcmd/
>
> So tools/objtool/.gitignore needs an update.

Done.

> > --- a/tools/objtool/Makefile
> > +++ b/tools/objtool/Makefile
> > @@ -12,9 +12,15 @@ srctree := $(patsubst %/,%,$(dir $(CURDIR)))
> >  srctree := $(patsubst %/,%,$(dir $(srctree)))
> >  endif
> >
> > -SUBCMD_SRCDIR                = $(srctree)/tools/lib/subcmd/
> > -LIBSUBCMD_OUTPUT     = $(or $(OUTPUT),$(CURDIR)/)
> > -LIBSUBCMD            = $(LIBSUBCMD_OUTPUT)libsubcmd.a
> > +LIBSUBCMD_DIR = $(srctree)/tools/lib/subcmd/
> > +ifneq ($(OUTPUT),)
> > +  LIBSUBCMD_OUTPUT = $(abspath $(OUTPUT))/libsubcmd
> > +else
> > +  LIBSUBCMD_OUTPUT = $(CURDIR)/libsubcmd
> > +endif
> > +LIBSUBCMD_DESTDIR = $(LIBSUBCMD_OUTPUT)
>
> Similar to Nicolas' comment, it's confusing to have two variables with
> the same value.  Please s/LIBSUBCMD_DESTDIR/LIBSUBCMD_OUTPUT/

Done. I feel this is more of a meta question for the standard in the
current build. DESTDIR is related to installation, in this case header
files, OUTPUT is a build directory. Anyway, LIBSUBCMD_DESTDIR is gone
in v4.

> > +LIBSUBCMD = $(LIBSUBCMD_OUTPUT)/libsubcmd.a
> > +CFLAGS += -I$(LIBSUBCMD_OUTPUT)/include
>
> As far as I can tell, this CFLAGS addition is both ineffective (it's
> overwritten later) and unnecessary (it's made redundant by the same
> addition to the INCLUDES variable).

Agreed, removed in v4.

> --
> Josh
Re: [PATCH v3 1/3] objtool: Install libsubcmd in build
Posted by Nicolas Schier 2 years, 8 months ago 
On Thu, Jan 05, 2023 at 01:01:53AM -0800 Ian Rogers wrote:
> Including from tools/lib can create inadvertent dependencies. Install
> libsubcmd in the objtool build and then include the headers from
> there.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>  tools/objtool/Build    |  2 --
>  tools/objtool/Makefile | 33 +++++++++++++++++++++++++--------
>  2 files changed, 25 insertions(+), 10 deletions(-)
> 
[...]
> diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
> index a3a9cc24e0e3..fd9b3e3113c6 100644
> --- a/tools/objtool/Makefile
> +++ b/tools/objtool/Makefile
> @@ -12,9 +12,15 @@ srctree := $(patsubst %/,%,$(dir $(CURDIR)))
>  srctree := $(patsubst %/,%,$(dir $(srctree)))
>  endif
>  
> -SUBCMD_SRCDIR		= $(srctree)/tools/lib/subcmd/
> -LIBSUBCMD_OUTPUT	= $(or $(OUTPUT),$(CURDIR)/)
> -LIBSUBCMD		= $(LIBSUBCMD_OUTPUT)libsubcmd.a
> +LIBSUBCMD_DIR = $(srctree)/tools/lib/subcmd/
> +ifneq ($(OUTPUT),)
> +  LIBSUBCMD_OUTPUT = $(abspath $(OUTPUT))/libsubcmd
> +else
> +  LIBSUBCMD_OUTPUT = $(CURDIR)/libsubcmd
> +endif
> +LIBSUBCMD_DESTDIR = $(LIBSUBCMD_OUTPUT)

Hi Ian,

Is there a reason for distinguishing between $(LIBSUBCMD_DESTDIR) and
$(LIBSUBCMD_OUTPUT)?

Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Re: [PATCH v3 1/3] objtool: Install libsubcmd in build
Posted by Ian Rogers 2 years, 8 months ago 
On Thu, Jan 12, 2023 at 12:32 PM Nicolas Schier <nicolas@fjasle.eu> wrote:
>
> On Thu, Jan 05, 2023 at 01:01:53AM -0800 Ian Rogers wrote:
> > Including from tools/lib can create inadvertent dependencies. Install
> > libsubcmd in the objtool build and then include the headers from
> > there.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > Tested-by: Nick Desaulniers <ndesaulniers@google.com>
> > ---
> >  tools/objtool/Build    |  2 --
> >  tools/objtool/Makefile | 33 +++++++++++++++++++++++++--------
> >  2 files changed, 25 insertions(+), 10 deletions(-)
> >
> [...]
> > diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
> > index a3a9cc24e0e3..fd9b3e3113c6 100644
> > --- a/tools/objtool/Makefile
> > +++ b/tools/objtool/Makefile
> > @@ -12,9 +12,15 @@ srctree := $(patsubst %/,%,$(dir $(CURDIR)))
> >  srctree := $(patsubst %/,%,$(dir $(srctree)))
> >  endif
> >
> > -SUBCMD_SRCDIR                = $(srctree)/tools/lib/subcmd/
> > -LIBSUBCMD_OUTPUT     = $(or $(OUTPUT),$(CURDIR)/)
> > -LIBSUBCMD            = $(LIBSUBCMD_OUTPUT)libsubcmd.a
> > +LIBSUBCMD_DIR = $(srctree)/tools/lib/subcmd/
> > +ifneq ($(OUTPUT),)
> > +  LIBSUBCMD_OUTPUT = $(abspath $(OUTPUT))/libsubcmd
> > +else
> > +  LIBSUBCMD_OUTPUT = $(CURDIR)/libsubcmd
> > +endif
> > +LIBSUBCMD_DESTDIR = $(LIBSUBCMD_OUTPUT)
>
> Hi Ian,
>
> Is there a reason for distinguishing between $(LIBSUBCMD_DESTDIR) and
> $(LIBSUBCMD_OUTPUT)?

I believe the naming aligns with their use when passed to the
corresponding sub-make variable, so "DESTDIR=$(LIBSUBCMD_DESTDIR)". It
is possible to do other this, a slightly different convention is in
some BPF related code:
https://lore.kernel.org/lkml/20230112004024.1934601-1-irogers@google.com/

Thanks,
Ian

> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Patchew 2.1-devel-b67e4c2

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