[ping2][PATCH 03/19 v2] Auto-generate libc-modules.h

[Siddhesh Poyarekar <siddhesh at redhat dot com>]

Ping!

On Wed, Sep 17, 2014 at 06:13:29PM +0530, Siddhesh Poyarekar wrote:
> Rebased on top of current master.  No changes to the patch.
> 
> Siddhesh
> 
> On Thu, Aug 28, 2014 at 11:41:28AM +0530, Siddhesh Poyarekar wrote:
> > Here's an updated patch to autogenerate libc-modules.h.  I now include
> > libc-symbols.h everywhere like before, so all of the %.v.i files can
> > once again use the macros libc-symbols.h defines.  To break the
> > circular dependency with shlib-versions, I include libc-modules.h in
> > the commandline instead of in libc-symbols.h and I don't include it
> > for shlib-versions.v.i and Versions.v.i.
> 
> From 1aefedff6666344d5368b82ca0f53f6dec9e7056 Mon Sep 17 00:00:00 2001
> From: Siddhesh Poyarekar <siddhesh@redhat.com>
> Date: Thu, 21 Aug 2014 11:44:54 +0530
> Subject: [PATCH] Auto-generate libc-modules.h
> 
> Remove libc-modules.h from the tree and auto-generate it from
> soversions.i and a new file build.list.  Macros generated from
> soversions.i have lower values starting from 1, while those from
> build.list start from a special value MODULE_OTHER_BEGIN, which has a
> high enough value (1000).  This allows us to conveniently
> differentiate between the versioned libraries and other built modules,
> which is needed in errno.h and netdb.h to decide whether to use an
> internal symbol or an external one.
> 
> Verified that generated code remains unchanged on x86_64.
> 
> 	* Makeconfig (module-cppflags): Include libc-modules.h for
> 	everything except shlib-versions.v.i.
> 	(CPPFLAGS): Use it.
> 	(before-compile): Add libc-modules.h.
> 	($(common-objpfx)libc-modules.h,
> 	$(common-objpfx)libc-modules.stmp): New targets.
> 	(common-generated): Add libc-modules.h and libc-modules.stmp.
> 	($(common-objpfx)Versions.v.i): Depend on libc-modules.h.
> 	* build.list: New file.
> 	* include/libc-symbols.h: Don't include libc-modules.h.
> 	* include/libc-modules.h: Remove file.
> 	* scripts/gen-libc-modules.awk: New script to generate
> 	libc-modules.h.
> 	* sysdeps/unix/Makefile ($(common-objpfx)sysd-syscalls):
> 	Depend on libc-modules.stmp.
> ---
>  Makeconfig                   | 44 +++++++++++++++++++++++++++++++++++++++-----
>  build.list                   | 15 +++++++++++++++
>  include/libc-modules.h       | 37 -------------------------------------
>  include/libc-symbols.h       |  2 --
>  scripts/gen-libc-modules.awk | 40 ++++++++++++++++++++++++++++++++++++++++
>  sysdeps/unix/Makefile        |  3 ++-
>  6 files changed, 96 insertions(+), 45 deletions(-)
>  create mode 100644 build.list
>  delete mode 100644 include/libc-modules.h
>  create mode 100644 scripts/gen-libc-modules.awk
> 
> diff --git a/Makeconfig b/Makeconfig
> index 5c85b81..9ce7287 100644
> --- a/Makeconfig
> +++ b/Makeconfig
> @@ -813,10 +813,22 @@ endif	# $(+cflags) == ""
>  # of many little headers in the include directory.
>  libio-include = -I$(..)libio
>  
> +# We don't include libc-modules.h when these targets are being built.  These
> +# targets don't (and will likely never need to) use the IS_IN facility.  In
> +# fact, shlib-versions should not use it because that will create a circular
> +# dependency as libc-modules.h is generated from shlib-versions.
> +skip-module-cppflags = shlib-versions.v.i Versions.v.i
> +
>  in-module = $(strip $(foreach lib,$(libof-$(basename $(@F))) $(libof-$(<F)) \
>  				  $(libof-$(@F)),-DIN_MODULE=MODULE_$(lib)))
>  
>  module-def = $(if $(in-module),$(in-module),-DIN_MODULE=MODULE_libc)
> +module-cppflags-real = -include $(common-objpfx)libc-modules.h $(module-def)
> +
> +# We don't need libc-modules.h and the IN_MODULE definition for
> +# shlib-version.v.i.
> +module-cppflags = $(if $(filter $(@F),$(skip-module-cppflags)), \
> +		       ,$(module-cppflags-real))
>  
>  # These are the variables that the implicit compilation rules use.
>  # Note that we can't use -std=* in CPPFLAGS, because it overrides
> @@ -824,9 +836,9 @@ module-def = $(if $(in-module),$(in-module),-DIN_MODULE=MODULE_libc)
>  # it causes cpp to stop predefining __ASSEMBLER__.
>  CPPFLAGS = $(config-extra-cppflags) $(CPPUNDEFS) $(CPPFLAGS-config) \
>  	   $($(subdir)-CPPFLAGS) \
> -	   $(+includes) $(defines) \
> +	   $(+includes) $(defines) $(module-cppflags) \
>  	   -include $(..)include/libc-symbols.h $(sysdep-CPPFLAGS) \
> -	   $(CPPFLAGS-$(suffix $@)) $(module-def) \
> +	   $(CPPFLAGS-$(suffix $@)) \
>  	   $(foreach lib,$(libof-$(basename $(@F))) \
>  			 $(libof-$(<F)) $(libof-$(@F)),$(CPPFLAGS-$(lib))) \
>  	   $(CPPFLAGS-$(<F)) $(CPPFLAGS-$(@F)) $(CPPFLAGS-$(basename $(@F)))
> @@ -986,9 +998,12 @@ endif
>  postclean-generated += soversions.mk soversions.i \
>  		       shlib-versions.v shlib-versions.v.i
>  
> -# Generate the header containing the names of all shared libraries.
> +# Generate a header containing the names of all shared libraries and another
> +# one containing macros that comprise valid values for the IN_MODULE and
> +# MODULE_NAME macros..
>  # We use a stamp file to avoid unnecessary recompilations.
> -before-compile += $(common-objpfx)gnu/lib-names.h
> +before-compile += $(common-objpfx)gnu/lib-names.h \
> +		  $(common-objpfx)libc-modules.h
>  ifeq ($(soversions.mk-done),t)
>  $(common-objpfx)gnu/lib-names.h: $(common-objpfx)gnu/lib-names.stmp; @:
>  $(common-objpfx)gnu/lib-names.stmp: $(..)scripts/lib-names.awk \
> @@ -1021,9 +1036,28 @@ $(common-objpfx)gnu/lib-names.stmp: $(..)scripts/lib-names.awk \
>  	} >  ${@:stmp=T}
>  	$(move-if-change) ${@:stmp=T} ${@:stmp=h}
>  	touch $@
> +
> +# Generate a header with macro definitions for use with the IS_IN macro.
> +# These are the possible values for the IN_MODULE macro defined when building
> +# sources, to identify which module the translation unit is going to be built
> +# into.  This needs to be one of the first headers to be generated since
> +# everything uses it.  We work around a one-time circular dependency with
> +# sysd-rules by touching an empty header file since the sysd-rules don't use
> +# the IN_MODULE macros even though it is defined in the compile command.  This
> +# is only necessary the first time, i.e. when there is no
> +# include/libc-modules.h.
> +$(common-objpfx)libc-modules.h: $(common-objpfx)libc-modules.stmp; @:
> +$(common-objpfx)libc-modules.stmp: $(..)scripts/gen-libc-modules.awk \
> +				   $(common-objpfx)soversions.i \
> +				   $(..)build.list
> +	$(AWK) -f $^ > ${@:stmp=T}
> +	$(move-if-change) ${@:stmp=T} ${@:stmp=h}
> +	touch $@
> +
>  endif
>  
> -common-generated += gnu/lib-names.h gnu/lib-names.stmp
> +common-generated += gnu/lib-names.h gnu/lib-names.stmp libc-modules.h \
> +		    libc-modules.stmp
>  
>  # The name under which the run-time dynamic linker is installed.
>  # We are currently going for the convention that `/lib/ld.so.1'
> diff --git a/build.list b/build.list
> new file mode 100644
> index 0000000..eab57c7
> --- /dev/null
> +++ b/build.list
> @@ -0,0 +1,15 @@
> +iconvprogs
> +iconvdata
> +ldconfig
> +lddlibc4
> +libmemusage
> +libSegFault
> +libpcprofile
> +librpcsvc
> +libutil
> +locale_programs
> +memusagestat
> +nonlib
> +nscd
> +extramodules
> +libnldbl
> diff --git a/include/libc-modules.h b/include/libc-modules.h
> deleted file mode 100644
> index d12fb90..0000000
> --- a/include/libc-modules.h
> +++ /dev/null
> @@ -1,37 +0,0 @@
> -#define MODULE_libc		1
> -#define MODULE_libpthread	2
> -#define MODULE_rtld		3
> -#define MODULE_libdl		4
> -#define MODULE_libm		5
> -#define MODULE_iconvprogs	6
> -#define MODULE_iconvdata	7
> -#define MODULE_lddlibc4		8
> -#define MODULE_locale_programs	9
> -#define MODULE_memusagestat	10
> -#define MODULE_libutil		12
> -#define MODULE_libBrokenLocale	13
> -#define MODULE_libmemusage	15
> -#define MODULE_libresolv	16
> -#define MODULE_libnss_db	17
> -#define MODULE_libnss_files	18
> -#define	MODULE_libnss_dns	19
> -#define MODULE_libnss_compat	20
> -#define MODULE_libnss_hesiod	21
> -#define MODULE_libnss_nis	22
> -#define MODULE_libnss_nisplus	23
> -#define MODULE_libanl		24
> -#define MODULE_librt		25
> -#define MODULE_libSegFault	26
> -#define MODULE_libthread_db	27
> -#define MODULE_libcidn		28
> -#define MODULE_libcrypt		29
> -#define MODULE_libnsl		30
> -#define MODULE_libpcprofile	31
> -#define MODULE_librpcsvc	32
> -#define MODULE_nscd		33
> -#define MODULE_ldconfig 	34
> -#define MODULE_libnldbl 	35
> -
> -/* Catch-all for test modules and other binaries.  */
> -#define MODULE_nonlib		98
> -#define MODULE_extramodules	99
> diff --git a/include/libc-symbols.h b/include/libc-symbols.h
> index 131d7eb..9b8208b 100644
> --- a/include/libc-symbols.h
> +++ b/include/libc-symbols.h
> @@ -20,8 +20,6 @@
>  #ifndef _LIBC_SYMBOLS_H
>  #define _LIBC_SYMBOLS_H	1
>  
> -#include "libc-modules.h"
> -
>  #define IS_IN(lib) (IN_MODULE == MODULE_##lib)
>  
>  /* This file's macros are included implicitly in the compilation of every
> diff --git a/scripts/gen-libc-modules.awk b/scripts/gen-libc-modules.awk
> new file mode 100644
> index 0000000..d3382b6
> --- /dev/null
> +++ b/scripts/gen-libc-modules.awk
> @@ -0,0 +1,40 @@
> +# Generate a header file that defines the MODULE_* macros for each library and
> +# module we build in glibc.  The library names are pulled in from soversions.i
> +# and the additional modules are mentioned one-per-line in build.list.
> +BEGIN {
> +  PROCINFO["sorted_in"] = "@val_type_asc"
> +  shlibs = 1
> +  others = 1000
> +  libs["OTHERS_BEGIN"] = others++
> +}
> +
> +# Skip over comments.
> +$1 == "#" {
> +  next
> +}
> +
> +# build.list is simply one module per line.
> +match (FILENAME, ".*build.list") {
> +  libs[$0] = others++
> +}
> +
> +# We have only one special case in soversions.i parsing, which is to replace ld
> +# with rtld since that's what we call it throughout the sources.
> +match (FILENAME, ".*soversions.i") {
> +  name = $2
> +  if (name == "ld")
> +    name = "rtld"
> +
> +  if (!(name in libs)) {
> +    libs[name] = shlibs++
> +  }
> +}
> +
> +# Finally, print out the header file.
> +END {
> +  printf ("/* AUTOGENERATED BY gen-libc-modules.awk, DO NOT EDIT.  */\n\n")
> +  i = 1
> +  for (l in libs) {
> +    printf ("#define MODULE_%s %d\n", l, libs[l])
> +  }
> +}
> diff --git a/sysdeps/unix/Makefile b/sysdeps/unix/Makefile
> index 0e535b6..573e90d 100644
> --- a/sysdeps/unix/Makefile
> +++ b/sysdeps/unix/Makefile
> @@ -79,7 +79,8 @@ compile-syscall = $(COMPILE.S) -o $@ -x assembler-with-cpp - \
>  
>  ifndef avoid-generated
>  $(common-objpfx)sysd-syscalls: $(..)sysdeps/unix/make-syscalls.sh \
> -			       $(wildcard $(+sysdep_dirs:%=%/syscalls.list))
> +			       $(wildcard $(+sysdep_dirs:%=%/syscalls.list)) \
> +			       $(common-objpfx)libc-modules.stmp
>  	for dir in $(+sysdep_dirs); do \
>  	  test -f $$dir/syscalls.list && \
>  	  { sysdirs='$(sysdirs)' \
> -- 
> 1.9.3
>

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