Re: [PATCH v2] kbuild: support byacc as alternative YACC to bison

[Frank Rowand <frowand.list@gmail.com>]

Hi Ethan,

On 10/29/19 10:01 AM, Ethan Sommer wrote:
> Switches to a more portable set of flags for generating the same file
> names instead of the bison-specific --defines, uses the more portable -V
> instead of --version, and explicitly defines YYSTYPE in lex.l, which
> bison implicitly defines if not present but byacc does not.
> 
> Add %locations to dtc-parser.y to explicitly enable location tracking
> for byacc, and define YYERROR_CALL explicitly to prevent the locations
> directive from causing it to be defined to a 2-parameter call to
> yyerror, which dtc-parser.y defines to accept one parameter.
> 
> Requires byacc to be built with --enable-btyacc.
> 
> Signed-off-by: Ethan Sommer <e5ten.arch@gmail.com>
> ---
>  scripts/Makefile.host     | 2 +-
>  scripts/dtc/dtc-parser.y  | 4 ++++
>  scripts/genksyms/Makefile | 2 +-
>  scripts/genksyms/lex.l    | 2 ++
>  4 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/Makefile.host b/scripts/Makefile.host
> index 4c51c95d40f4..64e98e1d4825 100644
> --- a/scripts/Makefile.host
> +++ b/scripts/Makefile.host
> @@ -11,7 +11,7 @@ $(obj)/%.lex.c: $(src)/%.l FORCE
>  # YACC
>  # ---------------------------------------------------------------------------
>  quiet_cmd_bison = YACC    $(basename $@).[ch]
> -      cmd_bison = $(YACC) -o $(basename $@).c --defines=$(basename $@).h -t -l $<
> +      cmd_bison = $(YACC) -b $(basename $(basename $@)) -d -t -l $<
>  
>  $(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE
>  	$(call if_changed,bison)
> diff --git a/scripts/dtc/dtc-parser.y b/scripts/dtc/dtc-parser.y
> index 2ed4dc1f07fd..40dcf4f149da 100644
> --- a/scripts/dtc/dtc-parser.y
> +++ b/scripts/dtc/dtc-parser.y

For file scripts/dtc/dtc-parser.y:

This file is maintained in the upstream dtc project.  We pull changes
from that project into the Linux kernel source tree.

The file is located at the root level of the upstream project.

Info on submitting patches is in the upstream file "Documentation/manual.txt":

   1) Sources

   Source code for the Device Tree Compiler can be found at git.kernel.org.

   The upstream repository is here:

       git://git.kernel.org/pub/scm/utils/dtc/dtc.git
       https://git.kernel.org/pub/scm/utils/dtc/dtc.git

   The gitweb interface for the upstream respository is:

       https://git.kernel.org/cgit/utils/dtc/dtc.git/

   1.1) Submitting Patches

   Patches should be sent to the maintainers:
           David Gibson <david@gibson.dropbear.id.au>
           Jon Loeliger <jdl@jdl.com>
   and CCed to <devicetree-compiler@vger.kernel.org>.

-Frank


> @@ -2,6 +2,8 @@
>  /*
>   * (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation.  2005.
>   */
> +%locations
> +
>  %{
>  #include <stdio.h>
>  #include <inttypes.h>
> @@ -17,6 +19,8 @@ extern void yyerror(char const *s);
>  		treesource_error = true; \
>  	} while (0)
>  
> +#define YYERROR_CALL(msg) yyerror(msg)
> +
>  extern struct dt_info *parser_output;
>  extern bool treesource_error;
>  %}
> diff --git a/scripts/genksyms/Makefile b/scripts/genksyms/Makefile
> index 78629f515e78..397c2dc8182b 100644
> --- a/scripts/genksyms/Makefile
> +++ b/scripts/genksyms/Makefile
> @@ -15,7 +15,7 @@ genksyms-objs	:= genksyms.o parse.tab.o lex.lex.o
>  ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
>  
>  quiet_cmd_bison_no_warn = $(quiet_cmd_bison)
> -      cmd_bison_no_warn = $(YACC) --version >/dev/null; \
> +      cmd_bison_no_warn = $(YACC) -V >/dev/null; \
>  			  $(cmd_bison) 2>/dev/null
>  
>  $(obj)/pars%.tab.c $(obj)/pars%.tab.h: $(src)/pars%.y FORCE
> diff --git a/scripts/genksyms/lex.l b/scripts/genksyms/lex.l
> index e265c5d96861..0580c088527f 100644
> --- a/scripts/genksyms/lex.l
> +++ b/scripts/genksyms/lex.l
> @@ -19,6 +19,8 @@
>  #include "genksyms.h"
>  #include "parse.tab.h"
>  
> +extern YYSTYPE yylval;
> +
>  /* We've got a two-level lexer here.  We let flex do basic tokenization
>     and then we categorize those basic tokens in the second stage.  */
>  #define YY_DECL		static int yylex1(void)
>