util/kconfig: Add pre-built parser

It avoids the dependency on bison/flex, minimally speeds up the build
and also works around weird race conditions in some versions of bison
that need more investigation.

The issue this avoids manifests as a build error when creating
parser.tab.c:

    input in flex scanner failed
    make: *** [util/kconfig/Makefile.inc:66: build/util/kconfig/parser.tab.c] Error 2

Since the error happens within bison the alternative would be to make
bison part of our crossgcc environment to ensure that no broken OS
build is used.

BUG=b:197515860
TEST=things build with bison not installed

Change-Id: Ib35dfb7beafc0a09dc333e962b1e3f33df46a854
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57409
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

src/Kconfig

@@ -112,7 +112,7 @@ config FMD_GENPARSER
 	  Otherwise, say N to use the provided pregenerated scanner/parser.
 
 config UTIL_GENPARSER
-	bool "Generate SCONFIG & BINCFG parser using flex and bison"
+	bool "Generate parsers for bincfg, sconfig and kconfig locally"
 	default n
 	help
 	  Enable this option if you are working on the sconfig device tree

util/kconfig/Makefile.inc

@@ -60,12 +60,25 @@ endef
 
 $(foreach prog,$(hostprogs),$(eval $(call hostprogs_template,$(prog))))
 
+# This might be a bit of a chicken & egg problem, using a kconfig flag when
+# building kconfig, but if you're messing with the parser you probably know
+# what you're doing: make CONFIG_UTIL_GENPARSER=y
+ifeq ($(CONFIG_UTIL_GENPARSER),y)
 $(objk)/%.tab.c $(objk)/%.tab.h: $(srck)/%.y
 	bison -t -l --defines -b $(objk)/$* $<
 
 $(objk)/%.lex.c: $(srck)/%.l
 	flex -L -o$@ $<
 
+else # !CONFIG_UTIL_GENPARSER
+
+$(objk)/parser.tab.c: | $(objk)/parser.tab.h
+
+$(objk)/%: $(srck)/%_shipped
+	cp $< $@
+
+endif
+
 # Support mingw by shipping our own regex implementation
 _OS=$(shell uname -s |cut -c-7)
 regex-objs=

util/kconfig/parser.tab.h_shipped

@@ -0,0 +1,132 @@
+/* A Bison parser, made by GNU Bison 3.7.6.  */
+
+/* Bison interface for Yacc-like parsers in C
+
+   Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2021 Free Software Foundation,
+   Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* As a special exception, you may create a larger work that contains
+   part or all of the Bison parser skeleton and distribute that work
+   under terms of your choice, so long as that work isn't itself a
+   parser generator using the skeleton or a modified version thereof
+   as a parser skeleton.  Alternatively, if you modify or redistribute
+   the parser skeleton itself, you may (at your option) remove this
+   special exception, which will cause the skeleton and the resulting
+   Bison output files to be licensed under the GNU General Public
+   License without this special exception.
+
+   This special exception was added by the Free Software Foundation in
+   version 2.2 of Bison.  */
+
+/* DO NOT RELY ON FEATURES THAT ARE NOT DOCUMENTED in the manual,
+   especially those whose name start with YY_ or yy_.  They are
+   private implementation details that can be changed or removed.  */
+
+#ifndef YY_YY_PARSER_TAB_H_INCLUDED
+# define YY_YY_PARSER_TAB_H_INCLUDED
+/* Debug traces.  */
+#ifndef YYDEBUG
+# define YYDEBUG 1
+#endif
+#if YYDEBUG
+extern int yydebug;
+#endif
+
+/* Token kinds.  */
+#ifndef YYTOKENTYPE
+# define YYTOKENTYPE
+  enum yytokentype
+  {
+    YYEMPTY = -2,
+    YYEOF = 0,                     /* "end of file"  */
+    YYerror = 256,                 /* error  */
+    YYUNDEF = 257,                 /* "invalid token"  */
+    T_HELPTEXT = 258,              /* T_HELPTEXT  */
+    T_WORD = 259,                  /* T_WORD  */
+    T_WORD_QUOTE = 260,            /* T_WORD_QUOTE  */
+    T_BOOL = 261,                  /* T_BOOL  */
+    T_CHOICE = 262,                /* T_CHOICE  */
+    T_CLOSE_PAREN = 263,           /* T_CLOSE_PAREN  */
+    T_COLON_EQUAL = 264,           /* T_COLON_EQUAL  */
+    T_COMMENT = 265,               /* T_COMMENT  */
+    T_CONFIG = 266,                /* T_CONFIG  */
+    T_DEFAULT = 267,               /* T_DEFAULT  */
+    T_DEF_BOOL = 268,              /* T_DEF_BOOL  */
+    T_DEF_TRISTATE = 269,          /* T_DEF_TRISTATE  */
+    T_DEPENDS = 270,               /* T_DEPENDS  */
+    T_ENDCHOICE = 271,             /* T_ENDCHOICE  */
+    T_ENDIF = 272,                 /* T_ENDIF  */
+    T_ENDMENU = 273,               /* T_ENDMENU  */
+    T_HELP = 274,                  /* T_HELP  */
+    T_HEX = 275,                   /* T_HEX  */
+    T_IF = 276,                    /* T_IF  */
+    T_IMPLY = 277,                 /* T_IMPLY  */
+    T_INT = 278,                   /* T_INT  */
+    T_MAINMENU = 279,              /* T_MAINMENU  */
+    T_MENU = 280,                  /* T_MENU  */
+    T_MENUCONFIG = 281,            /* T_MENUCONFIG  */
+    T_MODULES = 282,               /* T_MODULES  */
+    T_ON = 283,                    /* T_ON  */
+    T_OPEN_PAREN = 284,            /* T_OPEN_PAREN  */
+    T_OPTIONAL = 285,              /* T_OPTIONAL  */
+    T_PLUS_EQUAL = 286,            /* T_PLUS_EQUAL  */
+    T_PROMPT = 287,                /* T_PROMPT  */
+    T_RANGE = 288,                 /* T_RANGE  */
+    T_SELECT = 289,                /* T_SELECT  */
+    T_SOURCE = 290,                /* T_SOURCE  */
+    T_STRING = 291,                /* T_STRING  */
+    T_TRISTATE = 292,              /* T_TRISTATE  */
+    T_VISIBLE = 293,               /* T_VISIBLE  */
+    T_EOL = 294,                   /* T_EOL  */
+    T_ASSIGN_VAL = 295,            /* T_ASSIGN_VAL  */
+    T_OR = 296,                    /* T_OR  */
+    T_AND = 297,                   /* T_AND  */
+    T_EQUAL = 298,                 /* T_EQUAL  */
+    T_UNEQUAL = 299,               /* T_UNEQUAL  */
+    T_LESS = 300,                  /* T_LESS  */
+    T_LESS_EQUAL = 301,            /* T_LESS_EQUAL  */
+    T_GREATER = 302,               /* T_GREATER  */
+    T_GREATER_EQUAL = 303,         /* T_GREATER_EQUAL  */
+    T_NOT = 304                    /* T_NOT  */
+  };
+  typedef enum yytokentype yytoken_kind_t;
+#endif
+
+/* Value type.  */
+#if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
+union YYSTYPE
+{
+
+	char *string;
+	struct symbol *symbol;
+	struct expr *expr;
+	struct menu *menu;
+	enum symbol_type type;
+	enum variable_flavor flavor;
+
+
+};
+typedef union YYSTYPE YYSTYPE;
+# define YYSTYPE_IS_TRIVIAL 1
+# define YYSTYPE_IS_DECLARED 1
+#endif
+
+
+extern YYSTYPE yylval;
+
+int yyparse (void);
+
+#endif /* !YY_YY_PARSER_TAB_H_INCLUDED  */