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Extract calc++ from the documentation.

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* doc/bison.texinfo (Calc++): Add the extraction marks.
* examples/extexi: New, from the aborted GNU Programming 2E.
Separate the different paragraph of a file with empty lines.
* examples/Makefile: Use it to extract the whole calc++ example.
This commit is contained in:
Akim Demaille
2005-07-05 07:21:30 +00:00
parent 8a0adb0183
commit 1c59e0a121
9 changed files with 235 additions and 66 deletions
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8
ChangeLog
View File

@@ -1,3 +1,11 @@
2005-07-05 Akim Demaille <akim@epita.fr>
Extract calc++ from the documentation.
* doc/bison.texinfo (Calc++): Add the extraction marks.
* examples/extexi: New, from the aborted GNU Programming 2E.
Separate the different paragraph of a file with empty lines.
* examples/Makefile: Use it to extract the whole calc++ example.
2005-06-24 Akim Demaille <akim@epita.fr>
* doc/bison.texinfo (C++ Parser Interface): Use defcv to define

37
doc/bison.texinfo
View File

@@ -7031,6 +7031,7 @@ The declaration of this driver class, @file{calc++-driver.hh}, is as
follows. The first part includes the CPP guard and imports the
required standard library components.
@comment file: calc++-driver.hh
@example
#ifndef CALCXX_DRIVER_HH
# define CALCXX_DRIVER_HH
@@ -7045,10 +7046,15 @@ do. Because the driver's declaration is the one that will be imported
by the rest of the project, it is saner to forward declare the
parser's information here.
@comment file: calc++-driver.hh
@example
// Forward declarations.
union YYSTYPE;
namespace yy @{ class calcxx_parser; @}
namespace yy
@{
class location;
class calcxx_parser;
@}
class calcxx_driver;
@end example
@@ -7057,9 +7063,11 @@ Then comes the declaration of the scanning function. Flex expects
the signature of @code{yylex} to be defined in the macro
@code{YY_DECL}, and the C++ parser expects it to be declared. We can
factor both as follows.
@comment file: calc++-driver.hh
@example
// Announce to Flex the prototype we want for lexing function, ...
# define YY_DECL \
# define YY_DECL \
int yylex (YYSTYPE* yylval, yy::location* yylloc, calcxx_driver& driver)
// ... and declare it for the parser's sake.
YY_DECL;
@@ -7069,6 +7077,7 @@ YY_DECL;
The @code{calcxx_driver} class is then declared with its most obvious
members.
@comment file: calc++-driver.hh
@example
// Conducting the whole scanning and parsing of Calc++.
class calcxx_driver
@@ -7087,6 +7096,7 @@ To encapsulate the coordination with the Flex scanner, it is useful to
have two members function to open and close the scanning phase.
members.
@comment file: calc++-driver.hh
@example
// Handling the scanner.
void scan_begin ();
@@ -7097,6 +7107,7 @@ members.
@noindent
Similarly for the parser itself.
@comment file: calc++-driver.hh
@example
// Handling the parser.
void parse (const std::string& f);
@@ -7110,6 +7121,7 @@ dumping them on the standard error output, we will pass them to the
compiler driver using the following two member functions. Finally, we
close the class declaration and CPP guard.
@comment file: calc++-driver.hh
@example
// Error handling.
void error (const yy::location& l, const std::string& m);
@@ -7123,6 +7135,7 @@ member function deserves some attention. The @code{error} functions
are simple stubs, they should actually register the located error
messages and set error state.
@comment file: calc++-driver.cc
@example
#include "calc++-driver.hh"
#include "calc++-parser.hh"
@@ -7169,6 +7182,8 @@ The parser definition file @file{calc++-parser.yy} starts by asking
for the C++ skeleton, the creation of the parser header file, and
specifies the name of the parser class. It then includes the required
headers.
@comment file: calc++-parser.yy
@example
%skeleton "lalr1.cc" /* -*- C++ -*- */
%define "parser_class_name" "calcxx_parser"
@@ -7184,6 +7199,7 @@ The driver is passed by reference to the parser and to the scanner.
This provides a simple but effective pure interface, not relying on
global variables.
@comment file: calc++-parser.yy
@example
// The parsing context.
%parse-param @{ calcxx_driver& driver @}
@@ -7196,6 +7212,7 @@ first location's file name. Afterwards new locations are computed
relatively to the previous locations: the file name will be
automatically propagated.
@comment file: calc++-parser.yy
@example
%locations
%initial-action
@@ -7209,6 +7226,7 @@ automatically propagated.
Use the two following directives to enable parser tracing and verbose
error messages.
@comment file: calc++-parser.yy
@example
%debug
%error-verbose
@@ -7218,6 +7236,7 @@ error messages.
Semantic values cannot use ``real'' objects, but only pointers to
them.
@comment file: calc++-parser.yy
@example
// Symbols.
%union
@@ -7234,6 +7253,7 @@ of ``$end''. Similarly user friendly named are provided for each
symbol. Note that the tokens names are prefixed by @code{TOKEN_} to
avoid name clashes.
@comment file: calc++-parser.yy
@example
%token YYEOF 0 "end of file"
%token TOKEN_ASSIGN ":="
@@ -7246,6 +7266,7 @@ avoid name clashes.
To enable memory deallocation during error recovery, use
@code{%destructor}.
@comment file: calc++-parser.yy
@example
%printer @{ debug_stream () << *$$; @} "identifier"
%destructor @{ delete $$; @} "identifier"
@@ -7256,6 +7277,7 @@ To enable memory deallocation during error recovery, use
@noindent
The grammar itself is straightforward.
@comment file: calc++-parser.yy
@example
%%
%start unit;
@@ -7281,9 +7303,11 @@ exp: exp '+' exp @{ $$ = $1 + $3; @}
Finally the @code{error} member function registers the errors to the
driver.
@comment file: calc++-parser.yy
@example
void
yy::calcxx_parser::error (const location_type& l, const std::string& m)
yy::calcxx_parser::error (const yy::calcxx_parser::location_type& l,
const std::string& m)
@{
driver.error (l, m);
@}
@@ -7295,6 +7319,7 @@ yy::calcxx_parser::error (const location_type& l, const std::string& m)
The Flex scanner first includes the driver declaration, then the
parser's to get the set of defined tokens.
@comment file: calc++-scanner.ll
@example
%@{ /* -*- C++ -*- */
# include <string>
@@ -7309,6 +7334,7 @@ Because there is no @code{#include}-like feature we don't need
actual file, this is not an interactive session with the user.
Finally we enable the scanner tracing features.
@comment file: calc++-scanner.ll
@example
%option noyywrap nounput batch debug
@end example
@@ -7316,6 +7342,7 @@ Finally we enable the scanner tracing features.
@noindent
Abbreviations allow for more readable rules.
@comment file: calc++-scanner.ll
@example
id [a-zA-Z][a-zA-Z_0-9]*
int [0-9]+
@@ -7331,6 +7358,7 @@ cursor is adjusted, and each time blanks are matched, the begin cursor
is moved onto the end cursor to effectively ignore the blanks
preceding tokens. Comments would be treated equally.
@comment file: calc++-scanner.ll
@example
%%
%@{
@@ -7345,6 +7373,7 @@ preceding tokens. Comments would be treated equally.
The rules are simple, just note the use of the driver to report
errors.
@comment file: calc++-scanner.ll
@example
[-+*/] return yytext[0];
":=" return TOKEN_ASSIGN;
@@ -7358,6 +7387,7 @@ errors.
Finally, because the scanner related driver's member function depend
on the scanner's data, it is simpler to implement them in this file.
@comment file: calc++-scanner.ll
@example
void
calcxx_driver::scan_begin ()
@@ -7379,6 +7409,7 @@ calcxx_driver::scan_end ()
The top level file, @file{calc++.cc}, poses no problem.
@comment file: calc++.cc
@example
#include <iostream>
#include "calc++-driver.hh"

20
examples/calc++/Makefile
View File

@@ -13,3 +13,23 @@ clean:
calc++-parser.cc calc++-parser.hh \
calc++-scanner.cc \
calc++
## ------------ ##
## Extracting. ##
## ------------ ##
EXTRACTED = \
calc++-driver.hh calc++-driver.cc \
calc++-parser.yy \
calc++-scanner.ll \
calc++.cc
doc = ../../doc/bison.texinfo
extexi = gawk -f ../extexi
RECURSIVE_TARGETS += extract
$(EXTRACTED): $(doc) ../extexi
$(extexi) $(doc) -- $(EXTRACTED)
extract extract-am: $(EXTRACTED)

4
examples/calc++/calc++-driver.cc
View File

@@ -1,9 +1,9 @@
#line 7140 "../../doc/bison.texinfo"
#include "calc++-driver.hh"
#include "calc++-parser.hh"
calcxx_driver::calcxx_driver ()
: trace_scanning (false),
trace_parsing (false)
: trace_scanning (false), trace_parsing (false)
{
variables["one"] = 1;
variables["two"] = 2;

59
examples/calc++/calc++-driver.hh
View File

@@ -1,64 +1,47 @@
#line 7036 "../../doc/bison.texinfo"
#ifndef CALCXX_DRIVER_HH
# define CALCXX_DRIVER_HH
# include <string>
# include <map>
/// Forward declarations.
#line 7051 "../../doc/bison.texinfo"
// Forward declarations.
union YYSTYPE;
namespace yy
{
class calcxx_parser;
class location;
class calcxx_parser;
}
class calcxx_driver;
#line 7069 "../../doc/bison.texinfo"
// Announce to Flex the prototype we want for lexing function, ...
# define YY_DECL \
# define YY_DECL \
int yylex (YYSTYPE* yylval, yy::location* yylloc, calcxx_driver& driver)
// ... and declare it for the parser's sake.
YY_DECL;
/// Conducting the whole scanning and parsing of Calc++.
#line 7082 "../../doc/bison.texinfo"
// Conducting the whole scanning and parsing of Calc++.
class calcxx_driver
{
public:
calcxx_driver ();
virtual ~calcxx_driver ();
/// The variables.
std::map<std::string, int> variables;
/// \name Handling the scanner.
/// \{
/// Open \a file for scanning.
void scan_begin ();
/// End scanning, clean up memory.
void scan_end ();
/// Whether to enable scanner traces.
bool trace_scanning;
/// \}
/// \name Handling the parser.
/// \{
/// Parse the file \a f.
void parse (const std::string& f);
/// The file being parsed.
std::string file;
/// Whether to enable parsing traces.
bool trace_parsing;
/// \}
/// The result.
int result;
/// \name Error handling.
/// \{
/// Register a located error.
#line 7101 "../../doc/bison.texinfo"
// Handling the scanner.
void scan_begin ();
void scan_end ();
bool trace_scanning;
#line 7112 "../../doc/bison.texinfo"
// Handling the parser.
void parse (const std::string& f);
std::string file;
bool trace_parsing;
#line 7126 "../../doc/bison.texinfo"
// Error handling.
void error (const yy::location& l, const std::string& m);
/// Register an error.
void error (const std::string& m);
/// \}
};
#endif
#endif // ! CALCXX_DRIVER_HH

28
examples/calc++/calc++-parser.yy
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@@ -1,48 +1,44 @@
%skeleton "lalr1.cc" /* -*- C++ -*- */
#line 7188 "../../doc/bison.texinfo"
%skeleton "lalr1.cc" /* -*- C++ -*- */
%define "parser_class_name" "calcxx_parser"
%defines
%{
# include <string>
# include "calc++-driver.hh"
%}
%error-verbose
#line 7204 "../../doc/bison.texinfo"
// The parsing context.
%parse-param { calcxx_driver& driver }
%lex-param { calcxx_driver& driver }
#line 7217 "../../doc/bison.texinfo"
%locations
%initial-action
{
// Initialize the initial location.
@$.begin.filename = @$.end.filename = &driver.file;
};
// Define yydebug.
#line 7231 "../../doc/bison.texinfo"
%debug
%error-verbose
#line 7241 "../../doc/bison.texinfo"
// Symbols.
%union
{
/// Value of a numeric literal.
int ival;
/// Name of a variable.
std::string *sval;
};
#line 7258 "../../doc/bison.texinfo"
%token YYEOF 0 "end of file"
%token TOKEN_ASSIGN ":="
%token <sval> TOKEN_IDENTIFIER "identifier"
%token <ival> TOKEN_NUMBER "number"
%type <ival> exp "expression"
#line 7271 "../../doc/bison.texinfo"
%printer { debug_stream () << *$$; } "identifier"
%destructor { delete $$; } "identifier"
%printer { debug_stream () << $$; } "number" "expression"
#line 7282 "../../doc/bison.texinfo"
%%
%start unit;
unit: assignments exp { driver.result = $2; };
@@ -61,8 +57,10 @@ exp: exp '+' exp { $$ = $1 + $3; }
| TOKEN_IDENTIFIER { $$ = driver.variables[*$1]; }
| TOKEN_NUMBER { $$ = $1; };
%%
#line 7308 "../../doc/bison.texinfo"
void
yy::calcxx_parser::error (const location& l, const std::string& m)
yy::calcxx_parser::error (const yy::calcxx_parser::location_type& l,
const std::string& m)
{
driver.error (l, m);
}

11
examples/calc++/calc++-scanner.ll
View File

@@ -1,33 +1,28 @@
%{ /* -*- C++ -*- */
%{ /* -*- C++ -*- */
# include <string>
# include <cerrno>
# include "calc++-driver.hh"
# include "calc++-parser.hh"
%}
%option noyywrap nounput debug batch
%option noyywrap nounput batch debug
id [a-zA-Z][a-zA-Z_0-9]*
int [0-9]+
blank [ \t]
%%
%{
# define YY_USER_ACTION yylloc->columns (yyleng);
yylloc->step ();
# define YY_USER_ACTION yylloc->columns (yyleng);
%}
{blank}+ yylloc->step ();
[\n]+ yylloc->lines (yyleng); yylloc->step ();
[-+*/] return yytext[0];
":=" return TOKEN_ASSIGN;
{int} yylval->ival = atoi (yytext); return TOKEN_NUMBER;
{id} yylval->sval = new std::string (yytext); return TOKEN_IDENTIFIER;
. driver.error (*yylloc, "invalid character");
%%
void

1
examples/calc++/calc++.cc
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@@ -1,3 +1,4 @@
#line 7414 "../../doc/bison.texinfo"
#include <iostream>
#include "calc++-driver.hh"

133
examples/extexi Normal file
View File

@@ -0,0 +1,133 @@
# Extract all examples from the manual source. -*- AWK -*-
# This file is part of GNU M4
# Copyright 1992, 2000, 2001 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 2 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, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
# 02111-1307 USA
# This script is for use with any New AWK.
# Well, now it uses ARGV/ARGC, and I don't know if it's New AWK portable.
#
# Usage: extexi input-file.texi ... -- [FILES to extract]
BEGIN {
if (!output_dir)
output_dir = ".";
for (argc = 1; argc < ARGC; ++argc)
if (ARGV[argc] == "--")
break;
for (i = argc + 1; i < ARGC; ++i)
file_wanted[ARGV[i]] = 1;
ARGC = argc;
}
/^@node / {
if (seq > 0)
print "AT_CLEANUP";
split ($0, tmp, ",");
node = substr(tmp[1], 7);
seq = 0;
}
/^@comment file: / {
if (!file_wanted[$3])
message("ignoring " $3);
else
{
message("extracting " $3);
file = $3;
}
}
/^@example$/, /^@end example$/ {
if (!file)
next;
if ($0 ~ /^@example$/)
{
input = files_output[file] ? "\n" : "";
# FNR is starting at 0 instead of 1, and
# #line report the line number of the *next* line.
# => + 2.
# Note that recent Bison support it, but not Flex.
if (file ~ /\.[chy]*$/)
input = "#line " (FNR + 1) " \"" FILENAME "\"\n";
next;
}
if ($0 ~ /^@end example$/)
{
if (input == "")
fatal("no contents: " file);
input = normalize(input);
# No spurious end of line: use printf.
if (files_output[file])
printf ("%s", input) >> output_dir "/" file;
else
printf ("%s", input) > output_dir "/" file;
close (output_dir "/" file);
files_output[file] = 1;
file = input = "";
next;
}
input = input $0 "\n";
}
# We have to handle CONTENTS line per line, since anchors in AWK are
# referring to the whole string, not the lines.
function normalize(contents, i, lines, n, line, res) {
# Remove the Texinfo tags.
n = split (contents, lines, "\n");
# We don't want the last field which empty: it's behind the last \n.
for (i = 1; i < n; ++i)
{
line = lines[i];
# Whole line commands.
if (line ~ /^@(c |comment|dots|end (ignore|group)|ignore|group)/)
# Gperf accepts empty lines as valid input!!!
if (file ~ /\.gperf$/)
continue;
else
line = "";
gsub (/^@result\{\}/, "", line);
gsub (/^@error\{\}/, "", line);
gsub ("@[{]", "{", line);
gsub ("@}", "}", line);
gsub ("@@", "@", line);
gsub ("@comment.*", "", line);
res = res line "\n";
}
return res;
}
function message(msg) {
# FNR starts at 0 instead of 1 for line numbers.
print "extexi: " FILENAME ":" (FNR + 1) ": " msg > "/dev/stderr";
}
function fatal(msg) {
message(msg);
exit 1
}