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%{ /* -*- C++ -*- */
# include <cerrno>
# include <climits>
# include <cstdlib>
# include <cstring> // strerror
# include <string>
# include "driver.hh"
# include "parser.hh"
%}
%{
// Pacify warnings in yy_init_buffer (observed with Flex 2.6.4)
// and GCC 6.4.0, 7.3.0.
#if defined __GNUC__ && !defined __clang__ && 6 <= __GNUC__
# pragma GCC diagnostic ignored "-Wnull-dereference"
#endif
// Of course, when compiling C as C++, expect warnings about NULL.
#if defined __clang__
# pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
#elif defined __GNUC__ && 407 <= __GNUC__ * 100 + __GNUC_MINOR__
# pragma GCC diagnostic ignored "-Wzero-as-null-pointer-constant"
#endif
#define FLEX_VERSION (YY_FLEX_MAJOR_VERSION * 100 + YY_FLEX_MINOR_VERSION)
// Old versions of Flex (2.5.35) generate an incomplete documentation comment.
//
// In file included from src/scan-code-c.c:3:
// src/scan-code.c:2198:21: error: empty paragraph passed to '@param' command
// [-Werror,-Wdocumentation]
// * @param line_number
// ~~~~~~~~~~~~~~~~~^
// 1 error generated.
#if FLEX_VERSION < 206 && defined __clang__
# pragma clang diagnostic ignored "-Wdocumentation"
#endif
// Old versions of Flex (2.5.35) use 'register'. Warnings introduced in
// GCC 7 and Clang 6.
#if FLEX_VERSION < 206
# if defined __clang__ && 6 <= __clang_major__
# pragma clang diagnostic ignored "-Wdeprecated-register"
# elif defined __GNUC__ && 7 <= __GNUC__
# pragma GCC diagnostic ignored "-Wregister"
# endif
#endif
#if FLEX_VERSION < 206
# if defined __clang__
# pragma clang diagnostic ignored "-Wconversion"
# pragma clang diagnostic ignored "-Wdocumentation"
# pragma clang diagnostic ignored "-Wshorten-64-to-32"
# pragma clang diagnostic ignored "-Wsign-conversion"
# elif defined __GNUC__
# pragma GCC diagnostic ignored "-Wconversion"
# pragma GCC diagnostic ignored "-Wsign-conversion"
# endif
#endif
%}
%option noyywrap nounput noinput batch debug
%{
// A number symbol corresponding to the value in S.
yy::parser::symbol_type
make_NUMBER (const std::string &s, const yy::parser::location_type& loc);
%}
id [a-zA-Z][a-zA-Z_0-9]*
int [0-9]+
blank [ \t\r]
%{
// Code run each time a pattern is matched.
# define YY_USER_ACTION loc.columns (yyleng);
%}
%%
%{
// A handy shortcut to the location held by the driver.
yy::location& loc = drv.location;
// Code run each time yylex is called.
loc.step ();
%}
{blank}+ loc.step ();
\n+ loc.lines (yyleng); loc.step ();
"-" return yy::parser::make_MINUS (loc);
"+" return yy::parser::make_PLUS (loc);
"*" return yy::parser::make_STAR (loc);
"/" return yy::parser::make_SLASH (loc);
"(" return yy::parser::make_LPAREN (loc);
")" return yy::parser::make_RPAREN (loc);
":=" return yy::parser::make_ASSIGN (loc);
{int} return make_NUMBER (yytext, loc);
{id} return yy::parser::make_IDENTIFIER (yytext, loc);
. {
throw yy::parser::syntax_error
(loc, "invalid character: " + std::string(yytext));
}
<<EOF>> return yy::parser::make_END (loc);
%%
yy::parser::symbol_type
make_NUMBER (const std::string &s, const yy::parser::location_type& loc)
{
errno = 0;
long n = strtol (s.c_str(), NULL, 10);
if (! (INT_MIN <= n && n <= INT_MAX && errno != ERANGE))
throw yy::parser::syntax_error (loc, "integer is out of range: " + s);
return yy::parser::make_NUMBER ((int) n, loc);
}
void
driver::scan_begin ()
{
yy_flex_debug = trace_scanning;
if (file.empty () || file == "-")
yyin = stdin;
else if (!(yyin = fopen (file.c_str (), "r")))
{
std::cerr << "cannot open " << file << ": " << strerror(errno) << '\n';
exit (EXIT_FAILURE);
}
}
void
driver::scan_end ()
{
fclose (yyin);
}
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