src/compiler/glsl/s_expression.h

   1 /* -*- c++ -*- */
   2 /*
   3  * Copyright © 2010 Intel Corporation
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 #ifndef S_EXPRESSION_H
  26 #define S_EXPRESSION_H
  27
  28 #include "util/strtod.h"
  29 #include "list.h"
  30
  31 /* Type-safe downcasting macros (also safe to pass NULL) */
  32 #define SX_AS_(t,x) ((x) && ((s_expression*) x)->is_##t()) ? ((s_##t*) (x)) \
  33                                                            : NULL
  34 #define SX_AS_LIST(x)   SX_AS_(list, x)
  35 #define SX_AS_SYMBOL(x) SX_AS_(symbol, x)
  36 #define SX_AS_NUMBER(x) SX_AS_(number, x)
  37 #define SX_AS_INT(x)    SX_AS_(int, x)
  38
  39 /* Pattern matching macros */
  40 #define MATCH(list, pat) s_match(list, ARRAY_SIZE(pat), pat, false)
  41 #define PARTIAL_MATCH(list, pat) s_match(list, ARRAY_SIZE(pat), pat, true)
  42
  43 /* For our purposes, S-Expressions are:
  44  * - <int>
  45  * - <float>
  46  * - symbol
  47  * - (expr1 expr2 ... exprN)     where exprN is an S-Expression
  48  *
  49  * Unlike LISP/Scheme, we do not support (foo . bar) pairs.
  50  */
  51 class s_expression : public exec_node
  52 {
  53 public:
  54    /**
  55     * Read an S-Expression from the given string.
  56     * Advances the supplied pointer to just after the expression read.
  57     *
  58     * Any allocation will be performed with 'ctx' as the ralloc owner.
  59     */
  60    static s_expression *read_expression(void *ctx, const char *&src);
  61
  62    /**
  63     * Print out an S-Expression.  Useful for debugging.
  64     */
  65    virtual void print() = 0;
  66
  67    virtual bool is_list()   const { return false; }
  68    virtual bool is_symbol() const { return false; }
  69    virtual bool is_number() const { return false; }
  70    virtual bool is_int()    const { return false; }
  71
  72 protected:
  73    s_expression() { }
  74 };
  75
  76 /* Atoms */
  77
  78 class s_number : public s_expression
  79 {
  80 public:
  81    bool is_number() const { return true; }
  82
  83    virtual float fvalue() = 0;
  84
  85 protected:
  86    s_number() { }
  87 };
  88
  89 class s_int : public s_number
  90 {
  91 public:
  92    s_int(int x) : val(x) { }
  93
  94    bool is_int() const { return true; }
  95
  96    float fvalue() { return float(this->val); }
  97    int value() { return this->val; }
  98
  99    void print();
 100
 101 private:
 102    int val;
 103 };
 104
 105 class s_float : public s_number
 106 {
 107 public:
 108    s_float(float x) : val(x) { }
 109
 110    float fvalue() { return this->val; }
 111
 112    void print();
 113
 114 private:
 115    float val;
 116 };
 117
 118 class s_symbol : public s_expression
 119 {
 120 public:
 121    s_symbol(const char *, size_t);
 122
 123    bool is_symbol() const { return true; }
 124
 125    const char *value() { return this->str; }
 126
 127    void print();
 128
 129 private:
 130    const char *str;
 131 };
 132
 133 /* Lists of expressions: (expr1 ... exprN) */
 134 class s_list : public s_expression
 135 {
 136 public:
 137    s_list();
 138
 139    virtual bool is_list() const { return true; }
 140
 141    void print();
 142
 143    exec_list subexpressions;
 144 };
 145
 146 // ------------------------------------------------------------
 147
 148 /**
 149  * Part of a pattern to match - essentially a record holding a pointer to the
 150  * storage for the component to match, along with the appropriate type.
 151  */
 152 class s_pattern {
 153 public:
 154    s_pattern(s_expression *&s) : p_expr(&s),   type(EXPR)   { }
 155    s_pattern(s_list       *&s) : p_list(&s),   type(LIST)   { }
 156    s_pattern(s_symbol     *&s) : p_symbol(&s), type(SYMBOL) { }
 157    s_pattern(s_number     *&s) : p_number(&s), type(NUMBER) { }
 158    s_pattern(s_int        *&s) : p_int(&s),    type(INT)    { }
 159    s_pattern(const char *str)  : literal(str), type(STRING) { }
 160
 161    bool match(s_expression *expr);
 162
 163 private:
 164    union {
 165       s_expression **p_expr;
 166       s_list       **p_list;
 167       s_symbol     **p_symbol;
 168       s_number     **p_number;
 169       s_int        **p_int;
 170       const char *literal;
 171    };
 172    enum { EXPR, LIST, SYMBOL, NUMBER, INT, STRING } type;
 173 };
 174
 175 bool
 176 s_match(s_expression *top, unsigned n, s_pattern *pattern, bool partial);
 177
 178 #endif /* S_EXPRESSION_H */