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 "main/core.h" /* for Elements */
  29 #include "util/strtod.h"
  30 #include "list.h"
  31
  32 /* Type-safe downcasting macros (also safe to pass NULL) */
  33 #define SX_AS_(t,x) ((x) && ((s_expression*) x)->is_##t()) ? ((s_##t*) (x)) \
  34                                                            : NULL
  35 #define SX_AS_LIST(x)   SX_AS_(list, x)
  36 #define SX_AS_SYMBOL(x) SX_AS_(symbol, x)
  37 #define SX_AS_NUMBER(x) SX_AS_(number, x)
  38 #define SX_AS_INT(x)    SX_AS_(int, x)
  39
  40 /* Pattern matching macros */
  41 #define MATCH(list, pat) s_match(list, ARRAY_SIZE(pat), pat, false)
  42 #define PARTIAL_MATCH(list, pat) s_match(list, ARRAY_SIZE(pat), pat, true)
  43
  44 /* For our purposes, S-Expressions are:
  45  * - <int>
  46  * - <float>
  47  * - symbol
  48  * - (expr1 expr2 ... exprN)     where exprN is an S-Expression
  49  *
  50  * Unlike LISP/Scheme, we do not support (foo . bar) pairs.
  51  */
  52 class s_expression : public exec_node
  53 {
  54 public:
  55    /**
  56     * Read an S-Expression from the given string.
  57     * Advances the supplied pointer to just after the expression read.
  58     *
  59     * Any allocation will be performed with 'ctx' as the ralloc owner.
  60     */
  61    static s_expression *read_expression(void *ctx, const char *&src);
  62
  63    /**
  64     * Print out an S-Expression.  Useful for debugging.
  65     */
  66    virtual void print() = 0;
  67
  68    virtual bool is_list()   const { return false; }
  69    virtual bool is_symbol() const { return false; }
  70    virtual bool is_number() const { return false; }
  71    virtual bool is_int()    const { return false; }
  72
  73 protected:
  74    s_expression() { }
  75 };
  76
  77 /* Atoms */
  78
  79 class s_number : public s_expression
  80 {
  81 public:
  82    bool is_number() const { return true; }
  83
  84    virtual float fvalue() = 0;
  85
  86 protected:
  87    s_number() { }
  88 };
  89
  90 class s_int : public s_number
  91 {
  92 public:
  93    s_int(int x) : val(x) { }
  94
  95    bool is_int() const { return true; }
  96
  97    float fvalue() { return float(this->val); }
  98    int value() { return this->val; }
  99
 100    void print();
 101
 102 private:
 103    int val;
 104 };
 105
 106 class s_float : public s_number
 107 {
 108 public:
 109    s_float(float x) : val(x) { }
 110
 111    float fvalue() { return this->val; }
 112
 113    void print();
 114
 115 private:
 116    float val;
 117 };
 118
 119 class s_symbol : public s_expression
 120 {
 121 public:
 122    s_symbol(const char *, size_t);
 123
 124    bool is_symbol() const { return true; }
 125
 126    const char *value() { return this->str; }
 127
 128    void print();
 129
 130 private:
 131    const char *str;
 132 };
 133
 134 /* Lists of expressions: (expr1 ... exprN) */
 135 class s_list : public s_expression
 136 {
 137 public:
 138    s_list();
 139
 140    virtual bool is_list() const { return true; }
 141
 142    void print();
 143
 144    exec_list subexpressions;
 145 };
 146
 147 // ------------------------------------------------------------
 148
 149 /**
 150  * Part of a pattern to match - essentially a record holding a pointer to the
 151  * storage for the component to match, along with the appropriate type.
 152  */
 153 class s_pattern {
 154 public:
 155    s_pattern(s_expression *&s) : p_expr(&s),   type(EXPR)   { }
 156    s_pattern(s_list       *&s) : p_list(&s),   type(LIST)   { }
 157    s_pattern(s_symbol     *&s) : p_symbol(&s), type(SYMBOL) { }
 158    s_pattern(s_number     *&s) : p_number(&s), type(NUMBER) { }
 159    s_pattern(s_int        *&s) : p_int(&s),    type(INT)    { }
 160    s_pattern(const char *str)  : literal(str), type(STRING) { }
 161
 162    bool match(s_expression *expr);
 163
 164 private:
 165    union {
 166       s_expression **p_expr;
 167       s_list       **p_list;
 168       s_symbol     **p_symbol;
 169       s_number     **p_number;
 170       s_int        **p_int;
 171       const char *literal;
 172    };
 173    enum { EXPR, LIST, SYMBOL, NUMBER, INT, STRING } type;
 174 };
 175
 176 bool
 177 s_match(s_expression *top, unsigned n, s_pattern *pattern, bool partial);
 178
 179 #endif /* S_EXPRESSION_H */