src/glsl/ast.h

   1 /* -*- c++ -*- */
   2 /*
   3  * Copyright © 2009 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 #pragma once
  26 #ifndef AST_H
  27 #define AST_H
  28
  29 #include "list.h"
  30 #include "glsl_parser_extras.h"
  31
  32 struct _mesa_glsl_parse_state;
  33
  34 struct YYLTYPE;
  35
  36 /**
  37  * \defgroup AST Abstract syntax tree node definitions
  38  *
  39  * An abstract syntax tree is generated by the parser.  This is a fairly
  40  * direct representation of the gramma derivation for the source program.
  41  * No symantic checking is done during the generation of the AST.  Only
  42  * syntactic checking is done.  Symantic checking is performed by a later
  43  * stage that converts the AST to a more generic intermediate representation.
  44  *
  45  *@{
  46  */
  47 /**
  48  * Base class of all abstract syntax tree nodes
  49  */
  50 class ast_node {
  51 public:
  52    /* Callers of this talloc-based new need not call delete. It's
  53     * easier to just talloc_free 'ctx' (or any of its ancestors). */
  54    static void* operator new(size_t size, void *ctx)
  55    {
  56       void *node;
  57
  58       node = talloc_zero_size(ctx, size);
  59       assert(node != NULL);
  60
  61       return node;
  62    }
  63
  64    /* If the user *does* call delete, that's OK, we will just
  65     * talloc_free in that case. */
  66    static void operator delete(void *table)
  67    {
  68       talloc_free(table);
  69    }
  70
  71    /**
  72     * Print an AST node in something approximating the original GLSL code
  73     */
  74    virtual void print(void) const;
  75
  76    /**
  77     * Convert the AST node to the high-level intermediate representation
  78     */
  79    virtual ir_rvalue *hir(exec_list *instructions,
  80                           struct _mesa_glsl_parse_state *state);
  81
  82    /**
  83     * Retrieve the source location of an AST node
  84     *
  85     * This function is primarily used to get the source position of an AST node
  86     * into a form that can be passed to \c _mesa_glsl_error.
  87     *
  88     * \sa _mesa_glsl_error, ast_node::set_location
  89     */
  90    struct YYLTYPE get_location(void) const
  91    {
  92       struct YYLTYPE locp;
  93
  94       locp.source = this->location.source;
  95       locp.first_line = this->location.line;
  96       locp.first_column = this->location.column;
  97       locp.last_line = locp.first_line;
  98       locp.last_column = locp.first_column;
  99
 100       return locp;
 101    }
 102
 103    /**
 104     * Set the source location of an AST node from a parser location
 105     *
 106     * \sa ast_node::get_location
 107     */
 108    void set_location(const struct YYLTYPE &locp)
 109    {
 110       this->location.source = locp.source;
 111       this->location.line = locp.first_line;
 112       this->location.column = locp.first_column;
 113    }
 114
 115    /**
 116     * Source location of the AST node.
 117     */
 118    struct {
 119       unsigned source;    /**< GLSL source number. */
 120       unsigned line;      /**< Line number within the source string. */
 121       unsigned column;    /**< Column in the line. */
 122    } location;
 123
 124    exec_node link;
 125
 126 protected:
 127    /**
 128     * The only constructor is protected so that only derived class objects can
 129     * be created.
 130     */
 131    ast_node(void);
 132 };
 133
 134
 135 /**
 136  * Operators for AST expression nodes.
 137  */
 138 enum ast_operators {
 139    ast_assign,
 140    ast_plus,        /**< Unary + operator. */
 141    ast_neg,
 142    ast_add,
 143    ast_sub,
 144    ast_mul,
 145    ast_div,
 146    ast_mod,
 147    ast_lshift,
 148    ast_rshift,
 149    ast_less,
 150    ast_greater,
 151    ast_lequal,
 152    ast_gequal,
 153    ast_equal,
 154    ast_nequal,
 155    ast_bit_and,
 156    ast_bit_xor,
 157    ast_bit_or,
 158    ast_bit_not,
 159    ast_logic_and,
 160    ast_logic_xor,
 161    ast_logic_or,
 162    ast_logic_not,
 163
 164    ast_mul_assign,
 165    ast_div_assign,
 166    ast_mod_assign,
 167    ast_add_assign,
 168    ast_sub_assign,
 169    ast_ls_assign,
 170    ast_rs_assign,
 171    ast_and_assign,
 172    ast_xor_assign,
 173    ast_or_assign,
 174
 175    ast_conditional,
 176
 177    ast_pre_inc,
 178    ast_pre_dec,
 179    ast_post_inc,
 180    ast_post_dec,
 181    ast_field_selection,
 182    ast_array_index,
 183
 184    ast_function_call,
 185
 186    ast_identifier,
 187    ast_int_constant,
 188    ast_uint_constant,
 189    ast_float_constant,
 190    ast_bool_constant,
 191
 192    ast_sequence
 193 };
 194
 195 /**
 196  * Representation of any sort of expression.
 197  */
 198 class ast_expression : public ast_node {
 199 public:
 200    ast_expression(int oper, ast_expression *,
 201                   ast_expression *, ast_expression *);
 202
 203    ast_expression(const char *identifier) :
 204       oper(ast_identifier)
 205    {
 206       subexpressions[0] = NULL;
 207       subexpressions[1] = NULL;
 208       subexpressions[2] = NULL;
 209       primary_expression.identifier = (char *) identifier;
 210    }
 211
 212    static const char *operator_string(enum ast_operators op);
 213
 214    virtual ir_rvalue *hir(exec_list *instructions,
 215                           struct _mesa_glsl_parse_state *state);
 216
 217    virtual void print(void) const;
 218
 219    enum ast_operators oper;
 220
 221    ast_expression *subexpressions[3];
 222
 223    union {
 224       char *identifier;
 225       int int_constant;
 226       float float_constant;
 227       unsigned uint_constant;
 228       int bool_constant;
 229    } primary_expression;
 230
 231
 232    /**
 233     * List of expressions for an \c ast_sequence or parameters for an
 234     * \c ast_function_call
 235     */
 236    exec_list expressions;
 237 };
 238
 239 class ast_expression_bin : public ast_expression {
 240 public:
 241    ast_expression_bin(int oper, ast_expression *, ast_expression *);
 242
 243    virtual void print(void) const;
 244 };
 245
 246 /**
 247  * Subclass of expressions for function calls
 248  */
 249 class ast_function_expression : public ast_expression {
 250 public:
 251    ast_function_expression(ast_expression *callee)
 252       : ast_expression(ast_function_call, callee,
 253                        NULL, NULL),
 254         cons(false)
 255    {
 256       /* empty */
 257    }
 258
 259    ast_function_expression(class ast_type_specifier *type)
 260       : ast_expression(ast_function_call, (ast_expression *) type,
 261                        NULL, NULL),
 262         cons(true)
 263    {
 264       /* empty */
 265    }
 266
 267    bool is_constructor() const
 268    {
 269       return cons;
 270    }
 271
 272    virtual ir_rvalue *hir(exec_list *instructions,
 273                           struct _mesa_glsl_parse_state *state);
 274
 275 private:
 276    /**
 277     * Is this function call actually a constructor?
 278     */
 279    bool cons;
 280 };
 281
 282
 283 /**
 284  * Number of possible operators for an ast_expression
 285  *
 286  * This is done as a define instead of as an additional value in the enum so
 287  * that the compiler won't generate spurious messages like "warning:
 288  * enumeration value ‘ast_num_operators’ not handled in switch"
 289  */
 290 #define AST_NUM_OPERATORS (ast_sequence + 1)
 291
 292
 293 class ast_compound_statement : public ast_node {
 294 public:
 295    ast_compound_statement(int new_scope, ast_node *statements);
 296    virtual void print(void) const;
 297
 298    virtual ir_rvalue *hir(exec_list *instructions,
 299                           struct _mesa_glsl_parse_state *state);
 300
 301    int new_scope;
 302    exec_list statements;
 303 };
 304
 305 class ast_declaration : public ast_node {
 306 public:
 307    ast_declaration(char *identifier, int is_array, ast_expression *array_size,
 308                    ast_expression *initializer);
 309    virtual void print(void) const;
 310
 311    char *identifier;
 312
 313    int is_array;
 314    ast_expression *array_size;
 315
 316    ast_expression *initializer;
 317 };
 318
 319
 320 enum {
 321    ast_precision_none = 0, /**< Absence of precision qualifier. */
 322    ast_precision_high,
 323    ast_precision_medium,
 324    ast_precision_low
 325 };
 326
 327 struct ast_type_qualifier {
 328    union {
 329       struct {
 330          unsigned invariant:1;
 331          unsigned constant:1;
 332          unsigned attribute:1;
 333          unsigned varying:1;
 334          unsigned in:1;
 335          unsigned out:1;
 336          unsigned centroid:1;
 337          unsigned uniform:1;
 338          unsigned smooth:1;
 339          unsigned flat:1;
 340          unsigned noperspective:1;
 341
 342          /** \name Layout qualifiers for GL_ARB_fragment_coord_conventions */
 343          /*@{*/
 344          unsigned origin_upper_left:1;
 345          unsigned pixel_center_integer:1;
 346          /*@}*/
 347
 348          /**
 349           * Flag set if GL_ARB_explicit_attrib_location "location" layout
 350           * qualifier is used.
 351           */
 352          unsigned explicit_location:1;
 353       }
 354       /** \brief Set of flags, accessed by name. */
 355       q;
 356
 357       /** \brief Set of flags, accessed as a bitmask. */
 358       unsigned i;
 359    } flags;
 360
 361    /**
 362     * Location specified via GL_ARB_explicit_attrib_location layout
 363     *
 364     * \note
 365     * This field is only valid if \c explicit_location is set.
 366     */
 367    unsigned location;
 368
 369    /**
 370     * Return true if and only if an interpolation qualifier is present.
 371     */
 372    bool has_interpolation() const;
 373
 374    /**
 375     * \brief Return string representation of interpolation qualifier.
 376     *
 377     * If an interpolation qualifier is present, then return that qualifier's
 378     * string representation. Otherwise, return null. For example, if the
 379     * noperspective bit is set, then this returns "noperspective".
 380     *
 381     * If multiple interpolation qualifiers are somehow present, then the
 382     * returned string is undefined but not null.
 383     */
 384    const char *interpolation_string() const;
 385 };
 386
 387 class ast_struct_specifier : public ast_node {
 388 public:
 389    ast_struct_specifier(char *identifier, ast_node *declarator_list);
 390    virtual void print(void) const;
 391
 392    virtual ir_rvalue *hir(exec_list *instructions,
 393                           struct _mesa_glsl_parse_state *state);
 394
 395    char *name;
 396    exec_list declarations;
 397 };
 398
 399
 400 enum ast_types {
 401    ast_void,
 402    ast_float,
 403    ast_int,
 404    ast_uint,
 405    ast_bool,
 406    ast_vec2,
 407    ast_vec3,
 408    ast_vec4,
 409    ast_bvec2,
 410    ast_bvec3,
 411    ast_bvec4,
 412    ast_ivec2,
 413    ast_ivec3,
 414    ast_ivec4,
 415    ast_uvec2,
 416    ast_uvec3,
 417    ast_uvec4,
 418    ast_mat2,
 419    ast_mat2x3,
 420    ast_mat2x4,
 421    ast_mat3x2,
 422    ast_mat3,
 423    ast_mat3x4,
 424    ast_mat4x2,
 425    ast_mat4x3,
 426    ast_mat4,
 427    ast_sampler1d,
 428    ast_sampler2d,
 429    ast_sampler2drect,
 430    ast_sampler3d,
 431    ast_samplercube,
 432    ast_sampler1dshadow,
 433    ast_sampler2dshadow,
 434    ast_sampler2drectshadow,
 435    ast_samplercubeshadow,
 436    ast_sampler1darray,
 437    ast_sampler2darray,
 438    ast_sampler1darrayshadow,
 439    ast_sampler2darrayshadow,
 440    ast_isampler1d,
 441    ast_isampler2d,
 442    ast_isampler3d,
 443    ast_isamplercube,
 444    ast_isampler1darray,
 445    ast_isampler2darray,
 446    ast_usampler1d,
 447    ast_usampler2d,
 448    ast_usampler3d,
 449    ast_usamplercube,
 450    ast_usampler1darray,
 451    ast_usampler2darray,
 452
 453    ast_struct,
 454    ast_type_name
 455 };
 456
 457
 458 class ast_type_specifier : public ast_node {
 459 public:
 460    ast_type_specifier(int specifier);
 461
 462    /** Construct a type specifier from a type name */
 463    ast_type_specifier(const char *name)
 464       : type_specifier(ast_type_name), type_name(name), structure(NULL),
 465         is_array(false), array_size(NULL), precision(ast_precision_none),
 466         is_precision_statement(false)
 467    {
 468       /* empty */
 469    }
 470
 471    /** Construct a type specifier from a structure definition */
 472    ast_type_specifier(ast_struct_specifier *s)
 473       : type_specifier(ast_struct), type_name(s->name), structure(s),
 474         is_array(false), array_size(NULL), precision(ast_precision_none),
 475         is_precision_statement(false)
 476    {
 477       /* empty */
 478    }
 479
 480    const struct glsl_type *glsl_type(const char **name,
 481                                      struct _mesa_glsl_parse_state *state)
 482       const;
 483
 484    virtual void print(void) const;
 485
 486    ir_rvalue *hir(exec_list *, struct _mesa_glsl_parse_state *);
 487
 488    enum ast_types type_specifier;
 489
 490    const char *type_name;
 491    ast_struct_specifier *structure;
 492
 493    int is_array;
 494    ast_expression *array_size;
 495
 496    unsigned precision:2;
 497
 498    bool is_precision_statement;
 499 };
 500
 501
 502 class ast_fully_specified_type : public ast_node {
 503 public:
 504    virtual void print(void) const;
 505    bool has_qualifiers() const;
 506
 507    ast_type_qualifier qualifier;
 508    ast_type_specifier *specifier;
 509 };
 510
 511
 512 class ast_declarator_list : public ast_node {
 513 public:
 514    ast_declarator_list(ast_fully_specified_type *);
 515    virtual void print(void) const;
 516
 517    virtual ir_rvalue *hir(exec_list *instructions,
 518                           struct _mesa_glsl_parse_state *state);
 519
 520    ast_fully_specified_type *type;
 521    exec_list declarations;
 522
 523    /**
 524     * Special flag for vertex shader "invariant" declarations.
 525     *
 526     * Vertex shaders can contain "invariant" variable redeclarations that do
 527     * not include a type.  For example, "invariant gl_Position;".  This flag
 528     * is used to note these cases when no type is specified.
 529     */
 530    int invariant;
 531 };
 532
 533
 534 class ast_parameter_declarator : public ast_node {
 535 public:
 536    ast_parameter_declarator()
 537    {
 538       this->identifier = NULL;
 539       this->is_array = false;
 540       this->array_size = 0;
 541    }
 542
 543    virtual void print(void) const;
 544
 545    virtual ir_rvalue *hir(exec_list *instructions,
 546                           struct _mesa_glsl_parse_state *state);
 547
 548    ast_fully_specified_type *type;
 549    char *identifier;
 550    int is_array;
 551    ast_expression *array_size;
 552
 553    static void parameters_to_hir(exec_list *ast_parameters,
 554                                  bool formal, exec_list *ir_parameters,
 555                                  struct _mesa_glsl_parse_state *state);
 556
 557 private:
 558    /** Is this parameter declaration part of a formal parameter list? */
 559    bool formal_parameter;
 560
 561    /**
 562     * Is this parameter 'void' type?
 563     *
 564     * This field is set by \c ::hir.
 565     */
 566    bool is_void;
 567 };
 568
 569
 570 class ast_function : public ast_node {
 571 public:
 572    ast_function(void);
 573
 574    virtual void print(void) const;
 575
 576    virtual ir_rvalue *hir(exec_list *instructions,
 577                           struct _mesa_glsl_parse_state *state);
 578
 579    ast_fully_specified_type *return_type;
 580    char *identifier;
 581
 582    exec_list parameters;
 583
 584 private:
 585    /**
 586     * Is this prototype part of the function definition?
 587     *
 588     * Used by ast_function_definition::hir to process the parameters, etc.
 589     * of the function.
 590     *
 591     * \sa ::hir
 592     */
 593    bool is_definition;
 594
 595    /**
 596     * Function signature corresponding to this function prototype instance
 597     *
 598     * Used by ast_function_definition::hir to process the parameters, etc.
 599     * of the function.
 600     *
 601     * \sa ::hir
 602     */
 603    class ir_function_signature *signature;
 604
 605    friend class ast_function_definition;
 606 };
 607
 608
 609 class ast_expression_statement : public ast_node {
 610 public:
 611    ast_expression_statement(ast_expression *);
 612    virtual void print(void) const;
 613
 614    virtual ir_rvalue *hir(exec_list *instructions,
 615                           struct _mesa_glsl_parse_state *state);
 616
 617    ast_expression *expression;
 618 };
 619
 620
 621 class ast_case_label : public ast_node {
 622 public:
 623
 624    /**
 625     * An expression of NULL means 'default'.
 626     */
 627    ast_expression *expression;
 628 };
 629
 630 class ast_selection_statement : public ast_node {
 631 public:
 632    ast_selection_statement(ast_expression *condition,
 633                            ast_node *then_statement,
 634                            ast_node *else_statement);
 635    virtual void print(void) const;
 636
 637    virtual ir_rvalue *hir(exec_list *instructions,
 638                           struct _mesa_glsl_parse_state *state);
 639
 640    ast_expression *condition;
 641    ast_node *then_statement;
 642    ast_node *else_statement;
 643 };
 644
 645
 646 class ast_switch_statement : public ast_node {
 647 public:
 648    ast_expression *expression;
 649    exec_list statements;
 650 };
 651
 652 class ast_iteration_statement : public ast_node {
 653 public:
 654    ast_iteration_statement(int mode, ast_node *init, ast_node *condition,
 655                            ast_expression *rest_expression, ast_node *body);
 656
 657    virtual void print(void) const;
 658
 659    virtual ir_rvalue *hir(exec_list *, struct _mesa_glsl_parse_state *);
 660
 661    enum ast_iteration_modes {
 662       ast_for,
 663       ast_while,
 664       ast_do_while
 665    } mode;
 666
 667
 668    ast_node *init_statement;
 669    ast_node *condition;
 670    ast_expression *rest_expression;
 671
 672    ast_node *body;
 673
 674 private:
 675    /**
 676     * Generate IR from the condition of a loop
 677     *
 678     * This is factored out of ::hir because some loops have the condition
 679     * test at the top (for and while), and others have it at the end (do-while).
 680     */
 681    void condition_to_hir(class ir_loop *, struct _mesa_glsl_parse_state *);
 682 };
 683
 684
 685 class ast_jump_statement : public ast_node {
 686 public:
 687    ast_jump_statement(int mode, ast_expression *return_value);
 688    virtual void print(void) const;
 689
 690    virtual ir_rvalue *hir(exec_list *instructions,
 691                           struct _mesa_glsl_parse_state *state);
 692
 693    enum ast_jump_modes {
 694       ast_continue,
 695       ast_break,
 696       ast_return,
 697       ast_discard
 698    } mode;
 699
 700    ast_expression *opt_return_value;
 701 };
 702
 703
 704 class ast_function_definition : public ast_node {
 705 public:
 706    virtual void print(void) const;
 707
 708    virtual ir_rvalue *hir(exec_list *instructions,
 709                           struct _mesa_glsl_parse_state *state);
 710
 711    ast_function *prototype;
 712    ast_compound_statement *body;
 713 };
 714 /*@}*/
 715
 716 extern void
 717 _mesa_ast_to_hir(exec_list *instructions, struct _mesa_glsl_parse_state *state);
 718
 719 extern ir_rvalue *
 720 _mesa_ast_field_selection_to_hir(const ast_expression *expr,
 721                                  exec_list *instructions,
 722                                  struct _mesa_glsl_parse_state *state);
 723
 724 void
 725 emit_function(_mesa_glsl_parse_state *state, exec_list *instructions,
 726               ir_function *f);
 727
 728 #endif /* AST_H */