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 ralloc-based new need not call delete. It's
  53     * easier to just ralloc_free 'ctx' (or any of its ancestors). */
  54    static void* operator new(size_t size, void *ctx)
  55    {
  56       void *node;
  57
  58       node = rzalloc_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     * ralloc_free in that case. */
  66    static void operator delete(void *table)
  67    {
  68       ralloc_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 = identifier;
 210       this->non_lvalue_description = NULL;
 211    }
 212
 213    static const char *operator_string(enum ast_operators op);
 214
 215    virtual ir_rvalue *hir(exec_list *instructions,
 216                           struct _mesa_glsl_parse_state *state);
 217
 218    virtual void print(void) const;
 219
 220    enum ast_operators oper;
 221
 222    ast_expression *subexpressions[3];
 223
 224    union {
 225       const char *identifier;
 226       int int_constant;
 227       float float_constant;
 228       unsigned uint_constant;
 229       int bool_constant;
 230    } primary_expression;
 231
 232
 233    /**
 234     * List of expressions for an \c ast_sequence or parameters for an
 235     * \c ast_function_call
 236     */
 237    exec_list expressions;
 238
 239    /**
 240     * For things that can't be l-values, this describes what it is.
 241     *
 242     * This text is used by the code that generates IR for assignments to
 243     * detect and emit useful messages for assignments to some things that
 244     * can't be l-values.  For example, pre- or post-incerement expressions.
 245     *
 246     * \note
 247     * This pointer may be \c NULL.
 248     */
 249    const char *non_lvalue_description;
 250 };
 251
 252 class ast_expression_bin : public ast_expression {
 253 public:
 254    ast_expression_bin(int oper, ast_expression *, ast_expression *);
 255
 256    virtual void print(void) const;
 257 };
 258
 259 /**
 260  * Subclass of expressions for function calls
 261  */
 262 class ast_function_expression : public ast_expression {
 263 public:
 264    ast_function_expression(ast_expression *callee)
 265       : ast_expression(ast_function_call, callee,
 266                        NULL, NULL),
 267         cons(false)
 268    {
 269       /* empty */
 270    }
 271
 272    ast_function_expression(class ast_type_specifier *type)
 273       : ast_expression(ast_function_call, (ast_expression *) type,
 274                        NULL, NULL),
 275         cons(true)
 276    {
 277       /* empty */
 278    }
 279
 280    bool is_constructor() const
 281    {
 282       return cons;
 283    }
 284
 285    virtual ir_rvalue *hir(exec_list *instructions,
 286                           struct _mesa_glsl_parse_state *state);
 287
 288 private:
 289    /**
 290     * Is this function call actually a constructor?
 291     */
 292    bool cons;
 293 };
 294
 295
 296 /**
 297  * Number of possible operators for an ast_expression
 298  *
 299  * This is done as a define instead of as an additional value in the enum so
 300  * that the compiler won't generate spurious messages like "warning:
 301  * enumeration value ‘ast_num_operators’ not handled in switch"
 302  */
 303 #define AST_NUM_OPERATORS (ast_sequence + 1)
 304
 305
 306 class ast_compound_statement : public ast_node {
 307 public:
 308    ast_compound_statement(int new_scope, ast_node *statements);
 309    virtual void print(void) const;
 310
 311    virtual ir_rvalue *hir(exec_list *instructions,
 312                           struct _mesa_glsl_parse_state *state);
 313
 314    int new_scope;
 315    exec_list statements;
 316 };
 317
 318 class ast_declaration : public ast_node {
 319 public:
 320    ast_declaration(const char *identifier, bool is_array, ast_expression *array_size,
 321                    ast_expression *initializer);
 322    virtual void print(void) const;
 323
 324    const char *identifier;
 325
 326    bool is_array;
 327    ast_expression *array_size;
 328
 329    ast_expression *initializer;
 330 };
 331
 332
 333 enum {
 334    ast_precision_none = 0, /**< Absence of precision qualifier. */
 335    ast_precision_high,
 336    ast_precision_medium,
 337    ast_precision_low
 338 };
 339
 340 struct ast_type_qualifier {
 341    /* Callers of this ralloc-based new need not call delete. It's
 342     * easier to just ralloc_free 'ctx' (or any of its ancestors). */
 343    static void* operator new(size_t size, void *ctx)
 344    {
 345       void *node;
 346
 347       node = rzalloc_size(ctx, size);
 348       assert(node != NULL);
 349
 350       return node;
 351    }
 352
 353    /* If the user *does* call delete, that's OK, we will just
 354     * ralloc_free in that case. */
 355    static void operator delete(void *table)
 356    {
 357       ralloc_free(table);
 358    }
 359
 360    union {
 361       struct {
 362          unsigned invariant:1;
 363          unsigned constant:1;
 364          unsigned attribute:1;
 365          unsigned varying:1;
 366          unsigned in:1;
 367          unsigned out:1;
 368          unsigned centroid:1;
 369          unsigned uniform:1;
 370          unsigned smooth:1;
 371          unsigned flat:1;
 372          unsigned noperspective:1;
 373
 374          /** \name Layout qualifiers for GL_ARB_fragment_coord_conventions */
 375          /*@{*/
 376          unsigned origin_upper_left:1;
 377          unsigned pixel_center_integer:1;
 378          /*@}*/
 379
 380          /**
 381           * Flag set if GL_ARB_explicit_attrib_location "location" layout
 382           * qualifier is used.
 383           */
 384          unsigned explicit_location:1;
 385          /**
 386           * Flag set if GL_ARB_explicit_attrib_location "index" layout
 387           * qualifier is used.
 388           */
 389          unsigned explicit_index:1;
 390
 391          /** \name Layout qualifiers for GL_AMD_conservative_depth */
 392          /** \{ */
 393          unsigned depth_any:1;
 394          unsigned depth_greater:1;
 395          unsigned depth_less:1;
 396          unsigned depth_unchanged:1;
 397          /** \} */
 398
 399          /** \name Layout qualifiers for GL_ARB_uniform_buffer_object */
 400          /** \{ */
 401          unsigned std140:1;
 402          unsigned shared:1;
 403          unsigned packed:1;
 404          unsigned column_major:1;
 405          unsigned row_major:1;
 406          /** \} */
 407       }
 408       /** \brief Set of flags, accessed by name. */
 409       q;
 410
 411       /** \brief Set of flags, accessed as a bitmask. */
 412       unsigned i;
 413    } flags;
 414
 415    /**
 416     * Location specified via GL_ARB_explicit_attrib_location layout
 417     *
 418     * \note
 419     * This field is only valid if \c explicit_location is set.
 420     */
 421    int location;
 422    /**
 423     * Index specified via GL_ARB_explicit_attrib_location layout
 424     *
 425     * \note
 426     * This field is only valid if \c explicit_index is set.
 427     */
 428    int index;
 429
 430    /**
 431     * Return true if and only if an interpolation qualifier is present.
 432     */
 433    bool has_interpolation() const;
 434
 435    /**
 436     * \brief Return string representation of interpolation qualifier.
 437     *
 438     * If an interpolation qualifier is present, then return that qualifier's
 439     * string representation. Otherwise, return null. For example, if the
 440     * noperspective bit is set, then this returns "noperspective".
 441     *
 442     * If multiple interpolation qualifiers are somehow present, then the
 443     * returned string is undefined but not null.
 444     */
 445    const char *interpolation_string() const;
 446
 447    bool merge_qualifier(YYLTYPE *loc,
 448                         _mesa_glsl_parse_state *state,
 449                         ast_type_qualifier q);
 450 };
 451
 452 class ast_declarator_list;
 453
 454 class ast_struct_specifier : public ast_node {
 455 public:
 456    ast_struct_specifier(const char *identifier,
 457                         ast_declarator_list *declarator_list);
 458    virtual void print(void) const;
 459
 460    virtual ir_rvalue *hir(exec_list *instructions,
 461                           struct _mesa_glsl_parse_state *state);
 462
 463    const char *name;
 464    /* List of ast_declarator_list * */
 465    exec_list declarations;
 466 };
 467
 468
 469
 470 class ast_type_specifier : public ast_node {
 471 public:
 472    /** Construct a type specifier from a type name */
 473    ast_type_specifier(const char *name)
 474       : type_name(name), structure(NULL),
 475         is_array(false), array_size(NULL), precision(ast_precision_none),
 476         is_precision_statement(false)
 477    {
 478       /* empty */
 479    }
 480
 481    /** Construct a type specifier from a structure definition */
 482    ast_type_specifier(ast_struct_specifier *s)
 483       : type_name(s->name), structure(s),
 484         is_array(false), array_size(NULL), precision(ast_precision_none),
 485         is_precision_statement(false)
 486    {
 487       /* empty */
 488    }
 489
 490    const struct glsl_type *glsl_type(const char **name,
 491                                      struct _mesa_glsl_parse_state *state)
 492       const;
 493
 494    virtual void print(void) const;
 495
 496    ir_rvalue *hir(exec_list *, struct _mesa_glsl_parse_state *);
 497
 498    const char *type_name;
 499    ast_struct_specifier *structure;
 500
 501    bool is_array;
 502    ast_expression *array_size;
 503
 504    unsigned precision:2;
 505
 506    bool is_precision_statement;
 507 };
 508
 509
 510 class ast_fully_specified_type : public ast_node {
 511 public:
 512    virtual void print(void) const;
 513    bool has_qualifiers() const;
 514
 515    ast_type_qualifier qualifier;
 516    ast_type_specifier *specifier;
 517 };
 518
 519
 520 class ast_declarator_list : public ast_node {
 521 public:
 522    ast_declarator_list(ast_fully_specified_type *);
 523    virtual void print(void) const;
 524
 525    virtual ir_rvalue *hir(exec_list *instructions,
 526                           struct _mesa_glsl_parse_state *state);
 527
 528    ast_fully_specified_type *type;
 529    /** List of 'ast_declaration *' */
 530    exec_list declarations;
 531
 532    /**
 533     * Special flag for vertex shader "invariant" declarations.
 534     *
 535     * Vertex shaders can contain "invariant" variable redeclarations that do
 536     * not include a type.  For example, "invariant gl_Position;".  This flag
 537     * is used to note these cases when no type is specified.
 538     */
 539    int invariant;
 540
 541    /**
 542     * Flag indicating that these declarators are in a uniform block,
 543     * allowing UBO type qualifiers.
 544     */
 545    bool ubo_qualifiers_valid;
 546 };
 547
 548
 549 class ast_parameter_declarator : public ast_node {
 550 public:
 551    ast_parameter_declarator() :
 552       type(NULL),
 553       identifier(NULL),
 554       is_array(false),
 555       array_size(NULL),
 556       formal_parameter(false),
 557       is_void(false)
 558    {
 559       /* empty */
 560    }
 561
 562    virtual void print(void) const;
 563
 564    virtual ir_rvalue *hir(exec_list *instructions,
 565                           struct _mesa_glsl_parse_state *state);
 566
 567    ast_fully_specified_type *type;
 568    const char *identifier;
 569    bool is_array;
 570    ast_expression *array_size;
 571
 572    static void parameters_to_hir(exec_list *ast_parameters,
 573                                  bool formal, exec_list *ir_parameters,
 574                                  struct _mesa_glsl_parse_state *state);
 575
 576 private:
 577    /** Is this parameter declaration part of a formal parameter list? */
 578    bool formal_parameter;
 579
 580    /**
 581     * Is this parameter 'void' type?
 582     *
 583     * This field is set by \c ::hir.
 584     */
 585    bool is_void;
 586 };
 587
 588
 589 class ast_function : public ast_node {
 590 public:
 591    ast_function(void);
 592
 593    virtual void print(void) const;
 594
 595    virtual ir_rvalue *hir(exec_list *instructions,
 596                           struct _mesa_glsl_parse_state *state);
 597
 598    ast_fully_specified_type *return_type;
 599    const char *identifier;
 600
 601    exec_list parameters;
 602
 603 private:
 604    /**
 605     * Is this prototype part of the function definition?
 606     *
 607     * Used by ast_function_definition::hir to process the parameters, etc.
 608     * of the function.
 609     *
 610     * \sa ::hir
 611     */
 612    bool is_definition;
 613
 614    /**
 615     * Function signature corresponding to this function prototype instance
 616     *
 617     * Used by ast_function_definition::hir to process the parameters, etc.
 618     * of the function.
 619     *
 620     * \sa ::hir
 621     */
 622    class ir_function_signature *signature;
 623
 624    friend class ast_function_definition;
 625 };
 626
 627
 628 class ast_expression_statement : public ast_node {
 629 public:
 630    ast_expression_statement(ast_expression *);
 631    virtual void print(void) const;
 632
 633    virtual ir_rvalue *hir(exec_list *instructions,
 634                           struct _mesa_glsl_parse_state *state);
 635
 636    ast_expression *expression;
 637 };
 638
 639
 640 class ast_case_label : public ast_node {
 641 public:
 642    ast_case_label(ast_expression *test_value);
 643    virtual void print(void) const;
 644
 645    virtual ir_rvalue *hir(exec_list *instructions,
 646                           struct _mesa_glsl_parse_state *state);
 647
 648    /**
 649     * An test value of NULL means 'default'.
 650     */
 651    ast_expression *test_value;
 652 };
 653
 654
 655 class ast_case_label_list : public ast_node {
 656 public:
 657    ast_case_label_list(void);
 658    virtual void print(void) const;
 659
 660    virtual ir_rvalue *hir(exec_list *instructions,
 661                           struct _mesa_glsl_parse_state *state);
 662
 663    /**
 664     * A list of case labels.
 665     */
 666    exec_list labels;
 667 };
 668
 669
 670 class ast_case_statement : public ast_node {
 671 public:
 672    ast_case_statement(ast_case_label_list *labels);
 673    virtual void print(void) const;
 674
 675    virtual ir_rvalue *hir(exec_list *instructions,
 676                           struct _mesa_glsl_parse_state *state);
 677
 678    ast_case_label_list *labels;
 679
 680    /**
 681     * A list of statements.
 682     */
 683    exec_list stmts;
 684 };
 685
 686
 687 class ast_case_statement_list : public ast_node {
 688 public:
 689    ast_case_statement_list(void);
 690    virtual void print(void) const;
 691
 692    virtual ir_rvalue *hir(exec_list *instructions,
 693                           struct _mesa_glsl_parse_state *state);
 694
 695    /**
 696     * A list of cases.
 697     */
 698    exec_list cases;
 699 };
 700
 701
 702 class ast_switch_body : public ast_node {
 703 public:
 704    ast_switch_body(ast_case_statement_list *stmts);
 705    virtual void print(void) const;
 706
 707    virtual ir_rvalue *hir(exec_list *instructions,
 708                           struct _mesa_glsl_parse_state *state);
 709
 710    ast_case_statement_list *stmts;
 711 };
 712
 713
 714 class ast_selection_statement : public ast_node {
 715 public:
 716    ast_selection_statement(ast_expression *condition,
 717                            ast_node *then_statement,
 718                            ast_node *else_statement);
 719    virtual void print(void) const;
 720
 721    virtual ir_rvalue *hir(exec_list *instructions,
 722                           struct _mesa_glsl_parse_state *state);
 723
 724    ast_expression *condition;
 725    ast_node *then_statement;
 726    ast_node *else_statement;
 727 };
 728
 729
 730 class ast_switch_statement : public ast_node {
 731 public:
 732    ast_switch_statement(ast_expression *test_expression,
 733                         ast_node *body);
 734    virtual void print(void) const;
 735
 736    virtual ir_rvalue *hir(exec_list *instructions,
 737                           struct _mesa_glsl_parse_state *state);
 738
 739    ast_expression *test_expression;
 740    ast_node *body;
 741
 742 protected:
 743    void test_to_hir(exec_list *, struct _mesa_glsl_parse_state *);
 744 };
 745
 746 class ast_iteration_statement : public ast_node {
 747 public:
 748    ast_iteration_statement(int mode, ast_node *init, ast_node *condition,
 749                            ast_expression *rest_expression, ast_node *body);
 750
 751    virtual void print(void) const;
 752
 753    virtual ir_rvalue *hir(exec_list *, struct _mesa_glsl_parse_state *);
 754
 755    enum ast_iteration_modes {
 756       ast_for,
 757       ast_while,
 758       ast_do_while
 759    } mode;
 760
 761
 762    ast_node *init_statement;
 763    ast_node *condition;
 764    ast_expression *rest_expression;
 765
 766    ast_node *body;
 767
 768 private:
 769    /**
 770     * Generate IR from the condition of a loop
 771     *
 772     * This is factored out of ::hir because some loops have the condition
 773     * test at the top (for and while), and others have it at the end (do-while).
 774     */
 775    void condition_to_hir(class ir_loop *, struct _mesa_glsl_parse_state *);
 776 };
 777
 778
 779 class ast_jump_statement : public ast_node {
 780 public:
 781    ast_jump_statement(int mode, ast_expression *return_value);
 782    virtual void print(void) const;
 783
 784    virtual ir_rvalue *hir(exec_list *instructions,
 785                           struct _mesa_glsl_parse_state *state);
 786
 787    enum ast_jump_modes {
 788       ast_continue,
 789       ast_break,
 790       ast_return,
 791       ast_discard
 792    } mode;
 793
 794    ast_expression *opt_return_value;
 795 };
 796
 797
 798 class ast_function_definition : public ast_node {
 799 public:
 800    virtual void print(void) const;
 801
 802    virtual ir_rvalue *hir(exec_list *instructions,
 803                           struct _mesa_glsl_parse_state *state);
 804
 805    ast_function *prototype;
 806    ast_compound_statement *body;
 807 };
 808
 809 class ast_interface_block : public ast_node {
 810 public:
 811    ast_interface_block(ast_type_qualifier layout,
 812                      const char *instance_name,
 813                      ast_expression *array_size)
 814    : layout(layout), block_name(NULL), instance_name(instance_name),
 815      array_size(array_size)
 816    {
 817       /* empty */
 818    }
 819
 820    virtual ir_rvalue *hir(exec_list *instructions,
 821                           struct _mesa_glsl_parse_state *state);
 822
 823    ast_type_qualifier layout;
 824    const char *block_name;
 825
 826    /**
 827     * Declared name of the block instance, if specified.
 828     *
 829     * If the block does not have an instance name, this field will be
 830     * \c NULL.
 831     */
 832    const char *instance_name;
 833
 834    /** List of ast_declarator_list * */
 835    exec_list declarations;
 836
 837    /**
 838     * Declared array size of the block instance
 839     *
 840     * If the block is not declared as an array, this field will be \c NULL.
 841     *
 842     * \note
 843     * A block can only be an array if it also has an instance name.  If this
 844     * field is not \c NULL, ::instance_name must also not be \c NULL.
 845     */
 846    ast_expression *array_size;
 847 };
 848 /*@}*/
 849
 850 extern void
 851 _mesa_ast_to_hir(exec_list *instructions, struct _mesa_glsl_parse_state *state);
 852
 853 extern ir_rvalue *
 854 _mesa_ast_field_selection_to_hir(const ast_expression *expr,
 855                                  exec_list *instructions,
 856                                  struct _mesa_glsl_parse_state *state);
 857
 858 extern ir_rvalue *
 859 _mesa_ast_array_index_to_hir(void *mem_ctx,
 860                              struct _mesa_glsl_parse_state *state,
 861                              ir_rvalue *array, ir_rvalue *idx,
 862                              YYLTYPE &loc, YYLTYPE &idx_loc);
 863
 864 void
 865 emit_function(_mesa_glsl_parse_state *state, ir_function *f);
 866
 867 extern void
 868 check_builtin_array_max_size(const char *name, unsigned size,
 869                              YYLTYPE loc, struct _mesa_glsl_parse_state *state);
 870
 871 #endif /* AST_H */