/* * Copyright (C) 2012 * Wolfgang Bumiller * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies * of the Software, and to permit persons to whom the Software is furnished to do * so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #ifndef GMQCC_AST_HDR #define GMQCC_AST_HDR #include "ir.h" /* Note: I will not be using a _t suffix for the * "main" ast node types for now. */ typedef union ast_node_u ast_node; typedef union ast_expression_u ast_expression; typedef struct ast_value_s ast_value; typedef struct ast_function_s ast_function; typedef struct ast_block_s ast_block; typedef struct ast_binary_s ast_binary; typedef struct ast_store_s ast_store; typedef struct ast_entfield_s ast_entfield; typedef struct ast_ifthen_s ast_ifthen; typedef struct ast_ternary_s ast_ternary; typedef struct ast_loop_s ast_loop; typedef struct ast_call_s ast_call; /* Node interface with common components */ typedef void ast_node_delete(ast_node*); typedef struct { lex_ctx context; /* I don't feel comfortable using keywords like 'delete' as names... */ ast_node_delete *destroy; /* keep: if a node contains this node, 'keep' * prevents its dtor from destroying this node as well. */ bool keep; } ast_node_common; #define ast_delete(x) ( ( (ast_node*)(x) ) -> node.destroy )((ast_node*)(x)) #define ast_unref(x) do \ { \ if (! (((ast_node*)(x))->node.keep) ) { \ ast_delete(x); \ } \ } while(0) /* Expression interface * * Any expression or block returns an ir_value, and needs * to know the current function. */ typedef bool ast_expression_codegen(ast_expression*, ast_function*, bool lvalue, ir_value**); typedef struct { ast_node_common node; ast_expression_codegen *codegen; int vtype; ast_expression *next; } ast_expression_common; /* Value * * Types are also values, both have a type and a name. * especially considering possible constructs like typedefs. * typedef float foo; * is like creating a 'float foo', foo serving as the type's name. */ struct ast_value_s { ast_expression_common expression; const char *name; /* int vtype; ast_value *next; */ bool isconst; union { double vfloat; int vint; vector vvec; const char *vstring; int ventity; ast_function *vfunc; } constval; ir_value *ir_v; /* if vtype is qc_function, params contain parameters, and * 'next' the return type. */ MEM_VECTOR_MAKE(ast_value*, params); }; MEM_VECTOR_PROTO(ast_value, ast_value*, params); ast_value* ast_value_new(lex_ctx ctx, const char *name, int qctype); /* This will NOT delete an underlying ast_function */ void ast_value_delete(ast_value*); bool ast_value_set_name(ast_value*, const char *name); bool ast_value_codegen(ast_value*, ast_function*, bool lvalue, ir_value**); bool ast_local_codegen(ast_value *self, ir_function *func); bool ast_global_codegen(ast_value *self, ir_builder *ir); /* Binary * * A value-returning binary expression. */ struct ast_binary_s { ast_expression_common expression; int op; ast_expression *left; ast_expression *right; }; ast_binary* ast_binary_new(lex_ctx ctx, int op, ast_expression *left, ast_expression *right); void ast_binary_delete(ast_binary*); bool ast_binary_codegen(ast_binary*, ast_function*, bool lvalue, ir_value**); /* Entity-field * * This must do 2 things: * -) Provide a way to fetch an entity field value. (Rvalue) * -) Provide a pointer to an entity field. (Lvalue) * The problem: * In original QC, there's only a STORE via pointer, but * no LOAD via pointer. * So we must know beforehand if we are going to read or assign * the field. * For this we will have to extend the codegen() functions with * a flag saying whether or not we need an L or an R-value. */ struct ast_entfield_s { ast_expression_common expression; /* The entity can come from an expression of course. */ ast_expression *entity; /* As can the field, it just must result in a value of TYPE_FIELD */ ast_expression *field; }; ast_entfield* ast_entfield_new(lex_ctx ctx, ast_expression *entity, ast_expression *field); void ast_entfield_delete(ast_entfield*); bool ast_entfield_codegen(ast_entfield*, ast_function*, bool lvalue, ir_value**); /* Store * * Stores left<-right and returns left. * Specialized binary expression node */ struct ast_store_s { ast_expression_common expression; int op; ast_value *dest; /* When we add pointers this might have to change to expression */ ast_expression *source; }; ast_store* ast_store_new(lex_ctx ctx, int op, ast_value *d, ast_expression *s); void ast_store_delete(ast_store*); bool ast_store_codegen(ast_store*, ast_function*, bool lvalue, ir_value**); /* If * * A general 'if then else' statement, either side can be NULL and will * thus be omitted. It is an error for *both* cases to be NULL at once. * * During its 'codegen' it'll be changing the ast_function's block. * * An if is also an "expression". Its codegen will put NULL into the * output field though. For ternary expressions an ast_ternary will be * added. */ struct ast_ifthen_s { ast_expression_common expression; ast_expression *cond; /* It's all just 'expressions', since an ast_block is one too. */ ast_expression *on_true; ast_expression *on_false; }; ast_ifthen* ast_ifthen_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse); void ast_ifthen_delete(ast_ifthen*); bool ast_ifthen_codegen(ast_ifthen*, ast_function*, bool lvalue, ir_value**); /* Ternary expressions... * * Contrary to 'if-then-else' nodes, ternary expressions actually * return a value, otherwise they behave the very same way. * The difference in 'codegen' is that it'll return the value of * a PHI node. * * The other difference is that in an ast_ternary, NEITHER side * must be NULL, there's ALWAYS an else branch. * * This is the only ast_node beside ast_value which contains * an ir_value. Theoretically we don't need to remember it though. */ struct ast_ternary_s { ast_expression_common expression; ast_expression *cond; /* It's all just 'expressions', since an ast_block is one too. */ ast_expression *on_true; ast_expression *on_false; /* After a ternary expression we find ourselves in a new IR block * and start with a PHI node */ ir_value *phi_out; }; ast_ternary* ast_ternary_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse); void ast_ternary_delete(ast_ternary*); bool ast_ternary_codegen(ast_ternary*, ast_function*, bool lvalue, ir_value**); /* A general loop node * * For convenience it contains 4 parts: * -) (ini) = initializing expression * -) (pre) = pre-loop condition * -) (pst) = post-loop condition * -) (inc) = "increment" expression * The following is a psudo-representation of this loop * note that '=>' bears the logical meaning of "implies". * (a => b) equals (!a || b) {ini}; while (has_pre => {pre}) { {body}; continue: // a 'continue' will jump here if (has_pst => {pst}) break; {inc}; } */ struct ast_loop_s { ast_expression_common expression; ast_expression *initexpr; ast_expression *precond; ast_expression *postcond; ast_expression *increment; ast_expression *body; }; ast_loop* ast_loop_new(lex_ctx ctx, ast_expression *initexpr, ast_expression *precond, ast_expression *postcond, ast_expression *increment, ast_expression *body); void ast_loop_delete(ast_loop*); bool ast_loop_codegen(ast_loop*, ast_function*, bool lvalue, ir_value**); /* CALL node * * Contains an ast_expression as target, rather than an ast_function/value. * Since it's how QC works, every ast_function has an ast_value * associated anyway - in other words, the VM contains function * pointers for every function anyway. Thus, this node will call * expression. * Additionally it contains a list of ast_expressions as parameters. * Since calls can return values, an ast_call is also an ast_expression. */ struct ast_call_s { ast_expression_common expression; ast_expression *func; MEM_VECTOR_MAKE(ast_expression*, params); }; ast_call* ast_call_new(lex_ctx ctx, ast_expression *funcexpr); void ast_call_delete(ast_call*); bool ast_call_codegen(ast_call*, ast_function*, bool lvalue, ir_value**); MEM_VECTOR_PROTO(ast_call, ast_expression*, params); /* Blocks * */ struct ast_block_s { ast_expression_common expression; MEM_VECTOR_MAKE(ast_value*, locals); MEM_VECTOR_MAKE(ast_expression*, exprs); }; ast_block* ast_block_new(lex_ctx ctx); void ast_block_delete(ast_block*); MEM_VECTOR_PROTO(ast_block, ast_value*, locals); MEM_VECTOR_PROTO(ast_block, ast_expression*, exprs); bool ast_block_codegen(ast_block*, ast_function*, bool lvalue, ir_value**); /* Function * * Contains a list of blocks... at least in theory. * Usually there's just the main block, other blocks are inside that. * * Technically, functions don't need to be an AST node, since we have * neither functions inside functions, nor lambdas, and function * pointers could just work with a name. However, this way could be * more flexible, and adds no real complexity. */ struct ast_function_s { ast_node_common node; ast_value *vtype; const char *name; int builtin; ir_function *ir_func; ir_block *curblock; ir_block *breakblock; ir_block *continueblock; size_t labelcount; /* in order for thread safety - for the optional * channel abesed multithreading... keeping a buffer * here to use in ast_function_label. */ char labelbuf[64]; MEM_VECTOR_MAKE(ast_block*, blocks); /* contrary to the params in ast_value, these are the parameter variables * which are to be used in expressions. * The ast_value for the function contains only the parameter types used * to generate ast_calls, and ast_call contains the parameter values * used in that call. */ MEM_VECTOR_MAKE(ast_value*, params); }; ast_function* ast_function_new(lex_ctx ctx, const char *name, ast_value *vtype); /* This will NOT delete the underlying ast_value */ void ast_function_delete(ast_function*); /* For "optimized" builds this can just keep returning "foo"... * or whatever... */ const char* ast_function_label(ast_function*, const char *prefix); MEM_VECTOR_PROTO(ast_function, ast_block*, blocks); MEM_VECTOR_PROTO(ast_function, ast_value*, params); bool ast_function_codegen(ast_function *self, ir_builder *builder); /* Expression union */ union ast_expression_u { ast_expression_common expression; ast_value value; ast_binary binary; ast_block block; ast_ternary ternary; ast_ifthen ifthen; ast_store store; ast_entfield entfield; }; /* Node union */ union ast_node_u { ast_node_common node; ast_expression expression; }; #endif