diff options
| -rw-r--r-- | src/sys/include/np/piir.h | 39 | ||||
| -rw-r--r-- | src/sys/np/codegen/gen_piir.c | 18 | ||||
| -rw-r--r-- | src/sys/np/core/np_parse.c | 31 |
3 files changed, 65 insertions, 23 deletions
diff --git a/src/sys/include/np/piir.h b/src/sys/include/np/piir.h index 9c4b322..8277c1f 100644 --- a/src/sys/include/np/piir.h +++ b/src/sys/include/np/piir.h @@ -35,7 +35,13 @@ #include <os/spinlock.h> #include <os/np.h> -typedef uint8_t ir_byte_t; +/* + * Represents two different kinds of bytes, MI IR + * bytes and MD opcode / instruction bytes, less than + * zero values are reserved for error indication. + */ +typedef int8_t ir_byte_t; +typedef int8_t md_byte_t; /* * The maxiumum size of the bytecode stack per @@ -49,16 +55,33 @@ typedef uint8_t ir_byte_t; #define PIIR_LOAD_R16 0x02 #define PIIR_LOAD_R32 0x03 #define PIIR_LOAD_R64 0x04 +#define PIIR_RET_NIL 0x05 /* Return nothing */ + +/* + * Represents the PIIR virtual machine for storing + * state while converting IR to instruction bytes + * + * @code: Generated machine code + * @last_ir: Last IR byte used + * @code_i: Current index into code buffer + */ +struct piir_vm { + md_byte_t code[4096]; + ir_byte_t last_ir; + uint32_t code_i; +}; /* * Represents the Pi-IR (PIIR) bytecode stack * * @opstore: The actual stack - * @op_i: Index into the stack + * @op_head: Where new ops are written + * @op_tail: Where new ops are read */ struct piir_stack { ir_byte_t opstore[PIIR_STACK_SIZE]; - uint16_t op_i; + uint16_t op_head; + uint16_t op_tail; struct spinlock lock; }; @@ -94,4 +117,14 @@ int piir_push(struct piir_stack *stack, ir_byte_t byte); */ int piir_pop(struct piir_stack *stack); +/* + * Inject control flow via stack machine + * + * @work: Current work + * + * Returns zero on success, otherwise a less than + * zero value on failure. + */ +int piir_inject(struct np_work *work); + #endif /* !_NP_PIIR_H_ */ diff --git a/src/sys/np/codegen/gen_piir.c b/src/sys/np/codegen/gen_piir.c index e139465..e6623ac 100644 --- a/src/sys/np/codegen/gen_piir.c +++ b/src/sys/np/codegen/gen_piir.c @@ -66,12 +66,12 @@ piir_push(struct piir_stack *stack, ir_byte_t byte) return -EINVAL; } - if (stack->op_i >= PIIR_STACK_SIZE - 1) { + if (stack->op_head >= PIIR_STACK_SIZE - 1) { return -1; } spinlock_acquire(&stack->lock); - stack->opstore[stack->op_i++] = byte; + stack->opstore[stack->op_head++] = byte; spinlock_release(&stack->lock); return 0; } @@ -88,12 +88,22 @@ piir_pop(struct piir_stack *stack) return -EINVAL; } - if (stack->op_i == 0) { + /* Don't read past what we can */ + if (stack->op_tail == stack->op_head) { + stack->op_tail = 0; + stack->op_head = 0; return -1; } spinlock_acquire(&stack->lock); - byte = stack->opstore[--stack->op_i]; + + /* Grab a byte, reset pointers if empty */ + byte = stack->opstore[stack->op_tail++]; + if (stack->op_tail == stack->op_head) { + stack->op_tail = 0; + stack->op_head = 0; + } + spinlock_release(&stack->lock); return byte; } diff --git a/src/sys/np/core/np_parse.c b/src/sys/np/core/np_parse.c index fd35e3c..3eefde5 100644 --- a/src/sys/np/core/np_parse.c +++ b/src/sys/np/core/np_parse.c @@ -269,16 +269,16 @@ parse_proc(struct np_work *work, struct ast_node **npp, struct lex_token *tok) * Parse a token * * @work: Input work - * @root: Root AST node * @tok: Current token */ static int -parse_token(struct np_work *work, struct ast_node *root, struct lex_token *tok) +parse_token(struct np_work *work, struct lex_token *tok) { tt_t tt; int error; struct ast_node *np; +#define PIIR_PUSH(BYTE) piir_push(work->piir_stack, (BYTE)) /* * XXX: wrapped in "[]" indicates optional * @@ -296,9 +296,15 @@ parse_token(struct np_work *work, struct ast_node *root, struct lex_token *tok) ++work->begin_depth; case TT_END: - /* Do the begin statements match? */ + /* + * Check if the 'begin' statements match, if they do + * we'll decrease the depth and push a NIL return + * + * TODO: We'll need to handle returns better + */ if (work->begin_depth > 0) { --work->begin_depth; + PIIR_PUSH(PIIR_RET_NIL); break; } @@ -321,18 +327,17 @@ parse_token(struct np_work *work, struct ast_node *root, struct lex_token *tok) return -1; } - root->left = NULL; /* arguments */ - root->right = np; + /* XXX: NOP for testing */ + PIIR_PUSH(PIIR_NOP); break; } - +#undef PIIR_PUSH return 0; } int parse_work(struct np_work *work) { - struct ast_node *root; struct lex_token tok; int error = 0; @@ -341,14 +346,6 @@ parse_work(struct np_work *work) return -EINVAL; } - /* Get the AST root node */ - work->ast_root = ast_alloc(work); - root = work->ast_root; - if (work->ast_root == NULL) { - pr_error("failed to alloc root AST\n"); - return -ENOMEM; - } - /* Initialize PIIR */ error = piir_stack_new(work, &work->piir_stack); if (error < 0) { @@ -371,11 +368,13 @@ parse_work(struct np_work *work) return -1; } - if (parse_token(work, root, &tok) < 0) { + if (parse_token(work, &tok) < 0) { return -1; } } + piir_inject(work); + /* * If there are more begin clauses than end * clauses, someone mismatched them. |