diff options
| -rw-r--r-- | chunk.h | 3 | ||||
| -rw-r--r-- | com.c | 100 | ||||
| -rw-r--r-- | com.h | 1 | ||||
| -rw-r--r-- | dis.c | 2 | ||||
| -rw-r--r-- | tests/vars1.bth | 2 | ||||
| -rw-r--r-- | tests/vars1.out | 1 |
6 files changed, 82 insertions, 27 deletions
@@ -19,7 +19,4 @@ struct _chunk { } consts; }; Chunk chunk_new(State *S); -size_t compile_opcode(Compiler *C, uint8_t byte); -size_t compile_constant(Compiler *C, Val v); - #endif @@ -9,20 +9,8 @@ #include "read.h" #include "util.h" -#define BYTECODE(C) (C->ch->bc) - -static size_t placeholder(Compiler *C) { - size_t old_ix = BYTECODE(C).len; - compile_opcode(C, 0x00); - compile_opcode(C, 0x00); - return old_ix; -} - -static void patch(Compiler *C, size_t addr, uint16_t val) { - BYTECODE(C).d[addr] = val & 0xff; - BYTECODE(C).d[addr+1] = (val & 0xff00) >> 8; -} +#define BYTECODE(C) (C->ch->bc) Chunk chunk_new(State *S) { return (Chunk){ 0 }; @@ -32,11 +20,52 @@ Compiler compiler_new(Compiler *outer, Chunk *ch) { return (Compiler){ .S = outer->S, .ch = ch, + .stack_cur = 0, }; } +static void compile_byte(Compiler *C, uint8_t byte); +static void compile_opcode(Compiler *C, Op opcode); +static size_t compile_constant(Compiler *C, Val v); + +static int stack_effect_of(Op opcode) { + switch (opcode) { + case OP_LOADK: + case OP_GETGLOBAL: + case OP_NIL: + case OP_TRUE: + case OP_FALSE: + return 1; + case OP_PUTS: + case OP_PRINT: + case OP_SKIP: + case OP_REDO: + case OP_SETGLOBAL: + case OP_RET: + case OP_HALT: + return 0; + case OP_DROP: + case OP_0BRANCH: + case OP_ADD: + case OP_SUB: + case OP_MUL: + case OP_DIV: + case OP_CMP: + case OP_EQU: + case OP_MOD: + return -1; + + case OP_CALL: + // it depends. handle that one specifically + return 0; + default: + abort(); + } +} + -size_t compile_opcode(Compiler *C, uint8_t byte) { +// compile that byte directly +static void compile_byte(Compiler *C, uint8_t byte) { Chunk *ch = C->ch; if (ch->bc.len == ch->bc.cap) { size_t newsz = (ch->bc.cap == 0 ? 8 : ch->bc.cap * 2); @@ -46,9 +75,17 @@ size_t compile_opcode(Compiler *C, uint8_t byte) { size_t ix = ch->bc.len; ch->bc.d[ix] = byte; ch->bc.len ++; - return ix; } -size_t compile_constant(Compiler *C, Val v) { +// compile an opcode, keeping track of its stack effect +static void compile_opcode(Compiler *C, Op opcode) { + int stack_effect = stack_effect_of(opcode); + C->stack_cur += stack_effect; + compile_byte(C, opcode); +} +// add a new constant to the constant table, and return its index +// (but return the index of any existing identical constant instead of +// inserting a duplicate) +static size_t compile_constant(Compiler *C, Val v) { Chunk *ch = C->ch; for (int i = 0; i < ch->consts.len; i ++) if (val_equal(v, ch->consts.d[i])) return i; @@ -65,6 +102,24 @@ size_t compile_constant(Compiler *C, Val v) { return ix; } +static void compile_call_instr(Compiler *C, uint8_t len) { + compile_opcode(C, OP_CALL); + compile_byte(C, len); + C->stack_cur -= len; +} + +static size_t placeholder(Compiler *C) { + size_t old_ix = BYTECODE(C).len; + compile_byte(C, 0x00); + compile_byte(C, 0x00); + return old_ix; +} +static void patch(Compiler *C, size_t addr, uint16_t val) { + BYTECODE(C).d[addr] = val & 0xff; + BYTECODE(C).d[addr+1] = (val & 0xff00) >> 8; +} + + @@ -91,7 +146,7 @@ void set_form(Compiler *C, AstVec l, Op _) { ObjString *o = objstring_copy_cstr(C->S, ident.as.str); compile_node(C, l.vals[2]); compile_opcode(C, OP_SETGLOBAL); - compile_opcode(C, compile_constant(C, VAL_OBJ(o))); + compile_byte(C, compile_constant(C, VAL_OBJ(o))); } void do_form(Compiler *C, AstVec l, Op _) { @@ -174,7 +229,7 @@ void fn_form(Compiler *C, AstVec l, Op op) { compile_opcode(&subcompiler, OP_RET); compile_opcode(C, OP_LOADK); - compile_opcode(C, compile_constant(C, VAL_OBJ(func))); + compile_byte(C, compile_constant(C, VAL_OBJ(func))); } @@ -227,17 +282,17 @@ static void compile_node(Compiler *C, AstNode a) { // read global variable ObjString *o = objstring_copy_cstr(C->S, a.as.str); compile_opcode(C, OP_GETGLOBAL); - compile_opcode(C, compile_constant(C, VAL_OBJ(o))); + compile_byte(C, compile_constant(C, VAL_OBJ(o))); } break; case AST_NUM: compile_opcode(C, OP_LOADK); - compile_opcode(C, compile_constant(C, VAL_NUM(a.as.num))); + compile_byte(C, compile_constant(C, VAL_NUM(a.as.num))); break; case AST_STRING: { ObjString *o = objstring_copy_cstr(C->S, a.as.str); compile_opcode(C, OP_LOADK); - compile_opcode(C, compile_constant(C, VAL_OBJ(o))); + compile_byte(C, compile_constant(C, VAL_OBJ(o))); break; } case AST_LIST: { @@ -277,8 +332,7 @@ static void compile_node(Compiler *C, AstNode a) { for (int i = 0; i < l.len; i++) { compile_node(C, l.vals[i]); } - compile_opcode(C, OP_CALL); - compile_opcode(C, l.len); + compile_call_instr(C, l.len); } break; @@ -10,6 +10,7 @@ typedef struct _compiler Compiler; struct _compiler { State *S; Chunk *ch; + int stack_cur; }; Compiler compiler_new(Compiler *outer, Chunk *ch); @@ -24,7 +24,7 @@ size_t disasm_instr(Chunk *ch, size_t ip) { static size_t disasm_instr_h(Chunk *ch, size_t ip, int depth) { size_t orig_ip = ip; uint8_t instr = ch->bc.d[ip]; - printf("%*s%04zd\t",depth,"",ip); + printf("%*s%04zd\t%3d ",depth,"",ip,instr); ip ++; switch (instr) { case OP_LOADK: { diff --git a/tests/vars1.bth b/tests/vars1.bth new file mode 100644 index 0000000..718b52b --- /dev/null +++ b/tests/vars1.bth @@ -0,0 +1,2 @@ +(+ 2 (let (a 10) + (* a a))) diff --git a/tests/vars1.out b/tests/vars1.out new file mode 100644 index 0000000..257e563 --- /dev/null +++ b/tests/vars1.out @@ -0,0 +1 @@ +102 |