ref: 7bcf6ac7b612306d197d063aaf6d971ca5dd2e3f
dir: /maxstack.inc/
static uint32_t compute_maxstack(uint8_t *code, size_t len) { uint8_t *ip = code+4, *end = code+len; uint8_t op; uint32_t i, n, sp = 0, maxsp = 0; while(ip < end){ if((int32_t)sp > (int32_t)maxsp) maxsp = sp; op = *ip++; switch(op){ case OP_LOADA: case OP_LOADI8: case OP_LOADV: case OP_LOADG: ip++; // fallthrough case OP_LOADA0: case OP_LOADA1: case OP_DUP: case OP_LOADT: case OP_LOADF: case OP_LOADNIL: case OP_LOADVOID: case OP_LOAD0: case OP_LOAD1: case OP_LOADC0: case OP_LOADC1: sp++; break; case OP_BRF: case OP_BRT: SWAP_INT16(ip); ip += 2; sp--; break; case OP_POP: case OP_RET: case OP_CONS: case OP_SETCAR: case OP_SETCDR: case OP_EQ: case OP_EQV: case OP_EQUAL: case OP_ADD2: case OP_SUB2: case OP_IDIV: case OP_NUMEQ: case OP_LT: case OP_COMPARE: case OP_AREF2: case OP_TRYCATCH: sp--; break; case OP_AREF: n = 2 + *ip++; sp -= n; break; case OP_ARGC: case OP_SETG: case OP_SETA: case OP_BOX: ip++; break; case OP_TCALL: case OP_CALL: case OP_CLOSURE: case OP_SHIFT: n = *ip++; // nargs sp -= n; break; case OP_LOADVL: case OP_LOADGL: case OP_LOADAL: sp++; // fallthrough case OP_SETGL: case OP_SETAL: case OP_LARGC: SWAP_INT32(ip); ip += 4; break; case OP_LOADC: sp++; ip++; break; case OP_VARGC: n = *ip++; sp += n+2; break; case OP_LVARGC: SWAP_INT32(ip); n = GET_INT32(ip); ip += 4; sp += n+2; break; case OP_OPTARGS: SWAP_INT32(ip); i = GET_INT32(ip); ip += 4; SWAP_INT32(ip); n = abs(GET_INT32(ip)); ip += 4; sp += n-i; break; case OP_KEYARGS: SWAP_INT32(ip); i = GET_INT32(ip); ip += 4; SWAP_INT32(ip); ip += 4; SWAP_INT32(ip); n = abs(GET_INT32(ip)); ip += 4; sp += n-i; break; case OP_BRBOUND: SWAP_INT32(ip); ip += 4; sp++; break; case OP_TCALLL: case OP_CALLL: SWAP_INT32(ip); n = GET_INT32(ip); ip+=4; sp -= n; break; case OP_JMP: SWAP_INT16(ip); ip += 2; break; case OP_JMPL: SWAP_INT32(ip); ip += 4; break; case OP_BRFL: case OP_BRTL: SWAP_INT32(ip); ip += 4; sp--; break; case OP_BRNE: SWAP_INT16(ip); ip += 2; sp -= 2; break; case OP_BRNEL: SWAP_INT32(ip); ip += 4; sp -= 2; break; case OP_BRNN: case OP_BRN: SWAP_INT16(ip); ip += 2; sp--; break; case OP_BRNNL: case OP_BRNL: SWAP_INT32(ip); ip += 4; // fallthrough case OP_TAPPLY: case OP_APPLY: case OP_LIST: case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV: case OP_VECTOR: n = *ip++; sp -= n-1; break; case OP_FOR: if(maxsp < sp+2) maxsp = sp+2; // fallthrough case OP_ASET: sp -= 2; break; case OP_LOADCL: sp++; // fallthrough SWAP_INT32(ip); ip += 4; break; } } assert(ip == end); return maxsp+4; }