Commit 13ed3a65 authored by Damien's avatar Damien
Browse files

Native Python and Viper support for x64 and thumb all together.

parent 3410be80
CC = gcc
CFLAGS = -Wall -ansi -std=gnu99 -Os -DEMIT_ENABLE_CPY -DEMIT_ENABLE_X64 -DEMIT_ENABLE_THUMB #-DNDEBUG
CFLAGS = -Wall -ansi -std=gnu99 -Os -DEMIT_ENABLE_CPY -DEMIT_ENABLE_THUMB #-DNDEBUG
LDFLAGS =
SRC = \
......@@ -16,8 +16,6 @@ SRC = \
emitcpy.c \
emitbc.c \
asmx64.c \
emitx64.c \
emitthumb.c \
asmthumb.c \
emitinlinethumb.c \
runtime.c \
......@@ -26,7 +24,7 @@ SRC = \
SRC_ASM = \
OBJ = $(SRC:.c=.o) $(SRC_ASM:.s=.o)
OBJ = $(SRC:.c=.o) $(SRC_ASM:.s=.o) emitnx64.o emitnthumb.o
LIB =
PROG = py
......@@ -36,15 +34,19 @@ $(PROG): $(OBJ)
runtime.o: runtime.c
$(CC) $(CFLAGS) -O3 -c -o $@ $<
bc.o: bc.c
vm.o: vm.c
$(CC) $(CFLAGS) -O3 -c -o $@ $<
parse.o: grammar.h
compile.o: grammar.h
emitcpy.o: emit.h
emitbc.o: emit.h
emitx64.o: emit.h
emitthumb.o: emit.h
emitnx64.o: emitnative.c emit.h
$(CC) $(CFLAGS) -DN_X64 -c -o $@ $<
emitnthumb.o: emitnative.c emit.h
$(CC) $(CFLAGS) -DN_THUMB -c -o $@ $<
clean:
/bin/rm $(OBJ)
......@@ -2706,10 +2706,10 @@ void py_compile(py_parse_node_t pn) {
case EMIT_OPT_NATIVE_PYTHON:
case EMIT_OPT_VIPER:
if (emit_native == NULL) {
emit_native = emit_x64_new(max_num_labels);
emit_native = emit_native_x64_new(max_num_labels);
}
comp->emit = emit_native;
comp->emit_method_table = &emit_x64_method_table;
comp->emit_method_table = &emit_native_x64_method_table;
comp->emit_method_table->set_native_types(comp->emit, s->emit_options == EMIT_OPT_VIPER);
break;
......
......@@ -119,17 +119,15 @@ void emit_common_delete_id(emit_t *emit, const emit_method_table_t *emit_method_
extern const emit_method_table_t emit_pass1_method_table;
extern const emit_method_table_t emit_cpython_method_table;
extern const emit_method_table_t emit_bc_method_table;
extern const emit_method_table_t emit_x64_method_table;
extern const emit_method_table_t emit_viper_x64_method_table;
extern const emit_method_table_t emit_thumb_method_table;
extern const emit_method_table_t emit_native_x64_method_table;
extern const emit_method_table_t emit_native_thumb_method_table;
emit_t *emit_pass1_new(qstr qstr___class__);
void emit_pass1_free(emit_t *emit);
emit_t *emit_cpython_new(uint max_num_labels);
emit_t *emit_bc_new(uint max_num_labels);
emit_t *emit_x64_new(uint max_num_labels);
emit_t *emit_viper_x64_new(uint max_num_labels);
emit_t *emit_thumb_new(uint max_num_labels);
emit_t *emit_native_x64_new(uint max_num_labels);
emit_t *emit_native_thumb_new(uint max_num_labels);
typedef struct _emit_inline_asm_t emit_inline_asm_t;
......
// Essentially normal Python has 1 type: Python objects
// Viper has more than 1 type, and is just a more complicated (a superset of) Python.
// If you declare everything in Viper as a Python object (ie omit type decls) then
// it should in principle be exactly the same as Python native.
// Having types means having more opcodes, like binary_op_nat_nat, binary_op_nat_obj etc.
// In practice we won't have a VM but rather do this in asm which is actually very minimal.
// Because it breaks strict Python equivalence it should be a completely separate
// decorator. It breaks equivalence because overflow on integers wraps around.
// It shouldn't break equivalence if you don't use the new types, but since the
// type decls might be used in normal Python for other reasons, it's probably safest,
// cleanest and clearest to make it a separate decorator.
// Actually, it does break equivalence because integers default to native integers,
// not Python objects.
// for x in l[0:8]: can be compiled into a native loop if l has pointer type
#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "misc.h"
#include "lexer.h"
#include "machine.h"
#include "parse.h"
#include "scope.h"
#include "runtime.h"
#include "emit.h"
// select a machine architecture
#if 0
#if defined(EMIT_ENABLE_NATIVE_X64)
#define N_X64
#elif defined(EMIT_ENABLE_NATIVE_THUMB)
#define N_THUMB
#endif
#endif
// wrapper around everything in this file
#if defined(N_X64) || defined(N_THUMB)
#if defined(N_X64)
// x64 specific stuff
#include "asmx64.h"
#define REG_LOCAL_1 (REG_RBX)
#define REG_LOCAL_NUM (1)
#define EXPORT_FUN(name) emit_native_x64_##name
#define REG_TEMP0 (REG_RAX)
#define REG_TEMP1 (REG_RDI)
#define REG_TEMP2 (REG_RSI)
#define ASM_MOV_REG_TO_LOCAL(reg, local_num) asm_x64_mov_r64_to_local(emit->as, (reg), (local_num))
#define ASM_MOV_IMM_TO_REG(imm, reg) asm_x64_mov_i64_to_r64_optimised(emit->as, (imm), (reg))
#define ASM_MOV_IMM_TO_LOCAL(imm, local_num) do { asm_x64_mov_i64_to_r64_optimised(emit->as, (imm), REG_RAX); asm_x64_mov_r64_to_local(emit->as, REG_RAX, (local_num)); } while (false)
#define ASM_MOV_LOCAL_TO_REG(local_num, reg) asm_x64_mov_local_to_r64(emit->as, (local_num), (reg))
#define ASM_MOV_REG_TO_REG(reg_src, reg_dest) asm_x64_mov_r64_to_r64(emit->as, (reg_src), (reg_dest))
#define ASM_MOV_LOCAL_ADDR_TO_REG(local_num, reg) asm_x64_mov_local_addr_to_r64(emit->as, (local_num), (reg))
#elif defined(N_THUMB)
// thumb specific stuff
#include "asmthumb.h"
#define REG_LOCAL_1 (REG_R4)
#define REG_LOCAL_2 (REG_R5)
#define REG_LOCAL_3 (REG_R6)
#define REG_LOCAL_NUM (3)
#define EXPORT_FUN(name) emit_native_thumb_##name
#define REG_TEMP0 (REG_R0)
#define REG_TEMP1 (REG_R1)
#define REG_TEMP2 (REG_R2)
#define ASM_MOV_REG_TO_LOCAL(reg, local_num) asm_thumb_mov_local_reg(emit->as, (local_num), (reg))
#define ASM_MOV_IMM_TO_REG(imm, reg) asm_thumb_mov_reg_i32_optimised(emit->as, (reg), (imm))
#define ASM_MOV_IMM_TO_LOCAL(imm, local_num) do { asm_thumb_mov_reg_i32_optimised(emit->as, REG_R0, (imm)); asm_thumb_mov_local_reg(emit->as, (local_num), REG_R0); } while (false)
#define ASM_MOV_LOCAL_TO_REG(local_num, reg) asm_thumb_mov_reg_local(emit->as, (reg), (local_num))
#define ASM_MOV_REG_TO_REG(reg_src, reg_dest) asm_thumb_mov_reg_reg(emit->as, (reg_dest), (reg_src))
#define ASM_MOV_LOCAL_ADDR_TO_REG(local_num, reg) asm_thumb_mov_reg_local_addr(emit->as, (reg), (local_num))
#endif
typedef enum {
NEED_TO_PUSH_NOTHING,
NEED_TO_PUSH_REG,
NEED_TO_PUSH_IMM,
} need_to_push_t;
typedef enum {
VTYPE_UNBOUND,
VTYPE_PYOBJ,
VTYPE_BOOL,
VTYPE_INT,
VTYPE_PTR,
VTYPE_PTR_NONE,
VTYPE_BUILTIN_V_INT,
} vtype_kind_t;
struct _emit_t {
int pass;
bool do_viper_types;
int all_vtype_alloc;
vtype_kind_t *all_vtype;
vtype_kind_t *local_vtype;
vtype_kind_t *stack_vtype;
int stack_start;
int stack_size;
bool last_emit_was_return_value;
need_to_push_t need_to_push;
vtype_kind_t last_vtype;
int last_reg;
int64_t last_imm;
scope_t *scope;
#if defined(N_X64)
asm_x64_t *as;
#elif defined(N_THUMB)
asm_thumb_t *as;
#endif
};
emit_t *EXPORT_FUN(new)(uint max_num_labels) {
emit_t *emit = m_new(emit_t, 1);
emit->do_viper_types = false;
emit->all_vtype = NULL;
#if defined(N_X64)
emit->as = asm_x64_new(max_num_labels);
#elif defined(N_THUMB)
emit->as = asm_thumb_new(max_num_labels);
#endif
return emit;
}
static void emit_native_set_viper_types(emit_t *emit, bool do_viper_types) {
emit->do_viper_types = do_viper_types;
}
static void emit_native_start_pass(emit_t *emit, pass_kind_t pass, scope_t *scope) {
emit->pass = pass;
emit->stack_start = 0;
emit->stack_size = 0;
emit->last_emit_was_return_value = false;
emit->need_to_push = NEED_TO_PUSH_NOTHING;
emit->scope = scope;
if (emit->all_vtype == NULL) {
emit->all_vtype_alloc = scope->num_locals + scope->stack_size + 100; // XXX don't know stack size on entry, should be maximum over all scopes
emit->all_vtype = m_new(vtype_kind_t, emit->all_vtype_alloc);
emit->local_vtype = emit->all_vtype;
emit->stack_vtype = emit->all_vtype + scope->num_locals;
}
if (emit->do_viper_types) {
for (int i = 0; i < emit->all_vtype_alloc; i++) {
emit->all_vtype[i] = VTYPE_UNBOUND;
}
// TODO set types of arguments based on type signature
} else {
for (int i = 0; i < emit->all_vtype_alloc; i++) {
emit->all_vtype[i] = VTYPE_PYOBJ;
}
}
#if defined(N_X64)
asm_x64_start_pass(emit->as, pass);
#elif defined(N_THUMB)
asm_thumb_start_pass(emit->as, pass);
#endif
// entry to function
int num_locals = 0;
if (pass > PASS_1) {
num_locals = scope->num_locals - REG_LOCAL_NUM;
if (num_locals < 0) {
num_locals = 0;
}
emit->stack_start = num_locals;
num_locals += scope->stack_size;
}
#if defined(N_X64)
asm_x64_entry(emit->as, num_locals);
#elif defined(N_THUMB)
asm_thumb_entry(emit->as, num_locals);
#endif
// initialise locals from parameters
#if defined(N_X64)
for (int i = 0; i < scope->num_params; i++) {
if (i == 0) {
asm_x64_mov_r64_to_r64(emit->as, REG_ARG_1, REG_LOCAL_1);
} else if (i == 1) {
asm_x64_mov_r64_to_local(emit->as, REG_ARG_2, i - 1);
} else if (i == 2) {
asm_x64_mov_r64_to_local(emit->as, REG_ARG_3, i - 1);
} else {
// TODO not implemented
assert(0);
}
}
#elif defined(N_THUMB)
for (int i = 0; i < scope->num_params; i++) {
if (i == 0) {
asm_thumb_mov_reg_reg(emit->as, REG_LOCAL_1, REG_ARG_1);
} else if (i == 1) {
asm_thumb_mov_reg_reg(emit->as, REG_LOCAL_2, REG_ARG_2);
} else if (i == 2) {
asm_thumb_mov_reg_reg(emit->as, REG_LOCAL_3, REG_ARG_3);
} else if (i == 3) {
asm_thumb_mov_local_reg(emit->as, i - REG_LOCAL_NUM, REG_ARG_4);
} else {
// TODO not implemented
assert(0);
}
}
asm_thumb_mov_reg_i32(emit->as, REG_R7, (machine_uint_t)rt_fun_table);
#endif
}
static void emit_native_end_pass(emit_t *emit) {
#if defined(N_X64)
if (!emit->last_emit_was_return_value) {
asm_x64_exit(emit->as);
}
asm_x64_end_pass(emit->as);
#elif defined(N_THUMB)
if (!emit->last_emit_was_return_value) {
asm_thumb_exit(emit->as);
}
asm_thumb_end_pass(emit->as);
#endif
// check stack is back to zero size
if (emit->stack_size != 0) {
printf("ERROR: stack size not back to zero; got %d\n", emit->stack_size);
}
if (emit->pass == PASS_3) {
#if defined(N_X64)
py_fun_t f = asm_x64_get_code(emit->as);
rt_assign_native_code(emit->scope->unique_code_id, f, asm_x64_get_code_size(emit->as), emit->scope->num_params);
#elif defined(N_THUMB)
py_fun_t f = asm_thumb_get_code(emit->as);
rt_assign_native_code(emit->scope->unique_code_id, f, asm_thumb_get_code_size(emit->as), emit->scope->num_params);
#endif
}
}
static bool emit_native_last_emit_was_return_value(emit_t *emit) {
return emit->last_emit_was_return_value;
}
static int emit_native_get_stack_size(emit_t *emit) {
return emit->stack_size;
}
static void emit_native_set_stack_size(emit_t *emit, int size) {
emit->stack_size = size;
}
static void adjust_stack(emit_t *emit, int stack_size_delta) {
emit->stack_size += stack_size_delta;
assert(emit->stack_size >= 0);
if (emit->pass > PASS_1 && emit->stack_size > emit->scope->stack_size) {
emit->scope->stack_size = emit->stack_size;
}
}
static void stack_settle(emit_t *emit) {
switch (emit->need_to_push) {
case NEED_TO_PUSH_NOTHING:
break;
case NEED_TO_PUSH_REG:
emit->stack_vtype[emit->stack_size] = emit->last_vtype;
ASM_MOV_REG_TO_LOCAL(emit->last_reg, emit->stack_start + emit->stack_size);
adjust_stack(emit, 1);
break;
case NEED_TO_PUSH_IMM:
emit->stack_vtype[emit->stack_size] = emit->last_vtype;
ASM_MOV_IMM_TO_LOCAL(emit->last_imm, emit->stack_start + emit->stack_size);
adjust_stack(emit, 1);
break;
}
emit->need_to_push = NEED_TO_PUSH_NOTHING;
}
static void emit_pre_raw(emit_t *emit, int stack_size_delta) {
adjust_stack(emit, stack_size_delta);
emit->last_emit_was_return_value = false;
}
static void emit_pre(emit_t *emit) {
stack_settle(emit);
emit_pre_raw(emit, 0);
}
static vtype_kind_t peek_vtype(emit_t *emit) {
switch (emit->need_to_push) {
case NEED_TO_PUSH_NOTHING:
return emit->stack_vtype[emit->stack_size - 1];
case NEED_TO_PUSH_REG:
case NEED_TO_PUSH_IMM:
return emit->last_vtype;
default:
assert(0);
return VTYPE_UNBOUND;
}
}
static void emit_pre_pop_reg(emit_t *emit, vtype_kind_t *vtype, int reg_dest) {
switch (emit->need_to_push) {
case NEED_TO_PUSH_NOTHING:
*vtype = emit->stack_vtype[emit->stack_size - 1];
ASM_MOV_LOCAL_TO_REG(emit->stack_start + emit->stack_size - 1, reg_dest);
emit_pre_raw(emit, -1);
break;
case NEED_TO_PUSH_REG:
emit_pre_raw(emit, 0);
*vtype = emit->last_vtype;
if (emit->last_reg != reg_dest) {
ASM_MOV_REG_TO_REG(emit->last_reg, reg_dest);
}
break;
case NEED_TO_PUSH_IMM:
emit_pre_raw(emit, 0);
*vtype = emit->last_vtype;
ASM_MOV_IMM_TO_REG(emit->last_imm, reg_dest);
break;
}
emit->need_to_push = NEED_TO_PUSH_NOTHING;
}
static void emit_pre_pop_reg_reg(emit_t *emit, vtype_kind_t *vtypea, int rega, vtype_kind_t *vtypeb, int regb) {
emit_pre_pop_reg(emit, vtypea, rega);
*vtypeb = emit->stack_vtype[emit->stack_size - 1];
ASM_MOV_LOCAL_TO_REG(emit->stack_start + emit->stack_size - 1, regb);
adjust_stack(emit, -1);
}
static void emit_pre_pop_reg_reg_reg(emit_t *emit, vtype_kind_t *vtypea, int rega, vtype_kind_t *vtypeb, int regb, vtype_kind_t *vtypec, int regc) {
emit_pre_pop_reg(emit, vtypea, rega);
*vtypeb = emit->stack_vtype[emit->stack_size - 1];
*vtypec = emit->stack_vtype[emit->stack_size - 2];
ASM_MOV_LOCAL_TO_REG(emit->stack_start + emit->stack_size - 1, regb);
ASM_MOV_LOCAL_TO_REG(emit->stack_start + emit->stack_size - 2, regc);
adjust_stack(emit, -2);
}
static void emit_post(emit_t *emit) {
}
static void emit_post_push_reg(emit_t *emit, vtype_kind_t vtype, int reg) {
emit->need_to_push = NEED_TO_PUSH_REG;
emit->last_vtype = vtype;
emit->last_reg = reg;
}
static void emit_post_push_imm(emit_t *emit, vtype_kind_t vtype, machine_int_t imm) {
emit->need_to_push = NEED_TO_PUSH_IMM;
emit->last_vtype = vtype;
emit->last_imm = imm;
}
static void emit_post_push_reg_reg(emit_t *emit, vtype_kind_t vtypea, int rega, vtype_kind_t vtypeb, int regb) {
emit->stack_vtype[emit->stack_size] = vtypea;
ASM_MOV_REG_TO_LOCAL(rega, emit->stack_start + emit->stack_size);
emit->need_to_push = NEED_TO_PUSH_REG;
emit->last_vtype = vtypeb;
emit->last_reg = regb;
adjust_stack(emit, 1);
}
static void emit_post_push_reg_reg_reg(emit_t *emit, vtype_kind_t vtypea, int rega, vtype_kind_t vtypeb, int regb, vtype_kind_t vtypec, int regc) {
emit->stack_vtype[emit->stack_size] = vtypea;
emit->stack_vtype[emit->stack_size + 1] = vtypeb;
emit->stack_vtype[emit->stack_size + 2] = vtypec;
ASM_MOV_REG_TO_LOCAL(rega, emit->stack_start + emit->stack_size);
ASM_MOV_REG_TO_LOCAL(regb, emit->stack_start + emit->stack_size + 1);
ASM_MOV_REG_TO_LOCAL(regc, emit->stack_start + emit->stack_size + 2);
adjust_stack(emit, 3);
}
static void emit_post_push_reg_reg_reg_reg(emit_t *emit, vtype_kind_t vtypea, int rega, vtype_kind_t vtypeb, int regb, vtype_kind_t vtypec, int regc, vtype_kind_t vtyped, int regd) {
emit->stack_vtype[emit->stack_size] = vtypea;
emit->stack_vtype[emit->stack_size + 1] = vtypeb;
emit->stack_vtype[emit->stack_size + 2] = vtypec;
emit->stack_vtype[emit->stack_size + 3] = vtyped;
ASM_MOV_REG_TO_LOCAL(rega, emit->stack_start + emit->stack_size);
ASM_MOV_REG_TO_LOCAL(regb, emit->stack_start + emit->stack_size + 1);
ASM_MOV_REG_TO_LOCAL(regc, emit->stack_start + emit->stack_size + 2);
ASM_MOV_REG_TO_LOCAL(regd, emit->stack_start + emit->stack_size + 3);
adjust_stack(emit, 4);
}
// vtype of all n_pop objects is VTYPE_PYOBJ
static void emit_get_stack_pointer_to_reg_for_pop(emit_t *emit, int reg_dest, int n_pop) {
ASM_MOV_LOCAL_ADDR_TO_REG(emit->stack_start + emit->stack_size - 1, reg_dest);
adjust_stack(emit, -n_pop);
}
// vtype of all n_push objects is VTYPE_PYOBJ
static void emit_get_stack_pointer_to_reg_for_push(emit_t *emit, int reg_dest, int n_push) {
for (int i = 0; i < n_push; i++) {
emit->stack_vtype[emit->stack_size + i] = VTYPE_PYOBJ;
}
ASM_MOV_LOCAL_ADDR_TO_REG(emit->stack_start + emit->stack_size + n_push - 1, reg_dest);
adjust_stack(emit, n_push);
}
static void emit_call(emit_t *emit, rt_fun_kind_t fun_kind, void *fun) {
#if defined(N_X64)
asm_x64_call_ind(emit->as, fun, REG_RAX);
#elif defined(N_THUMB)
asm_thumb_bl_ind(emit->as, rt_fun_table[fun_kind], fun_kind, REG_R3);
#endif
}
static void emit_call_with_imm_arg(emit_t *emit, rt_fun_kind_t fun_kind, void *fun, machine_int_t arg_val, int arg_reg) {
ASM_MOV_IMM_TO_REG(arg_val, arg_reg);
emit_call(emit, fun_kind, fun);
}
static void emit_native_load_id(emit_t *emit, qstr qstr) {
// check for built-ins
if (strcmp(qstr_str(qstr), "v_int") == 0) {
emit_pre(emit);
//emit_post_push_blank(emit, VTYPE_BUILTIN_V_INT);
// not a built-in, so do usual thing
} else {
emit_common_load_id(emit, &EXPORT_FUN(method_table), emit->scope, qstr);
}
}
static void emit_native_store_id(emit_t *emit, qstr qstr) {
// TODO check for built-ins and disallow
emit_common_store_id(emit, &EXPORT_FUN(method_table), emit->scope, qstr);
}
static void emit_native_delete_id(emit_t *emit, qstr qstr) {
// TODO check for built-ins and disallow
emit_common_delete_id(emit, &EXPORT_FUN(method_table), emit->scope, qstr);
}
static void emit_native_label_assign(emit_t *emit, int l) {
#if defined(N_X64)
asm_x64_label_assign(emit->as, l);
#elif defined(N_THUMB)
asm_thumb_label_assign(emit->as, l);
#endif
}
static void emit_native_import_name(emit_t *emit, qstr qstr) {
// not implemented
assert(0);
}
static void emit_native_import_from(emit_t *emit, qstr qstr) {
// not implemented
assert(0);
}
static void emit_native_import_star(emit_t *emit) {
// not implemented
assert(0);
}
static void emit_native_load_const_tok(emit_t *emit, py_token_kind_t tok) {
emit_pre(emit);
int vtype;
machine_uint_t val;
if (emit->do_viper_types) {
switch (tok) {
case PY_TOKEN_KW_NONE: vtype = VTYPE_PTR_NONE; val = 0; break;
case PY_TOKEN_KW_FALSE: vtype = VTYPE_BOOL; val = 0; break;
case PY_TOKEN_KW_TRUE: vtype = VTYPE_BOOL; val = 1; break;
default: assert(0); vtype = 0; val = 0; // shouldn't happen
}
} else {
vtype = VTYPE_PYOBJ;
switch (tok) {
case PY_TOKEN_KW_NONE: val = (machine_uint_t)py_const_none; break;
case PY_TOKEN_KW_FALSE: val = (machine_uint_t)py_const_false; break;
case PY_TOKEN_KW_TRUE: val = (machine_uint_t)py_const_true; break;
default: assert(0); vtype = 0; val = 0; // shouldn't happen
}
}
emit_post_push_imm(emit, vtype, val);
}
static void emit_native_load_const_small_int(emit_t *emit, int arg) {
emit_pre(emit);
if (emit->do_viper_types) {
emit_post_push_imm(emit, VTYPE_INT, arg);
} else {
emit_post_push_imm(emit, VTYPE_PYOBJ, (arg << 1) | 1);
}
}
static void emit_native_load_const_int(emit_t *emit, qstr qstr) {
// not implemented
// load integer, check fits in 32 bits
assert(0);
}
static void emit_native_load_const_dec(emit_t *emit, qstr qstr) {
// not supported for viper (although, could support floats in future)
assert(0);
}
static void emit_native_load_const_id(emit_t *emit, qstr qstr) {
// not supported for viper?
assert(0);
}
static void emit_native_load_const_str(emit_t *emit, qstr qstr, bool bytes) {
emit_pre(emit);
if (emit->do_viper_types) {
// not implemented properly
// load a pointer to the asciiz string?
assert(0);