// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// A Disassembler object is used to disassemble a block of code instruction by
+// instruction. The default implementation of the NameConverter object can be
+// overriden to modify register names or to do symbol lookup on addresses.
+//
+// The example below will disassemble a block of code and print it to stdout.
+//
+// NameConverter converter;
+// Disassembler d(converter);
+// for (byte* pc = begin; pc < end;) {
+// char buffer[128];
+// buffer[0] = '\0';
+// byte* prev_pc = pc;
+// pc += d.InstructionDecode(buffer, sizeof buffer, pc);
+// printf("%p %08x %s\n",
+// prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer);
+// }
+//
+// The Disassembler class also has a convenience method to disassemble a block
+// of code into a FILE*, meaning that the above functionality could also be
+// achieved by just calling Disassembler::Disassemble(stdout, begin, end);
+
+
#include <assert.h>
#include <stdio.h>
#include <stdarg.h>
#include "macro-assembler.h"
#include "platform.h"
+
namespace assembler { namespace arm {
namespace v8i = v8::internal;
int InstructionDecode(byte* instruction);
private:
- const disasm::NameConverter& converter_;
- v8::internal::Vector<char> out_buffer_;
- int out_buffer_pos_;
-
+ // Bottleneck functions to print into the out_buffer.
void PrintChar(const char ch);
void Print(const char* str);
+ // Printing of common values.
void PrintRegister(int reg);
void PrintCondition(Instr* instr);
void PrintShiftRm(Instr* instr);
void PrintShiftImm(Instr* instr);
+ void PrintPU(Instr* instr);
+ void PrintSoftwareInterrupt(SoftwareInterruptCodes swi);
+ // Handle formatting of instructions and their options.
+ int FormatRegister(Instr* instr, const char* option);
int FormatOption(Instr* instr, const char* option);
void Format(Instr* instr, const char* format);
void Unknown(Instr* instr);
- void DecodeType0(Instr* instr);
- void DecodeType1(Instr* instr);
+ // Each of these functions decodes one particular instruction type, a 3-bit
+ // field in the instruction encoding.
+ // Types 0 and 1 are combined as they are largely the same except for the way
+ // they interpret the shifter operand.
+ void DecodeType01(Instr* instr);
void DecodeType2(Instr* instr);
void DecodeType3(Instr* instr);
void DecodeType4(Instr* instr);
void DecodeType5(Instr* instr);
void DecodeType6(Instr* instr);
void DecodeType7(Instr* instr);
+
+ const disasm::NameConverter& converter_;
+ v8::internal::Vector<char> out_buffer_;
+ int out_buffer_pos_;
+
+ DISALLOW_COPY_AND_ASSIGN(Decoder);
};
+// Support for assertions in the Decoder formatting functions.
+#define STRING_STARTS_WITH(string, compare_string) \
+ (strncmp(string, compare_string, strlen(compare_string)) == 0)
+
+
// Append the ch to the output buffer.
void Decoder::PrintChar(const char ch) {
out_buffer_[out_buffer_pos_++] = ch;
// Append the str to the output buffer.
void Decoder::Print(const char* str) {
char cur = *str++;
- while (cur != 0 && (out_buffer_pos_ < (out_buffer_.length()-1))) {
+ while (cur != '\0' && (out_buffer_pos_ < (out_buffer_.length() - 1))) {
PrintChar(cur);
cur = *str++;
}
}
-static const char* cond_names[16] = {
-"eq", "ne", "cs" , "cc" , "mi" , "pl" , "vs" , "vc" ,
-"hi", "ls", "ge", "lt", "gt", "le", "", "invalid",
+// These condition names are defined in a way to match the native disassembler
+// formatting. See for example the command "objdump -d <binary file>".
+static const char* cond_names[max_condition] = {
+ "eq", "ne", "cs" , "cc" , "mi" , "pl" , "vs" , "vc" ,
+ "hi", "ls", "ge", "lt", "gt", "le", "", "invalid",
};
}
-static const char* shift_names[4] = {
+// These shift names are defined in a way to match the native disassembler
+// formatting. See for example the command "objdump -d <binary file>".
+static const char* shift_names[max_shift] = {
"lsl", "lsr", "asr", "ror"
};
}
+// Print PU formatting to reduce complexity of FormatOption.
+void Decoder::PrintPU(Instr* instr) {
+ switch (instr->PUField()) {
+ case 0: {
+ Print("da");
+ break;
+ }
+ case 1: {
+ Print("ia");
+ break;
+ }
+ case 2: {
+ Print("db");
+ break;
+ }
+ case 3: {
+ Print("ib");
+ break;
+ }
+ default: {
+ UNREACHABLE();
+ break;
+ }
+ }
+}
+
+
+// Print SoftwareInterrupt codes. Factoring this out reduces the complexity of
+// the FormatOption method.
+void Decoder::PrintSoftwareInterrupt(SoftwareInterruptCodes swi) {
+ switch (swi) {
+ case call_rt_r5:
+ Print("call_rt_r5");
+ return;
+ case call_rt_r2:
+ Print("call_rt_r2");
+ return;
+ case break_point:
+ Print("break_point");
+ return;
+ default:
+ out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_,
+ "%d",
+ swi);
+ return;
+ }
+}
+
+
+// Handle all register based formatting in this function to reduce the
+// complexity of FormatOption.
+int Decoder::FormatRegister(Instr* instr, const char* format) {
+ ASSERT(format[0] == 'r');
+ if (format[1] == 'n') { // 'rn: Rn register
+ int reg = instr->RnField();
+ PrintRegister(reg);
+ return 2;
+ } else if (format[1] == 'd') { // 'rd: Rd register
+ int reg = instr->RdField();
+ PrintRegister(reg);
+ return 2;
+ } else if (format[1] == 's') { // 'rs: Rs register
+ int reg = instr->RsField();
+ PrintRegister(reg);
+ return 2;
+ } else if (format[1] == 'm') { // 'rm: Rm register
+ int reg = instr->RmField();
+ PrintRegister(reg);
+ return 2;
+ } else if (format[1] == 'l') {
+ // 'rlist: register list for load and store multiple instructions
+ ASSERT(STRING_STARTS_WITH(format, "rlist"));
+ int rlist = instr->RlistField();
+ int reg = 0;
+ Print("{");
+ // Print register list in ascending order, by scanning the bit mask.
+ while (rlist != 0) {
+ if ((rlist & 1) != 0) {
+ PrintRegister(reg);
+ if ((rlist >> 1) != 0) {
+ Print(", ");
+ }
+ }
+ reg++;
+ rlist >>= 1;
+ }
+ Print("}");
+ return 5;
+ }
+ UNREACHABLE();
+ return -1;
+}
+
+
// FormatOption takes a formatting string and interprets it based on
// the current instructions. The format string points to the first
// character of the option string (the option escape has already been
Print("la");
}
return 1;
- break;
}
case 'b': { // 'b: byte loads or stores
if (instr->HasB()) {
Print("b");
}
return 1;
- break;
}
case 'c': { // 'cond: conditional execution
- ASSERT((format[1] == 'o') && (format[2] == 'n') && (format[3] =='d'));
+ ASSERT(STRING_STARTS_WITH(format, "cond"));
PrintCondition(instr);
return 4;
- break;
}
case 'h': { // 'h: halfword operation for extra loads and stores
if (instr->HasH()) {
Print("b");
}
return 1;
- break;
- }
- case 'i': { // 'imm: immediate value for data processing instructions
- ASSERT((format[1] == 'm') && (format[2] == 'm'));
- PrintShiftImm(instr);
- return 3;
- break;
}
case 'l': { // 'l: branch and link
if (instr->HasLink()) {
Print("l");
}
return 1;
- break;
}
- case 'm': { // 'msg: for simulator break instructions
- if (format[1] == 'e') {
- ASSERT((format[2] == 'm') && (format[3] == 'o') && (format[4] == 'p'));
+ case 'm': {
+ if (format[1] == 'e') { // 'memop: load/store instructions
+ ASSERT(STRING_STARTS_WITH(format, "memop"));
if (instr->HasL()) {
Print("ldr");
} else {
Print("str");
}
return 5;
- } else {
- ASSERT(format[1] == 's' && format[2] == 'g');
- byte* str =
- reinterpret_cast<byte*>(instr->InstructionBits() & 0x0fffffff);
- out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_,
- "%s", converter_.NameInCode(str));
- return 3;
}
- break;
+ // 'msg: for simulator break instructions
+ ASSERT(STRING_STARTS_WITH(format, "msg"));
+ byte* str =
+ reinterpret_cast<byte*>(instr->InstructionBits() & 0x0fffffff);
+ out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_,
+ "%s", converter_.NameInCode(str));
+ return 3;
}
case 'o': {
- ASSERT(format[1] == 'f' && format[2] == 'f');
if (format[3] == '1') {
// 'off12: 12-bit offset for load and store instructions
- ASSERT(format[4] == '2');
+ ASSERT(STRING_STARTS_WITH(format, "off12"));
out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%d", instr->Offset12Field());
return 5;
- } else {
- // 'off8: 8-bit offset for extra load and store instructions
- ASSERT(format[3] == '8');
- int offs8 = (instr->ImmedHField() << 4) | instr->ImmedLField();
- out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_,
- "%d", offs8);
- return 4;
}
- break;
+ // 'off8: 8-bit offset for extra load and store instructions
+ ASSERT(STRING_STARTS_WITH(format, "off8"));
+ int offs8 = (instr->ImmedHField() << 4) | instr->ImmedLField();
+ out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_,
+ "%d", offs8);
+ return 4;
}
case 'p': { // 'pu: P and U bits for load and store instructions
- ASSERT(format[1] == 'u');
- switch (instr->PUField()) {
- case 0: {
- Print("da");
- break;
- }
- case 1: {
- Print("ia");
- break;
- }
- case 2: {
- Print("db");
- break;
- }
- case 3: {
- Print("ib");
- break;
- }
- default: {
- UNREACHABLE();
- break;
- }
- }
+ ASSERT(STRING_STARTS_WITH(format, "pu"));
+ PrintPU(instr);
return 2;
- break;
}
case 'r': {
- if (format[1] == 'n') { // 'rn: Rn register
- int reg = instr->RnField();
- PrintRegister(reg);
- return 2;
- } else if (format[1] == 'd') { // 'rd: Rd register
- int reg = instr->RdField();
- PrintRegister(reg);
- return 2;
- } else if (format[1] == 's') { // 'rs: Rs register
- int reg = instr->RsField();
- PrintRegister(reg);
- return 2;
- } else if (format[1] == 'm') { // 'rm: Rm register
- int reg = instr->RmField();
- PrintRegister(reg);
- return 2;
- } else if (format[1] == 'l') {
- // 'rlist: register list for load and store multiple instructions
- ASSERT(format[2] == 'i' && format[3] == 's' && format[4] == 't');
- int rlist = instr->RlistField();
- int reg = 0;
- Print("{");
- while (rlist != 0) {
- if ((rlist & 1) != 0) {
- PrintRegister(reg);
- if ((rlist >> 1) != 0) {
- Print(", ");
- }
- }
- reg++;
- rlist >>= 1;
- }
- Print("}");
- return 5;
- } else {
- UNREACHABLE();
- }
- UNREACHABLE();
- return -1;
- break;
+ return FormatRegister(instr, format);
}
case 's': {
- if (format[1] == 'h') { // 'shift_rm: register shift operands
- ASSERT(format[2] == 'i' && format[3] == 'f' && format[4] == 't'
- && format[5] == '_' && format[6] == 'r' && format[7] == 'm');
- PrintShiftRm(instr);
- return 8;
- } else if (format[1] == 'w') {
- ASSERT(format[2] == 'i');
- SoftwareInterruptCodes swi = instr->SwiField();
- switch (swi) {
- case call_rt_r5:
- Print("call_rt_r5");
- break;
- case call_rt_r2:
- Print("call_rt_r2");
- break;
- case break_point:
- Print("break_point");
- break;
- default:
- out_buffer_pos_ += v8i::OS::SNPrintF(
- out_buffer_ + out_buffer_pos_,
- "%d",
- swi);
- break;
+ if (format[1] == 'h') { // 'shift_op or 'shift_rm
+ if (format[6] == 'o') { // 'shift_op
+ ASSERT(STRING_STARTS_WITH(format, "shift_op"));
+ if (instr->TypeField() == 0) {
+ PrintShiftRm(instr);
+ } else {
+ ASSERT(instr->TypeField() == 1);
+ PrintShiftImm(instr);
+ }
+ return 8;
+ } else { // 'shift_rm
+ ASSERT(STRING_STARTS_WITH(format, "shift_rm"));
+ PrintShiftRm(instr);
+ return 8;
}
+ } else if (format[1] == 'w') { // 'swi
+ ASSERT(STRING_STARTS_WITH(format, "swi"));
+ PrintSoftwareInterrupt(instr->SwiField());
return 3;
} else if (format[1] == 'i') { // 'sign: signed extra loads and stores
- ASSERT(format[2] == 'g' && format[3] == 'n');
+ ASSERT(STRING_STARTS_WITH(format, "sign"));
if (instr->HasSign()) {
Print("s");
}
return 4;
- break;
- } else { // 's: S field of data processing instructions
- if (instr->HasS()) {
- Print("s");
- }
- return 1;
}
- break;
+ // 's: S field of data processing instructions
+ if (instr->HasS()) {
+ Print("s");
+ }
+ return 1;
}
case 't': { // 'target: target of branch instructions
- ASSERT(format[1] == 'a' && format[2] == 'r' && format[3] == 'g'
- && format[4] == 'e' && format[5] == 't');
+ ASSERT(STRING_STARTS_WITH(format, "target"));
int off = (instr->SImmed24Field() << 2) + 8;
out_buffer_pos_ += v8i::OS::SNPrintF(
out_buffer_ + out_buffer_pos_,
off,
converter_.NameOfAddress(reinterpret_cast<byte*>(instr) + off));
return 6;
- break;
}
case 'u': { // 'u: signed or unsigned multiplies
if (instr->Bit(22) == 0) {
Print("s");
}
return 1;
- break;
}
case 'w': { // 'w: W field of load and store instructions
if (instr->HasW()) {
Print("!");
}
return 1;
- break;
}
default: {
UNREACHABLE();
}
-void Decoder::DecodeType0(Instr* instr) {
- if (instr->IsSpecialType0()) {
+void Decoder::DecodeType01(Instr* instr) {
+ int type = instr->TypeField();
+ if ((type == 0) && instr->IsSpecialType0()) {
// multiply instruction or extra loads and stores
if (instr->Bits(7, 4) == 9) {
if (instr->Bit(24) == 0) {
} else {
switch (instr->OpcodeField()) {
case AND: {
- Format(instr, "and'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "and'cond's 'rd, 'rn, 'shift_op");
break;
}
case EOR: {
- Format(instr, "eor'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "eor'cond's 'rd, 'rn, 'shift_op");
break;
}
case SUB: {
- Format(instr, "sub'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "sub'cond's 'rd, 'rn, 'shift_op");
break;
}
case RSB: {
- Format(instr, "rsb'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "rsb'cond's 'rd, 'rn, 'shift_op");
break;
}
case ADD: {
- Format(instr, "add'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "add'cond's 'rd, 'rn, 'shift_op");
break;
}
case ADC: {
- Format(instr, "adc'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "adc'cond's 'rd, 'rn, 'shift_op");
break;
}
case SBC: {
- Format(instr, "sbc'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "sbc'cond's 'rd, 'rn, 'shift_op");
break;
}
case RSC: {
- Format(instr, "rsc'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "rsc'cond's 'rd, 'rn, 'shift_op");
break;
}
case TST: {
if (instr->HasS()) {
- Format(instr, "tst'cond 'rn, 'shift_rm");
+ Format(instr, "tst'cond 'rn, 'shift_op");
} else {
Unknown(instr); // not used by V8
- return;
}
break;
}
case TEQ: {
if (instr->HasS()) {
- Format(instr, "teq'cond 'rn, 'shift_rm");
+ Format(instr, "teq'cond 'rn, 'shift_op");
} else {
Unknown(instr); // not used by V8
- return;
}
break;
}
case CMP: {
if (instr->HasS()) {
- Format(instr, "cmp'cond 'rn, 'shift_rm");
+ Format(instr, "cmp'cond 'rn, 'shift_op");
} else {
Unknown(instr); // not used by V8
- return;
}
break;
}
case CMN: {
if (instr->HasS()) {
- Format(instr, "cmn'cond 'rn, 'shift_rm");
+ Format(instr, "cmn'cond 'rn, 'shift_op");
} else {
Unknown(instr); // not used by V8
- return;
}
break;
}
case ORR: {
- Format(instr, "orr'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "orr'cond's 'rd, 'rn, 'shift_op");
break;
}
case MOV: {
- Format(instr, "mov'cond's 'rd, 'shift_rm");
+ Format(instr, "mov'cond's 'rd, 'shift_op");
break;
}
case BIC: {
- Format(instr, "bic'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "bic'cond's 'rd, 'rn, 'shift_op");
break;
}
case MVN: {
- Format(instr, "mvn'cond's 'rd, 'shift_rm");
+ Format(instr, "mvn'cond's 'rd, 'shift_op");
break;
}
default: {
}
-void Decoder::DecodeType1(Instr* instr) {
- switch (instr->OpcodeField()) {
- case AND: {
- Format(instr, "and'cond's 'rd, 'rn, 'imm");
- break;
- }
- case EOR: {
- Format(instr, "eor'cond's 'rd, 'rn, 'imm");
- break;
- }
- case SUB: {
- Format(instr, "sub'cond's 'rd, 'rn, 'imm");
- break;
- }
- case RSB: {
- Format(instr, "rsb'cond's 'rd, 'rn, 'imm");
- break;
- }
- case ADD: {
- Format(instr, "add'cond's 'rd, 'rn, 'imm");
- break;
- }
- case ADC: {
- Format(instr, "adc'cond's 'rd, 'rn, 'imm");
- break;
- }
- case SBC: {
- Format(instr, "sbc'cond's 'rd, 'rn, 'imm");
- break;
- }
- case RSC: {
- Format(instr, "rsc'cond's 'rd, 'rn, 'imm");
- break;
- }
- case TST: {
- if (instr->HasS()) {
- Format(instr, "tst'cond 'rn, 'imm");
- } else {
- Unknown(instr); // not used by V8
- return;
- }
- break;
- }
- case TEQ: {
- if (instr->HasS()) {
- Format(instr, "teq'cond 'rn, 'imm");
- } else {
- Unknown(instr); // not used by V8
- return;
- }
- break;
- }
- case CMP: {
- if (instr->HasS()) {
- Format(instr, "cmp'cond 'rn, 'imm");
- } else {
- Unknown(instr); // not used by V8
- return;
- }
- break;
- }
- case CMN: {
- if (instr->HasS()) {
- Format(instr, "cmn'cond 'rn, 'imm");
- } else {
- Unknown(instr); // not used by V8
- return;
- }
- break;
- }
- case ORR: {
- Format(instr, "orr'cond's 'rd, 'rn, 'imm");
- break;
- }
- case MOV: {
- Format(instr, "mov'cond's 'rd, 'imm");
- break;
- }
- case BIC: {
- Format(instr, "bic'cond's 'rd, 'rn, 'imm");
- break;
- }
- case MVN: {
- Format(instr, "mvn'cond's 'rd, 'imm");
- break;
- }
- default: {
- // The Opcode field is a 4-bit field.
- UNREACHABLE();
- break;
- }
- }
-}
-
-
void Decoder::DecodeType2(Instr* instr) {
switch (instr->PUField()) {
case 0: {
if (instr->HasW()) {
Unknown(instr); // not used in V8
- return;
}
Format(instr, "'memop'cond'b 'rd, ['rn], #-'off12");
break;
case 1: {
if (instr->HasW()) {
Unknown(instr); // not used in V8
- return;
}
Format(instr, "'memop'cond'b 'rd, ['rn], #+'off12");
break;
return Instr::kInstrSize;
}
switch (instr->TypeField()) {
- case 0: {
- DecodeType0(instr);
- break;
- }
+ case 0:
case 1: {
- DecodeType1(instr);
+ DecodeType01(instr);
break;
}
case 2: {
namespace disasm {
-static const char* reg_names[16] = {
- "r0", "r1", "r2" , "r3" , "r4" , "r5" , "r6" , "r7" ,
+namespace v8i = v8::internal;
+
+
+static const int kMaxRegisters = 16;
+
+// These register names are defined in a way to match the native disassembler
+// formatting. See for example the command "objdump -d <binary file>".
+static const char* reg_names[kMaxRegisters] = {
+ "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
"r8", "r9", "sl", "fp", "ip", "sp", "lr", "pc",
};
const char* NameConverter::NameOfCPURegister(int reg) const {
const char* result;
- if ((0 <= reg) && (reg < 16)) {
+ if ((0 <= reg) && (reg < kMaxRegisters)) {
result = reg_names[reg];
} else {
result = "noreg";
//------------------------------------------------------------------------------
-static NameConverter defaultConverter;
-
-Disassembler::Disassembler() : converter_(defaultConverter) {}
-
-
Disassembler::Disassembler(const NameConverter& converter)
: converter_(converter) {}
void Disassembler::Disassemble(FILE* f, byte* begin, byte* end) {
- Disassembler d;
+ NameConverter converter;
+ Disassembler d(converter);
for (byte* pc = begin; pc < end;) {
v8::internal::EmbeddedVector<char, 128> buffer;
buffer[0] = '\0';
projects / platform / upstream / v8.git / commitdiff