1//===-- ABISysV_arc.cpp ---------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "ABISysV_arc.h"
10
11// C Includes
12// C++ Includes
13#include <array>
14#include <limits>
15#include <type_traits>
16
17// Other libraries and framework includes
18#include "llvm/IR/DerivedTypes.h"
19#include "llvm/Support/MathExtras.h"
20#include "llvm/TargetParser/Triple.h"
21
22#include "lldb/Core/Module.h"
23#include "lldb/Core/PluginManager.h"
24#include "lldb/Core/Value.h"
25#include "lldb/Core/ValueObjectConstResult.h"
26#include "lldb/Core/ValueObjectMemory.h"
27#include "lldb/Core/ValueObjectRegister.h"
28#include "lldb/Symbol/UnwindPlan.h"
29#include "lldb/Target/Process.h"
30#include "lldb/Target/RegisterContext.h"
31#include "lldb/Target/StackFrame.h"
32#include "lldb/Target/Target.h"
33#include "lldb/Target/Thread.h"
34#include "lldb/Utility/ConstString.h"
35#include "lldb/Utility/RegisterValue.h"
36#include "lldb/Utility/Status.h"
37
38#define DEFINE_REG_NAME(reg_num) ConstString(#reg_num).GetCString()
39#define DEFINE_REG_NAME_STR(reg_name) ConstString(reg_name).GetCString()
40
41// The ABI is not a source of such information as size, offset, encoding, etc.
42// of a register. Just provides correct dwarf and eh_frame numbers.
43
44#define DEFINE_GENERIC_REGISTER_STUB(dwarf_num, str_name, generic_num) \
45 { \
46 DEFINE_REG_NAME(dwarf_num), DEFINE_REG_NAME_STR(str_name), \
47 0, 0, eEncodingInvalid, eFormatDefault, \
48 { dwarf_num, dwarf_num, generic_num, LLDB_INVALID_REGNUM, dwarf_num }, \
49 nullptr, nullptr, nullptr, \
50 }
51
52#define DEFINE_REGISTER_STUB(dwarf_num, str_name) \
53 DEFINE_GENERIC_REGISTER_STUB(dwarf_num, str_name, LLDB_INVALID_REGNUM)
54
55using namespace lldb;
56using namespace lldb_private;
57
58LLDB_PLUGIN_DEFINE_ADV(ABISysV_arc, ABIARC)
59
60namespace {
61namespace dwarf {
62enum regnums {
63 r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16,
64 r17, r18, r19, r20, r21, r22, r23, r24, r25, r26,
65 r27, fp = r27, r28, sp = r28, r29, r30, r31, blink = r31,
66 r32, r33, r34, r35, r36, r37, r38, r39, r40, r41, r42, r43, r44, r45, r46,
67 r47, r48, r49, r50, r51, r52, r53, r54, r55, r56, r57, r58, r59, r60,
68 /*reserved,*/ /*limm indicator,*/ r63 = 63, pc = 70, status32 = 74
69};
70
71static const std::array<RegisterInfo, 64> g_register_infos = { ._M_elems: {
72 DEFINE_GENERIC_REGISTER_STUB(r0, nullptr, LLDB_REGNUM_GENERIC_ARG1),
73 DEFINE_GENERIC_REGISTER_STUB(r1, nullptr, LLDB_REGNUM_GENERIC_ARG2),
74 DEFINE_GENERIC_REGISTER_STUB(r2, nullptr, LLDB_REGNUM_GENERIC_ARG3),
75 DEFINE_GENERIC_REGISTER_STUB(r3, nullptr, LLDB_REGNUM_GENERIC_ARG4),
76 DEFINE_GENERIC_REGISTER_STUB(r4, nullptr, LLDB_REGNUM_GENERIC_ARG5),
77 DEFINE_GENERIC_REGISTER_STUB(r5, nullptr, LLDB_REGNUM_GENERIC_ARG6),
78 DEFINE_GENERIC_REGISTER_STUB(r6, nullptr, LLDB_REGNUM_GENERIC_ARG7),
79 DEFINE_GENERIC_REGISTER_STUB(r7, nullptr, LLDB_REGNUM_GENERIC_ARG8),
80 DEFINE_REGISTER_STUB(r8, nullptr),
81 DEFINE_REGISTER_STUB(r9, nullptr),
82 DEFINE_REGISTER_STUB(r10, nullptr),
83 DEFINE_REGISTER_STUB(r11, nullptr),
84 DEFINE_REGISTER_STUB(r12, nullptr),
85 DEFINE_REGISTER_STUB(r13, nullptr),
86 DEFINE_REGISTER_STUB(r14, nullptr),
87 DEFINE_REGISTER_STUB(r15, nullptr),
88 DEFINE_REGISTER_STUB(r16, nullptr),
89 DEFINE_REGISTER_STUB(r17, nullptr),
90 DEFINE_REGISTER_STUB(r18, nullptr),
91 DEFINE_REGISTER_STUB(r19, nullptr),
92 DEFINE_REGISTER_STUB(r20, nullptr),
93 DEFINE_REGISTER_STUB(r21, nullptr),
94 DEFINE_REGISTER_STUB(r22, nullptr),
95 DEFINE_REGISTER_STUB(r23, nullptr),
96 DEFINE_REGISTER_STUB(r24, nullptr),
97 DEFINE_REGISTER_STUB(r25, nullptr),
98 DEFINE_REGISTER_STUB(r26, "gp"),
99 DEFINE_GENERIC_REGISTER_STUB(r27, "fp", LLDB_REGNUM_GENERIC_FP),
100 DEFINE_GENERIC_REGISTER_STUB(r28, "sp", LLDB_REGNUM_GENERIC_SP),
101 DEFINE_REGISTER_STUB(r29, "ilink"),
102 DEFINE_REGISTER_STUB(r30, nullptr),
103 DEFINE_GENERIC_REGISTER_STUB(r31, "blink", LLDB_REGNUM_GENERIC_RA),
104 DEFINE_REGISTER_STUB(r32, nullptr),
105 DEFINE_REGISTER_STUB(r33, nullptr),
106 DEFINE_REGISTER_STUB(r34, nullptr),
107 DEFINE_REGISTER_STUB(r35, nullptr),
108 DEFINE_REGISTER_STUB(r36, nullptr),
109 DEFINE_REGISTER_STUB(r37, nullptr),
110 DEFINE_REGISTER_STUB(r38, nullptr),
111 DEFINE_REGISTER_STUB(r39, nullptr),
112 DEFINE_REGISTER_STUB(r40, nullptr),
113 DEFINE_REGISTER_STUB(r41, nullptr),
114 DEFINE_REGISTER_STUB(r42, nullptr),
115 DEFINE_REGISTER_STUB(r43, nullptr),
116 DEFINE_REGISTER_STUB(r44, nullptr),
117 DEFINE_REGISTER_STUB(r45, nullptr),
118 DEFINE_REGISTER_STUB(r46, nullptr),
119 DEFINE_REGISTER_STUB(r47, nullptr),
120 DEFINE_REGISTER_STUB(r48, nullptr),
121 DEFINE_REGISTER_STUB(r49, nullptr),
122 DEFINE_REGISTER_STUB(r50, nullptr),
123 DEFINE_REGISTER_STUB(r51, nullptr),
124 DEFINE_REGISTER_STUB(r52, nullptr),
125 DEFINE_REGISTER_STUB(r53, nullptr),
126 DEFINE_REGISTER_STUB(r54, nullptr),
127 DEFINE_REGISTER_STUB(r55, nullptr),
128 DEFINE_REGISTER_STUB(r56, nullptr),
129 DEFINE_REGISTER_STUB(r57, nullptr),
130 DEFINE_REGISTER_STUB(r58, "accl"),
131 DEFINE_REGISTER_STUB(r59, "acch"),
132 DEFINE_REGISTER_STUB(r60, "lp_count"),
133 DEFINE_REGISTER_STUB(r63, "pcl"),
134 DEFINE_GENERIC_REGISTER_STUB(pc, nullptr, LLDB_REGNUM_GENERIC_PC),
135 DEFINE_GENERIC_REGISTER_STUB(status32, nullptr, LLDB_REGNUM_GENERIC_FLAGS)} };
136} // namespace dwarf
137} // namespace
138
139const RegisterInfo *ABISysV_arc::GetRegisterInfoArray(uint32_t &count) {
140 count = dwarf::g_register_infos.size();
141 return dwarf::g_register_infos.data();
142}
143
144size_t ABISysV_arc::GetRedZoneSize() const { return 0; }
145
146bool ABISysV_arc::IsRegisterFileReduced(RegisterContext &reg_ctx) const {
147 if (!m_is_reg_file_reduced) {
148 const auto *const rf_build_reg = reg_ctx.GetRegisterInfoByName(reg_name: "rf_build");
149
150 const auto reg_value = reg_ctx.ReadRegisterAsUnsigned(reg_info: rf_build_reg,
151 /*fail_value*/ 0);
152 // RF_BUILD "Number of Entries" bit.
153 const uint32_t rf_entries_bit = 1U << 9U;
154 m_is_reg_file_reduced = (reg_value & rf_entries_bit) != 0;
155 }
156
157 return m_is_reg_file_reduced.value_or(u: false);
158}
159
160//------------------------------------------------------------------
161// Static Functions
162//------------------------------------------------------------------
163
164ABISP ABISysV_arc::CreateInstance(ProcessSP process_sp, const ArchSpec &arch) {
165 return llvm::Triple::arc == arch.GetTriple().getArch() ?
166 ABISP(new ABISysV_arc(std::move(process_sp), MakeMCRegisterInfo(arch))) :
167 ABISP();
168}
169
170static const size_t word_size = 4U;
171static const size_t reg_size = word_size;
172
173static inline size_t AugmentArgSize(size_t size_in_bytes) {
174 return llvm::alignTo(Value: size_in_bytes, Align: word_size);
175}
176
177static size_t
178TotalArgsSizeInWords(const llvm::ArrayRef<ABI::CallArgument> &args) {
179 size_t total_size = 0;
180 for (const auto &arg : args)
181 total_size +=
182 (ABI::CallArgument::TargetValue == arg.type ? AugmentArgSize(size_in_bytes: arg.size)
183 : reg_size) /
184 word_size;
185
186 return total_size;
187}
188
189bool ABISysV_arc::PrepareTrivialCall(Thread &thread, addr_t sp,
190 addr_t func_addr, addr_t return_addr,
191 llvm::ArrayRef<addr_t> args) const {
192 // We don't use the traditional trivial call specialized for jit.
193 return false;
194}
195
196bool ABISysV_arc::PrepareTrivialCall(Thread &thread, addr_t sp, addr_t pc,
197 addr_t ra, llvm::Type &prototype,
198 llvm::ArrayRef<ABI::CallArgument> args) const {
199 auto reg_ctx = thread.GetRegisterContext();
200 if (!reg_ctx)
201 return false;
202
203 uint32_t pc_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(
204 kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
205 if (pc_reg == LLDB_INVALID_REGNUM)
206 return false;
207
208 uint32_t ra_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(
209 kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA);
210 if (ra_reg == LLDB_INVALID_REGNUM)
211 return false;
212
213 uint32_t sp_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(
214 kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
215 if (sp_reg == LLDB_INVALID_REGNUM)
216 return false;
217
218 Status error;
219 ProcessSP process = thread.GetProcess();
220 if (!process)
221 return false;
222
223 // Push host data onto target.
224 for (const auto &arg : args) {
225 // Skip over target values.
226 if (arg.type == ABI::CallArgument::TargetValue)
227 continue;
228
229 // Create space on the stack for this data 4-byte aligned.
230 sp -= AugmentArgSize(size_in_bytes: arg.size);
231
232 if (process->WriteMemory(vm_addr: sp, buf: arg.data_up.get(), size: arg.size, error) < arg.size
233 || error.Fail())
234 return false;
235
236 // Update the argument with the target pointer.
237 *const_cast<addr_t *>(&arg.value) = sp;
238 }
239
240 // Make sure number of parameters matches prototype.
241 assert(!prototype.isFunctionVarArg());
242 assert(prototype.getFunctionNumParams() == args.size());
243
244 const size_t regs_for_args_count = IsRegisterFileReduced(reg_ctx&: *reg_ctx) ? 4U : 8U;
245
246 // Number of arguments passed on stack.
247 auto args_size = TotalArgsSizeInWords(args);
248 auto on_stack =
249 args_size <= regs_for_args_count ? 0 : args_size - regs_for_args_count;
250 auto offset = on_stack * word_size;
251
252 uint8_t reg_value[reg_size];
253 size_t reg_index = LLDB_REGNUM_GENERIC_ARG1;
254
255 for (const auto &arg : args) {
256 auto value = reinterpret_cast<const uint8_t *>(&arg.value);
257 auto size =
258 ABI::CallArgument::TargetValue == arg.type ? arg.size : reg_size;
259
260 // Pass arguments via registers.
261 while (size > 0 && reg_index < regs_for_args_count) {
262 size_t byte_index = 0;
263 auto end = size < reg_size ? size : reg_size;
264
265 while (byte_index < end) {
266 reg_value[byte_index++] = *(value++);
267 --size;
268 }
269
270 while (byte_index < reg_size) {
271 reg_value[byte_index++] = 0;
272 }
273
274 RegisterValue reg_val_obj(llvm::ArrayRef(reg_value, reg_size),
275 eByteOrderLittle);
276 if (!reg_ctx->WriteRegister(
277 reg_info: reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric, reg_num: reg_index),
278 reg_value: reg_val_obj))
279 return false;
280
281 // NOTE: It's unsafe to iterate through LLDB_REGNUM_GENERICs.
282 ++reg_index;
283 }
284
285 if (reg_index < regs_for_args_count || size == 0)
286 continue;
287
288 // Remaining arguments are passed on the stack.
289 if (process->WriteMemory(vm_addr: sp - offset, buf: value, size, error) < size ||
290 !error.Success())
291 return false;
292
293 offset -= AugmentArgSize(size_in_bytes: size);
294 }
295
296 // Set stack pointer immediately below arguments.
297 sp -= on_stack * word_size;
298
299 // Update registers with current function call state.
300 reg_ctx->WriteRegisterFromUnsigned(reg: pc_reg, uval: pc);
301 reg_ctx->WriteRegisterFromUnsigned(reg: ra_reg, uval: ra);
302 reg_ctx->WriteRegisterFromUnsigned(reg: sp_reg, uval: sp);
303
304 return true;
305}
306
307bool ABISysV_arc::GetArgumentValues(Thread &thread, ValueList &values) const {
308 return false;
309}
310
311Status ABISysV_arc::SetReturnValueObject(StackFrameSP &frame_sp,
312 ValueObjectSP &new_value_sp) {
313 Status result;
314 if (!new_value_sp) {
315 result.SetErrorString("Empty value object for return value.");
316 return result;
317 }
318
319 CompilerType compiler_type = new_value_sp->GetCompilerType();
320 if (!compiler_type) {
321 result.SetErrorString("Null clang type for return value.");
322 return result;
323 }
324
325 auto &reg_ctx = *frame_sp->GetThread()->GetRegisterContext();
326
327 bool is_signed = false;
328 if (!compiler_type.IsIntegerOrEnumerationType(is_signed) &&
329 !compiler_type.IsPointerType()) {
330 result.SetErrorString("We don't support returning other types at present");
331 return result;
332 }
333
334 DataExtractor data;
335 size_t num_bytes = new_value_sp->GetData(data, error&: result);
336
337 if (result.Fail()) {
338 result.SetErrorStringWithFormat(
339 "Couldn't convert return value to raw data: %s", result.AsCString());
340 return result;
341 }
342
343 if (num_bytes <= 2 * reg_size) {
344 offset_t offset = 0;
345 uint64_t raw_value = data.GetMaxU64(offset_ptr: &offset, byte_size: num_bytes);
346
347 auto reg_info =
348 reg_ctx.GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);
349 if (!reg_ctx.WriteRegisterFromUnsigned(reg_info, uval: raw_value)) {
350 result.SetErrorStringWithFormat("Couldn't write value to register %s",
351 reg_info->name);
352 return result;
353 }
354
355 if (num_bytes <= reg_size)
356 return result; // Successfully written.
357
358 raw_value >>= 32;
359 reg_info =
360 reg_ctx.GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2);
361 if (!reg_ctx.WriteRegisterFromUnsigned(reg_info, uval: raw_value)) {
362 result.SetErrorStringWithFormat("Couldn't write value to register %s",
363 reg_info->name);
364 }
365
366 return result;
367 }
368
369 result.SetErrorString(
370 "We don't support returning large integer values at present.");
371 return result;
372}
373
374template <typename T>
375static void SetInteger(Scalar &scalar, uint64_t raw_value, bool is_signed) {
376 raw_value &= std::numeric_limits<T>::max();
377 if (is_signed)
378 scalar = static_cast<typename std::make_signed<T>::type>(raw_value);
379 else
380 scalar = static_cast<T>(raw_value);
381}
382
383static bool SetSizedInteger(Scalar &scalar, uint64_t raw_value,
384 uint8_t size_in_bytes, bool is_signed) {
385 switch (size_in_bytes) {
386 default:
387 return false;
388
389 case sizeof(uint64_t):
390 SetInteger<uint64_t>(scalar, raw_value, is_signed);
391 break;
392
393 case sizeof(uint32_t):
394 SetInteger<uint32_t>(scalar, raw_value, is_signed);
395 break;
396
397 case sizeof(uint16_t):
398 SetInteger<uint16_t>(scalar, raw_value, is_signed);
399 break;
400
401 case sizeof(uint8_t):
402 SetInteger<uint8_t>(scalar, raw_value, is_signed);
403 break;
404 }
405
406 return true;
407}
408
409static bool SetSizedFloat(Scalar &scalar, uint64_t raw_value,
410 uint8_t size_in_bytes) {
411 switch (size_in_bytes) {
412 default:
413 return false;
414
415 case sizeof(uint64_t):
416 scalar = *reinterpret_cast<double *>(&raw_value);
417 break;
418
419 case sizeof(uint32_t):
420 scalar = *reinterpret_cast<float *>(&raw_value);
421 break;
422 }
423
424 return true;
425}
426
427static uint64_t ReadRawValue(const RegisterContextSP &reg_ctx,
428 uint8_t size_in_bytes) {
429 auto reg_info_r0 =
430 reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1);
431
432 // Extract the register context so we can read arguments from registers.
433 uint64_t raw_value =
434 reg_ctx->ReadRegisterAsUnsigned(reg_info: reg_info_r0, fail_value: 0) & UINT32_MAX;
435
436 if (sizeof(uint64_t) == size_in_bytes)
437 raw_value |= (reg_ctx->ReadRegisterAsUnsigned(
438 reg_info: reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric,
439 LLDB_REGNUM_GENERIC_ARG2), fail_value: 0) &
440 UINT64_MAX) << 32U;
441
442 return raw_value;
443}
444
445ValueObjectSP
446ABISysV_arc::GetReturnValueObjectSimple(Thread &thread,
447 CompilerType &compiler_type) const {
448 if (!compiler_type)
449 return ValueObjectSP();
450
451 auto reg_ctx = thread.GetRegisterContext();
452 if (!reg_ctx)
453 return ValueObjectSP();
454
455 Value value;
456 value.SetCompilerType(compiler_type);
457
458 const uint32_t type_flags = compiler_type.GetTypeInfo();
459 // Integer return type.
460 if (type_flags & eTypeIsInteger) {
461 const size_t byte_size = compiler_type.GetByteSize(exe_scope: &thread).value_or(u: 0);
462 auto raw_value = ReadRawValue(reg_ctx, size_in_bytes: byte_size);
463
464 const bool is_signed = (type_flags & eTypeIsSigned) != 0;
465 if (!SetSizedInteger(scalar&: value.GetScalar(), raw_value, size_in_bytes: byte_size, is_signed))
466 return ValueObjectSP();
467
468 value.SetValueType(Value::ValueType::Scalar);
469 }
470 // Pointer return type.
471 else if (type_flags & eTypeIsPointer) {
472 auto reg_info_r0 = reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric,
473 LLDB_REGNUM_GENERIC_ARG1);
474 value.GetScalar() = reg_ctx->ReadRegisterAsUnsigned(reg_info: reg_info_r0, fail_value: 0);
475
476 value.SetValueType(Value::ValueType::Scalar);
477 }
478 // Floating point return type.
479 else if (type_flags & eTypeIsFloat) {
480 uint32_t float_count = 0;
481 bool is_complex = false;
482
483 if (compiler_type.IsFloatingPointType(count&: float_count, is_complex) &&
484 1 == float_count && !is_complex) {
485 const size_t byte_size = compiler_type.GetByteSize(exe_scope: &thread).value_or(u: 0);
486 auto raw_value = ReadRawValue(reg_ctx, size_in_bytes: byte_size);
487
488 if (!SetSizedFloat(scalar&: value.GetScalar(), raw_value, size_in_bytes: byte_size))
489 return ValueObjectSP();
490 }
491 }
492 // Unsupported return type.
493 else
494 return ValueObjectSP();
495
496 return ValueObjectConstResult::Create(exe_scope: thread.GetStackFrameAtIndex(idx: 0).get(),
497 value, name: ConstString(""));
498}
499
500ValueObjectSP ABISysV_arc::GetReturnValueObjectImpl(
501 Thread &thread, CompilerType &return_compiler_type) const {
502 ValueObjectSP return_valobj_sp;
503
504 if (!return_compiler_type)
505 return return_valobj_sp;
506
507 ExecutionContext exe_ctx(thread.shared_from_this());
508 return GetReturnValueObjectSimple(thread, compiler_type&: return_compiler_type);
509}
510
511ValueObjectSP ABISysV_arc::GetReturnValueObjectImpl(Thread &thread,
512 llvm::Type &retType) const {
513 auto reg_ctx = thread.GetRegisterContext();
514 if (!reg_ctx)
515 return ValueObjectSP();
516
517 Value value;
518 // Void return type.
519 if (retType.isVoidTy()) {
520 value.GetScalar() = 0;
521 }
522 // Integer return type.
523 else if (retType.isIntegerTy()) {
524 size_t byte_size = retType.getPrimitiveSizeInBits();
525 if (1 != byte_size) // For boolean type.
526 byte_size /= CHAR_BIT;
527
528 auto raw_value = ReadRawValue(reg_ctx, size_in_bytes: byte_size);
529
530 const bool is_signed = false; // IR Type doesn't provide this info.
531 if (!SetSizedInteger(scalar&: value.GetScalar(), raw_value, size_in_bytes: byte_size, is_signed))
532 return ValueObjectSP();
533 }
534 // Pointer return type.
535 else if (retType.isPointerTy()) {
536 auto reg_info_r0 = reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric,
537 LLDB_REGNUM_GENERIC_ARG1);
538 value.GetScalar() = reg_ctx->ReadRegisterAsUnsigned(reg_info: reg_info_r0, fail_value: 0);
539 value.SetValueType(Value::ValueType::Scalar);
540 }
541 // Floating point return type.
542 else if (retType.isFloatingPointTy()) {
543 const size_t byte_size = retType.getPrimitiveSizeInBits() / CHAR_BIT;
544 auto raw_value = ReadRawValue(reg_ctx, size_in_bytes: byte_size);
545
546 if (!SetSizedFloat(scalar&: value.GetScalar(), raw_value, size_in_bytes: byte_size))
547 return ValueObjectSP();
548 }
549 // Unsupported return type.
550 else
551 return ValueObjectSP();
552
553 return ValueObjectConstResult::Create(exe_scope: thread.GetStackFrameAtIndex(idx: 0).get(),
554 value, name: ConstString(""));
555}
556
557bool ABISysV_arc::CreateFunctionEntryUnwindPlan(UnwindPlan &unwind_plan) {
558 unwind_plan.Clear();
559 unwind_plan.SetRegisterKind(eRegisterKindDWARF);
560
561 UnwindPlan::RowSP row(new UnwindPlan::Row);
562
563 // Our Call Frame Address is the stack pointer value.
564 row->GetCFAValue().SetIsRegisterPlusOffset(reg_num: dwarf::sp, offset: 0);
565
566 // The previous PC is in the BLINK.
567 row->SetRegisterLocationToRegister(reg_num: dwarf::pc, other_reg_num: dwarf::blink, can_replace: true);
568 unwind_plan.AppendRow(row_sp: row);
569
570 // All other registers are the same.
571 unwind_plan.SetSourceName("arc at-func-entry default");
572 unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
573
574 return true;
575}
576
577bool ABISysV_arc::CreateDefaultUnwindPlan(UnwindPlan &unwind_plan) {
578 return false;
579}
580
581bool ABISysV_arc::RegisterIsVolatile(const RegisterInfo *reg_info) {
582 if (nullptr == reg_info)
583 return false;
584
585 // Volatile registers are: r0..r12.
586 uint32_t regnum = reg_info->kinds[eRegisterKindDWARF];
587 if (regnum <= 12)
588 return true;
589
590 static const std::string ra_reg_name = "blink";
591 return ra_reg_name == reg_info->name;
592}
593
594void ABISysV_arc::Initialize() {
595 PluginManager::RegisterPlugin(name: GetPluginNameStatic(),
596 description: "System V ABI for ARC targets", create_callback: CreateInstance);
597}
598
599void ABISysV_arc::Terminate() {
600 PluginManager::UnregisterPlugin(create_callback: CreateInstance);
601}
602

source code of lldb/source/Plugins/ABI/ARC/ABISysV_arc.cpp