1//===-- ABISysV_s390x.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_s390x.h"
10
11#include "llvm/ADT/STLExtras.h"
12#include "llvm/TargetParser/Triple.h"
13
14#include "lldb/Core/Module.h"
15#include "lldb/Core/PluginManager.h"
16#include "lldb/Core/Value.h"
17#include "lldb/Core/ValueObjectConstResult.h"
18#include "lldb/Core/ValueObjectMemory.h"
19#include "lldb/Core/ValueObjectRegister.h"
20#include "lldb/Symbol/UnwindPlan.h"
21#include "lldb/Target/Process.h"
22#include "lldb/Target/RegisterContext.h"
23#include "lldb/Target/StackFrame.h"
24#include "lldb/Target/Target.h"
25#include "lldb/Target/Thread.h"
26#include "lldb/Utility/ConstString.h"
27#include "lldb/Utility/DataExtractor.h"
28#include "lldb/Utility/LLDBLog.h"
29#include "lldb/Utility/Log.h"
30#include "lldb/Utility/RegisterValue.h"
31#include "lldb/Utility/Status.h"
32#include <optional>
33
34using namespace lldb;
35using namespace lldb_private;
36
37LLDB_PLUGIN_DEFINE_ADV(ABISysV_s390x, ABISystemZ)
38
39enum dwarf_regnums {
40 // General Purpose Registers
41 dwarf_r0_s390x = 0,
42 dwarf_r1_s390x,
43 dwarf_r2_s390x,
44 dwarf_r3_s390x,
45 dwarf_r4_s390x,
46 dwarf_r5_s390x,
47 dwarf_r6_s390x,
48 dwarf_r7_s390x,
49 dwarf_r8_s390x,
50 dwarf_r9_s390x,
51 dwarf_r10_s390x,
52 dwarf_r11_s390x,
53 dwarf_r12_s390x,
54 dwarf_r13_s390x,
55 dwarf_r14_s390x,
56 dwarf_r15_s390x,
57 // Floating Point Registers / Vector Registers 0-15
58 dwarf_f0_s390x = 16,
59 dwarf_f2_s390x,
60 dwarf_f4_s390x,
61 dwarf_f6_s390x,
62 dwarf_f1_s390x,
63 dwarf_f3_s390x,
64 dwarf_f5_s390x,
65 dwarf_f7_s390x,
66 dwarf_f8_s390x,
67 dwarf_f10_s390x,
68 dwarf_f12_s390x,
69 dwarf_f14_s390x,
70 dwarf_f9_s390x,
71 dwarf_f11_s390x,
72 dwarf_f13_s390x,
73 dwarf_f15_s390x,
74 // Access Registers
75 dwarf_acr0_s390x = 48,
76 dwarf_acr1_s390x,
77 dwarf_acr2_s390x,
78 dwarf_acr3_s390x,
79 dwarf_acr4_s390x,
80 dwarf_acr5_s390x,
81 dwarf_acr6_s390x,
82 dwarf_acr7_s390x,
83 dwarf_acr8_s390x,
84 dwarf_acr9_s390x,
85 dwarf_acr10_s390x,
86 dwarf_acr11_s390x,
87 dwarf_acr12_s390x,
88 dwarf_acr13_s390x,
89 dwarf_acr14_s390x,
90 dwarf_acr15_s390x,
91 // Program Status Word
92 dwarf_pswm_s390x = 64,
93 dwarf_pswa_s390x,
94 // Vector Registers 16-31
95 dwarf_v16_s390x = 68,
96 dwarf_v18_s390x,
97 dwarf_v20_s390x,
98 dwarf_v22_s390x,
99 dwarf_v17_s390x,
100 dwarf_v19_s390x,
101 dwarf_v21_s390x,
102 dwarf_v23_s390x,
103 dwarf_v24_s390x,
104 dwarf_v26_s390x,
105 dwarf_v28_s390x,
106 dwarf_v30_s390x,
107 dwarf_v25_s390x,
108 dwarf_v27_s390x,
109 dwarf_v29_s390x,
110 dwarf_v31_s390x,
111};
112
113// RegisterKind: EHFrame, DWARF, Generic, Process Plugin, LLDB
114
115#define DEFINE_REG(name, size, alt, generic) \
116 { \
117 #name, alt, size, 0, eEncodingUint, eFormatHex, \
118 {dwarf_##name##_s390x, dwarf_##name##_s390x, generic, \
119 LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM }, \
120 nullptr, nullptr, nullptr, \
121 }
122
123static const RegisterInfo g_register_infos[] = {
124 DEFINE_REG(r0, 8, nullptr, LLDB_INVALID_REGNUM),
125 DEFINE_REG(r1, 8, nullptr, LLDB_INVALID_REGNUM),
126 DEFINE_REG(r2, 8, nullptr, LLDB_REGNUM_GENERIC_ARG1),
127 DEFINE_REG(r3, 8, nullptr, LLDB_REGNUM_GENERIC_ARG2),
128 DEFINE_REG(r4, 8, nullptr, LLDB_REGNUM_GENERIC_ARG3),
129 DEFINE_REG(r5, 8, nullptr, LLDB_REGNUM_GENERIC_ARG4),
130 DEFINE_REG(r6, 8, nullptr, LLDB_REGNUM_GENERIC_ARG5),
131 DEFINE_REG(r7, 8, nullptr, LLDB_INVALID_REGNUM),
132 DEFINE_REG(r8, 8, nullptr, LLDB_INVALID_REGNUM),
133 DEFINE_REG(r9, 8, nullptr, LLDB_INVALID_REGNUM),
134 DEFINE_REG(r10, 8, nullptr, LLDB_INVALID_REGNUM),
135 DEFINE_REG(r11, 8, nullptr, LLDB_REGNUM_GENERIC_FP),
136 DEFINE_REG(r12, 8, nullptr, LLDB_INVALID_REGNUM),
137 DEFINE_REG(r13, 8, nullptr, LLDB_INVALID_REGNUM),
138 DEFINE_REG(r14, 8, nullptr, LLDB_INVALID_REGNUM),
139 DEFINE_REG(r15, 8, "sp", LLDB_REGNUM_GENERIC_SP),
140 DEFINE_REG(acr0, 4, nullptr, LLDB_INVALID_REGNUM),
141 DEFINE_REG(acr1, 4, nullptr, LLDB_INVALID_REGNUM),
142 DEFINE_REG(acr2, 4, nullptr, LLDB_INVALID_REGNUM),
143 DEFINE_REG(acr3, 4, nullptr, LLDB_INVALID_REGNUM),
144 DEFINE_REG(acr4, 4, nullptr, LLDB_INVALID_REGNUM),
145 DEFINE_REG(acr5, 4, nullptr, LLDB_INVALID_REGNUM),
146 DEFINE_REG(acr6, 4, nullptr, LLDB_INVALID_REGNUM),
147 DEFINE_REG(acr7, 4, nullptr, LLDB_INVALID_REGNUM),
148 DEFINE_REG(acr8, 4, nullptr, LLDB_INVALID_REGNUM),
149 DEFINE_REG(acr9, 4, nullptr, LLDB_INVALID_REGNUM),
150 DEFINE_REG(acr10, 4, nullptr, LLDB_INVALID_REGNUM),
151 DEFINE_REG(acr11, 4, nullptr, LLDB_INVALID_REGNUM),
152 DEFINE_REG(acr12, 4, nullptr, LLDB_INVALID_REGNUM),
153 DEFINE_REG(acr13, 4, nullptr, LLDB_INVALID_REGNUM),
154 DEFINE_REG(acr14, 4, nullptr, LLDB_INVALID_REGNUM),
155 DEFINE_REG(acr15, 4, nullptr, LLDB_INVALID_REGNUM),
156 DEFINE_REG(pswm, 8, nullptr, LLDB_REGNUM_GENERIC_FLAGS),
157 DEFINE_REG(pswa, 8, nullptr, LLDB_REGNUM_GENERIC_PC),
158 DEFINE_REG(f0, 8, nullptr, LLDB_INVALID_REGNUM),
159 DEFINE_REG(f1, 8, nullptr, LLDB_INVALID_REGNUM),
160 DEFINE_REG(f2, 8, nullptr, LLDB_INVALID_REGNUM),
161 DEFINE_REG(f3, 8, nullptr, LLDB_INVALID_REGNUM),
162 DEFINE_REG(f4, 8, nullptr, LLDB_INVALID_REGNUM),
163 DEFINE_REG(f5, 8, nullptr, LLDB_INVALID_REGNUM),
164 DEFINE_REG(f6, 8, nullptr, LLDB_INVALID_REGNUM),
165 DEFINE_REG(f7, 8, nullptr, LLDB_INVALID_REGNUM),
166 DEFINE_REG(f8, 8, nullptr, LLDB_INVALID_REGNUM),
167 DEFINE_REG(f9, 8, nullptr, LLDB_INVALID_REGNUM),
168 DEFINE_REG(f10, 8, nullptr, LLDB_INVALID_REGNUM),
169 DEFINE_REG(f11, 8, nullptr, LLDB_INVALID_REGNUM),
170 DEFINE_REG(f12, 8, nullptr, LLDB_INVALID_REGNUM),
171 DEFINE_REG(f13, 8, nullptr, LLDB_INVALID_REGNUM),
172 DEFINE_REG(f14, 8, nullptr, LLDB_INVALID_REGNUM),
173 DEFINE_REG(f15, 8, nullptr, LLDB_INVALID_REGNUM),
174};
175
176static const uint32_t k_num_register_infos = std::size(g_register_infos);
177
178const lldb_private::RegisterInfo *
179ABISysV_s390x::GetRegisterInfoArray(uint32_t &count) {
180 count = k_num_register_infos;
181 return g_register_infos;
182}
183
184size_t ABISysV_s390x::GetRedZoneSize() const { return 0; }
185
186// Static Functions
187
188ABISP
189ABISysV_s390x::CreateInstance(lldb::ProcessSP process_sp, const ArchSpec &arch) {
190 if (arch.GetTriple().getArch() == llvm::Triple::systemz) {
191 return ABISP(new ABISysV_s390x(std::move(process_sp), MakeMCRegisterInfo(arch)));
192 }
193 return ABISP();
194}
195
196bool ABISysV_s390x::PrepareTrivialCall(Thread &thread, addr_t sp,
197 addr_t func_addr, addr_t return_addr,
198 llvm::ArrayRef<addr_t> args) const {
199 Log *log = GetLog(mask: LLDBLog::Expressions);
200
201 if (log) {
202 StreamString s;
203 s.Printf(format: "ABISysV_s390x::PrepareTrivialCall (tid = 0x%" PRIx64
204 ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64
205 ", return_addr = 0x%" PRIx64,
206 thread.GetID(), (uint64_t)sp, (uint64_t)func_addr,
207 (uint64_t)return_addr);
208
209 for (size_t i = 0; i < args.size(); ++i)
210 s.Printf(format: ", arg%" PRIu64 " = 0x%" PRIx64, static_cast<uint64_t>(i + 1),
211 args[i]);
212 s.PutCString(cstr: ")");
213 log->PutString(str: s.GetString());
214 }
215
216 RegisterContext *reg_ctx = thread.GetRegisterContext().get();
217 if (!reg_ctx)
218 return false;
219
220 const RegisterInfo *pc_reg_info =
221 reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
222 const RegisterInfo *sp_reg_info =
223 reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
224 const RegisterInfo *ra_reg_info = reg_ctx->GetRegisterInfoByName(reg_name: "r14", start_idx: 0);
225 ProcessSP process_sp(thread.GetProcess());
226
227 // Allocate a new stack frame and space for stack arguments if necessary
228
229 addr_t arg_pos = 0;
230 if (args.size() > 5) {
231 sp -= 8 * (args.size() - 5);
232 arg_pos = sp;
233 }
234
235 sp -= 160;
236
237 // Process arguments
238
239 for (size_t i = 0; i < args.size(); ++i) {
240 if (i < 5) {
241 const RegisterInfo *reg_info = reg_ctx->GetRegisterInfo(
242 reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + i);
243 LLDB_LOGF(log, "About to write arg%" PRIu64 " (0x%" PRIx64 ") into %s",
244 static_cast<uint64_t>(i + 1), args[i], reg_info->name);
245 if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, uval: args[i]))
246 return false;
247 } else {
248 Status error;
249 LLDB_LOGF(log, "About to write arg%" PRIu64 " (0x%" PRIx64 ") onto stack",
250 static_cast<uint64_t>(i + 1), args[i]);
251 if (!process_sp->WritePointerToMemory(vm_addr: arg_pos, ptr_value: args[i], error))
252 return false;
253 arg_pos += 8;
254 }
255 }
256
257 // %r14 is set to the return address
258
259 LLDB_LOGF(log, "Writing RA: 0x%" PRIx64, (uint64_t)return_addr);
260
261 if (!reg_ctx->WriteRegisterFromUnsigned(reg_info: ra_reg_info, uval: return_addr))
262 return false;
263
264 // %r15 is set to the actual stack value.
265
266 LLDB_LOGF(log, "Writing SP: 0x%" PRIx64, (uint64_t)sp);
267
268 if (!reg_ctx->WriteRegisterFromUnsigned(reg_info: sp_reg_info, uval: sp))
269 return false;
270
271 // %pc is set to the address of the called function.
272
273 LLDB_LOGF(log, "Writing PC: 0x%" PRIx64, (uint64_t)func_addr);
274
275 if (!reg_ctx->WriteRegisterFromUnsigned(reg_info: pc_reg_info, uval: func_addr))
276 return false;
277
278 return true;
279}
280
281static bool ReadIntegerArgument(Scalar &scalar, unsigned int bit_width,
282 bool is_signed, Thread &thread,
283 uint32_t *argument_register_ids,
284 unsigned int &current_argument_register,
285 addr_t &current_stack_argument) {
286 if (bit_width > 64)
287 return false; // Scalar can't hold large integer arguments
288
289 if (current_argument_register < 5) {
290 scalar = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
291 reg: argument_register_ids[current_argument_register], fail_value: 0);
292 current_argument_register++;
293 if (is_signed)
294 scalar.SignExtend(bit_pos: bit_width);
295 } else {
296 uint32_t byte_size = (bit_width + (8 - 1)) / 8;
297 Status error;
298 if (thread.GetProcess()->ReadScalarIntegerFromMemory(
299 addr: current_stack_argument + 8 - byte_size, byte_size, is_signed,
300 scalar, error)) {
301 current_stack_argument += 8;
302 return true;
303 }
304 return false;
305 }
306 return true;
307}
308
309bool ABISysV_s390x::GetArgumentValues(Thread &thread, ValueList &values) const {
310 unsigned int num_values = values.GetSize();
311 unsigned int value_index;
312
313 // Extract the register context so we can read arguments from registers
314
315 RegisterContext *reg_ctx = thread.GetRegisterContext().get();
316
317 if (!reg_ctx)
318 return false;
319
320 // Get the pointer to the first stack argument so we have a place to start
321 // when reading data
322
323 addr_t sp = reg_ctx->GetSP(fail_value: 0);
324
325 if (!sp)
326 return false;
327
328 addr_t current_stack_argument = sp + 160;
329
330 uint32_t argument_register_ids[5];
331
332 argument_register_ids[0] =
333 reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1)
334 ->kinds[eRegisterKindLLDB];
335 argument_register_ids[1] =
336 reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2)
337 ->kinds[eRegisterKindLLDB];
338 argument_register_ids[2] =
339 reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG3)
340 ->kinds[eRegisterKindLLDB];
341 argument_register_ids[3] =
342 reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG4)
343 ->kinds[eRegisterKindLLDB];
344 argument_register_ids[4] =
345 reg_ctx->GetRegisterInfo(reg_kind: eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG5)
346 ->kinds[eRegisterKindLLDB];
347
348 unsigned int current_argument_register = 0;
349
350 for (value_index = 0; value_index < num_values; ++value_index) {
351 Value *value = values.GetValueAtIndex(idx: value_index);
352
353 if (!value)
354 return false;
355
356 // We currently only support extracting values with Clang QualTypes. Do we
357 // care about others?
358 CompilerType compiler_type = value->GetCompilerType();
359 std::optional<uint64_t> bit_size = compiler_type.GetBitSize(exe_scope: &thread);
360 if (!bit_size)
361 return false;
362 bool is_signed;
363
364 if (compiler_type.IsIntegerOrEnumerationType(is_signed)) {
365 ReadIntegerArgument(scalar&: value->GetScalar(), bit_width: *bit_size, is_signed, thread,
366 argument_register_ids, current_argument_register,
367 current_stack_argument);
368 } else if (compiler_type.IsPointerType()) {
369 ReadIntegerArgument(scalar&: value->GetScalar(), bit_width: *bit_size, is_signed: false, thread,
370 argument_register_ids, current_argument_register,
371 current_stack_argument);
372 }
373 }
374
375 return true;
376}
377
378Status ABISysV_s390x::SetReturnValueObject(lldb::StackFrameSP &frame_sp,
379 lldb::ValueObjectSP &new_value_sp) {
380 Status error;
381 if (!new_value_sp) {
382 error.SetErrorString("Empty value object for return value.");
383 return error;
384 }
385
386 CompilerType compiler_type = new_value_sp->GetCompilerType();
387 if (!compiler_type) {
388 error.SetErrorString("Null clang type for return value.");
389 return error;
390 }
391
392 Thread *thread = frame_sp->GetThread().get();
393
394 bool is_signed;
395 uint32_t count;
396 bool is_complex;
397
398 RegisterContext *reg_ctx = thread->GetRegisterContext().get();
399
400 bool set_it_simple = false;
401 if (compiler_type.IsIntegerOrEnumerationType(is_signed) ||
402 compiler_type.IsPointerType()) {
403 const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName(reg_name: "r2", start_idx: 0);
404
405 DataExtractor data;
406 Status data_error;
407 size_t num_bytes = new_value_sp->GetData(data, error&: data_error);
408 if (data_error.Fail()) {
409 error.SetErrorStringWithFormat(
410 "Couldn't convert return value to raw data: %s",
411 data_error.AsCString());
412 return error;
413 }
414 lldb::offset_t offset = 0;
415 if (num_bytes <= 8) {
416 uint64_t raw_value = data.GetMaxU64(offset_ptr: &offset, byte_size: num_bytes);
417
418 if (reg_ctx->WriteRegisterFromUnsigned(reg_info, uval: raw_value))
419 set_it_simple = true;
420 } else {
421 error.SetErrorString("We don't support returning longer than 64 bit "
422 "integer values at present.");
423 }
424 } else if (compiler_type.IsFloatingPointType(count, is_complex)) {
425 if (is_complex)
426 error.SetErrorString(
427 "We don't support returning complex values at present");
428 else {
429 std::optional<uint64_t> bit_width =
430 compiler_type.GetBitSize(exe_scope: frame_sp.get());
431 if (!bit_width) {
432 error.SetErrorString("can't get type size");
433 return error;
434 }
435 if (*bit_width <= 64) {
436 const RegisterInfo *f0_info = reg_ctx->GetRegisterInfoByName(reg_name: "f0", start_idx: 0);
437 RegisterValue f0_value;
438 DataExtractor data;
439 Status data_error;
440 size_t num_bytes = new_value_sp->GetData(data, error&: data_error);
441 if (data_error.Fail()) {
442 error.SetErrorStringWithFormat(
443 "Couldn't convert return value to raw data: %s",
444 data_error.AsCString());
445 return error;
446 }
447
448 unsigned char buffer[8];
449 ByteOrder byte_order = data.GetByteOrder();
450
451 data.CopyByteOrderedData(src_offset: 0, src_len: num_bytes, dst: buffer, dst_len: 8, dst_byte_order: byte_order);
452 f0_value.SetBytes(bytes: buffer, length: 8, byte_order);
453 reg_ctx->WriteRegister(reg_info: f0_info, reg_value: f0_value);
454 set_it_simple = true;
455 } else {
456 // FIXME - don't know how to do long doubles yet.
457 error.SetErrorString(
458 "We don't support returning float values > 64 bits at present");
459 }
460 }
461 }
462
463 if (!set_it_simple) {
464 // Okay we've got a structure or something that doesn't fit in a simple
465 // register. We should figure out where it really goes, but we don't
466 // support this yet.
467 error.SetErrorString("We only support setting simple integer and float "
468 "return types at present.");
469 }
470
471 return error;
472}
473
474ValueObjectSP ABISysV_s390x::GetReturnValueObjectSimple(
475 Thread &thread, CompilerType &return_compiler_type) const {
476 ValueObjectSP return_valobj_sp;
477 Value value;
478
479 if (!return_compiler_type)
480 return return_valobj_sp;
481
482 // value.SetContext (Value::eContextTypeClangType, return_value_type);
483 value.SetCompilerType(return_compiler_type);
484
485 RegisterContext *reg_ctx = thread.GetRegisterContext().get();
486 if (!reg_ctx)
487 return return_valobj_sp;
488
489 const uint32_t type_flags = return_compiler_type.GetTypeInfo();
490 if (type_flags & eTypeIsScalar) {
491 value.SetValueType(Value::ValueType::Scalar);
492
493 bool success = false;
494 if (type_flags & eTypeIsInteger) {
495 // Extract the register context so we can read arguments from registers.
496 std::optional<uint64_t> byte_size =
497 return_compiler_type.GetByteSize(exe_scope: &thread);
498 if (!byte_size)
499 return return_valobj_sp;
500 uint64_t raw_value = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
501 reg_info: reg_ctx->GetRegisterInfoByName(reg_name: "r2", start_idx: 0), fail_value: 0);
502 const bool is_signed = (type_flags & eTypeIsSigned) != 0;
503 switch (*byte_size) {
504 default:
505 break;
506
507 case sizeof(uint64_t):
508 if (is_signed)
509 value.GetScalar() = (int64_t)(raw_value);
510 else
511 value.GetScalar() = (uint64_t)(raw_value);
512 success = true;
513 break;
514
515 case sizeof(uint32_t):
516 if (is_signed)
517 value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);
518 else
519 value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);
520 success = true;
521 break;
522
523 case sizeof(uint16_t):
524 if (is_signed)
525 value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);
526 else
527 value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);
528 success = true;
529 break;
530
531 case sizeof(uint8_t):
532 if (is_signed)
533 value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);
534 else
535 value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);
536 success = true;
537 break;
538 }
539 } else if (type_flags & eTypeIsFloat) {
540 if (type_flags & eTypeIsComplex) {
541 // Don't handle complex yet.
542 } else {
543 std::optional<uint64_t> byte_size =
544 return_compiler_type.GetByteSize(exe_scope: &thread);
545 if (byte_size && *byte_size <= sizeof(long double)) {
546 const RegisterInfo *f0_info = reg_ctx->GetRegisterInfoByName(reg_name: "f0", start_idx: 0);
547 RegisterValue f0_value;
548 if (reg_ctx->ReadRegister(reg_info: f0_info, reg_value&: f0_value)) {
549 DataExtractor data;
550 if (f0_value.GetData(data)) {
551 lldb::offset_t offset = 0;
552 if (*byte_size == sizeof(float)) {
553 value.GetScalar() = (float)data.GetFloat(offset_ptr: &offset);
554 success = true;
555 } else if (*byte_size == sizeof(double)) {
556 value.GetScalar() = (double)data.GetDouble(offset_ptr: &offset);
557 success = true;
558 } else if (*byte_size == sizeof(long double)) {
559 // Don't handle long double yet.
560 }
561 }
562 }
563 }
564 }
565 }
566
567 if (success)
568 return_valobj_sp = ValueObjectConstResult::Create(
569 exe_scope: thread.GetStackFrameAtIndex(idx: 0).get(), value, name: ConstString(""));
570 } else if (type_flags & eTypeIsPointer) {
571 unsigned r2_id =
572 reg_ctx->GetRegisterInfoByName(reg_name: "r2", start_idx: 0)->kinds[eRegisterKindLLDB];
573 value.GetScalar() =
574 (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(reg: r2_id, fail_value: 0);
575 value.SetValueType(Value::ValueType::Scalar);
576 return_valobj_sp = ValueObjectConstResult::Create(
577 exe_scope: thread.GetStackFrameAtIndex(idx: 0).get(), value, name: ConstString(""));
578 }
579
580 return return_valobj_sp;
581}
582
583ValueObjectSP ABISysV_s390x::GetReturnValueObjectImpl(
584 Thread &thread, CompilerType &return_compiler_type) const {
585 ValueObjectSP return_valobj_sp;
586
587 if (!return_compiler_type)
588 return return_valobj_sp;
589
590 ExecutionContext exe_ctx(thread.shared_from_this());
591 return_valobj_sp = GetReturnValueObjectSimple(thread, return_compiler_type);
592 if (return_valobj_sp)
593 return return_valobj_sp;
594
595 RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();
596 if (!reg_ctx_sp)
597 return return_valobj_sp;
598
599 if (return_compiler_type.IsAggregateType()) {
600 // FIXME: This is just taking a guess, r2 may very well no longer hold the
601 // return storage location.
602 // If we are going to do this right, when we make a new frame we should
603 // check to see if it uses a memory return, and if we are at the first
604 // instruction and if so stash away the return location. Then we would
605 // only return the memory return value if we know it is valid.
606
607 unsigned r2_id =
608 reg_ctx_sp->GetRegisterInfoByName(reg_name: "r2", start_idx: 0)->kinds[eRegisterKindLLDB];
609 lldb::addr_t storage_addr =
610 (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(reg: r2_id, fail_value: 0);
611 return_valobj_sp = ValueObjectMemory::Create(
612 exe_scope: &thread, name: "", address: Address(storage_addr, nullptr), ast_type: return_compiler_type);
613 }
614
615 return return_valobj_sp;
616}
617
618bool ABISysV_s390x::CreateFunctionEntryUnwindPlan(UnwindPlan &unwind_plan) {
619 unwind_plan.Clear();
620 unwind_plan.SetRegisterKind(eRegisterKindDWARF);
621
622 UnwindPlan::RowSP row(new UnwindPlan::Row);
623
624 // Our Call Frame Address is the stack pointer value + 160
625 row->GetCFAValue().SetIsRegisterPlusOffset(reg_num: dwarf_r15_s390x, offset: 160);
626
627 // The previous PC is in r14
628 row->SetRegisterLocationToRegister(reg_num: dwarf_pswa_s390x, other_reg_num: dwarf_r14_s390x, can_replace: true);
629
630 // All other registers are the same.
631 unwind_plan.AppendRow(row_sp: row);
632 unwind_plan.SetSourceName("s390x at-func-entry default");
633 unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
634 return true;
635}
636
637bool ABISysV_s390x::CreateDefaultUnwindPlan(UnwindPlan &unwind_plan) {
638 // There's really no default way to unwind on s390x. Trust the .eh_frame CFI,
639 // which should always be good.
640 return false;
641}
642
643bool ABISysV_s390x::GetFallbackRegisterLocation(
644 const RegisterInfo *reg_info,
645 UnwindPlan::Row::RegisterLocation &unwind_regloc) {
646 // If a volatile register is being requested, we don't want to forward the
647 // next frame's register contents up the stack -- the register is not
648 // retrievable at this frame.
649 if (RegisterIsVolatile(reg_info)) {
650 unwind_regloc.SetUndefined();
651 return true;
652 }
653
654 return false;
655}
656
657bool ABISysV_s390x::RegisterIsVolatile(const RegisterInfo *reg_info) {
658 return !RegisterIsCalleeSaved(reg_info);
659}
660
661bool ABISysV_s390x::RegisterIsCalleeSaved(const RegisterInfo *reg_info) {
662 if (reg_info) {
663 // Preserved registers are :
664 // r6-r13, r15
665 // f8-f15
666
667 const char *name = reg_info->name;
668 if (name[0] == 'r') {
669 switch (name[1]) {
670 case '6': // r6
671 case '7': // r7
672 case '8': // r8
673 case '9': // r9
674 return name[2] == '\0';
675
676 case '1': // r10, r11, r12, r13, r15
677 if ((name[2] >= '0' && name[2] <= '3') || name[2] == '5')
678 return name[3] == '\0';
679 break;
680
681 default:
682 break;
683 }
684 }
685 if (name[0] == 'f') {
686 switch (name[1]) {
687 case '8': // r8
688 case '9': // r9
689 return name[2] == '\0';
690
691 case '1': // r10, r11, r12, r13, r14, r15
692 if (name[2] >= '0' && name[2] <= '5')
693 return name[3] == '\0';
694 break;
695
696 default:
697 break;
698 }
699 }
700
701 // Accept shorter-variant versions
702 if (name[0] == 's' && name[1] == 'p' && name[2] == '\0') // sp
703 return true;
704 if (name[0] == 'f' && name[1] == 'p' && name[2] == '\0') // fp
705 return true;
706 if (name[0] == 'p' && name[1] == 'c' && name[2] == '\0') // pc
707 return true;
708 }
709 return false;
710}
711
712void ABISysV_s390x::Initialize() {
713 PluginManager::RegisterPlugin(
714 name: GetPluginNameStatic(), description: "System V ABI for s390x targets", create_callback: CreateInstance);
715}
716
717void ABISysV_s390x::Terminate() {
718 PluginManager::UnregisterPlugin(create_callback: CreateInstance);
719}
720

source code of lldb/source/Plugins/ABI/SystemZ/ABISysV_s390x.cpp