xref: /freebsd/contrib/llvm-project/lldb/source/Plugins/ABI/PowerPC/ABISysV_ppc64.cpp (revision 700637cbb5e582861067a11aaca4d053546871d2)
1 //===-- ABISysV_ppc64.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_ppc64.h"
10 
11 #include "llvm/ADT/STLExtras.h"
12 #include "llvm/TargetParser/Triple.h"
13 
14 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
15 #include "Utility/PPC64LE_DWARF_Registers.h"
16 #include "Utility/PPC64_DWARF_Registers.h"
17 #include "lldb/Core/Module.h"
18 #include "lldb/Core/PluginManager.h"
19 #include "lldb/Core/Value.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 "lldb/ValueObject/ValueObjectConstResult.h"
33 #include "lldb/ValueObject/ValueObjectMemory.h"
34 #include "lldb/ValueObject/ValueObjectRegister.h"
35 
36 #include "clang/AST/ASTContext.h"
37 #include "clang/AST/Attr.h"
38 #include "clang/AST/Decl.h"
39 
40 #define DECLARE_REGISTER_INFOS_PPC64_STRUCT
41 #include "Plugins/Process/Utility/RegisterInfos_ppc64.h"
42 #undef DECLARE_REGISTER_INFOS_PPC64_STRUCT
43 
44 #define DECLARE_REGISTER_INFOS_PPC64LE_STRUCT
45 #include "Plugins/Process/Utility/RegisterInfos_ppc64le.h"
46 #undef DECLARE_REGISTER_INFOS_PPC64LE_STRUCT
47 #include <optional>
48 
49 using namespace lldb;
50 using namespace lldb_private;
51 
LLDB_PLUGIN_DEFINE(ABISysV_ppc64) const52 LLDB_PLUGIN_DEFINE(ABISysV_ppc64)
53 
54 const lldb_private::RegisterInfo *
55 ABISysV_ppc64::GetRegisterInfoArray(uint32_t &count) {
56   if (GetByteOrder() == lldb::eByteOrderLittle) {
57     count = std::size(g_register_infos_ppc64le);
58     return g_register_infos_ppc64le;
59   } else {
60     count = std::size(g_register_infos_ppc64);
61     return g_register_infos_ppc64;
62   }
63 }
64 
GetRedZoneSize() const65 size_t ABISysV_ppc64::GetRedZoneSize() const { return 224; }
66 
GetByteOrder() const67 lldb::ByteOrder ABISysV_ppc64::GetByteOrder() const {
68   return GetProcessSP()->GetByteOrder();
69 }
70 
71 // Static Functions
72 
73 ABISP
CreateInstance(lldb::ProcessSP process_sp,const ArchSpec & arch)74 ABISysV_ppc64::CreateInstance(lldb::ProcessSP process_sp,
75                               const ArchSpec &arch) {
76   if (arch.GetTriple().isPPC64())
77     return ABISP(
78         new ABISysV_ppc64(std::move(process_sp), MakeMCRegisterInfo(arch)));
79   return ABISP();
80 }
81 
PrepareTrivialCall(Thread & thread,addr_t sp,addr_t func_addr,addr_t return_addr,llvm::ArrayRef<addr_t> args) const82 bool ABISysV_ppc64::PrepareTrivialCall(Thread &thread, addr_t sp,
83                                        addr_t func_addr, addr_t return_addr,
84                                        llvm::ArrayRef<addr_t> args) const {
85   Log *log = GetLog(LLDBLog::Expressions);
86 
87   if (log) {
88     StreamString s;
89     s.Printf("ABISysV_ppc64::PrepareTrivialCall (tid = 0x%" PRIx64
90              ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64
91              ", return_addr = 0x%" PRIx64,
92              thread.GetID(), (uint64_t)sp, (uint64_t)func_addr,
93              (uint64_t)return_addr);
94 
95     for (size_t i = 0; i < args.size(); ++i)
96       s.Printf(", arg%" PRIu64 " = 0x%" PRIx64, static_cast<uint64_t>(i + 1),
97                args[i]);
98     s.PutCString(")");
99     log->PutString(s.GetString());
100   }
101 
102   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
103   if (!reg_ctx)
104     return false;
105 
106   const RegisterInfo *reg_info = nullptr;
107 
108   if (args.size() > 8) // TODO handle more than 8 arguments
109     return false;
110 
111   for (size_t i = 0; i < args.size(); ++i) {
112     reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,
113                                         LLDB_REGNUM_GENERIC_ARG1 + i);
114     LLDB_LOGF(log, "About to write arg%" PRIu64 " (0x%" PRIx64 ") into %s",
115               static_cast<uint64_t>(i + 1), args[i], reg_info->name);
116     if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, args[i]))
117       return false;
118   }
119 
120   // First, align the SP
121 
122   LLDB_LOGF(log, "16-byte aligning SP: 0x%" PRIx64 " to 0x%" PRIx64,
123             (uint64_t)sp, (uint64_t)(sp & ~0xfull));
124 
125   sp &= ~(0xfull); // 16-byte alignment
126 
127   sp -= 544; // allocate frame to save TOC, RA and SP.
128 
129   Status error;
130   uint64_t reg_value;
131   const RegisterInfo *pc_reg_info =
132       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
133   const RegisterInfo *sp_reg_info =
134       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
135   ProcessSP process_sp(thread.GetProcess());
136   const RegisterInfo *lr_reg_info =
137       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_RA);
138   const RegisterInfo *r2_reg_info = reg_ctx->GetRegisterInfoAtIndex(2);
139   const RegisterInfo *r12_reg_info = reg_ctx->GetRegisterInfoAtIndex(12);
140 
141   // Save return address onto the stack.
142   LLDB_LOGF(log,
143             "Pushing the return address onto the stack: 0x%" PRIx64
144             "(+16): 0x%" PRIx64,
145             (uint64_t)sp, (uint64_t)return_addr);
146   if (!process_sp->WritePointerToMemory(sp + 16, return_addr, error))
147     return false;
148 
149   // Write the return address to link register.
150   LLDB_LOGF(log, "Writing LR: 0x%" PRIx64, (uint64_t)return_addr);
151   if (!reg_ctx->WriteRegisterFromUnsigned(lr_reg_info, return_addr))
152     return false;
153 
154   // Write target address to %r12 register.
155   LLDB_LOGF(log, "Writing R12: 0x%" PRIx64, (uint64_t)func_addr);
156   if (!reg_ctx->WriteRegisterFromUnsigned(r12_reg_info, func_addr))
157     return false;
158 
159   // Read TOC pointer value.
160   reg_value = reg_ctx->ReadRegisterAsUnsigned(r2_reg_info, 0);
161 
162   // Write TOC pointer onto the stack.
163   uint64_t stack_offset;
164   if (GetByteOrder() == lldb::eByteOrderLittle)
165     stack_offset = 24;
166   else
167     stack_offset = 40;
168 
169   LLDB_LOGF(log, "Writing R2 (TOC) at SP(0x%" PRIx64 ")+%d: 0x%" PRIx64,
170             (uint64_t)(sp + stack_offset), (int)stack_offset,
171             (uint64_t)reg_value);
172   if (!process_sp->WritePointerToMemory(sp + stack_offset, reg_value, error))
173     return false;
174 
175   // Read the current SP value.
176   reg_value = reg_ctx->ReadRegisterAsUnsigned(sp_reg_info, 0);
177 
178   // Save current SP onto the stack.
179   LLDB_LOGF(log, "Writing SP at SP(0x%" PRIx64 ")+0: 0x%" PRIx64, (uint64_t)sp,
180             (uint64_t)reg_value);
181   if (!process_sp->WritePointerToMemory(sp, reg_value, error))
182     return false;
183 
184   // %r1 is set to the actual stack value.
185   LLDB_LOGF(log, "Writing SP: 0x%" PRIx64, (uint64_t)sp);
186 
187   if (!reg_ctx->WriteRegisterFromUnsigned(sp_reg_info, sp))
188     return false;
189 
190   // %pc is set to the address of the called function.
191 
192   LLDB_LOGF(log, "Writing IP: 0x%" PRIx64, (uint64_t)func_addr);
193 
194   if (!reg_ctx->WriteRegisterFromUnsigned(pc_reg_info, func_addr))
195     return false;
196 
197   return true;
198 }
199 
ReadIntegerArgument(Scalar & scalar,unsigned int bit_width,bool is_signed,Thread & thread,uint32_t * argument_register_ids,unsigned int & current_argument_register,addr_t & current_stack_argument)200 static bool ReadIntegerArgument(Scalar &scalar, unsigned int bit_width,
201                                 bool is_signed, Thread &thread,
202                                 uint32_t *argument_register_ids,
203                                 unsigned int &current_argument_register,
204                                 addr_t &current_stack_argument) {
205   if (bit_width > 64)
206     return false; // Scalar can't hold large integer arguments
207 
208   if (current_argument_register < 6) {
209     scalar = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
210         argument_register_ids[current_argument_register], 0);
211     current_argument_register++;
212     if (is_signed)
213       scalar.SignExtend(bit_width);
214   } else {
215     uint32_t byte_size = (bit_width + (8 - 1)) / 8;
216     Status error;
217     if (thread.GetProcess()->ReadScalarIntegerFromMemory(
218             current_stack_argument, byte_size, is_signed, scalar, error)) {
219       current_stack_argument += byte_size;
220       return true;
221     }
222     return false;
223   }
224   return true;
225 }
226 
GetArgumentValues(Thread & thread,ValueList & values) const227 bool ABISysV_ppc64::GetArgumentValues(Thread &thread, ValueList &values) const {
228   unsigned int num_values = values.GetSize();
229   unsigned int value_index;
230 
231   // Extract the register context so we can read arguments from registers
232 
233   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
234 
235   if (!reg_ctx)
236     return false;
237 
238   // Get the pointer to the first stack argument so we have a place to start
239   // when reading data
240 
241   addr_t sp = reg_ctx->GetSP(0);
242 
243   if (!sp)
244     return false;
245 
246   uint64_t stack_offset;
247   if (GetByteOrder() == lldb::eByteOrderLittle)
248     stack_offset = 32;
249   else
250     stack_offset = 48;
251 
252   // jump over return address.
253   addr_t current_stack_argument = sp + stack_offset;
254   uint32_t argument_register_ids[8];
255 
256   for (size_t i = 0; i < 8; ++i) {
257     argument_register_ids[i] =
258         reg_ctx
259             ->GetRegisterInfo(eRegisterKindGeneric,
260                               LLDB_REGNUM_GENERIC_ARG1 + i)
261             ->kinds[eRegisterKindLLDB];
262   }
263 
264   unsigned int current_argument_register = 0;
265 
266   for (value_index = 0; value_index < num_values; ++value_index) {
267     Value *value = values.GetValueAtIndex(value_index);
268 
269     if (!value)
270       return false;
271 
272     // We currently only support extracting values with Clang QualTypes. Do we
273     // care about others?
274     CompilerType compiler_type = value->GetCompilerType();
275     std::optional<uint64_t> bit_size =
276         llvm::expectedToOptional(compiler_type.GetBitSize(&thread));
277     if (!bit_size)
278       return false;
279     bool is_signed;
280 
281     if (compiler_type.IsIntegerOrEnumerationType(is_signed)) {
282       ReadIntegerArgument(value->GetScalar(), *bit_size, is_signed, thread,
283                           argument_register_ids, current_argument_register,
284                           current_stack_argument);
285     } else if (compiler_type.IsPointerType()) {
286       ReadIntegerArgument(value->GetScalar(), *bit_size, false, thread,
287                           argument_register_ids, current_argument_register,
288                           current_stack_argument);
289     }
290   }
291 
292   return true;
293 }
294 
SetReturnValueObject(lldb::StackFrameSP & frame_sp,lldb::ValueObjectSP & new_value_sp)295 Status ABISysV_ppc64::SetReturnValueObject(lldb::StackFrameSP &frame_sp,
296                                            lldb::ValueObjectSP &new_value_sp) {
297   Status error;
298   if (!new_value_sp) {
299     error = Status::FromErrorString("Empty value object for return value.");
300     return error;
301   }
302 
303   CompilerType compiler_type = new_value_sp->GetCompilerType();
304   if (!compiler_type) {
305     error = Status::FromErrorString("Null clang type for return value.");
306     return error;
307   }
308 
309   Thread *thread = frame_sp->GetThread().get();
310 
311   bool is_signed;
312   uint32_t count;
313   bool is_complex;
314 
315   RegisterContext *reg_ctx = thread->GetRegisterContext().get();
316 
317   bool set_it_simple = false;
318   if (compiler_type.IsIntegerOrEnumerationType(is_signed) ||
319       compiler_type.IsPointerType()) {
320     const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName("r3", 0);
321 
322     DataExtractor data;
323     Status data_error;
324     size_t num_bytes = new_value_sp->GetData(data, data_error);
325     if (data_error.Fail()) {
326       error = Status::FromErrorStringWithFormat(
327           "Couldn't convert return value to raw data: %s",
328           data_error.AsCString());
329       return error;
330     }
331     lldb::offset_t offset = 0;
332     if (num_bytes <= 8) {
333       uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);
334 
335       if (reg_ctx->WriteRegisterFromUnsigned(reg_info, raw_value))
336         set_it_simple = true;
337     } else {
338       error = Status::FromErrorString(
339           "We don't support returning longer than 64 bit "
340           "integer values at present.");
341     }
342   } else if (compiler_type.IsFloatingPointType(count, is_complex)) {
343     if (is_complex)
344       error = Status::FromErrorString(
345           "We don't support returning complex values at present");
346     else {
347       std::optional<uint64_t> bit_width =
348           llvm::expectedToOptional(compiler_type.GetBitSize(frame_sp.get()));
349       if (!bit_width) {
350         error = Status::FromErrorString("can't get size of type");
351         return error;
352       }
353       if (*bit_width <= 64) {
354         DataExtractor data;
355         Status data_error;
356         size_t num_bytes = new_value_sp->GetData(data, data_error);
357         if (data_error.Fail()) {
358           error = Status::FromErrorStringWithFormat(
359               "Couldn't convert return value to raw data: %s",
360               data_error.AsCString());
361           return error;
362         }
363 
364         unsigned char buffer[16];
365         ByteOrder byte_order = data.GetByteOrder();
366 
367         data.CopyByteOrderedData(0, num_bytes, buffer, 16, byte_order);
368         set_it_simple = true;
369       } else {
370         // FIXME - don't know how to do 80 bit long doubles yet.
371         error = Status::FromErrorString(
372             "We don't support returning float values > 64 bits at present");
373       }
374     }
375   }
376 
377   if (!set_it_simple) {
378     // Okay we've got a structure or something that doesn't fit in a simple
379     // register. We should figure out where it really goes, but we don't
380     // support this yet.
381     error = Status::FromErrorString(
382         "We only support setting simple integer and float "
383         "return types at present.");
384   }
385 
386   return error;
387 }
388 
389 //
390 // ReturnValueExtractor
391 //
392 
393 namespace {
394 
395 #define LOG_PREFIX "ReturnValueExtractor: "
396 
397 class ReturnValueExtractor {
398   // This class represents a register, from which data may be extracted.
399   //
400   // It may be constructed by directly specifying its index (where 0 is the
401   // first register used to return values) or by specifying the offset of a
402   // given struct field, in which case the appropriated register index will be
403   // calculated.
404   class Register {
405   public:
406     enum Type {
407       GPR, // General Purpose Register
408       FPR  // Floating Point Register
409     };
410 
411     // main constructor
412     //
413     // offs - field offset in struct
Register(Type ty,uint32_t index,uint32_t offs,RegisterContext * reg_ctx,ByteOrder byte_order)414     Register(Type ty, uint32_t index, uint32_t offs, RegisterContext *reg_ctx,
415              ByteOrder byte_order)
416         : m_index(index), m_offs(offs % sizeof(uint64_t)),
417           m_avail(sizeof(uint64_t) - m_offs), m_type(ty), m_reg_ctx(reg_ctx),
418           m_byte_order(byte_order) {}
419 
420     // explicit index, no offset
Register(Type ty,uint32_t index,RegisterContext * reg_ctx,ByteOrder byte_order)421     Register(Type ty, uint32_t index, RegisterContext *reg_ctx,
422              ByteOrder byte_order)
423         : Register(ty, index, 0, reg_ctx, byte_order) {}
424 
425     // GPR, calculate index from offs
Register(uint32_t offs,RegisterContext * reg_ctx,ByteOrder byte_order)426     Register(uint32_t offs, RegisterContext *reg_ctx, ByteOrder byte_order)
427         : Register(GPR, offs / sizeof(uint64_t), offs, reg_ctx, byte_order) {}
428 
Index() const429     uint32_t Index() const { return m_index; }
430 
431     // register offset where data is located
Offs() const432     uint32_t Offs() const { return m_offs; }
433 
434     // available bytes in this register
Avail() const435     uint32_t Avail() const { return m_avail; }
436 
IsValid() const437     bool IsValid() const {
438       if (m_index > 7) {
439         LLDB_LOG(m_log, LOG_PREFIX
440                  "No more than 8 registers should be used to return values");
441         return false;
442       }
443       return true;
444     }
445 
GetName() const446     std::string GetName() const {
447       if (m_type == GPR)
448         return ("r" + llvm::Twine(m_index + 3)).str();
449       else
450         return ("f" + llvm::Twine(m_index + 1)).str();
451     }
452 
453     // get raw register data
GetRawData(uint64_t & raw_data)454     bool GetRawData(uint64_t &raw_data) {
455       const RegisterInfo *reg_info =
456           m_reg_ctx->GetRegisterInfoByName(GetName());
457       if (!reg_info) {
458         LLDB_LOG(m_log, LOG_PREFIX "Failed to get RegisterInfo");
459         return false;
460       }
461 
462       RegisterValue reg_val;
463       if (!m_reg_ctx->ReadRegister(reg_info, reg_val)) {
464         LLDB_LOG(m_log, LOG_PREFIX "ReadRegister() failed");
465         return false;
466       }
467 
468       Status error;
469       uint32_t rc = reg_val.GetAsMemoryData(
470           *reg_info, &raw_data, sizeof(raw_data), m_byte_order, error);
471       if (rc != sizeof(raw_data)) {
472         LLDB_LOG(m_log, LOG_PREFIX "GetAsMemoryData() failed");
473         return false;
474       }
475 
476       return true;
477     }
478 
479   private:
480     uint32_t m_index;
481     uint32_t m_offs;
482     uint32_t m_avail;
483     Type m_type;
484     RegisterContext *m_reg_ctx;
485     ByteOrder m_byte_order;
486     Log *m_log = GetLog(LLDBLog::Expressions);
487   };
488 
GetGPR(uint32_t index) const489   Register GetGPR(uint32_t index) const {
490     return Register(Register::GPR, index, m_reg_ctx, m_byte_order);
491   }
492 
GetFPR(uint32_t index) const493   Register GetFPR(uint32_t index) const {
494     return Register(Register::FPR, index, m_reg_ctx, m_byte_order);
495   }
496 
GetGPRByOffs(uint32_t offs) const497   Register GetGPRByOffs(uint32_t offs) const {
498     return Register(offs, m_reg_ctx, m_byte_order);
499   }
500 
501 public:
502   // factory
Create(Thread & thread,CompilerType & type)503   static llvm::Expected<ReturnValueExtractor> Create(Thread &thread,
504                                                      CompilerType &type) {
505     RegisterContext *reg_ctx = thread.GetRegisterContext().get();
506     if (!reg_ctx)
507       return llvm::createStringError(LOG_PREFIX
508                                      "Failed to get RegisterContext");
509 
510     ProcessSP process_sp = thread.GetProcess();
511     if (!process_sp)
512       return llvm::createStringError(LOG_PREFIX "GetProcess() failed");
513 
514     return ReturnValueExtractor(thread, type, reg_ctx, process_sp);
515   }
516 
517   // main method: get value of the type specified at construction time
GetValue()518   ValueObjectSP GetValue() {
519     const uint32_t type_flags = m_type.GetTypeInfo();
520 
521     // call the appropriate type handler
522     ValueSP value_sp;
523     ValueObjectSP valobj_sp;
524     if (type_flags & eTypeIsScalar) {
525       if (type_flags & eTypeIsInteger) {
526         value_sp = GetIntegerValue(0);
527       } else if (type_flags & eTypeIsFloat) {
528         if (type_flags & eTypeIsComplex) {
529           LLDB_LOG(m_log, LOG_PREFIX "Complex numbers are not supported yet");
530           return ValueObjectSP();
531         } else {
532           value_sp = GetFloatValue(m_type, 0);
533         }
534       }
535     } else if (type_flags & eTypeIsPointer) {
536       value_sp = GetPointerValue(0);
537     }
538 
539     if (value_sp) {
540       valobj_sp = ValueObjectConstResult::Create(
541           m_thread.GetStackFrameAtIndex(0).get(), *value_sp, ConstString(""));
542     } else if (type_flags & eTypeIsVector) {
543       valobj_sp = GetVectorValueObject();
544     } else if (type_flags & eTypeIsStructUnion || type_flags & eTypeIsClass) {
545       valobj_sp = GetStructValueObject();
546     }
547 
548     return valobj_sp;
549   }
550 
551 private:
552   // data
553   Thread &m_thread;
554   CompilerType &m_type;
555   uint64_t m_byte_size;
556   std::unique_ptr<DataBufferHeap> m_data_up;
557   int32_t m_src_offs = 0;
558   int32_t m_dst_offs = 0;
559   bool m_packed = false;
560   Log *m_log = GetLog(LLDBLog::Expressions);
561   RegisterContext *m_reg_ctx;
562   ProcessSP m_process_sp;
563   ByteOrder m_byte_order;
564   uint32_t m_addr_size;
565 
566   // methods
567 
568   // constructor
ReturnValueExtractor(Thread & thread,CompilerType & type,RegisterContext * reg_ctx,ProcessSP process_sp)569   ReturnValueExtractor(Thread &thread, CompilerType &type,
570                        RegisterContext *reg_ctx, ProcessSP process_sp)
571       : m_thread(thread), m_type(type),
572         m_byte_size(
573             llvm::expectedToOptional(m_type.GetByteSize(&thread)).value_or(0)),
574         m_data_up(new DataBufferHeap(m_byte_size, 0)), m_reg_ctx(reg_ctx),
575         m_process_sp(process_sp), m_byte_order(process_sp->GetByteOrder()),
576         m_addr_size(
577             process_sp->GetTarget().GetArchitecture().GetAddressByteSize()) {}
578 
579   // build a new scalar value
NewScalarValue(CompilerType & type)580   ValueSP NewScalarValue(CompilerType &type) {
581     ValueSP value_sp(new Value);
582     value_sp->SetCompilerType(type);
583     value_sp->SetValueType(Value::ValueType::Scalar);
584     return value_sp;
585   }
586 
587   // get an integer value in the specified register
GetIntegerValue(uint32_t reg_index)588   ValueSP GetIntegerValue(uint32_t reg_index) {
589     uint64_t raw_value;
590     auto reg = GetGPR(reg_index);
591     if (!reg.GetRawData(raw_value))
592       return ValueSP();
593 
594     // build value from data
595     ValueSP value_sp(NewScalarValue(m_type));
596 
597     uint32_t type_flags = m_type.GetTypeInfo();
598     bool is_signed = (type_flags & eTypeIsSigned) != 0;
599 
600     switch (m_byte_size) {
601     case sizeof(uint64_t):
602       if (is_signed)
603         value_sp->GetScalar() = (int64_t)(raw_value);
604       else
605         value_sp->GetScalar() = (uint64_t)(raw_value);
606       break;
607 
608     case sizeof(uint32_t):
609       if (is_signed)
610         value_sp->GetScalar() = (int32_t)(raw_value & UINT32_MAX);
611       else
612         value_sp->GetScalar() = (uint32_t)(raw_value & UINT32_MAX);
613       break;
614 
615     case sizeof(uint16_t):
616       if (is_signed)
617         value_sp->GetScalar() = (int16_t)(raw_value & UINT16_MAX);
618       else
619         value_sp->GetScalar() = (uint16_t)(raw_value & UINT16_MAX);
620       break;
621 
622     case sizeof(uint8_t):
623       if (is_signed)
624         value_sp->GetScalar() = (int8_t)(raw_value & UINT8_MAX);
625       else
626         value_sp->GetScalar() = (uint8_t)(raw_value & UINT8_MAX);
627       break;
628 
629     default:
630       llvm_unreachable("Invalid integer size");
631     }
632 
633     return value_sp;
634   }
635 
636   // get a floating point value on the specified register
GetFloatValue(CompilerType & type,uint32_t reg_index)637   ValueSP GetFloatValue(CompilerType &type, uint32_t reg_index) {
638     uint64_t raw_data;
639     auto reg = GetFPR(reg_index);
640     if (!reg.GetRawData(raw_data))
641       return {};
642 
643     // build value from data
644     ValueSP value_sp(NewScalarValue(type));
645 
646     DataExtractor de(&raw_data, sizeof(raw_data), m_byte_order, m_addr_size);
647 
648     lldb::offset_t offset = 0;
649     std::optional<uint64_t> byte_size =
650         llvm::expectedToOptional(type.GetByteSize(m_process_sp.get()));
651     if (!byte_size)
652       return {};
653     switch (*byte_size) {
654     case sizeof(float):
655       value_sp->GetScalar() = (float)de.GetDouble(&offset);
656       break;
657 
658     case sizeof(double):
659       value_sp->GetScalar() = de.GetDouble(&offset);
660       break;
661 
662     default:
663       llvm_unreachable("Invalid floating point size");
664     }
665 
666     return value_sp;
667   }
668 
669   // get pointer value from register
GetPointerValue(uint32_t reg_index)670   ValueSP GetPointerValue(uint32_t reg_index) {
671     uint64_t raw_data;
672     auto reg = GetGPR(reg_index);
673     if (!reg.GetRawData(raw_data))
674       return ValueSP();
675 
676     // build value from raw data
677     ValueSP value_sp(NewScalarValue(m_type));
678     value_sp->GetScalar() = raw_data;
679     return value_sp;
680   }
681 
682   // build the ValueObject from our data buffer
BuildValueObject()683   ValueObjectSP BuildValueObject() {
684     DataExtractor de(DataBufferSP(m_data_up.release()), m_byte_order,
685                      m_addr_size);
686     return ValueObjectConstResult::Create(&m_thread, m_type, ConstString(""),
687                                           de);
688   }
689 
690   // get a vector return value
GetVectorValueObject()691   ValueObjectSP GetVectorValueObject() {
692     const uint32_t MAX_VRS = 2;
693 
694     // get first V register used to return values
695     const RegisterInfo *vr[MAX_VRS];
696     vr[0] = m_reg_ctx->GetRegisterInfoByName("vr2");
697     if (!vr[0]) {
698       LLDB_LOG(m_log, LOG_PREFIX "Failed to get vr2 RegisterInfo");
699       return ValueObjectSP();
700     }
701 
702     const uint32_t vr_size = vr[0]->byte_size;
703     size_t vrs = 1;
704     if (m_byte_size > 2 * vr_size) {
705       LLDB_LOG(
706           m_log, LOG_PREFIX
707           "Returning vectors that don't fit in 2 VR regs is not supported");
708       return ValueObjectSP();
709     }
710 
711     // load vr3, if needed
712     if (m_byte_size > vr_size) {
713       vrs++;
714       vr[1] = m_reg_ctx->GetRegisterInfoByName("vr3");
715       if (!vr[1]) {
716         LLDB_LOG(m_log, LOG_PREFIX "Failed to get vr3 RegisterInfo");
717         return ValueObjectSP();
718       }
719     }
720 
721     // Get the whole contents of vector registers and let the logic here
722     // arrange the data properly.
723 
724     RegisterValue vr_val[MAX_VRS];
725     Status error;
726     std::unique_ptr<DataBufferHeap> vr_data(
727         new DataBufferHeap(vrs * vr_size, 0));
728 
729     for (uint32_t i = 0; i < vrs; i++) {
730       if (!m_reg_ctx->ReadRegister(vr[i], vr_val[i])) {
731         LLDB_LOG(m_log, LOG_PREFIX "Failed to read vector register contents");
732         return ValueObjectSP();
733       }
734       if (!vr_val[i].GetAsMemoryData(*vr[i], vr_data->GetBytes() + i * vr_size,
735                                      vr_size, m_byte_order, error)) {
736         LLDB_LOG(m_log, LOG_PREFIX "Failed to extract vector register bytes");
737         return ValueObjectSP();
738       }
739     }
740 
741     // The compiler generated code seems to always put the vector elements at
742     // the end of the vector register, in case they don't occupy all of it.
743     // This offset variable handles this.
744     uint32_t offs = 0;
745     if (m_byte_size < vr_size)
746       offs = vr_size - m_byte_size;
747 
748     // copy extracted data to our buffer
749     memcpy(m_data_up->GetBytes(), vr_data->GetBytes() + offs, m_byte_size);
750     return BuildValueObject();
751   }
752 
753   // get a struct return value
GetStructValueObject()754   ValueObjectSP GetStructValueObject() {
755     // case 1: get from stack
756     if (m_byte_size > 2 * sizeof(uint64_t)) {
757       uint64_t addr;
758       auto reg = GetGPR(0);
759       if (!reg.GetRawData(addr))
760         return {};
761 
762       Status error;
763       size_t rc = m_process_sp->ReadMemory(addr, m_data_up->GetBytes(),
764                                            m_byte_size, error);
765       if (rc != m_byte_size) {
766         LLDB_LOG(m_log, LOG_PREFIX "Failed to read memory pointed by r3");
767         return ValueObjectSP();
768       }
769       return BuildValueObject();
770     }
771 
772     // get number of children
773     const bool omit_empty_base_classes = true;
774     auto n_or_err = m_type.GetNumChildren(omit_empty_base_classes, nullptr);
775     if (!n_or_err) {
776       LLDB_LOG_ERROR(m_log, n_or_err.takeError(), LOG_PREFIX "{0}");
777       return {};
778     }
779     uint32_t n = *n_or_err;
780     if (!n) {
781       LLDB_LOG(m_log, LOG_PREFIX "No children found in struct");
782       return {};
783     }
784 
785     // case 2: homogeneous double or float aggregate
786     CompilerType elem_type;
787     if (m_type.IsHomogeneousAggregate(&elem_type)) {
788       uint32_t type_flags = elem_type.GetTypeInfo();
789       std::optional<uint64_t> elem_size =
790           llvm::expectedToOptional(elem_type.GetByteSize(m_process_sp.get()));
791       if (!elem_size)
792         return {};
793       if (type_flags & eTypeIsComplex || !(type_flags & eTypeIsFloat)) {
794         LLDB_LOG(m_log,
795                  LOG_PREFIX "Unexpected type found in homogeneous aggregate");
796         return {};
797       }
798 
799       for (uint32_t i = 0; i < n; i++) {
800         ValueSP val_sp = GetFloatValue(elem_type, i);
801         if (!val_sp)
802           return {};
803 
804         // copy to buffer
805         Status error;
806         size_t rc = val_sp->GetScalar().GetAsMemoryData(
807             m_data_up->GetBytes() + m_dst_offs, *elem_size, m_byte_order,
808             error);
809         if (rc != *elem_size) {
810           LLDB_LOG(m_log, LOG_PREFIX "Failed to get float data");
811           return {};
812         }
813         m_dst_offs += *elem_size;
814       }
815       return BuildValueObject();
816     }
817 
818     // case 3: get from GPRs
819 
820     // first, check if this is a packed struct or not
821     auto ast = m_type.GetTypeSystem().dyn_cast_or_null<TypeSystemClang>();
822     if (ast) {
823       clang::RecordDecl *record_decl = TypeSystemClang::GetAsRecordDecl(m_type);
824 
825       if (record_decl) {
826         auto attrs = record_decl->attrs();
827         for (const auto &attr : attrs) {
828           if (attr->getKind() == clang::attr::Packed) {
829             m_packed = true;
830             break;
831           }
832         }
833       }
834     }
835 
836     LLDB_LOG(m_log, LOG_PREFIX "{0} struct",
837              m_packed ? "packed" : "not packed");
838 
839     for (uint32_t i = 0; i < n; i++) {
840       std::string name;
841       uint32_t size;
842       (void)GetChildType(i, name, size);
843       // NOTE: the offset returned by GetChildCompilerTypeAtIndex()
844       //       can't be used because it never considers alignment bytes
845       //       between struct fields.
846       LLDB_LOG(m_log, LOG_PREFIX "field={0}, size={1}", name, size);
847       if (!ExtractField(size))
848         return ValueObjectSP();
849     }
850 
851     return BuildValueObject();
852   }
853 
854   // extract 'size' bytes at 'offs' from GPRs
ExtractFromRegs(int32_t offs,uint32_t size,void * buf)855   bool ExtractFromRegs(int32_t offs, uint32_t size, void *buf) {
856     while (size) {
857       auto reg = GetGPRByOffs(offs);
858       if (!reg.IsValid())
859         return false;
860 
861       uint32_t n = std::min(reg.Avail(), size);
862       uint64_t raw_data;
863 
864       if (!reg.GetRawData(raw_data))
865         return false;
866 
867       memcpy(buf, (char *)&raw_data + reg.Offs(), n);
868       offs += n;
869       size -= n;
870       buf = (char *)buf + n;
871     }
872     return true;
873   }
874 
875   // extract one field from GPRs and put it in our buffer
ExtractField(uint32_t size)876   bool ExtractField(uint32_t size) {
877     auto reg = GetGPRByOffs(m_src_offs);
878     if (!reg.IsValid())
879       return false;
880 
881     // handle padding
882     if (!m_packed) {
883       uint32_t n = m_src_offs % size;
884 
885       // not 'size' bytes aligned
886       if (n) {
887         LLDB_LOG(m_log,
888                  LOG_PREFIX "Extracting {0} alignment bytes at offset {1}", n,
889                  m_src_offs);
890         // get alignment bytes
891         if (!ExtractFromRegs(m_src_offs, n, m_data_up->GetBytes() + m_dst_offs))
892           return false;
893         m_src_offs += n;
894         m_dst_offs += n;
895       }
896     }
897 
898     // get field
899     LLDB_LOG(m_log, LOG_PREFIX "Extracting {0} field bytes at offset {1}", size,
900              m_src_offs);
901     if (!ExtractFromRegs(m_src_offs, size, m_data_up->GetBytes() + m_dst_offs))
902       return false;
903     m_src_offs += size;
904     m_dst_offs += size;
905     return true;
906   }
907 
908   // get child
GetChildType(uint32_t i,std::string & name,uint32_t & size)909   llvm::Expected<CompilerType> GetChildType(uint32_t i, std::string &name,
910                                             uint32_t &size) {
911     // GetChild constant inputs
912     const bool transparent_pointers = false;
913     const bool omit_empty_base_classes = true;
914     const bool ignore_array_bounds = false;
915     // GetChild output params
916     int32_t child_offs;
917     uint32_t child_bitfield_bit_size;
918     uint32_t child_bitfield_bit_offset;
919     bool child_is_base_class;
920     bool child_is_deref_of_parent;
921     ValueObject *valobj = nullptr;
922     uint64_t language_flags;
923     ExecutionContext exe_ctx;
924     m_thread.CalculateExecutionContext(exe_ctx);
925 
926     return m_type.GetChildCompilerTypeAtIndex(
927         &exe_ctx, i, transparent_pointers, omit_empty_base_classes,
928         ignore_array_bounds, name, size, child_offs, child_bitfield_bit_size,
929         child_bitfield_bit_offset, child_is_base_class,
930         child_is_deref_of_parent, valobj, language_flags);
931   }
932 };
933 
934 #undef LOG_PREFIX
935 
936 } // anonymous namespace
937 
938 ValueObjectSP
GetReturnValueObjectSimple(Thread & thread,CompilerType & type) const939 ABISysV_ppc64::GetReturnValueObjectSimple(Thread &thread,
940                                           CompilerType &type) const {
941   if (!type)
942     return ValueObjectSP();
943 
944   auto exp_extractor = ReturnValueExtractor::Create(thread, type);
945   if (!exp_extractor) {
946     Log *log = GetLog(LLDBLog::Expressions);
947     LLDB_LOG_ERROR(log, exp_extractor.takeError(),
948                    "Extracting return value failed: {0}");
949     return ValueObjectSP();
950   }
951 
952   return exp_extractor.get().GetValue();
953 }
954 
GetReturnValueObjectImpl(Thread & thread,CompilerType & return_compiler_type) const955 ValueObjectSP ABISysV_ppc64::GetReturnValueObjectImpl(
956     Thread &thread, CompilerType &return_compiler_type) const {
957   return GetReturnValueObjectSimple(thread, return_compiler_type);
958 }
959 
CreateFunctionEntryUnwindPlan()960 UnwindPlanSP ABISysV_ppc64::CreateFunctionEntryUnwindPlan() {
961 
962   uint32_t lr_reg_num;
963   uint32_t sp_reg_num;
964   uint32_t pc_reg_num;
965 
966   if (GetByteOrder() == lldb::eByteOrderLittle) {
967     lr_reg_num = ppc64le_dwarf::dwarf_lr_ppc64le;
968     sp_reg_num = ppc64le_dwarf::dwarf_r1_ppc64le;
969     pc_reg_num = ppc64le_dwarf::dwarf_pc_ppc64le;
970   } else {
971     lr_reg_num = ppc64_dwarf::dwarf_lr_ppc64;
972     sp_reg_num = ppc64_dwarf::dwarf_r1_ppc64;
973     pc_reg_num = ppc64_dwarf::dwarf_pc_ppc64;
974   }
975 
976   UnwindPlan::Row row;
977 
978   // Our Call Frame Address is the stack pointer value
979   row.GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 0);
980 
981   // The previous PC is in the LR. All other registers are the same.
982   row.SetRegisterLocationToRegister(pc_reg_num, lr_reg_num, true);
983 
984   auto plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);
985   plan_sp->AppendRow(std::move(row));
986   plan_sp->SetSourceName("ppc64 at-func-entry default");
987   plan_sp->SetSourcedFromCompiler(eLazyBoolNo);
988   return plan_sp;
989 }
990 
CreateDefaultUnwindPlan()991 UnwindPlanSP ABISysV_ppc64::CreateDefaultUnwindPlan() {
992   uint32_t sp_reg_num;
993   uint32_t pc_reg_num;
994   uint32_t cr_reg_num;
995 
996   if (GetByteOrder() == lldb::eByteOrderLittle) {
997     sp_reg_num = ppc64le_dwarf::dwarf_r1_ppc64le;
998     pc_reg_num = ppc64le_dwarf::dwarf_lr_ppc64le;
999     cr_reg_num = ppc64le_dwarf::dwarf_cr_ppc64le;
1000   } else {
1001     sp_reg_num = ppc64_dwarf::dwarf_r1_ppc64;
1002     pc_reg_num = ppc64_dwarf::dwarf_lr_ppc64;
1003     cr_reg_num = ppc64_dwarf::dwarf_cr_ppc64;
1004   }
1005 
1006   UnwindPlan::Row row;
1007   const int32_t ptr_size = 8;
1008   row.SetUnspecifiedRegistersAreUndefined(true);
1009   row.GetCFAValue().SetIsRegisterDereferenced(sp_reg_num);
1010 
1011   row.SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, ptr_size * 2, true);
1012   row.SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);
1013   row.SetRegisterLocationToAtCFAPlusOffset(cr_reg_num, ptr_size, true);
1014 
1015   auto plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);
1016   plan_sp->AppendRow(std::move(row));
1017   plan_sp->SetSourceName("ppc64 default unwind plan");
1018   plan_sp->SetSourcedFromCompiler(eLazyBoolNo);
1019   plan_sp->SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
1020   plan_sp->SetUnwindPlanForSignalTrap(eLazyBoolNo);
1021   plan_sp->SetReturnAddressRegister(pc_reg_num);
1022   return plan_sp;
1023 }
1024 
RegisterIsVolatile(const RegisterInfo * reg_info)1025 bool ABISysV_ppc64::RegisterIsVolatile(const RegisterInfo *reg_info) {
1026   return !RegisterIsCalleeSaved(reg_info);
1027 }
1028 
1029 // See "Register Usage" in the
1030 // "System V Application Binary Interface"
1031 // "64-bit PowerPC ELF Application Binary Interface Supplement" current version
1032 // is 2 released 2015 at
1033 // https://members.openpowerfoundation.org/document/dl/576
RegisterIsCalleeSaved(const RegisterInfo * reg_info)1034 bool ABISysV_ppc64::RegisterIsCalleeSaved(const RegisterInfo *reg_info) {
1035   if (reg_info) {
1036     // Preserved registers are :
1037     //    r1,r2,r13-r31
1038     //    cr2-cr4 (partially preserved)
1039     //    f14-f31 (not yet)
1040     //    v20-v31 (not yet)
1041     //    vrsave (not yet)
1042 
1043     const char *name = reg_info->name;
1044     if (name[0] == 'r') {
1045       if ((name[1] == '1' || name[1] == '2') && name[2] == '\0')
1046         return true;
1047       if (name[1] == '1' && name[2] > '2')
1048         return true;
1049       if ((name[1] == '2' || name[1] == '3') && name[2] != '\0')
1050         return true;
1051     }
1052 
1053     if (name[0] == 'f' && name[1] >= '0' && name[2] <= '9') {
1054       if (name[2] == '\0')
1055         return false;
1056       if (name[1] == '1' && name[2] >= '4')
1057         return true;
1058       if ((name[1] == '2' || name[1] == '3') && name[2] != '\0')
1059         return true;
1060     }
1061 
1062     if (name[0] == 's' && name[1] == 'p' && name[2] == '\0') // sp
1063       return true;
1064     if (name[0] == 'f' && name[1] == 'p' && name[2] == '\0') // fp
1065       return false;
1066     if (name[0] == 'p' && name[1] == 'c' && name[2] == '\0') // pc
1067       return true;
1068   }
1069   return false;
1070 }
1071 
Initialize()1072 void ABISysV_ppc64::Initialize() {
1073   PluginManager::RegisterPlugin(
1074       GetPluginNameStatic(), "System V ABI for ppc64 targets", CreateInstance);
1075 }
1076 
Terminate()1077 void ABISysV_ppc64::Terminate() {
1078   PluginManager::UnregisterPlugin(CreateInstance);
1079 }
1080