1 //===-- IRExecutionUnit.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 "llvm/ExecutionEngine/ExecutionEngine.h"
10 #include "llvm/ExecutionEngine/ObjectCache.h"
11 #include "llvm/IR/Constants.h"
12 #include "llvm/IR/DiagnosticHandler.h"
13 #include "llvm/IR/DiagnosticInfo.h"
14 #include "llvm/IR/LLVMContext.h"
15 #include "llvm/IR/Module.h"
16 #include "llvm/Support/SourceMgr.h"
17 #include "llvm/Support/raw_ostream.h"
18 
19 #include "lldb/Core/Debugger.h"
20 #include "lldb/Core/Disassembler.h"
21 #include "lldb/Core/Module.h"
22 #include "lldb/Core/Section.h"
23 #include "lldb/Expression/IRExecutionUnit.h"
24 #include "lldb/Host/HostInfo.h"
25 #include "lldb/Symbol/CompileUnit.h"
26 #include "lldb/Symbol/SymbolContext.h"
27 #include "lldb/Symbol/SymbolFile.h"
28 #include "lldb/Symbol/SymbolVendor.h"
29 #include "lldb/Target/ExecutionContext.h"
30 #include "lldb/Target/Language.h"
31 #include "lldb/Target/LanguageRuntime.h"
32 #include "lldb/Target/Target.h"
33 #include "lldb/Utility/DataBufferHeap.h"
34 #include "lldb/Utility/DataExtractor.h"
35 #include "lldb/Utility/LLDBAssert.h"
36 #include "lldb/Utility/LLDBLog.h"
37 #include "lldb/Utility/Log.h"
38 
39 #include "lldb/../../source/Plugins/ObjectFile/JIT/ObjectFileJIT.h"
40 
41 using namespace lldb_private;
42 
43 IRExecutionUnit::IRExecutionUnit(std::unique_ptr<llvm::LLVMContext> &context_up,
44                                  std::unique_ptr<llvm::Module> &module_up,
45                                  ConstString &name,
46                                  const lldb::TargetSP &target_sp,
47                                  const SymbolContext &sym_ctx,
48                                  std::vector<std::string> &cpu_features)
49     : IRMemoryMap(target_sp), m_context_up(context_up.release()),
50       m_module_up(module_up.release()), m_module(m_module_up.get()),
51       m_cpu_features(cpu_features), m_name(name), m_sym_ctx(sym_ctx),
52       m_did_jit(false), m_function_load_addr(LLDB_INVALID_ADDRESS),
53       m_function_end_load_addr(LLDB_INVALID_ADDRESS),
54       m_reported_allocations(false) {}
55 
56 lldb::addr_t IRExecutionUnit::WriteNow(const uint8_t *bytes, size_t size,
57                                        Status &error) {
58   const bool zero_memory = false;
59   lldb::addr_t allocation_process_addr =
60       Malloc(size, 8, lldb::ePermissionsWritable | lldb::ePermissionsReadable,
61              eAllocationPolicyMirror, zero_memory, error);
62 
63   if (!error.Success())
64     return LLDB_INVALID_ADDRESS;
65 
66   WriteMemory(allocation_process_addr, bytes, size, error);
67 
68   if (!error.Success()) {
69     Status err;
70     Free(allocation_process_addr, err);
71 
72     return LLDB_INVALID_ADDRESS;
73   }
74 
75   if (Log *log = GetLog(LLDBLog::Expressions)) {
76     DataBufferHeap my_buffer(size, 0);
77     Status err;
78     ReadMemory(my_buffer.GetBytes(), allocation_process_addr, size, err);
79 
80     if (err.Success()) {
81       DataExtractor my_extractor(my_buffer.GetBytes(), my_buffer.GetByteSize(),
82                                  lldb::eByteOrderBig, 8);
83       my_extractor.PutToLog(log, 0, my_buffer.GetByteSize(),
84                             allocation_process_addr, 16,
85                             DataExtractor::TypeUInt8);
86     }
87   }
88 
89   return allocation_process_addr;
90 }
91 
92 void IRExecutionUnit::FreeNow(lldb::addr_t allocation) {
93   if (allocation == LLDB_INVALID_ADDRESS)
94     return;
95 
96   Status err;
97 
98   Free(allocation, err);
99 }
100 
101 Status IRExecutionUnit::DisassembleFunction(Stream &stream,
102                                             lldb::ProcessSP &process_wp) {
103   Log *log = GetLog(LLDBLog::Expressions);
104 
105   ExecutionContext exe_ctx(process_wp);
106 
107   Status ret;
108 
109   ret.Clear();
110 
111   lldb::addr_t func_local_addr = LLDB_INVALID_ADDRESS;
112   lldb::addr_t func_remote_addr = LLDB_INVALID_ADDRESS;
113 
114   for (JittedFunction &function : m_jitted_functions) {
115     if (function.m_name == m_name) {
116       func_local_addr = function.m_local_addr;
117       func_remote_addr = function.m_remote_addr;
118     }
119   }
120 
121   if (func_local_addr == LLDB_INVALID_ADDRESS) {
122     ret.SetErrorToGenericError();
123     ret.SetErrorStringWithFormat("Couldn't find function %s for disassembly",
124                                  m_name.AsCString());
125     return ret;
126   }
127 
128   LLDB_LOGF(log,
129             "Found function, has local address 0x%" PRIx64
130             " and remote address 0x%" PRIx64,
131             (uint64_t)func_local_addr, (uint64_t)func_remote_addr);
132 
133   std::pair<lldb::addr_t, lldb::addr_t> func_range;
134 
135   func_range = GetRemoteRangeForLocal(func_local_addr);
136 
137   if (func_range.first == 0 && func_range.second == 0) {
138     ret.SetErrorToGenericError();
139     ret.SetErrorStringWithFormat("Couldn't find code range for function %s",
140                                  m_name.AsCString());
141     return ret;
142   }
143 
144   LLDB_LOGF(log, "Function's code range is [0x%" PRIx64 "+0x%" PRIx64 "]",
145             func_range.first, func_range.second);
146 
147   Target *target = exe_ctx.GetTargetPtr();
148   if (!target) {
149     ret.SetErrorToGenericError();
150     ret.SetErrorString("Couldn't find the target");
151     return ret;
152   }
153 
154   lldb::WritableDataBufferSP buffer_sp(
155       new DataBufferHeap(func_range.second, 0));
156 
157   Process *process = exe_ctx.GetProcessPtr();
158   Status err;
159   process->ReadMemory(func_remote_addr, buffer_sp->GetBytes(),
160                       buffer_sp->GetByteSize(), err);
161 
162   if (!err.Success()) {
163     ret.SetErrorToGenericError();
164     ret.SetErrorStringWithFormat("Couldn't read from process: %s",
165                                  err.AsCString("unknown error"));
166     return ret;
167   }
168 
169   ArchSpec arch(target->GetArchitecture());
170 
171   const char *plugin_name = nullptr;
172   const char *flavor_string = nullptr;
173   lldb::DisassemblerSP disassembler_sp =
174       Disassembler::FindPlugin(arch, flavor_string, plugin_name);
175 
176   if (!disassembler_sp) {
177     ret.SetErrorToGenericError();
178     ret.SetErrorStringWithFormat(
179         "Unable to find disassembler plug-in for %s architecture.",
180         arch.GetArchitectureName());
181     return ret;
182   }
183 
184   if (!process) {
185     ret.SetErrorToGenericError();
186     ret.SetErrorString("Couldn't find the process");
187     return ret;
188   }
189 
190   DataExtractor extractor(buffer_sp, process->GetByteOrder(),
191                           target->GetArchitecture().GetAddressByteSize());
192 
193   if (log) {
194     LLDB_LOGF(log, "Function data has contents:");
195     extractor.PutToLog(log, 0, extractor.GetByteSize(), func_remote_addr, 16,
196                        DataExtractor::TypeUInt8);
197   }
198 
199   disassembler_sp->DecodeInstructions(Address(func_remote_addr), extractor, 0,
200                                       UINT32_MAX, false, false);
201 
202   InstructionList &instruction_list = disassembler_sp->GetInstructionList();
203   instruction_list.Dump(&stream, true, true, /*show_control_flow_kind=*/true,
204                         &exe_ctx);
205 
206   return ret;
207 }
208 
209 namespace {
210 struct IRExecDiagnosticHandler : public llvm::DiagnosticHandler {
211   Status *err;
212   IRExecDiagnosticHandler(Status *err) : err(err) {}
213   bool handleDiagnostics(const llvm::DiagnosticInfo &DI) override {
214     if (DI.getKind() == llvm::DK_SrcMgr) {
215       const auto &DISM = llvm::cast<llvm::DiagnosticInfoSrcMgr>(DI);
216       if (err && err->Success()) {
217         err->SetErrorToGenericError();
218         err->SetErrorStringWithFormat(
219             "Inline assembly error: %s",
220             DISM.getSMDiag().getMessage().str().c_str());
221       }
222       return true;
223     }
224 
225     return false;
226   }
227 };
228 } // namespace
229 
230 void IRExecutionUnit::ReportSymbolLookupError(ConstString name) {
231   m_failed_lookups.push_back(name);
232 }
233 
234 void IRExecutionUnit::GetRunnableInfo(Status &error, lldb::addr_t &func_addr,
235                                       lldb::addr_t &func_end) {
236   lldb::ProcessSP process_sp(GetProcessWP().lock());
237 
238   static std::recursive_mutex s_runnable_info_mutex;
239 
240   func_addr = LLDB_INVALID_ADDRESS;
241   func_end = LLDB_INVALID_ADDRESS;
242 
243   if (!process_sp) {
244     error.SetErrorToGenericError();
245     error.SetErrorString("Couldn't write the JIT compiled code into the "
246                          "process because the process is invalid");
247     return;
248   }
249 
250   if (m_did_jit) {
251     func_addr = m_function_load_addr;
252     func_end = m_function_end_load_addr;
253 
254     return;
255   };
256 
257   std::lock_guard<std::recursive_mutex> guard(s_runnable_info_mutex);
258 
259   m_did_jit = true;
260 
261   Log *log = GetLog(LLDBLog::Expressions);
262 
263   std::string error_string;
264 
265   if (log) {
266     std::string s;
267     llvm::raw_string_ostream oss(s);
268 
269     m_module->print(oss, nullptr);
270 
271     oss.flush();
272 
273     LLDB_LOGF(log, "Module being sent to JIT: \n%s", s.c_str());
274   }
275 
276   m_module_up->getContext().setDiagnosticHandler(
277       std::make_unique<IRExecDiagnosticHandler>(&error));
278 
279   llvm::EngineBuilder builder(std::move(m_module_up));
280   llvm::Triple triple(m_module->getTargetTriple());
281 
282   builder.setEngineKind(llvm::EngineKind::JIT)
283       .setErrorStr(&error_string)
284       .setRelocationModel(triple.isOSBinFormatMachO() ? llvm::Reloc::PIC_
285                                                       : llvm::Reloc::Static)
286       .setMCJITMemoryManager(std::make_unique<MemoryManager>(*this))
287       .setOptLevel(llvm::CodeGenOpt::Less);
288 
289   llvm::StringRef mArch;
290   llvm::StringRef mCPU;
291   llvm::SmallVector<std::string, 0> mAttrs;
292 
293   for (std::string &feature : m_cpu_features)
294     mAttrs.push_back(feature);
295 
296   llvm::TargetMachine *target_machine =
297       builder.selectTarget(triple, mArch, mCPU, mAttrs);
298 
299   m_execution_engine_up.reset(builder.create(target_machine));
300 
301   if (!m_execution_engine_up) {
302     error.SetErrorToGenericError();
303     error.SetErrorStringWithFormat("Couldn't JIT the function: %s",
304                                    error_string.c_str());
305     return;
306   }
307 
308   m_strip_underscore =
309       (m_execution_engine_up->getDataLayout().getGlobalPrefix() == '_');
310 
311   class ObjectDumper : public llvm::ObjectCache {
312   public:
313     ObjectDumper(FileSpec output_dir)  : m_out_dir(output_dir) {}
314     void notifyObjectCompiled(const llvm::Module *module,
315                               llvm::MemoryBufferRef object) override {
316       int fd = 0;
317       llvm::SmallVector<char, 256> result_path;
318       std::string object_name_model =
319           "jit-object-" + module->getModuleIdentifier() + "-%%%.o";
320       FileSpec model_spec
321           = m_out_dir.CopyByAppendingPathComponent(object_name_model);
322       std::string model_path = model_spec.GetPath();
323 
324       std::error_code result
325         = llvm::sys::fs::createUniqueFile(model_path, fd, result_path);
326       if (!result) {
327           llvm::raw_fd_ostream fds(fd, true);
328           fds.write(object.getBufferStart(), object.getBufferSize());
329       }
330     }
331     std::unique_ptr<llvm::MemoryBuffer>
332     getObject(const llvm::Module *module) override  {
333       // Return nothing - we're just abusing the object-cache mechanism to dump
334       // objects.
335       return nullptr;
336   }
337   private:
338     FileSpec m_out_dir;
339   };
340 
341   FileSpec save_objects_dir = process_sp->GetTarget().GetSaveJITObjectsDir();
342   if (save_objects_dir) {
343     m_object_cache_up = std::make_unique<ObjectDumper>(save_objects_dir);
344     m_execution_engine_up->setObjectCache(m_object_cache_up.get());
345   }
346 
347   // Make sure we see all sections, including ones that don't have
348   // relocations...
349   m_execution_engine_up->setProcessAllSections(true);
350 
351   m_execution_engine_up->DisableLazyCompilation();
352 
353   for (llvm::Function &function : *m_module) {
354     if (function.isDeclaration() || function.hasPrivateLinkage())
355       continue;
356 
357     const bool external = !function.hasLocalLinkage();
358 
359     void *fun_ptr = m_execution_engine_up->getPointerToFunction(&function);
360 
361     if (!error.Success()) {
362       // We got an error through our callback!
363       return;
364     }
365 
366     if (!fun_ptr) {
367       error.SetErrorToGenericError();
368       error.SetErrorStringWithFormat(
369           "'%s' was in the JITted module but wasn't lowered",
370           function.getName().str().c_str());
371       return;
372     }
373     m_jitted_functions.push_back(JittedFunction(
374         function.getName().str().c_str(), external, reinterpret_cast<uintptr_t>(fun_ptr)));
375   }
376 
377   CommitAllocations(process_sp);
378   ReportAllocations(*m_execution_engine_up);
379 
380   // We have to do this after calling ReportAllocations because for the MCJIT,
381   // getGlobalValueAddress will cause the JIT to perform all relocations.  That
382   // can only be done once, and has to happen after we do the remapping from
383   // local -> remote. That means we don't know the local address of the
384   // Variables, but we don't need that for anything, so that's okay.
385 
386   std::function<void(llvm::GlobalValue &)> RegisterOneValue = [this](
387       llvm::GlobalValue &val) {
388     if (val.hasExternalLinkage() && !val.isDeclaration()) {
389       uint64_t var_ptr_addr =
390           m_execution_engine_up->getGlobalValueAddress(val.getName().str());
391 
392       lldb::addr_t remote_addr = GetRemoteAddressForLocal(var_ptr_addr);
393 
394       // This is a really unfortunae API that sometimes returns local addresses
395       // and sometimes returns remote addresses, based on whether the variable
396       // was relocated during ReportAllocations or not.
397 
398       if (remote_addr == LLDB_INVALID_ADDRESS) {
399         remote_addr = var_ptr_addr;
400       }
401 
402       if (var_ptr_addr != 0)
403         m_jitted_global_variables.push_back(JittedGlobalVariable(
404             val.getName().str().c_str(), LLDB_INVALID_ADDRESS, remote_addr));
405     }
406   };
407 
408   for (llvm::GlobalVariable &global_var : m_module->getGlobalList()) {
409     RegisterOneValue(global_var);
410   }
411 
412   for (llvm::GlobalAlias &global_alias : m_module->getAliasList()) {
413     RegisterOneValue(global_alias);
414   }
415 
416   WriteData(process_sp);
417 
418   if (m_failed_lookups.size()) {
419     StreamString ss;
420 
421     ss.PutCString("Couldn't lookup symbols:\n");
422 
423     bool emitNewLine = false;
424 
425     for (ConstString failed_lookup : m_failed_lookups) {
426       if (emitNewLine)
427         ss.PutCString("\n");
428       emitNewLine = true;
429       ss.PutCString("  ");
430       ss.PutCString(Mangled(failed_lookup).GetDemangledName().GetStringRef());
431     }
432 
433     m_failed_lookups.clear();
434 
435     error.SetErrorString(ss.GetString());
436 
437     return;
438   }
439 
440   m_function_load_addr = LLDB_INVALID_ADDRESS;
441   m_function_end_load_addr = LLDB_INVALID_ADDRESS;
442 
443   for (JittedFunction &jitted_function : m_jitted_functions) {
444     jitted_function.m_remote_addr =
445         GetRemoteAddressForLocal(jitted_function.m_local_addr);
446 
447     if (!m_name.IsEmpty() && jitted_function.m_name == m_name) {
448       AddrRange func_range =
449           GetRemoteRangeForLocal(jitted_function.m_local_addr);
450       m_function_end_load_addr = func_range.first + func_range.second;
451       m_function_load_addr = jitted_function.m_remote_addr;
452     }
453   }
454 
455   if (log) {
456     LLDB_LOGF(log, "Code can be run in the target.");
457 
458     StreamString disassembly_stream;
459 
460     Status err = DisassembleFunction(disassembly_stream, process_sp);
461 
462     if (!err.Success()) {
463       LLDB_LOGF(log, "Couldn't disassemble function : %s",
464                 err.AsCString("unknown error"));
465     } else {
466       LLDB_LOGF(log, "Function disassembly:\n%s", disassembly_stream.GetData());
467     }
468 
469     LLDB_LOGF(log, "Sections: ");
470     for (AllocationRecord &record : m_records) {
471       if (record.m_process_address != LLDB_INVALID_ADDRESS) {
472         record.dump(log);
473 
474         DataBufferHeap my_buffer(record.m_size, 0);
475         Status err;
476         ReadMemory(my_buffer.GetBytes(), record.m_process_address,
477                    record.m_size, err);
478 
479         if (err.Success()) {
480           DataExtractor my_extractor(my_buffer.GetBytes(),
481                                      my_buffer.GetByteSize(),
482                                      lldb::eByteOrderBig, 8);
483           my_extractor.PutToLog(log, 0, my_buffer.GetByteSize(),
484                                 record.m_process_address, 16,
485                                 DataExtractor::TypeUInt8);
486         }
487       } else {
488         record.dump(log);
489 
490         DataExtractor my_extractor((const void *)record.m_host_address,
491                                    record.m_size, lldb::eByteOrderBig, 8);
492         my_extractor.PutToLog(log, 0, record.m_size, record.m_host_address, 16,
493                               DataExtractor::TypeUInt8);
494       }
495     }
496   }
497 
498   func_addr = m_function_load_addr;
499   func_end = m_function_end_load_addr;
500 }
501 
502 IRExecutionUnit::~IRExecutionUnit() {
503   m_module_up.reset();
504   m_execution_engine_up.reset();
505   m_context_up.reset();
506 }
507 
508 IRExecutionUnit::MemoryManager::MemoryManager(IRExecutionUnit &parent)
509     : m_default_mm_up(new llvm::SectionMemoryManager()), m_parent(parent) {}
510 
511 IRExecutionUnit::MemoryManager::~MemoryManager() = default;
512 
513 lldb::SectionType IRExecutionUnit::GetSectionTypeFromSectionName(
514     const llvm::StringRef &name, IRExecutionUnit::AllocationKind alloc_kind) {
515   lldb::SectionType sect_type = lldb::eSectionTypeCode;
516   switch (alloc_kind) {
517   case AllocationKind::Stub:
518     sect_type = lldb::eSectionTypeCode;
519     break;
520   case AllocationKind::Code:
521     sect_type = lldb::eSectionTypeCode;
522     break;
523   case AllocationKind::Data:
524     sect_type = lldb::eSectionTypeData;
525     break;
526   case AllocationKind::Global:
527     sect_type = lldb::eSectionTypeData;
528     break;
529   case AllocationKind::Bytes:
530     sect_type = lldb::eSectionTypeOther;
531     break;
532   }
533 
534   if (!name.empty()) {
535     if (name.equals("__text") || name.equals(".text"))
536       sect_type = lldb::eSectionTypeCode;
537     else if (name.equals("__data") || name.equals(".data"))
538       sect_type = lldb::eSectionTypeCode;
539     else if (name.startswith("__debug_") || name.startswith(".debug_")) {
540       const uint32_t name_idx = name[0] == '_' ? 8 : 7;
541       llvm::StringRef dwarf_name(name.substr(name_idx));
542       switch (dwarf_name[0]) {
543       case 'a':
544         if (dwarf_name.equals("abbrev"))
545           sect_type = lldb::eSectionTypeDWARFDebugAbbrev;
546         else if (dwarf_name.equals("aranges"))
547           sect_type = lldb::eSectionTypeDWARFDebugAranges;
548         else if (dwarf_name.equals("addr"))
549           sect_type = lldb::eSectionTypeDWARFDebugAddr;
550         break;
551 
552       case 'f':
553         if (dwarf_name.equals("frame"))
554           sect_type = lldb::eSectionTypeDWARFDebugFrame;
555         break;
556 
557       case 'i':
558         if (dwarf_name.equals("info"))
559           sect_type = lldb::eSectionTypeDWARFDebugInfo;
560         break;
561 
562       case 'l':
563         if (dwarf_name.equals("line"))
564           sect_type = lldb::eSectionTypeDWARFDebugLine;
565         else if (dwarf_name.equals("loc"))
566           sect_type = lldb::eSectionTypeDWARFDebugLoc;
567         else if (dwarf_name.equals("loclists"))
568           sect_type = lldb::eSectionTypeDWARFDebugLocLists;
569         break;
570 
571       case 'm':
572         if (dwarf_name.equals("macinfo"))
573           sect_type = lldb::eSectionTypeDWARFDebugMacInfo;
574         break;
575 
576       case 'p':
577         if (dwarf_name.equals("pubnames"))
578           sect_type = lldb::eSectionTypeDWARFDebugPubNames;
579         else if (dwarf_name.equals("pubtypes"))
580           sect_type = lldb::eSectionTypeDWARFDebugPubTypes;
581         break;
582 
583       case 's':
584         if (dwarf_name.equals("str"))
585           sect_type = lldb::eSectionTypeDWARFDebugStr;
586         else if (dwarf_name.equals("str_offsets"))
587           sect_type = lldb::eSectionTypeDWARFDebugStrOffsets;
588         break;
589 
590       case 'r':
591         if (dwarf_name.equals("ranges"))
592           sect_type = lldb::eSectionTypeDWARFDebugRanges;
593         break;
594 
595       default:
596         break;
597       }
598     } else if (name.startswith("__apple_") || name.startswith(".apple_"))
599       sect_type = lldb::eSectionTypeInvalid;
600     else if (name.equals("__objc_imageinfo"))
601       sect_type = lldb::eSectionTypeOther;
602   }
603   return sect_type;
604 }
605 
606 uint8_t *IRExecutionUnit::MemoryManager::allocateCodeSection(
607     uintptr_t Size, unsigned Alignment, unsigned SectionID,
608     llvm::StringRef SectionName) {
609   Log *log = GetLog(LLDBLog::Expressions);
610 
611   uint8_t *return_value = m_default_mm_up->allocateCodeSection(
612       Size, Alignment, SectionID, SectionName);
613 
614   m_parent.m_records.push_back(AllocationRecord(
615       (uintptr_t)return_value,
616       lldb::ePermissionsReadable | lldb::ePermissionsExecutable,
617       GetSectionTypeFromSectionName(SectionName, AllocationKind::Code), Size,
618       Alignment, SectionID, SectionName.str().c_str()));
619 
620   LLDB_LOGF(log,
621             "IRExecutionUnit::allocateCodeSection(Size=0x%" PRIx64
622             ", Alignment=%u, SectionID=%u) = %p",
623             (uint64_t)Size, Alignment, SectionID, (void *)return_value);
624 
625   if (m_parent.m_reported_allocations) {
626     Status err;
627     lldb::ProcessSP process_sp =
628         m_parent.GetBestExecutionContextScope()->CalculateProcess();
629 
630     m_parent.CommitOneAllocation(process_sp, err, m_parent.m_records.back());
631   }
632 
633   return return_value;
634 }
635 
636 uint8_t *IRExecutionUnit::MemoryManager::allocateDataSection(
637     uintptr_t Size, unsigned Alignment, unsigned SectionID,
638     llvm::StringRef SectionName, bool IsReadOnly) {
639   Log *log = GetLog(LLDBLog::Expressions);
640 
641   uint8_t *return_value = m_default_mm_up->allocateDataSection(
642       Size, Alignment, SectionID, SectionName, IsReadOnly);
643 
644   uint32_t permissions = lldb::ePermissionsReadable;
645   if (!IsReadOnly)
646     permissions |= lldb::ePermissionsWritable;
647   m_parent.m_records.push_back(AllocationRecord(
648       (uintptr_t)return_value, permissions,
649       GetSectionTypeFromSectionName(SectionName, AllocationKind::Data), Size,
650       Alignment, SectionID, SectionName.str().c_str()));
651   LLDB_LOGF(log,
652             "IRExecutionUnit::allocateDataSection(Size=0x%" PRIx64
653             ", Alignment=%u, SectionID=%u) = %p",
654             (uint64_t)Size, Alignment, SectionID, (void *)return_value);
655 
656   if (m_parent.m_reported_allocations) {
657     Status err;
658     lldb::ProcessSP process_sp =
659         m_parent.GetBestExecutionContextScope()->CalculateProcess();
660 
661     m_parent.CommitOneAllocation(process_sp, err, m_parent.m_records.back());
662   }
663 
664   return return_value;
665 }
666 
667 void IRExecutionUnit::CollectCandidateCNames(std::vector<ConstString> &C_names,
668                                              ConstString name) {
669   if (m_strip_underscore && name.AsCString()[0] == '_')
670     C_names.insert(C_names.begin(), ConstString(&name.AsCString()[1]));
671   C_names.push_back(name);
672 }
673 
674 void IRExecutionUnit::CollectCandidateCPlusPlusNames(
675     std::vector<ConstString> &CPP_names,
676     const std::vector<ConstString> &C_names, const SymbolContext &sc) {
677   if (auto *cpp_lang = Language::FindPlugin(lldb::eLanguageTypeC_plus_plus)) {
678     for (const ConstString &name : C_names) {
679       Mangled mangled(name);
680       if (cpp_lang->SymbolNameFitsToLanguage(mangled)) {
681         if (ConstString best_alternate =
682                 cpp_lang->FindBestAlternateFunctionMangledName(mangled, sc)) {
683           CPP_names.push_back(best_alternate);
684         }
685       }
686 
687       std::vector<ConstString> alternates =
688           cpp_lang->GenerateAlternateFunctionManglings(name);
689       CPP_names.insert(CPP_names.end(), alternates.begin(), alternates.end());
690 
691       // As a last-ditch fallback, try the base name for C++ names.  It's
692       // terrible, but the DWARF doesn't always encode "extern C" correctly.
693       ConstString basename =
694           cpp_lang->GetDemangledFunctionNameWithoutArguments(mangled);
695       CPP_names.push_back(basename);
696     }
697   }
698 }
699 
700 class LoadAddressResolver {
701 public:
702   LoadAddressResolver(Target *target, bool &symbol_was_missing_weak)
703       : m_target(target), m_symbol_was_missing_weak(symbol_was_missing_weak) {}
704 
705   llvm::Optional<lldb::addr_t> Resolve(SymbolContextList &sc_list) {
706     if (sc_list.IsEmpty())
707       return llvm::None;
708 
709     lldb::addr_t load_address = LLDB_INVALID_ADDRESS;
710 
711     // Missing_weak_symbol will be true only if we found only weak undefined
712     // references to this symbol.
713     m_symbol_was_missing_weak = true;
714 
715     for (auto candidate_sc : sc_list.SymbolContexts()) {
716       // Only symbols can be weak undefined.
717       if (!candidate_sc.symbol ||
718           candidate_sc.symbol->GetType() != lldb::eSymbolTypeUndefined ||
719           !candidate_sc.symbol->IsWeak())
720         m_symbol_was_missing_weak = false;
721 
722       // First try the symbol.
723       if (candidate_sc.symbol) {
724         load_address = candidate_sc.symbol->ResolveCallableAddress(*m_target);
725         if (load_address == LLDB_INVALID_ADDRESS) {
726           Address addr = candidate_sc.symbol->GetAddress();
727           load_address = m_target->GetProcessSP()
728                              ? addr.GetLoadAddress(m_target)
729                              : addr.GetFileAddress();
730         }
731       }
732 
733       // If that didn't work, try the function.
734       if (load_address == LLDB_INVALID_ADDRESS && candidate_sc.function) {
735         Address addr =
736             candidate_sc.function->GetAddressRange().GetBaseAddress();
737         load_address = m_target->GetProcessSP() ? addr.GetLoadAddress(m_target)
738                                                 : addr.GetFileAddress();
739       }
740 
741       // We found a load address.
742       if (load_address != LLDB_INVALID_ADDRESS) {
743         // If the load address is external, we're done.
744         const bool is_external =
745             (candidate_sc.function) ||
746             (candidate_sc.symbol && candidate_sc.symbol->IsExternal());
747         if (is_external)
748           return load_address;
749 
750         // Otherwise, remember the best internal load address.
751         if (m_best_internal_load_address == LLDB_INVALID_ADDRESS)
752           m_best_internal_load_address = load_address;
753       }
754     }
755 
756     // You test the address of a weak symbol against NULL to see if it is
757     // present. So we should return 0 for a missing weak symbol.
758     if (m_symbol_was_missing_weak)
759       return 0;
760 
761     return llvm::None;
762   }
763 
764   lldb::addr_t GetBestInternalLoadAddress() const {
765     return m_best_internal_load_address;
766   }
767 
768 private:
769   Target *m_target;
770   bool &m_symbol_was_missing_weak;
771   lldb::addr_t m_best_internal_load_address = LLDB_INVALID_ADDRESS;
772 };
773 
774 lldb::addr_t
775 IRExecutionUnit::FindInSymbols(const std::vector<ConstString> &names,
776                                const lldb_private::SymbolContext &sc,
777                                bool &symbol_was_missing_weak) {
778   symbol_was_missing_weak = false;
779 
780   Target *target = sc.target_sp.get();
781   if (!target) {
782     // We shouldn't be doing any symbol lookup at all without a target.
783     return LLDB_INVALID_ADDRESS;
784   }
785 
786   LoadAddressResolver resolver(target, symbol_was_missing_weak);
787 
788   ModuleFunctionSearchOptions function_options;
789   function_options.include_symbols = true;
790   function_options.include_inlines = false;
791 
792   for (const ConstString &name : names) {
793     if (sc.module_sp) {
794       SymbolContextList sc_list;
795       sc.module_sp->FindFunctions(name, CompilerDeclContext(),
796                                   lldb::eFunctionNameTypeFull, function_options,
797                                   sc_list);
798       if (auto load_addr = resolver.Resolve(sc_list))
799         return *load_addr;
800     }
801 
802     if (sc.target_sp) {
803       SymbolContextList sc_list;
804       sc.target_sp->GetImages().FindFunctions(name, lldb::eFunctionNameTypeFull,
805                                               function_options, sc_list);
806       if (auto load_addr = resolver.Resolve(sc_list))
807         return *load_addr;
808     }
809 
810     if (sc.target_sp) {
811       SymbolContextList sc_list;
812       sc.target_sp->GetImages().FindSymbolsWithNameAndType(
813           name, lldb::eSymbolTypeAny, sc_list);
814       if (auto load_addr = resolver.Resolve(sc_list))
815         return *load_addr;
816     }
817 
818     lldb::addr_t best_internal_load_address =
819         resolver.GetBestInternalLoadAddress();
820     if (best_internal_load_address != LLDB_INVALID_ADDRESS)
821       return best_internal_load_address;
822   }
823 
824   return LLDB_INVALID_ADDRESS;
825 }
826 
827 lldb::addr_t
828 IRExecutionUnit::FindInRuntimes(const std::vector<ConstString> &names,
829                                 const lldb_private::SymbolContext &sc) {
830   lldb::TargetSP target_sp = sc.target_sp;
831 
832   if (!target_sp) {
833     return LLDB_INVALID_ADDRESS;
834   }
835 
836   lldb::ProcessSP process_sp = sc.target_sp->GetProcessSP();
837 
838   if (!process_sp) {
839     return LLDB_INVALID_ADDRESS;
840   }
841 
842   for (const ConstString &name : names) {
843     for (LanguageRuntime *runtime : process_sp->GetLanguageRuntimes()) {
844       lldb::addr_t symbol_load_addr = runtime->LookupRuntimeSymbol(name);
845 
846       if (symbol_load_addr != LLDB_INVALID_ADDRESS)
847         return symbol_load_addr;
848     }
849   }
850 
851   return LLDB_INVALID_ADDRESS;
852 }
853 
854 lldb::addr_t IRExecutionUnit::FindInUserDefinedSymbols(
855     const std::vector<ConstString> &names,
856     const lldb_private::SymbolContext &sc) {
857   lldb::TargetSP target_sp = sc.target_sp;
858 
859   for (const ConstString &name : names) {
860     lldb::addr_t symbol_load_addr = target_sp->GetPersistentSymbol(name);
861 
862     if (symbol_load_addr != LLDB_INVALID_ADDRESS)
863       return symbol_load_addr;
864   }
865 
866   return LLDB_INVALID_ADDRESS;
867 }
868 
869 lldb::addr_t IRExecutionUnit::FindSymbol(lldb_private::ConstString name,
870                                          bool &missing_weak) {
871   std::vector<ConstString> candidate_C_names;
872   std::vector<ConstString> candidate_CPlusPlus_names;
873 
874   CollectCandidateCNames(candidate_C_names, name);
875 
876   lldb::addr_t ret = FindInSymbols(candidate_C_names, m_sym_ctx, missing_weak);
877   if (ret != LLDB_INVALID_ADDRESS)
878     return ret;
879 
880   // If we find the symbol in runtimes or user defined symbols it can't be
881   // a missing weak symbol.
882   missing_weak = false;
883   ret = FindInRuntimes(candidate_C_names, m_sym_ctx);
884   if (ret != LLDB_INVALID_ADDRESS)
885     return ret;
886 
887   ret = FindInUserDefinedSymbols(candidate_C_names, m_sym_ctx);
888   if (ret != LLDB_INVALID_ADDRESS)
889     return ret;
890 
891   CollectCandidateCPlusPlusNames(candidate_CPlusPlus_names, candidate_C_names,
892                                  m_sym_ctx);
893   ret = FindInSymbols(candidate_CPlusPlus_names, m_sym_ctx, missing_weak);
894   return ret;
895 }
896 
897 void IRExecutionUnit::GetStaticInitializers(
898     std::vector<lldb::addr_t> &static_initializers) {
899   Log *log = GetLog(LLDBLog::Expressions);
900 
901   llvm::GlobalVariable *global_ctors =
902       m_module->getNamedGlobal("llvm.global_ctors");
903   if (!global_ctors) {
904     LLDB_LOG(log, "Couldn't find llvm.global_ctors.");
905     return;
906   }
907   auto *ctor_array =
908       llvm::dyn_cast<llvm::ConstantArray>(global_ctors->getInitializer());
909   if (!ctor_array) {
910     LLDB_LOG(log, "llvm.global_ctors not a ConstantArray.");
911     return;
912   }
913 
914   for (llvm::Use &ctor_use : ctor_array->operands()) {
915     auto *ctor_struct = llvm::dyn_cast<llvm::ConstantStruct>(ctor_use);
916     if (!ctor_struct)
917       continue;
918     // this is standardized
919     lldbassert(ctor_struct->getNumOperands() == 3);
920     auto *ctor_function =
921         llvm::dyn_cast<llvm::Function>(ctor_struct->getOperand(1));
922     if (!ctor_function) {
923       LLDB_LOG(log, "global_ctor doesn't contain an llvm::Function");
924       continue;
925     }
926 
927     ConstString ctor_function_name(ctor_function->getName().str());
928     LLDB_LOG(log, "Looking for callable jitted function with name {0}.",
929              ctor_function_name);
930 
931     for (JittedFunction &jitted_function : m_jitted_functions) {
932       if (ctor_function_name != jitted_function.m_name)
933         continue;
934       if (jitted_function.m_remote_addr == LLDB_INVALID_ADDRESS) {
935         LLDB_LOG(log, "Found jitted function with invalid address.");
936         continue;
937       }
938       static_initializers.push_back(jitted_function.m_remote_addr);
939       LLDB_LOG(log, "Calling function at address {0:x}.",
940                jitted_function.m_remote_addr);
941       break;
942     }
943   }
944 }
945 
946 llvm::JITSymbol
947 IRExecutionUnit::MemoryManager::findSymbol(const std::string &Name) {
948     bool missing_weak = false;
949     uint64_t addr = GetSymbolAddressAndPresence(Name, missing_weak);
950     // This is a weak symbol:
951     if (missing_weak)
952       return llvm::JITSymbol(addr,
953           llvm::JITSymbolFlags::Exported | llvm::JITSymbolFlags::Weak);
954     else
955       return llvm::JITSymbol(addr, llvm::JITSymbolFlags::Exported);
956 }
957 
958 uint64_t
959 IRExecutionUnit::MemoryManager::getSymbolAddress(const std::string &Name) {
960   bool missing_weak = false;
961   return GetSymbolAddressAndPresence(Name, missing_weak);
962 }
963 
964 uint64_t
965 IRExecutionUnit::MemoryManager::GetSymbolAddressAndPresence(
966     const std::string &Name, bool &missing_weak) {
967   Log *log = GetLog(LLDBLog::Expressions);
968 
969   ConstString name_cs(Name.c_str());
970 
971   lldb::addr_t ret = m_parent.FindSymbol(name_cs, missing_weak);
972 
973   if (ret == LLDB_INVALID_ADDRESS) {
974     LLDB_LOGF(log,
975               "IRExecutionUnit::getSymbolAddress(Name=\"%s\") = <not found>",
976               Name.c_str());
977 
978     m_parent.ReportSymbolLookupError(name_cs);
979     return 0;
980   } else {
981     LLDB_LOGF(log, "IRExecutionUnit::getSymbolAddress(Name=\"%s\") = %" PRIx64,
982               Name.c_str(), ret);
983     return ret;
984   }
985 }
986 
987 void *IRExecutionUnit::MemoryManager::getPointerToNamedFunction(
988     const std::string &Name, bool AbortOnFailure) {
989   return (void *)getSymbolAddress(Name);
990 }
991 
992 lldb::addr_t
993 IRExecutionUnit::GetRemoteAddressForLocal(lldb::addr_t local_address) {
994   Log *log = GetLog(LLDBLog::Expressions);
995 
996   for (AllocationRecord &record : m_records) {
997     if (local_address >= record.m_host_address &&
998         local_address < record.m_host_address + record.m_size) {
999       if (record.m_process_address == LLDB_INVALID_ADDRESS)
1000         return LLDB_INVALID_ADDRESS;
1001 
1002       lldb::addr_t ret =
1003           record.m_process_address + (local_address - record.m_host_address);
1004 
1005       LLDB_LOGF(log,
1006                 "IRExecutionUnit::GetRemoteAddressForLocal() found 0x%" PRIx64
1007                 " in [0x%" PRIx64 "..0x%" PRIx64 "], and returned 0x%" PRIx64
1008                 " from [0x%" PRIx64 "..0x%" PRIx64 "].",
1009                 local_address, (uint64_t)record.m_host_address,
1010                 (uint64_t)record.m_host_address + (uint64_t)record.m_size, ret,
1011                 record.m_process_address,
1012                 record.m_process_address + record.m_size);
1013 
1014       return ret;
1015     }
1016   }
1017 
1018   return LLDB_INVALID_ADDRESS;
1019 }
1020 
1021 IRExecutionUnit::AddrRange
1022 IRExecutionUnit::GetRemoteRangeForLocal(lldb::addr_t local_address) {
1023   for (AllocationRecord &record : m_records) {
1024     if (local_address >= record.m_host_address &&
1025         local_address < record.m_host_address + record.m_size) {
1026       if (record.m_process_address == LLDB_INVALID_ADDRESS)
1027         return AddrRange(0, 0);
1028 
1029       return AddrRange(record.m_process_address, record.m_size);
1030     }
1031   }
1032 
1033   return AddrRange(0, 0);
1034 }
1035 
1036 bool IRExecutionUnit::CommitOneAllocation(lldb::ProcessSP &process_sp,
1037                                           Status &error,
1038                                           AllocationRecord &record) {
1039   if (record.m_process_address != LLDB_INVALID_ADDRESS) {
1040     return true;
1041   }
1042 
1043   switch (record.m_sect_type) {
1044   case lldb::eSectionTypeInvalid:
1045   case lldb::eSectionTypeDWARFDebugAbbrev:
1046   case lldb::eSectionTypeDWARFDebugAddr:
1047   case lldb::eSectionTypeDWARFDebugAranges:
1048   case lldb::eSectionTypeDWARFDebugCuIndex:
1049   case lldb::eSectionTypeDWARFDebugFrame:
1050   case lldb::eSectionTypeDWARFDebugInfo:
1051   case lldb::eSectionTypeDWARFDebugLine:
1052   case lldb::eSectionTypeDWARFDebugLoc:
1053   case lldb::eSectionTypeDWARFDebugLocLists:
1054   case lldb::eSectionTypeDWARFDebugMacInfo:
1055   case lldb::eSectionTypeDWARFDebugPubNames:
1056   case lldb::eSectionTypeDWARFDebugPubTypes:
1057   case lldb::eSectionTypeDWARFDebugRanges:
1058   case lldb::eSectionTypeDWARFDebugStr:
1059   case lldb::eSectionTypeDWARFDebugStrOffsets:
1060   case lldb::eSectionTypeDWARFAppleNames:
1061   case lldb::eSectionTypeDWARFAppleTypes:
1062   case lldb::eSectionTypeDWARFAppleNamespaces:
1063   case lldb::eSectionTypeDWARFAppleObjC:
1064   case lldb::eSectionTypeDWARFGNUDebugAltLink:
1065     error.Clear();
1066     break;
1067   default:
1068     const bool zero_memory = false;
1069     record.m_process_address =
1070         Malloc(record.m_size, record.m_alignment, record.m_permissions,
1071                eAllocationPolicyProcessOnly, zero_memory, error);
1072     break;
1073   }
1074 
1075   return error.Success();
1076 }
1077 
1078 bool IRExecutionUnit::CommitAllocations(lldb::ProcessSP &process_sp) {
1079   bool ret = true;
1080 
1081   lldb_private::Status err;
1082 
1083   for (AllocationRecord &record : m_records) {
1084     ret = CommitOneAllocation(process_sp, err, record);
1085 
1086     if (!ret) {
1087       break;
1088     }
1089   }
1090 
1091   if (!ret) {
1092     for (AllocationRecord &record : m_records) {
1093       if (record.m_process_address != LLDB_INVALID_ADDRESS) {
1094         Free(record.m_process_address, err);
1095         record.m_process_address = LLDB_INVALID_ADDRESS;
1096       }
1097     }
1098   }
1099 
1100   return ret;
1101 }
1102 
1103 void IRExecutionUnit::ReportAllocations(llvm::ExecutionEngine &engine) {
1104   m_reported_allocations = true;
1105 
1106   for (AllocationRecord &record : m_records) {
1107     if (record.m_process_address == LLDB_INVALID_ADDRESS)
1108       continue;
1109 
1110     if (record.m_section_id == eSectionIDInvalid)
1111       continue;
1112 
1113     engine.mapSectionAddress((void *)record.m_host_address,
1114                              record.m_process_address);
1115   }
1116 
1117   // Trigger re-application of relocations.
1118   engine.finalizeObject();
1119 }
1120 
1121 bool IRExecutionUnit::WriteData(lldb::ProcessSP &process_sp) {
1122   bool wrote_something = false;
1123   for (AllocationRecord &record : m_records) {
1124     if (record.m_process_address != LLDB_INVALID_ADDRESS) {
1125       lldb_private::Status err;
1126       WriteMemory(record.m_process_address, (uint8_t *)record.m_host_address,
1127                   record.m_size, err);
1128       if (err.Success())
1129         wrote_something = true;
1130     }
1131   }
1132   return wrote_something;
1133 }
1134 
1135 void IRExecutionUnit::AllocationRecord::dump(Log *log) {
1136   if (!log)
1137     return;
1138 
1139   LLDB_LOGF(log,
1140             "[0x%llx+0x%llx]->0x%llx (alignment %d, section ID %d, name %s)",
1141             (unsigned long long)m_host_address, (unsigned long long)m_size,
1142             (unsigned long long)m_process_address, (unsigned)m_alignment,
1143             (unsigned)m_section_id, m_name.c_str());
1144 }
1145 
1146 lldb::ByteOrder IRExecutionUnit::GetByteOrder() const {
1147   ExecutionContext exe_ctx(GetBestExecutionContextScope());
1148   return exe_ctx.GetByteOrder();
1149 }
1150 
1151 uint32_t IRExecutionUnit::GetAddressByteSize() const {
1152   ExecutionContext exe_ctx(GetBestExecutionContextScope());
1153   return exe_ctx.GetAddressByteSize();
1154 }
1155 
1156 void IRExecutionUnit::PopulateSymtab(lldb_private::ObjectFile *obj_file,
1157                                      lldb_private::Symtab &symtab) {
1158   // No symbols yet...
1159 }
1160 
1161 void IRExecutionUnit::PopulateSectionList(
1162     lldb_private::ObjectFile *obj_file,
1163     lldb_private::SectionList &section_list) {
1164   for (AllocationRecord &record : m_records) {
1165     if (record.m_size > 0) {
1166       lldb::SectionSP section_sp(new lldb_private::Section(
1167           obj_file->GetModule(), obj_file, record.m_section_id,
1168           ConstString(record.m_name), record.m_sect_type,
1169           record.m_process_address, record.m_size,
1170           record.m_host_address, // file_offset (which is the host address for
1171                                  // the data)
1172           record.m_size,         // file_size
1173           0,
1174           record.m_permissions)); // flags
1175       section_list.AddSection(section_sp);
1176     }
1177   }
1178 }
1179 
1180 ArchSpec IRExecutionUnit::GetArchitecture() {
1181   ExecutionContext exe_ctx(GetBestExecutionContextScope());
1182   if(Target *target = exe_ctx.GetTargetPtr())
1183     return target->GetArchitecture();
1184   return ArchSpec();
1185 }
1186 
1187 lldb::ModuleSP IRExecutionUnit::GetJITModule() {
1188   ExecutionContext exe_ctx(GetBestExecutionContextScope());
1189   Target *target = exe_ctx.GetTargetPtr();
1190   if (!target)
1191     return nullptr;
1192 
1193   auto Delegate = std::static_pointer_cast<lldb_private::ObjectFileJITDelegate>(
1194       shared_from_this());
1195 
1196   lldb::ModuleSP jit_module_sp =
1197       lldb_private::Module::CreateModuleFromObjectFile<ObjectFileJIT>(Delegate);
1198   if (!jit_module_sp)
1199     return nullptr;
1200 
1201   bool changed = false;
1202   jit_module_sp->SetLoadAddress(*target, 0, true, changed);
1203   return jit_module_sp;
1204 }
1205