[Symbol] Search symbols with name and type in a symbol file

Summary:
This patch adds possibility of searching a public symbol with name and type in a
symbol file. It is helpful when working with PE, because PE's symtabs contain
only imported / exported symbols only. Such a search is required for e.g.
evaluation of an expression that calls some function of the debuggee.

Reviewers: zturner, asmith, labath, clayborg, espindola

Reviewed By: clayborg

Subscribers: emaste, arichardson, aleksandr.urakov, jingham, lldb-commits, stella.stamenova

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D53368

llvm-svn: 345957

lldb/include/lldb/Symbol/SymbolFile.h

@@ -214,6 +214,8 @@ public:
     return {};
   }
 
+  virtual void AddSymbols(Symtab &symtab) {}
+
   //------------------------------------------------------------------
   /// Notify the SymbolFile that the file addresses in the Sections
   /// for this module have been changed.

lldb/include/lldb/Symbol/SymbolVendor.h

@@ -165,6 +165,8 @@ protected:
                                    // file)
   std::unique_ptr<SymbolFile> m_sym_file_ap; // A single symbol file. Subclasses
                                              // can add more of these if needed.
+  Symtab *m_symtab; // Save a symtab once to not pass it through `AddSymbols` of
+                    // the symbol file each time when it is needed
 
 private:
   //------------------------------------------------------------------

lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp

@@ -2876,8 +2876,6 @@ Symtab *ObjectFileELF::GetSymtab() {
     // do the section lookup next time.
     if (m_symtab_ap == nullptr)
       m_symtab_ap.reset(new Symtab(this));
-
-    m_symtab_ap->CalculateSymbolSizes();
   }
 
   return m_symtab_ap.get();

lldb/source/Plugins/ObjectFile/JIT/ObjectFileJIT.cpp

@@ -124,7 +124,6 @@ Symtab *ObjectFileJIT::GetSymtab() {
       if (delegate_sp)
         delegate_sp->PopulateSymtab(this, *m_symtab_ap);
       // TODO: get symbols from delegate
-      m_symtab_ap->Finalize();
     }
   }
   return m_symtab_ap.get();

lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp

@@ -1315,7 +1315,6 @@ Symtab *ObjectFileMachO::GetSymtab() {
       std::lock_guard<std::recursive_mutex> symtab_guard(
           m_symtab_ap->GetMutex());
       ParseSymtab();
-      m_symtab_ap->Finalize();
     }
   }
   return m_symtab_ap.get();
@@ -4807,16 +4806,6 @@ size_t ObjectFileMachO::ParseSymtab() {
       }
     }
 
-    //        StreamFile s(stdout, false);
-    //        s.Printf ("Symbol table before CalculateSymbolSizes():\n");
-    //        symtab->Dump(&s, NULL, eSortOrderNone);
-    // Set symbol byte sizes correctly since mach-o nlist entries don't have
-    // sizes
-    symtab->CalculateSymbolSizes();
-
-    //        s.Printf ("Symbol table after CalculateSymbolSizes():\n");
-    //        symtab->Dump(&s, NULL, eSortOrderNone);
-
     return symtab->GetNumSymbols();
   }
   return 0;

lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp

@@ -651,7 +651,6 @@ Symtab *ObjectFilePECOFF::GetSymtab() {
           symbols[i].SetDebug(true);
         }
       }
-      m_symtab_ap->CalculateSymbolSizes();
     }
   }
   return m_symtab_ap.get();

lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp

@@ -1331,6 +1331,55 @@ void SymbolFilePDB::GetMangledNamesForFunction(
     const std::string &scope_qualified_name,
     std::vector<lldb_private::ConstString> &mangled_names) {}
 
+void SymbolFilePDB::AddSymbols(lldb_private::Symtab &symtab) {
+  std::set<lldb::addr_t> sym_addresses;
+  for (size_t i = 0; i < symtab.GetNumSymbols(); i++)
+    sym_addresses.insert(symtab.SymbolAtIndex(i)->GetFileAddress());
+
+  auto results = m_global_scope_up->findAllChildren<PDBSymbolPublicSymbol>();
+  if (!results)
+    return;
+
+  auto section_list = m_obj_file->GetSectionList();
+  if (!section_list)
+    return;
+
+  while (auto pub_symbol = results->getNext()) {
+    auto section_idx = pub_symbol->getAddressSection() - 1;
+    if (section_idx >= section_list->GetSize())
+      continue;
+
+    auto section = section_list->GetSectionAtIndex(section_idx);
+    if (!section)
+      continue;
+
+    auto offset = pub_symbol->getAddressOffset();
+
+    auto file_addr = section->GetFileAddress() + offset;
+    if (sym_addresses.find(file_addr) != sym_addresses.end())
+      continue;
+    sym_addresses.insert(file_addr);
+
+    auto size = pub_symbol->getLength();
+    symtab.AddSymbol(
+        Symbol(pub_symbol->getSymIndexId(),   // symID
+               pub_symbol->getName().c_str(), // name
+               true,                          // name_is_mangled
+               pub_symbol->isCode() ? eSymbolTypeCode : eSymbolTypeData, // type
+               true,      // external
+               false,     // is_debug
+               false,     // is_trampoline
+               false,     // is_artificial
+               section,   // section_sp
+               offset,    // value
+               size,      // size
+               size != 0, // size_is_valid
+               false,     // contains_linker_annotations
+               0          // flags
+               ));
+  }
+}
+
 uint32_t SymbolFilePDB::FindTypes(
     const lldb_private::SymbolContext &sc,
     const lldb_private::ConstString &name,

lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.h

@@ -133,6 +133,8 @@ public:
       const std::string &scope_qualified_name,
       std::vector<lldb_private::ConstString> &mangled_names) override;
 
+  void AddSymbols(lldb_private::Symtab &symtab) override;
+
   uint32_t
   FindTypes(const lldb_private::SymbolContext &sc,
             const lldb_private::ConstString &name,

lldb/source/Symbol/SymbolVendor.cpp

@@ -61,7 +61,7 @@ SymbolVendor *SymbolVendor::FindPlugin(const lldb::ModuleSP &module_sp,
 //----------------------------------------------------------------------
 SymbolVendor::SymbolVendor(const lldb::ModuleSP &module_sp)
     : ModuleChild(module_sp), m_type_list(), m_compile_units(),
-      m_sym_file_ap() {}
+      m_sym_file_ap(), m_symtab() {}
 
 //----------------------------------------------------------------------
 // Destructor
@@ -438,14 +438,26 @@ FileSpec SymbolVendor::GetMainFileSpec() const {
 
 Symtab *SymbolVendor::GetSymtab() {
   ModuleSP module_sp(GetModule());
-  if (module_sp) {
-    ObjectFile *objfile = module_sp->GetObjectFile();
-    if (objfile) {
-      // Get symbol table from unified section list.
-      return objfile->GetSymtab();
-    }
-  }
-  return nullptr;
+  if (!module_sp)
+    return nullptr;
+
+  std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
+
+  if (m_symtab)
+    return m_symtab;
+
+  ObjectFile *objfile = module_sp->GetObjectFile();
+  if (!objfile)
+    return nullptr;
+
+  m_symtab = objfile->GetSymtab();
+  if (m_symtab && m_sym_file_ap)
+    m_sym_file_ap->AddSymbols(*m_symtab);
+
+  m_symtab->CalculateSymbolSizes();
+  m_symtab->Finalize();
+
+  return m_symtab;
 }
 
 void SymbolVendor::ClearSymtab() {

lldb/unittests/SymbolFile/PDB/SymbolFilePDBTests.cpp

@@ -621,3 +621,20 @@ TEST_F(SymbolFilePDBTests, TestNullName) {
   EXPECT_EQ(0u, num_results);
   EXPECT_EQ(0u, results.GetSize());
 }
+
+TEST_F(SymbolFilePDBTests, TestFindSymbolsWithNameAndType) {
+  FileSpec fspec(m_pdb_test_exe.c_str(), false);
+  ArchSpec aspec("i686-pc-windows");
+  lldb::ModuleSP module = std::make_shared<Module>(fspec, aspec);
+
+  SymbolContextList sc_list;
+  EXPECT_EQ(1u,
+            module->FindSymbolsWithNameAndType(ConstString("?foo@@YAHH@Z"),
+                                               lldb::eSymbolTypeAny, sc_list));
+  EXPECT_EQ(1u, sc_list.GetSize());
+
+  SymbolContext sc;
+  EXPECT_TRUE(sc_list.GetContextAtIndex(0, sc));
+  EXPECT_STREQ("int foo(int)",
+               sc.GetFunctionName(Mangled::ePreferDemangled).AsCString());
+}