[Symbolize] Check if the PE file has a PDB and emit an error if we can't load it

Summary:
Previously we would try to load PDBs for every PE executable we tried to
symbolize. If that failed, we would fall back to DWARF. If there wasn't
any DWARF, we'd print mostly useless symbol information using the export
table.

With this change, we only try to load PDBs for executables that claim to
have them. If that fails, we can now print an error rather than falling
back silently. This should make it a lot easier to diagnose and fix
common symbolization issues, such as not having DIA or not having a PDB.

Reviewers: zturner, eugenis

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D20982

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271725 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/DebugInfo/Symbolize/Symbolize.h b/include/llvm/DebugInfo/Symbolize/Symbolize.h
index 1c487aa..9253adf 100644 (file)
--- a/include/llvm/DebugInfo/Symbolize/Symbolize.h
+++ b/include/llvm/DebugInfo/Symbolize/Symbolize.h
@@ -49,12 +49,12 @@ public:
     flush();
   }
 
-  ErrorOr<DILineInfo> symbolizeCode(const std::string &ModuleName,
-                                    uint64_t ModuleOffset);
-  ErrorOr<DIInliningInfo> symbolizeInlinedCode(const std::string &ModuleName,
-                                               uint64_t ModuleOffset);
-  ErrorOr<DIGlobal> symbolizeData(const std::string &ModuleName,
-                                  uint64_t ModuleOffset);
+  Expected<DILineInfo> symbolizeCode(const std::string &ModuleName,
+                                     uint64_t ModuleOffset);
+  Expected<DIInliningInfo> symbolizeInlinedCode(const std::string &ModuleName,
+                                                uint64_t ModuleOffset);
+  Expected<DIGlobal> symbolizeData(const std::string &ModuleName,
+                                   uint64_t ModuleOffset);
   void flush();
   static std::string DemangleName(const std::string &Name,
                                   const SymbolizableModule *ModInfo);
@@ -64,8 +64,13 @@ private:
   // corresponding debug info. These objects can be the same.
   typedef std::pair<ObjectFile*, ObjectFile*> ObjectPair;
 
-  ErrorOr<SymbolizableModule *>
+  /// Returns a SymbolizableModule or an error if loading debug info failed.
+  /// Only one attempt is made to load a module, and errors during loading are
+  /// only reported once. Subsequent calls to get module info for a module that
+  /// failed to load will return nullptr.
+  Expected<SymbolizableModule *>
   getOrCreateModuleInfo(const std::string &ModuleName);
+
   ObjectFile *lookUpDsymFile(const std::string &Path,
                              const MachOObjectFile *ExeObj,
                              const std::string &ArchName);
@@ -74,27 +79,27 @@ private:
                                     const std::string &ArchName);
 
   /// \brief Returns pair of pointers to object and debug object.
-  ErrorOr<ObjectPair> getOrCreateObjectPair(const std::string &Path,
+  Expected<ObjectPair> getOrCreateObjectPair(const std::string &Path,
                                             const std::string &ArchName);
 
   /// \brief Return a pointer to object file at specified path, for a specified
   /// architecture (e.g. if path refers to a Mach-O universal binary, only one
   /// object file from it will be returned).
-  ErrorOr<ObjectFile *> getOrCreateObject(const std::string &Path,
+  Expected<ObjectFile *> getOrCreateObject(const std::string &Path,
                                           const std::string &ArchName);
 
-  std::map<std::string, ErrorOr<std::unique_ptr<SymbolizableModule>>> Modules;
+  std::map<std::string, std::unique_ptr<SymbolizableModule>> Modules;
 
   /// \brief Contains cached results of getOrCreateObjectPair().
-  std::map<std::pair<std::string, std::string>, ErrorOr<ObjectPair>>
+  std::map<std::pair<std::string, std::string>, ObjectPair>
       ObjectPairForPathArch;
 
   /// \brief Contains parsed binary for each path, or parsing error.
-  std::map<std::string, ErrorOr<OwningBinary<Binary>>> BinaryForPath;
+  std::map<std::string, OwningBinary<Binary>> BinaryForPath;
 
   /// \brief Parsed object file for path/architecture pair, where "path" refers
   /// to Mach-O universal binary.
-  std::map<std::pair<std::string, std::string>, ErrorOr<std::unique_ptr<ObjectFile>>>
+  std::map<std::pair<std::string, std::string>, std::unique_ptr<ObjectFile>>
       ObjectForUBPathAndArch;
 
   Options Opts;

diff --git a/include/llvm/Object/COFF.h b/include/llvm/Object/COFF.h
index f859b7d..4578ce1 100644 (file)
--- a/include/llvm/Object/COFF.h
+++ b/include/llvm/Object/COFF.h
@@ -870,10 +870,18 @@ public:
   std::error_code getHintName(uint32_t Rva, uint16_t &Hint,
                               StringRef &Name) const;
 
+  /// Get PDB information out of a codeview debug directory entry.
   std::error_code getDebugPDBInfo(const debug_directory *DebugDir,
                                   const debug_pdb_info *&Info,
                                   StringRef &PDBFileName) const;
 
+  /// Get PDB information from an executable. If the information is not present,
+  /// Info will be set to nullptr and PDBFileName will be empty. An error is
+  /// returned only on corrupt object files. Convenience accessor that can be
+  /// used if the debug directory is not already handy.
+  std::error_code getDebugPDBInfo(const debug_pdb_info *&Info,
+                                  StringRef &PDBFileName) const;
+
   bool isRelocatableObject() const override;
   bool is64() const { return PE32PlusHeader; }
 

diff --git a/lib/DebugInfo/Symbolize/Symbolize.cpp b/lib/DebugInfo/Symbolize/Symbolize.cpp
index 9c12169..e2732bf 100644 (file)
--- a/lib/DebugInfo/Symbolize/Symbolize.cpp
+++ b/lib/DebugInfo/Symbolize/Symbolize.cpp
@@ -50,12 +50,18 @@
 namespace llvm {
 namespace symbolize {
 
-ErrorOr<DILineInfo> LLVMSymbolizer::symbolizeCode(const std::string &ModuleName,
+Expected<DILineInfo> LLVMSymbolizer::symbolizeCode(const std::string &ModuleName,
                                                   uint64_t ModuleOffset) {
-  auto InfoOrErr = getOrCreateModuleInfo(ModuleName);
-  if (auto EC = InfoOrErr.getError())
-    return EC;
-  SymbolizableModule *Info = InfoOrErr.get();
+  SymbolizableModule *Info;
+  if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
+    Info = InfoOrErr.get();
+  else
+    return InfoOrErr.takeError();
+
+  // A null module means an error has already been reported. Return an empty
+  // result.
+  if (!Info)
+    return DILineInfo();
 
   // If the user is giving us relative addresses, add the preferred base of the
   // object to the offset before we do the query. It's what DIContext expects.
@@ -69,13 +75,19 @@ ErrorOr<DILineInfo> LLVMSymbolizer::symbolizeCode(const std::string &ModuleName,
   return LineInfo;
 }
 
-ErrorOr<DIInliningInfo>
+Expected<DIInliningInfo>
 LLVMSymbolizer::symbolizeInlinedCode(const std::string &ModuleName,
                                      uint64_t ModuleOffset) {
-  auto InfoOrErr = getOrCreateModuleInfo(ModuleName);
-  if (auto EC = InfoOrErr.getError())
-    return EC;
-  SymbolizableModule *Info = InfoOrErr.get();
+  SymbolizableModule *Info;
+  if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
+    Info = InfoOrErr.get();
+  else
+    return InfoOrErr.takeError();
+
+  // A null module means an error has already been reported. Return an empty
+  // result.
+  if (!Info)
+    return DIInliningInfo();
 
   // If the user is giving us relative addresses, add the preferred base of the
   // object to the offset before we do the query. It's what DIContext expects.
@@ -93,12 +105,18 @@ LLVMSymbolizer::symbolizeInlinedCode(const std::string &ModuleName,
   return InlinedContext;
 }
 
-ErrorOr<DIGlobal> LLVMSymbolizer::symbolizeData(const std::string &ModuleName,
-                                                uint64_t ModuleOffset) {
-  auto InfoOrErr = getOrCreateModuleInfo(ModuleName);
-  if (auto EC = InfoOrErr.getError())
-    return EC;
-  SymbolizableModule *Info = InfoOrErr.get();
+Expected<DIGlobal> LLVMSymbolizer::symbolizeData(const std::string &ModuleName,
+                                                 uint64_t ModuleOffset) {
+  SymbolizableModule *Info;
+  if (auto InfoOrErr = getOrCreateModuleInfo(ModuleName))
+    Info = InfoOrErr.get();
+  else
+    return InfoOrErr.takeError();
+
+  // A null module means an error has already been reported. Return an empty
+  // result.
+  if (!Info)
+    return DIGlobal();
 
   // If the user is giving us relative addresses, add the preferred base of
   // the object to the offset before we do the query. It's what DIContext
@@ -232,9 +250,14 @@ ObjectFile *LLVMSymbolizer::lookUpDsymFile(const std::string &ExePath,
   }
   for (const auto &Path : DsymPaths) {
     auto DbgObjOrErr = getOrCreateObject(Path, ArchName);
-    if (!DbgObjOrErr)
+    if (!DbgObjOrErr) {
+      // Ignore errors, the file might not exist.
+      consumeError(DbgObjOrErr.takeError());
       continue;
+    }
     ObjectFile *DbgObj = DbgObjOrErr.get();
+    if (!DbgObj)
+      continue;
     const MachOObjectFile *MachDbgObj = dyn_cast<const MachOObjectFile>(DbgObj);
     if (!MachDbgObj)
       continue;
@@ -255,23 +278,27 @@ ObjectFile *LLVMSymbolizer::lookUpDebuglinkObject(const std::string &Path,
   if (!findDebugBinary(Path, DebuglinkName, CRCHash, DebugBinaryPath))
     return nullptr;
   auto DbgObjOrErr = getOrCreateObject(DebugBinaryPath, ArchName);
-  if (!DbgObjOrErr)
+  if (!DbgObjOrErr) {
+    // Ignore errors, the file might not exist.
+    consumeError(DbgObjOrErr.takeError());
     return nullptr;
+  }
   return DbgObjOrErr.get();
 }
 
-ErrorOr<LLVMSymbolizer::ObjectPair>
+Expected<LLVMSymbolizer::ObjectPair>
 LLVMSymbolizer::getOrCreateObjectPair(const std::string &Path,
                                       const std::string &ArchName) {
   const auto &I = ObjectPairForPathArch.find(std::make_pair(Path, ArchName));
-  if (I != ObjectPairForPathArch.end())
+  if (I != ObjectPairForPathArch.end()) {
     return I->second;
+  }
 
   auto ObjOrErr = getOrCreateObject(Path, ArchName);
-  if (auto EC = ObjOrErr.getError()) {
-    ObjectPairForPathArch.insert(
-        std::make_pair(std::make_pair(Path, ArchName), EC));
-    return EC;
+  if (!ObjOrErr) {
+    ObjectPairForPathArch.insert(std::make_pair(std::make_pair(Path, ArchName),
+                                                ObjectPair(nullptr, nullptr)));
+    return ObjOrErr.takeError();
   }
 
   ObjectFile *Obj = ObjOrErr.get();
@@ -290,7 +317,7 @@ LLVMSymbolizer::getOrCreateObjectPair(const std::string &Path,
   return Res;
 }
 
-ErrorOr<ObjectFile *>
+Expected<ObjectFile *>
 LLVMSymbolizer::getOrCreateObject(const std::string &Path,
                                   const std::string &ArchName) {
   const auto &I = BinaryForPath.find(Path);
@@ -298,34 +325,29 @@ LLVMSymbolizer::getOrCreateObject(const std::string &Path,
   if (I == BinaryForPath.end()) {
     Expected<OwningBinary<Binary>> BinOrErr = createBinary(Path);
     if (!BinOrErr) {
-      auto EC = errorToErrorCode(BinOrErr.takeError());
-      BinaryForPath.insert(std::make_pair(Path, EC));
-      return EC;
+      BinaryForPath.insert({Path, OwningBinary<Binary>()});
+      return BinOrErr.takeError();
     }
     Bin = BinOrErr->getBinary();
     BinaryForPath.insert(std::make_pair(Path, std::move(BinOrErr.get())));
-  } else if (auto EC = I->second.getError()) {
-    return EC;
   } else {
-    Bin = I->second->getBinary();
+    Bin = I->second.getBinary();
   }
 
-  assert(Bin != nullptr);
+  if (!Bin)
+    return static_cast<ObjectFile *>(nullptr);
 
-  if (MachOUniversalBinary *UB = dyn_cast<MachOUniversalBinary>(Bin)) {
+  if (MachOUniversalBinary *UB = dyn_cast_or_null<MachOUniversalBinary>(Bin)) {
     const auto &I = ObjectForUBPathAndArch.find(std::make_pair(Path, ArchName));
     if (I != ObjectForUBPathAndArch.end()) {
-      if (auto EC = I->second.getError())
-        return EC;
-      return I->second->get();
+      return I->second.get();
     }
     Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
         UB->getObjectForArch(ArchName);
     if (!ObjOrErr) {
-      auto EC = errorToErrorCode(ObjOrErr.takeError());
-      ObjectForUBPathAndArch.insert(
-          std::make_pair(std::make_pair(Path, ArchName), EC));
-      return EC;
+      ObjectForUBPathAndArch.insert(std::make_pair(
+          std::make_pair(Path, ArchName), std::unique_ptr<ObjectFile>()));
+      return ObjOrErr.takeError();
     }
     ObjectFile *Res = ObjOrErr->get();
     ObjectForUBPathAndArch.insert(std::make_pair(std::make_pair(Path, ArchName),
@@ -335,17 +357,14 @@ LLVMSymbolizer::getOrCreateObject(const std::string &Path,
   if (Bin->isObject()) {
     return cast<ObjectFile>(Bin);
   }
-  return object_error::arch_not_found;
+  return errorCodeToError(object_error::arch_not_found);
 }
 
-ErrorOr<SymbolizableModule *>
+Expected<SymbolizableModule *>
 LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName) {
   const auto &I = Modules.find(ModuleName);
   if (I != Modules.end()) {
-    auto &InfoOrErr = I->second;
-    if (auto EC = InfoOrErr.getError())
-      return EC;
-    return InfoOrErr->get();
+    return I->second.get();
   }
   std::string BinaryName = ModuleName;
   std::string ArchName = Opts.DefaultArch;
@@ -359,27 +378,31 @@ LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName) {
     }
   }
   auto ObjectsOrErr = getOrCreateObjectPair(BinaryName, ArchName);
-  if (auto EC = ObjectsOrErr.getError()) {
+  if (!ObjectsOrErr) {
     // Failed to find valid object file.
-    Modules.insert(std::make_pair(ModuleName, EC));
-    return EC;
+    Modules.insert(
+        std::make_pair(ModuleName, std::unique_ptr<SymbolizableModule>()));
+    return ObjectsOrErr.takeError();
   }
   ObjectPair Objects = ObjectsOrErr.get();
 
   std::unique_ptr<DIContext> Context;
+  // If this is a COFF object containing PDB info, use a PDBContext to
+  // symbolize. Otherwise, use DWARF.
   if (auto CoffObject = dyn_cast<COFFObjectFile>(Objects.first)) {
-    using namespace pdb;
-    // If this is a COFF object, assume it contains PDB debug information.  If
-    // we don't find any we will fall back to the DWARF case.
-    std::unique_ptr<IPDBSession> Session;
-    auto Error = loadDataForEXE(
-        PDB_ReaderType::DIA, Objects.first->getFileName(), Session);
-    if (!Error) {
+    const debug_pdb_info *PDBInfo;
+    StringRef PDBFileName;
+    auto EC = CoffObject->getDebugPDBInfo(PDBInfo, PDBFileName);
+    if (!EC && PDBInfo != nullptr) {
+      using namespace pdb;
+      std::unique_ptr<IPDBSession> Session;
+      if (auto Err = loadDataForEXE(PDB_ReaderType::DIA,
+                                    Objects.first->getFileName(), Session)) {
+        Modules.insert(
+            std::make_pair(ModuleName, std::unique_ptr<SymbolizableModule>()));
+        return std::move(Err);
+      }
       Context.reset(new PDBContext(*CoffObject, std::move(Session)));
-    } else {
-      // Drop error
-      handleAllErrors(std::move(Error),
-                      [](const ErrorInfoBase &) { return Error::success(); });
     }
   }
   if (!Context)
@@ -387,12 +410,15 @@ LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName) {
   assert(Context);
   auto InfoOrErr =
       SymbolizableObjectFile::create(Objects.first, std::move(Context));
+  std::unique_ptr<SymbolizableModule> SymMod;
+  if (InfoOrErr)
+    SymMod = std::move(InfoOrErr.get());
   auto InsertResult =
-      Modules.insert(std::make_pair(ModuleName, std::move(InfoOrErr)));
+      Modules.insert(std::make_pair(ModuleName, std::move(SymMod)));
   assert(InsertResult.second);
-  if (auto EC = InsertResult.first->second.getError())
-    return EC;
-  return InsertResult.first->second->get();
+  if (auto EC = InfoOrErr.getError())
+    return errorCodeToError(EC);
+  return InsertResult.first->second.get();
 }
 
 namespace {

diff --git a/lib/Object/COFFObjectFile.cpp b/lib/Object/COFFObjectFile.cpp
index 8390edd..28627cd 100644 (file)
--- a/lib/Object/COFFObjectFile.cpp
+++ b/lib/Object/COFFObjectFile.cpp
@@ -505,6 +505,17 @@ std::error_code COFFObjectFile::getDebugPDBInfo(const debug_directory *DebugDir,
   return std::error_code();
 }
 
+std::error_code COFFObjectFile::getDebugPDBInfo(const debug_pdb_info *&PDBInfo,
+                                                StringRef &PDBFileName) const {
+  for (const debug_directory &D : debug_directories())
+    if (D.Type == COFF::IMAGE_DEBUG_TYPE_CODEVIEW)
+      return getDebugPDBInfo(&D, PDBInfo, PDBFileName);
+  // If we get here, there is no PDB info to return.
+  PDBInfo = nullptr;
+  PDBFileName = StringRef();
+  return std::error_code();
+}
+
 // Find the import table.
 std::error_code COFFObjectFile::initImportTablePtr() {
   // First, we get the RVA of the import table. If the file lacks a pointer to

diff --git a/test/tools/llvm-symbolizer/pdb/Inputs/missing_pdb.exe b/test/tools/llvm-symbolizer/pdb/Inputs/missing_pdb.exe
new file mode 100644 (file)
index 0000000..320e1f3
Binary files /dev/null and b/test/tools/llvm-symbolizer/pdb/Inputs/missing_pdb.exe differ

diff --git a/test/tools/llvm-symbolizer/pdb/missing_pdb.test b/test/tools/llvm-symbolizer/pdb/missing_pdb.test
new file mode 100644 (file)
index 0000000..0478dfb
--- /dev/null
+++ b/test/tools/llvm-symbolizer/pdb/missing_pdb.test
@@ -0,0 +1,17 @@
+RUN: grep '^ADDR:' %s | sed -s 's/ADDR: //' \
+RUN:    | llvm-symbolizer -obj="%p/Inputs/missing_pdb.exe" 2>%t.err \
+RUN:    | FileCheck %s
+RUN: FileCheck --check-prefix=ERROR %s < %t.err
+
+ADDR: 0x401000
+ADDR: 0x401001
+
+llvm-symbolizer should print one error and two unknown line info records.
+
+ERROR: LLVMSymbolizer: error reading file: PDB Error: Unable to load PDB.  Make sure the file exists and is readable.
+ERROR-NOT: error reading file
+
+CHECK: ??
+CHECK: ??:0:0
+CHECK: ??
+CHECK: ??:0:0

diff --git a/tools/llvm-symbolizer/llvm-symbolizer.cpp b/tools/llvm-symbolizer/llvm-symbolizer.cpp
index 9503493..4a3a7b3 100644 (file)
--- a/tools/llvm-symbolizer/llvm-symbolizer.cpp
+++ b/tools/llvm-symbolizer/llvm-symbolizer.cpp
@@ -86,10 +86,12 @@ static cl::opt<int> ClPrintSourceContextLines(
     "print-source-context-lines", cl::init(0),
     cl::desc("Print N number of source file context"));
 
-static bool error(std::error_code ec) {
-  if (!ec)
+template<typename T>
+static bool error(Expected<T> &ResOrErr) {
+  if (ResOrErr)
     return false;
-  errs() << "LLVMSymbolizer: error reading file: " << ec.message() << ".\n";
+  logAllUnhandledErrors(ResOrErr.takeError(), errs(),
+                        "LLVMSymbolizer: error reading file: ");
   return true;
 }
 
@@ -185,14 +187,14 @@ int main(int argc, char **argv) {
     }
     if (IsData) {
       auto ResOrErr = Symbolizer.symbolizeData(ModuleName, ModuleOffset);
-      Printer << (error(ResOrErr.getError()) ? DIGlobal() : ResOrErr.get());
+      Printer << (error(ResOrErr) ? DIGlobal() : ResOrErr.get());
     } else if (ClPrintInlining) {
       auto ResOrErr = Symbolizer.symbolizeInlinedCode(ModuleName, ModuleOffset);
-      Printer << (error(ResOrErr.getError()) ? DIInliningInfo()
+      Printer << (error(ResOrErr) ? DIInliningInfo()
                                              : ResOrErr.get());
     } else {
       auto ResOrErr = Symbolizer.symbolizeCode(ModuleName, ModuleOffset);
-      Printer << (error(ResOrErr.getError()) ? DILineInfo() : ResOrErr.get());
+      Printer << (error(ResOrErr) ? DILineInfo() : ResOrErr.get());
     }
     outs() << "\n";
     outs().flush();

diff --git a/tools/sancov/sancov.cc b/tools/sancov/sancov.cc
index efeb46a..e4e83b0 100644 (file)
--- a/tools/sancov/sancov.cc
+++ b/tools/sancov/sancov.cc
@@ -135,6 +135,12 @@ template <typename T> static void FailIfError(const ErrorOr<T> &E) {
   FailIfError(E.getError());
 }
 
+template <typename T> static void FailIfError(Expected<T> &E) {
+  if (E)
+    return;
+  logAllUnhandledErrors(E.takeError(), errs(), "Error: ");
+}
+
 static void FailIfNotEmpty(const llvm::Twine &E) {
   if (E.str().empty())
     return;

diff --git a/tools/sanstats/sanstats.cpp b/tools/sanstats/sanstats.cpp
index 3a8cc9a..b2216ea 100644 (file)
--- a/tools/sanstats/sanstats.cpp
+++ b/tools/sanstats/sanstats.cpp
@@ -76,12 +76,12 @@ const char *ReadModule(char SizeofPtr, const char *Begin, const char *End) {
     if (Begin == End)
       return nullptr;
 
-    ErrorOr<DILineInfo> LineInfo = Symbolizer.symbolizeCode(Filename, Addr);
-    if (LineInfo) {
+    if (Expected<DILineInfo> LineInfo =
+            Symbolizer.symbolizeCode(Filename, Addr)) {
       llvm::outs() << LineInfo->FileName << ':' << LineInfo->Line << ' '
                    << LineInfo->FunctionName << ' ';
     } else {
-      llvm::outs() << "<error> ";
+      logAllUnhandledErrors(LineInfo.takeError(), llvm::outs(), "<error> ");
     }
 
     switch (KindFromData(Data, SizeofPtr)) {