[dsymutil] Upstream update feature.

Now that dsymutil can generate accelerator tables, we can upstream the
update logic that, as the name implies, updates the accelerator tables
in an existing dSYM bundle. In combination with `-minimize` this can be
used to remove redundant .debug_(inlines|pubtypes|pubnames).

Differential revision: https://reviews.llvm.org/D42880

llvm-svn: 324480

1 files changed, 115 insertions, 14 deletions

diff --git a/llvm/tools/dsymutil/dsymutil.cpp b/llvm/tools/dsymutil/dsymutil.cpp
index 4a01b1d9db4..dae872fe165 100644
--- a/llvm/tools/dsymutil/dsymutil.cpp
+++ b/llvm/tools/dsymutil/dsymutil.cpp
@@ -80,10 +80,21 @@ static opt<bool> Minimize(
     desc("When used when creating a dSYM file, this option will suppress\n"
          "the emission of the .debug_inlines, .debug_pubnames, and\n"
          ".debug_pubtypes sections since dsymutil currently has better\n"
-         "equivalents: .apple_names and .apple_types."),
+         "equivalents: .apple_names and .apple_types. When used in\n"
+         "conjunction with --update option, this option will cause redundant\n"
+         "accelerator tables to be removed."),
     init(false), cat(DsymCategory));
 static alias MinimizeA("z", desc("Alias for --minimize"), aliasopt(Minimize));
 
+static opt<bool> Update(
+    "update",
+    desc("Updates existing dSYM files to contain the latest accelerator\n"
+         "tables and other DWARF optimizations. This option will currently\n"
+         "add the new .apple_names and .apple_types hashed accelerator\n"
+         "tables."),
+    init(false), cat(DsymCategory));
+static alias UpdateA("u", desc("Alias for --update"), aliasopt(Update));
+
 static opt<unsigned> NumThreads(
     "num-threads",
     desc("Specifies the maximum number (n) of simultaneous threads to use\n"
@@ -230,8 +241,12 @@ static bool verify(llvm::StringRef OutputFile, llvm::StringRef Arch) {
 }
 
 static std::string getOutputFileName(llvm::StringRef InputFile) {
+  // When updating, do in place replacement.
+  if (OutputFileOpt.empty() && Update)
+    return InputFile;
+
+  // If a flat dSYM has been requested, things are pretty simple.
   if (FlatOut) {
-    // If a flat dSYM has been requested, things are pretty simple.
     if (OutputFileOpt.empty()) {
       if (InputFile == "-")
         return "a.out.dwarf";
@@ -269,6 +284,76 @@ static Expected<sys::fs::TempFile> createTempFile() {
   return sys::fs::TempFile::create(TmpModel);
 }
 
+/// Parses the command line options into the LinkOptions struct and performs
+/// some sanity checking. Returns an error in case the latter fails.
+static Expected<LinkOptions> getOptions() {
+  LinkOptions Options;
+
+  Options.Verbose = Verbose;
+  Options.NoOutput = NoOutput;
+  Options.NoODR = NoODR;
+  Options.Minimize = Minimize;
+  Options.Update = Update;
+  Options.NoTimestamp = NoTimestamp;
+  Options.PrependPath = OsoPrependPath;
+
+  if (Options.Update && std::find(InputFiles.begin(), InputFiles.end(), "-") !=
+                            InputFiles.end()) {
+    // FIXME: We cannot use stdin for an update because stdin will be
+    // consumed by the BinaryHolder during the debugmap parsing, and
+    // then we will want to consume it again in DwarfLinker. If we
+    // used a unique BinaryHolder object that could cache multiple
+    // binaries this restriction would go away.
+    return make_error<StringError>(
+        "error: standard input cannot be used as input for a dSYM update.",
+        inconvertibleErrorCode());
+  }
+
+  return Options;
+}
+
+/// Return a list of input files. This function has logic for dealing with the
+/// special case where we might have dSYM bundles as input. The function
+/// returns an error when the directory structure doesn't match that of a dSYM
+/// bundle.
+static Expected<std::vector<std::string>> getInputs(bool DsymAsInput) {
+  if (!DsymAsInput)
+    return InputFiles;
+
+  // If we are updating, we might get dSYM bundles as input.
+  std::vector<std::string> Inputs;
+  for (const auto &Input : InputFiles) {
+    if (!llvm::sys::fs::is_directory(Input)) {
+      Inputs.push_back(Input);
+      continue;
+    }
+
+    // Make sure that we're dealing with a dSYM bundle.
+    std::string dSYMDir = Input + "/Contents/Resources/DWARF";
+    if (!llvm::sys::fs::is_directory(dSYMDir))
+      return make_error<StringError>(
+          Input + " is a directory, but doesn't look like a dSYM bundle.",
+          inconvertibleErrorCode());
+
+    // Create a directory iterator to iterate over all the entries in the
+    // bundle.
+    std::error_code EC;
+    llvm::sys::fs::directory_iterator DirIt(dSYMDir, EC);
+    llvm::sys::fs::directory_iterator DirEnd;
+    if (EC)
+      return errorCodeToError(EC);
+
+    // Add each entry to the list of inputs.
+    while (DirIt != DirEnd) {
+      Inputs.push_back(DirIt->path());
+      DirIt.increment(EC);
+      if (EC)
+        return errorCodeToError(EC);
+    }
+  }
+  return Inputs;
+}
+
 namespace {
 struct TempFileVector {
   std::vector<sys::fs::TempFile> Files;
@@ -285,7 +370,6 @@ int main(int argc, char **argv) {
   llvm::sys::PrintStackTraceOnErrorSignal(argv[0]);
   llvm::PrettyStackTraceProgram StackPrinter(argc, argv);
   llvm::llvm_shutdown_obj Shutdown;
-  LinkOptions Options;
   void *P = (void *)(intptr_t)getOutputFileName;
   std::string SDKPath = llvm::sys::fs::getMainExecutable(argv[0], P);
   SDKPath = llvm::sys::path::parent_path(SDKPath);
@@ -308,24 +392,29 @@ int main(int argc, char **argv) {
     return 0;
   }
 
-  Options.Verbose = Verbose;
-  Options.NoOutput = NoOutput;
-  Options.NoODR = NoODR;
-  Options.Minimize = Minimize;
-  Options.NoTimestamp = NoTimestamp;
-  Options.PrependPath = OsoPrependPath;
+  auto OptionsOrErr = getOptions();
+  if (!OptionsOrErr) {
+    errs() << "error: " << toString(OptionsOrErr.takeError());
+    return 1;
+  }
 
   llvm::InitializeAllTargetInfos();
   llvm::InitializeAllTargetMCs();
   llvm::InitializeAllTargets();
   llvm::InitializeAllAsmPrinters();
 
+  auto InputsOrErr = getInputs(OptionsOrErr->Update);
+  if (!InputsOrErr) {
+    errs() << "error: " << toString(InputsOrErr.takeError()) << '\n';
+    return 1;
+  }
+
   if (!FlatOut && OutputFileOpt == "-") {
     llvm::errs() << "error: cannot emit to standard output without --flat\n";
     return 1;
   }
 
-  if (InputFiles.size() > 1 && FlatOut && !OutputFileOpt.empty()) {
+  if (InputsOrErr->size() > 1 && FlatOut && !OutputFileOpt.empty()) {
     llvm::errs() << "error: cannot use -o with multiple inputs in flat mode\n";
     return 1;
   }
@@ -337,7 +426,7 @@ int main(int argc, char **argv) {
       return 1;
     }
 
-  for (auto &InputFile : InputFiles) {
+  for (auto &InputFile : *InputsOrErr) {
     // Dump the symbol table for each input file and requested arch
     if (DumpStab) {
       if (!dumpStab(InputFile, ArchFlags, OsoPrependPath))
@@ -354,6 +443,15 @@ int main(int argc, char **argv) {
       return 1;
     }
 
+    if (OptionsOrErr->Update) {
+      // The debug map should be empty. Add one object file corresponding to
+      // the input file.
+      for (auto &Map : *DebugMapPtrsOrErr)
+        Map->addDebugMapObject(InputFile,
+                               llvm::sys::TimePoint<std::chrono::seconds>());
+    }
+
+    // Ensure that the debug map is not empty (anymore).
     if (DebugMapPtrsOrErr->empty()) {
       llvm::errs() << "error: no architecture to link\n";
       return 1;
@@ -369,7 +467,10 @@ int main(int argc, char **argv) {
 
     // If there is more than one link to execute, we need to generate
     // temporary files.
-    bool NeedsTempFiles = !DumpDebugMap && (*DebugMapPtrsOrErr).size() != 1;
+    bool NeedsTempFiles =
+        !DumpDebugMap && (OutputFileOpt != "-") &&
+        (DebugMapPtrsOrErr->size() != 1 || OptionsOrErr->Update);
+
     llvm::SmallVector<MachOUtils::ArchAndFilename, 4> TempFiles;
     TempFileVector TempFileStore;
     std::atomic_char AllOK(1);
@@ -412,7 +513,7 @@ int main(int argc, char **argv) {
 
       auto LinkLambda = [&,
                          OutputFile](std::shared_ptr<raw_fd_ostream> Stream) {
-        AllOK.fetch_and(linkDwarf(*Stream, *Map, Options));
+        AllOK.fetch_and(linkDwarf(*Stream, *Map, *OptionsOrErr));
         Stream->flush();
         if (Verify && !NoOutput)
           AllOK.fetch_and(verify(OutputFile, Map->getTriple().getArchName()));
@@ -434,7 +535,7 @@ int main(int argc, char **argv) {
 
     if (NeedsTempFiles &&
         !MachOUtils::generateUniversalBinary(
-            TempFiles, getOutputFileName(InputFile), Options, SDKPath))
+            TempFiles, getOutputFileName(InputFile), *OptionsOrErr, SDKPath))
       return 1;
   }