[dsymutil] Implement the --threads option

This patch adds the --threads option to dsymutil to process
architectures in parallel. The feature is already present in the version
distributed with Xcode, but was not yet upstreamed.

This is NFC as far as the linking behavior is concerned. As threads are
used automatically, the current tests cover the change in
implementation.

Differential revision: https://reviews.llvm.org/D39355

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316999 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/tools/dsymutil/cmdline.test b/test/tools/dsymutil/cmdline.test
new file mode 100644 (file)
index 0000000..983df4b
--- /dev/null
+++ b/test/tools/dsymutil/cmdline.test
@@ -0,0 +1,21 @@
+RUN: llvm-dsymutil -help 2>&1 | FileCheck --check-prefix=HELP %s
+HELP: OVERVIEW: manipulate archived DWARF debug symbol files.
+HELP: USAGE: llvm-dsymutil [options] <input files>
+HELP-NOT: -reverse-iterate
+HELP: Specific Options:
+HELP: -arch=<string>
+HELP: -dump-debug-map
+HELP: -flat
+HELP: -no-odr
+HELP: -no-output
+HELP: -no-swiftmodule-timestamp
+HELP: -o=<filename>
+HELP: -oso-prepend-path=<path>
+HELP: -symtab
+HELP: -threads=<n>
+HELP: -verbose
+HELP: -y
+HELP-NOT: -reverse-iterate
+
+RUN: llvm-dsymutil --version 2>&1 | FileCheck --check-prefix=VERSION %s
+VERSION: {{ version }}

diff --git a/tools/dsymutil/DwarfLinker.cpp b/tools/dsymutil/DwarfLinker.cpp
index b22b7a9dd1ad56a24bb3ea3fd1fce7428af7ac89..a726ba4e7b61b198b315a45703c8eb5554f26e0a 100644 (file)
--- a/tools/dsymutil/DwarfLinker.cpp
+++ b/tools/dsymutil/DwarfLinker.cpp
@@ -35,6 +35,7 @@
 #include "llvm/Object/MachO.h"
 #include "llvm/Support/LEB128.h"
 #include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/ToolOutputFile.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
 #include <memory>
@@ -479,7 +480,7 @@ class DwarfStreamer {
   /// @}
 
   /// The file we stream the linked Dwarf to.
-  std::unique_ptr<raw_fd_ostream> OutFile;
+  std::unique_ptr<ToolOutputFile> OutFile;
 
   uint32_t RangesSectionSize;
   uint32_t LocSectionSize;
@@ -617,13 +618,13 @@ bool DwarfStreamer::init(Triple TheTriple, StringRef OutputFilename) {
   // Create the output file.
   std::error_code EC;
   OutFile =
-      llvm::make_unique<raw_fd_ostream>(OutputFilename, EC, sys::fs::F_None);
+      llvm::make_unique<ToolOutputFile>(OutputFilename, EC, sys::fs::F_None);
   if (EC)
     return error(Twine(OutputFilename) + ": " + EC.message(), Context);
 
   MCTargetOptions MCOptions = InitMCTargetOptionsFromFlags();
   MS = TheTarget->createMCObjectStreamer(
-      TheTriple, *MC, std::unique_ptr<MCAsmBackend>(MAB), *OutFile,
+      TheTriple, *MC, std::unique_ptr<MCAsmBackend>(MAB), OutFile->os(),
       std::unique_ptr<MCCodeEmitter>(MCE), *MSTI, MCOptions.MCRelaxAll,
       MCOptions.MCIncrementalLinkerCompatible,
       /*DWARFMustBeAtTheEnd*/ false);
@@ -649,11 +650,16 @@ bool DwarfStreamer::init(Triple TheTriple, StringRef OutputFilename) {
 }
 
 bool DwarfStreamer::finish(const DebugMap &DM) {
+  bool Result = true;
   if (DM.getTriple().isOSDarwin() && !DM.getBinaryPath().empty())
-    return MachOUtils::generateDsymCompanion(DM, *MS, *OutFile);
+    Result = MachOUtils::generateDsymCompanion(DM, *MS, OutFile->os());
+  else
+    MS->Finish();
 
-  MS->Finish();
-  return true;
+  // Declare success.
+  OutFile->keep();
+
+  return Result;
 }
 
 /// Set the current output section to debug_info and change

diff --git a/tools/dsymutil/dsymutil.cpp b/tools/dsymutil/dsymutil.cpp
index 975f8a5f09507ff618264b2518d15da95564be5c..5f224b6bb8a116ccfd2527fac7c72936a1a03738 100644 (file)
--- a/tools/dsymutil/dsymutil.cpp
+++ b/tools/dsymutil/dsymutil.cpp
@@ -12,9 +12,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "dsymutil.h"
 #include "DebugMap.h"
 #include "MachOUtils.h"
-#include "dsymutil.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/FileUtilities.h"
@@ -22,8 +22,9 @@
 #include "llvm/Support/Options.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/Signals.h"
-#include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/ThreadPool.h"
+#include "llvm/Support/raw_ostream.h"
 #include <cstdint>
 #include <string>
 
@@ -61,6 +62,13 @@ static opt<bool> FlatOut("flat",
                          init(false), cat(DsymCategory));
 static alias FlatOutA("f", desc("Alias for --flat"), aliasopt(FlatOut));
 
+static opt<unsigned> Threads(
+    "threads",
+    desc("Specifies the maximum number (n) of simultaneous threads to use\n"
+         "when linking multiple architectures."),
+    value_desc("n"), init(0), cat(DsymCategory));
+static alias ThreadsA("t", desc("Alias for --threads"), aliasopt(Threads));
+
 static opt<bool> Verbose("verbose", desc("Verbosity level"), init(false),
                          cat(DsymCategory));
 
@@ -316,6 +324,15 @@ int main(int argc, char **argv) {
       exitDsymutil(1);
     }
 
+    unsigned NumThreads = Threads;
+    if (!NumThreads)
+      NumThreads = llvm::thread::hardware_concurrency();
+    if (DumpDebugMap || Verbose)
+      NumThreads = 1;
+    NumThreads = std::min(NumThreads, (unsigned)DebugMapPtrsOrErr->size());
+
+    llvm::ThreadPool Threads(NumThreads);
+
     // If there is more than one link to execute, we need to generate
     // temporary files.
     bool NeedsTempFiles = !DumpDebugMap && (*DebugMapPtrsOrErr).size() != 1;
@@ -333,14 +350,27 @@ int main(int argc, char **argv) {
                      << ")\n";
 
       std::string OutputFile = getOutputFileName(InputFile, NeedsTempFiles);
-      if (OutputFile.empty() || !linkDwarf(OutputFile, *Map, Options))
-        exitDsymutil(1);
+
+      auto LinkLambda = [OutputFile, Options, &Map]() {
+        if (OutputFile.empty() || !linkDwarf(OutputFile, *Map, Options))
+          exitDsymutil(1);
+      };
+
+      // FIXME: The DwarfLinker can have some very deep recursion that can max
+      // out the (significantly smaller) stack when using threads. We don't
+      // want this limitation when we only have a single thread.
+      if (NumThreads == 1)
+        LinkLambda();
+      else
+        Threads.async(LinkLambda);
 
       if (NeedsTempFiles)
         TempFiles.emplace_back(Map->getTriple().getArchName().str(),
                                OutputFile);
     }
 
+    Threads.wait();
+
     if (NeedsTempFiles &&
         !MachOUtils::generateUniversalBinary(
             TempFiles, getOutputFileName(InputFile), Options, SDKPath))