[lld] Move Threads to Common

Summary:
This will allow using the functionality from other linkers. It is also
a prerequisite for sharing the error logging code.

Reviewers: ruiu

Reviewed By: ruiu

Subscribers: emaste, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D38822

llvm-svn: 315725

lld/Common/CMakeLists.txt

@@ -5,6 +5,7 @@ endif()
 add_lld_library(lldCommon
   Reproduce.cpp
   TargetOptionsCommandFlags.cpp
+  Threads.cpp
   Version.cpp
 
   ADDITIONAL_HEADER_DIRS

lld/Common/Threads.cpp

@@ -7,13 +7,15 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "Threads.h"
+#include "lld/Common/Threads.h"
 #include <thread>
 
 static std::vector<std::thread> Threads;
 
+bool lld::ThreadsEnabled = true;
+
 // Runs a given function in a new thread.
-void lld::elf::runBackground(std::function<void()> Fn) {
+void lld::runBackground(std::function<void()> Fn) {
   Threads.emplace_back(Fn);
 }
 
@@ -22,7 +24,7 @@ void lld::elf::runBackground(std::function<void()> Fn) {
 // You need to call this function from the main thread before exiting
 // because it is not defined what will happen to non-main threads when
 // the main thread exits.
-void lld::elf::waitForBackgroundThreads() {
+void lld::waitForBackgroundThreads() {
   for (std::thread &T : Threads)
     if (T.joinable())
       T.join();

lld/ELF/CMakeLists.txt

@@ -40,7 +40,6 @@ add_lld_library(lldELF
   Symbols.cpp
   SyntheticSections.cpp
   Target.cpp
-  Threads.cpp
   Thunks.cpp
   Writer.cpp
 

lld/ELF/Config.h

@@ -139,7 +139,6 @@ struct Configuration {
   bool Static = false;
   bool SysvHash = false;
   bool Target1Rel;
-  bool Threads;
   bool Trace;
   bool Verbose;
   bool WarnCommon;

lld/ELF/Driver.cpp

@@ -38,9 +38,9 @@
 #include "SymbolTable.h"
 #include "SyntheticSections.h"
 #include "Target.h"
-#include "Threads.h"
 #include "Writer.h"
 #include "lld/Common/Driver.h"
+#include "lld/Common/Threads.h"
 #include "lld/Common/Version.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
@@ -684,7 +684,7 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) {
       parseCachePruningPolicy(Args.getLastArgValue(OPT_thinlto_cache_policy)),
       "--thinlto-cache-policy: invalid cache policy");
   Config->ThinLTOJobs = getInteger(Args, OPT_thinlto_jobs, -1u);
-  Config->Threads = getArg(Args, OPT_threads, OPT_no_threads, true);
+  ThreadsEnabled = getArg(Args, OPT_threads, OPT_no_threads, true);
   Config->Trace = Args.hasArg(OPT_trace);
   Config->Undefined = getArgs(Args, OPT_undefined);
   Config->UnresolvedSymbols = getUnresolvedSymbolPolicy(Args);

lld/ELF/Error.cpp

@@ -9,7 +9,8 @@
 
 #include "Error.h"
 #include "Config.h"
-#include "Threads.h"
+
+#include "lld/Common/Threads.h"
 
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/Error.h"

lld/ELF/Filesystem.cpp

@@ -13,7 +13,7 @@
 
 #include "Filesystem.h"
 #include "Config.h"
-#include "Threads.h"
+#include "lld/Common/Threads.h"
 #include "llvm/Support/FileOutputBuffer.h"
 #include "llvm/Support/FileSystem.h"
 
@@ -38,7 +38,7 @@ using namespace lld::elf;
 // This function spawns a background thread to call unlink.
 // The calling thread returns almost immediately.
 void elf::unlinkAsync(StringRef Path) {
-  if (!Config->Threads || !sys::fs::exists(Config->OutputFile) ||
+  if (!ThreadsEnabled || !sys::fs::exists(Config->OutputFile) ||
       !sys::fs::is_regular_file(Config->OutputFile))
     return;
 

lld/ELF/ICF.cpp

@@ -76,7 +76,7 @@
 #include "ICF.h"
 #include "Config.h"
 #include "SymbolTable.h"
-#include "Threads.h"
+#include "lld/Common/Threads.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/Object/ELF.h"
@@ -366,7 +366,7 @@ template <class ELFT>
 void ICF<ELFT>::forEachClass(std::function<void(size_t, size_t)> Fn) {
   // If threading is disabled or the number of sections are
   // too small to use threading, call Fn sequentially.
-  if (!Config->Threads || Sections.size() < 1024) {
+  if (!ThreadsEnabled || Sections.size() < 1024) {
     forEachClassRange(0, Sections.size(), Fn);
     ++Cnt;
     return;

lld/ELF/LinkerScript.cpp

@@ -21,8 +21,8 @@
 #include "Symbols.h"
 #include "SyntheticSections.h"
 #include "Target.h"
-#include "Threads.h"
 #include "Writer.h"
+#include "lld/Common/Threads.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/BinaryFormat/ELF.h"

lld/ELF/MapFile.cpp

@@ -26,7 +26,8 @@
 #include "Strings.h"
 #include "SymbolTable.h"
 #include "SyntheticSections.h"
-#include "Threads.h"
+
+#include "lld/Common/Threads.h"
 
 #include "llvm/Support/raw_ostream.h"
 

lld/ELF/OutputSections.cpp

@@ -15,7 +15,7 @@
 #include "SymbolTable.h"
 #include "SyntheticSections.h"
 #include "Target.h"
-#include "Threads.h"
+#include "lld/Common/Threads.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/Support/Compression.h"
 #include "llvm/Support/MD5.h"

lld/ELF/SyntheticSections.cpp

@@ -24,8 +24,8 @@
 #include "Strings.h"
 #include "SymbolTable.h"
 #include "Target.h"
-#include "Threads.h"
 #include "Writer.h"
+#include "lld/Common/Threads.h"
 #include "lld/Common/Version.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
@@ -2258,7 +2258,7 @@ void MergeNoTailSection::finalizeContents() {
   // Concurrency level. Must be a power of 2 to avoid expensive modulo
   // operations in the following tight loop.
   size_t Concurrency = 1;
-  if (Config->Threads)
+  if (ThreadsEnabled)
     Concurrency =
         std::min<size_t>(PowerOf2Floor(hardware_concurrency()), NumShards);
 

lld/ELF/Writer.cpp

@@ -19,7 +19,7 @@
 #include "SymbolTable.h"
 #include "SyntheticSections.h"
 #include "Target.h"
-#include "Threads.h"
+#include "lld/Common/Threads.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/FileOutputBuffer.h"

lld/include/lld/Common/Threads.h

@@ -56,19 +56,18 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLD_ELF_THREADS_H
-#define LLD_ELF_THREADS_H
-
-#include "Config.h"
+#ifndef LLD_COMMON_THREADS_H
+#define LLD_COMMON_THREADS_H
 
 #include "llvm/Support/Parallel.h"
 #include <functional>
 
 namespace lld {
-namespace elf {
+
+extern bool ThreadsEnabled;
 
 template <typename R, class FuncTy> void parallelForEach(R &&Range, FuncTy Fn) {
-  if (Config->Threads)
+  if (ThreadsEnabled)
     for_each(llvm::parallel::par, std::begin(Range), std::end(Range), Fn);
   else
     for_each(llvm::parallel::seq, std::begin(Range), std::end(Range), Fn);
@@ -76,7 +75,7 @@ template <typename R, class FuncTy> void parallelForEach(R &&Range, FuncTy Fn) {
 
 inline void parallelForEachN(size_t Begin, size_t End,
                              std::function<void(size_t)> Fn) {
-  if (Config->Threads)
+  if (ThreadsEnabled)
     for_each_n(llvm::parallel::par, Begin, End, Fn);
   else
     for_each_n(llvm::parallel::seq, Begin, End, Fn);
@@ -85,7 +84,6 @@ inline void parallelForEachN(size_t Begin, size_t End,
 void runBackground(std::function<void()> Fn);
 void waitForBackgroundThreads();
 
-} // namespace elf
 } // namespace lld
 
 #endif