Move SymbolTable::addCombinedLTOObject() to LinkerDriver.

rui314 · rui314 · commit 0baaf45be707 · 2019-05-23T09:26:27.000Z
Also renames it LinkerDriver::compileBitcodeFiles. The function doesn't logically belong to SymbolTable. We added this function to the symbol table because symbol table used to be a container of input files. This is no longer the case. Differential Revision: https://reviews.llvm.org/D62291 llvm-svn: 361469
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
@@ -1436,6 +1436,29 @@ template <class ELFT> static Symbol *addUndefined(StringRef Name) {
       Undefined{nullptr, Name, STB_GLOBAL, STV_DEFAULT, 0});
 }
 
+// This function is where all the optimizations of link-time
+// optimization takes place. When LTO is in use, some input files are
+// not in native object file format but in the LLVM bitcode format.
+// This function compiles bitcode files into a few big native files
+// using LLVM functions and replaces bitcode symbols with the results.
+// Because all bitcode files that the program consists of are passed to
+// the compiler at once, it can do a whole-program optimization.
+template <class ELFT> void LinkerDriver::compileBitcodeFiles() {
+  // Compile bitcode files and replace bitcode symbols.
+  LTO.reset(new BitcodeCompiler);
+  for (BitcodeFile *File : BitcodeFiles)
+    LTO->add(*File);
+
+  for (InputFile *File : LTO->compile()) {
+    DenseMap<CachedHashStringRef, const InputFile *> DummyGroups;
+    auto *Obj = cast<ObjFile<ELFT>>(File);
+    Obj->parse(DummyGroups);
+    for (Symbol *Sym : Obj->getGlobalSymbols())
+      Sym->parseSymbolVersion();
+    ObjectFiles.push_back(File);
+  }
+}
+
 // The --wrap option is a feature to rename symbols so that you can write
 // wrappers for existing functions. If you pass `-wrap=foo`, all
 // occurrences of symbol `foo` are resolved to `wrap_foo` (so, you are
@@ -1645,7 +1668,7 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
   //
   // With this the symbol table should be complete. After this, no new names
   // except a few linker-synthesized ones will be added to the symbol table.
-  Symtab->addCombinedLTOObject<ELFT>();
+  compileBitcodeFiles<ELFT>();
   if (errorCount())
     return;
 
diff --git a/lld/ELF/Driver.h b/lld/ELF/Driver.h
@@ -9,6 +9,7 @@
 #ifndef LLD_ELF_DRIVER_H
 #define LLD_ELF_DRIVER_H
 
+#include "LTO.h"
 #include "SymbolTable.h"
 #include "lld/Common/LLVM.h"
 #include "lld/Common/Reproduce.h"
@@ -33,13 +34,17 @@ class LinkerDriver {
   void createFiles(llvm::opt::InputArgList &Args);
   void inferMachineType();
   template <class ELFT> void link(llvm::opt::InputArgList &Args);
+  template <class ELFT> void compileBitcodeFiles();
 
   // True if we are in --whole-archive and --no-whole-archive.
   bool InWholeArchive = false;
 
   // True if we are in --start-lib and --end-lib.
   bool InLib = false;
 
+  // For LTO.
+  std::unique_ptr<BitcodeCompiler> LTO;
+
   std::vector<InputFile *> Files;
 };
 
diff --git a/lld/ELF/SymbolTable.cpp b/lld/ELF/SymbolTable.cpp
@@ -32,29 +32,6 @@ using namespace lld::elf;
 
 SymbolTable *elf::Symtab;
 
-// This function is where all the optimizations of link-time
-// optimization happens. When LTO is in use, some input files are
-// not in native object file format but in the LLVM bitcode format.
-// This function compiles bitcode files into a few big native files
-// using LLVM functions and replaces bitcode symbols with the results.
-// Because all bitcode files that the program consists of are passed
-// to the compiler at once, it can do whole-program optimization.
-template <class ELFT> void SymbolTable::addCombinedLTOObject() {
-  // Compile bitcode files and replace bitcode symbols.
-  LTO.reset(new BitcodeCompiler);
-  for (BitcodeFile *F : BitcodeFiles)
-    LTO->add(*F);
-
-  for (InputFile *File : LTO->compile()) {
-    DenseMap<CachedHashStringRef, const InputFile *> DummyGroups;
-    auto *Obj = cast<ObjFile<ELFT>>(File);
-    Obj->parse(DummyGroups);
-    for (Symbol *Sym : Obj->getGlobalSymbols())
-      Sym->parseSymbolVersion();
-    ObjectFiles.push_back(File);
-  }
-}
-
 // Set a flag for --trace-symbol so that we can print out a log message
 // if a new symbol with the same name is inserted into the symbol table.
 void SymbolTable::trace(StringRef Name) {
@@ -609,8 +586,3 @@ void elf::resolveSymbol(Symbol *Old, const Symbol &New) {
     llvm_unreachable("bad symbol kind");
   }
 }
-
-template void SymbolTable::addCombinedLTOObject<ELF32LE>();
-template void SymbolTable::addCombinedLTOObject<ELF32BE>();
-template void SymbolTable::addCombinedLTOObject<ELF64LE>();
-template void SymbolTable::addCombinedLTOObject<ELF64BE>();
diff --git a/lld/ELF/SymbolTable.h b/lld/ELF/SymbolTable.h
@@ -10,7 +10,6 @@
 #define LLD_ELF_SYMBOL_TABLE_H
 
 #include "InputFiles.h"
-#include "LTO.h"
 #include "lld/Common/Strings.h"
 #include "llvm/ADT/CachedHashString.h"
 #include "llvm/ADT/DenseMap.h"
@@ -40,7 +39,6 @@ class Undefined;
 // is one add* function per symbol type.
 class SymbolTable {
 public:
-  template <class ELFT> void addCombinedLTOObject();
   void wrap(Symbol *Sym, Symbol *Real, Symbol *Wrap);
 
   ArrayRef<Symbol *> getSymbols() const { return SymVector; }
@@ -92,9 +90,6 @@ class SymbolTable {
   // can have the same name. We use this map to handle "extern C++ {}"
   // directive in version scripts.
   llvm::Optional<llvm::StringMap<std::vector<Symbol *>>> DemangledSyms;
-
-  // For LTO.
-  std::unique_ptr<BitcodeCompiler> LTO;
 };
 
 extern SymbolTable *Symtab;
