Move SymbolTable::addFile to InputFiles.cpp.

The symbol table used to be a container of vectors of input files,
but that's no longer the case because the vectors are moved out of
SymbolTable and are now global variables.

Therefore, addFile doesn't have to belong to any class. This patch
moves the function out of the class.

This patch is a preparation for my RFC [1].

[1] http://lists.llvm.org/pipermail/llvm-dev/2019-April/131902.html

Differential Revision: https://reviews.llvm.org/D61854

llvm-svn: 360666

lld/ELF/Driver.cpp

@@ -1526,7 +1526,7 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
   // Add all files to the symbol table. This will add almost all
   // symbols that we need to the symbol table.
   for (InputFile *F : Files)
-    Symtab->addFile<ELFT>(F);
+    parseFile<ELFT>(F);
 
   // Now that we have every file, we can decide if we will need a
   // dynamic symbol table.

lld/ELF/InputFiles.cpp

@@ -78,6 +78,88 @@ Optional<MemoryBufferRef> elf::readFile(StringRef Path) {
   return MBRef;
 }
 
+// All input object files must be for the same architecture
+// (e.g. it does not make sense to link x86 object files with
+// MIPS object files.) This function checks for that error.
+static bool isCompatible(InputFile *File) {
+  if (!File->isElf() && !isa<BitcodeFile>(File))
+    return true;
+
+  if (File->EKind == Config->EKind && File->EMachine == Config->EMachine) {
+    if (Config->EMachine != EM_MIPS)
+      return true;
+    if (isMipsN32Abi(File) == Config->MipsN32Abi)
+      return true;
+  }
+
+  if (!Config->Emulation.empty()) {
+    error(toString(File) + " is incompatible with " + Config->Emulation);
+  } else {
+    InputFile *Existing;
+    if (!ObjectFiles.empty())
+      Existing = ObjectFiles[0];
+    else if (!SharedFiles.empty())
+      Existing = SharedFiles[0];
+    else
+      Existing = BitcodeFiles[0];
+
+    error(toString(File) + " is incompatible with " + toString(Existing));
+  }
+
+  return false;
+}
+
+// Add symbols in File to the symbol table.
+template <class ELFT> void elf::parseFile(InputFile *File) {
+  // Comdat groups define "link once" sections. If two comdat groups have the
+  // same name, only one of them is linked, and the other is ignored. This set
+  // is used to uniquify them.
+  static llvm::DenseSet<llvm::CachedHashStringRef> ComdatGroups;
+
+  if (!isCompatible(File))
+    return;
+
+  // Binary file
+  if (auto *F = dyn_cast<BinaryFile>(File)) {
+    BinaryFiles.push_back(F);
+    F->parse();
+    return;
+  }
+
+  // .a file
+  if (auto *F = dyn_cast<ArchiveFile>(File)) {
+    F->parse<ELFT>();
+    return;
+  }
+
+  // Lazy object file
+  if (auto *F = dyn_cast<LazyObjFile>(File)) {
+    LazyObjFiles.push_back(F);
+    F->parse<ELFT>();
+    return;
+  }
+
+  if (Config->Trace)
+    message(toString(File));
+
+  // .so file
+  if (auto *F = dyn_cast<SharedFile>(File)) {
+    F->parse<ELFT>();
+    return;
+  }
+
+  // LLVM bitcode file
+  if (auto *F = dyn_cast<BitcodeFile>(File)) {
+    BitcodeFiles.push_back(F);
+    F->parse<ELFT>(ComdatGroups);
+    return;
+  }
+
+  // Regular object file
+  ObjectFiles.push_back(File);
+  cast<ObjFile<ELFT>>(File)->parse(ComdatGroups);
+}
+
 // Concatenates arguments to construct a string representing an error location.
 static std::string createFileLineMsg(StringRef Path, unsigned Line) {
   std::string Filename = path::filename(Path);
@@ -1359,6 +1441,11 @@ std::string elf::replaceThinLTOSuffix(StringRef Path) {
   return Path;
 }
 
+template void elf::parseFile<ELF32LE>(InputFile *);
+template void elf::parseFile<ELF32BE>(InputFile *);
+template void elf::parseFile<ELF64LE>(InputFile *);
+template void elf::parseFile<ELF64BE>(InputFile *);
+
 template void ArchiveFile::parse<ELF32LE>();
 template void ArchiveFile::parse<ELF32BE>();
 template void ArchiveFile::parse<ELF64LE>();

lld/ELF/InputFiles.h

@@ -54,6 +54,9 @@ extern std::unique_ptr<llvm::TarWriter> Tar;
 // Opens a given file.
 llvm::Optional<MemoryBufferRef> readFile(StringRef Path);
 
+// Add symbols in File to the symbol table.
+template <class ELFT> void parseFile(InputFile *File);
+
 // The root class of input files.
 class InputFile {
 public:

lld/ELF/SymbolTable.cpp

@@ -32,81 +32,6 @@ using namespace lld::elf;
 
 SymbolTable *elf::Symtab;
 
-static InputFile *getFirstElf() {
-  if (!ObjectFiles.empty())
-    return ObjectFiles[0];
-  if (!SharedFiles.empty())
-    return SharedFiles[0];
-  return BitcodeFiles[0];
-}
-
-// All input object files must be for the same architecture
-// (e.g. it does not make sense to link x86 object files with
-// MIPS object files.) This function checks for that error.
-static bool isCompatible(InputFile *F) {
-  if (!F->isElf() && !isa<BitcodeFile>(F))
-    return true;
-
-  if (F->EKind == Config->EKind && F->EMachine == Config->EMachine) {
-    if (Config->EMachine != EM_MIPS)
-      return true;
-    if (isMipsN32Abi(F) == Config->MipsN32Abi)
-      return true;
-  }
-
-  if (!Config->Emulation.empty())
-    error(toString(F) + " is incompatible with " + Config->Emulation);
-  else
-    error(toString(F) + " is incompatible with " + toString(getFirstElf()));
-  return false;
-}
-
-// Add symbols in File to the symbol table.
-template <class ELFT> void SymbolTable::addFile(InputFile *File) {
-  if (!isCompatible(File))
-    return;
-
-  // Binary file
-  if (auto *F = dyn_cast<BinaryFile>(File)) {
-    BinaryFiles.push_back(F);
-    F->parse();
-    return;
-  }
-
-  // .a file
-  if (auto *F = dyn_cast<ArchiveFile>(File)) {
-    F->parse<ELFT>();
-    return;
-  }
-
-  // Lazy object file
-  if (auto *F = dyn_cast<LazyObjFile>(File)) {
-    LazyObjFiles.push_back(F);
-    F->parse<ELFT>();
-    return;
-  }
-
-  if (Config->Trace)
-    message(toString(File));
-
-  // .so file
-  if (auto *F = dyn_cast<SharedFile>(File)) {
-    F->parse<ELFT>();
-    return;
-  }
-
-  // LLVM bitcode file
-  if (auto *F = dyn_cast<BitcodeFile>(File)) {
-    BitcodeFiles.push_back(F);
-    F->parse<ELFT>(ComdatGroups);
-    return;
-  }
-
-  // Regular object file
-  ObjectFiles.push_back(File);
-  cast<ObjFile<ELFT>>(File)->parse(ComdatGroups);
-}
-
 // 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.
@@ -539,7 +464,7 @@ void SymbolTable::addLazyArchive(StringRef Name, ArchiveFile &File,
   }
 
   if (InputFile *F = File.fetch(Sym))
-    addFile<ELFT>(F);
+    parseFile<ELFT>(F);
 }
 
 template <class ELFT>
@@ -563,19 +488,19 @@ void SymbolTable::addLazyObject(StringRef Name, LazyObjFile &File) {
   }
 
   if (InputFile *F = File.fetch())
-    addFile<ELFT>(F);
+    parseFile<ELFT>(F);
 }
 
 template <class ELFT> void SymbolTable::fetchLazy(Symbol *Sym) {
   if (auto *S = dyn_cast<LazyArchive>(Sym)) {
     if (InputFile *File = S->fetch())
-      addFile<ELFT>(File);
+      parseFile<ELFT>(File);
     return;
   }
 
   auto *S = cast<LazyObject>(Sym);
   if (InputFile *File = cast<LazyObjFile>(S->File)->fetch())
-    addFile<ELFT>(File);
+    parseFile<ELFT>(File);
 }
 
 // Initialize DemangledSyms with a map from demangled symbols to symbol
@@ -739,11 +664,6 @@ void SymbolTable::scanVersionScript() {
     Sym->parseSymbolVersion();
 }
 
-template void SymbolTable::addFile<ELF32LE>(InputFile *);
-template void SymbolTable::addFile<ELF32BE>(InputFile *);
-template void SymbolTable::addFile<ELF64LE>(InputFile *);
-template void SymbolTable::addFile<ELF64BE>(InputFile *);
-
 template Symbol *SymbolTable::addUndefined<ELF32LE>(StringRef, uint8_t, uint8_t,
                                                     uint8_t, bool, InputFile *);
 template Symbol *SymbolTable::addUndefined<ELF32BE>(StringRef, uint8_t, uint8_t,

lld/ELF/SymbolTable.h

@@ -34,7 +34,6 @@ class SectionBase;
 // is one add* function per symbol type.
 class SymbolTable {
 public:
-  template <class ELFT> void addFile(InputFile *File);
   template <class ELFT> void addCombinedLTOObject();
   void wrap(Symbol *Sym, Symbol *Real, Symbol *Wrap);