[WebAssembly] Simplify check for emitting relocations

[sbc100]

Summary

This is a small change I split of from a larger one. It simplifies the
condition that needs to be checked when decided if we need to emi
relocation and all the things they depend on (symbols, etc),

[ruiu]

LGTM

lld/trunk/wasm/Driver.cpp

void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   Config->OutputFile = Args.getLastArgValue(OPT_o);
   Config->Relocatable = Args.hasArg(OPT_relocatable);
   Config->SearchPaths = args::getStrings(Args, OPT_L);
   Config->StripAll = Args.hasArg(OPT_strip_all);
   Config->StripDebug = Args.hasArg(OPT_strip_debug);
   Config->Sysroot = Args.getLastArgValue(OPT_sysroot);
   errorHandler().Verbose = Args.hasArg(OPT_verbose);
   ThreadsEnabled = Args.hasFlag(OPT_threads, OPT_no_threads, true);
+  if (Config->Relocatable)
+    Config->EmitRelocs = true;
 
   Config->InitialMemory = args::getInteger(Args, OPT_initial_memory, 0);
   Config->GlobalBase = args::getInteger(Args, OPT_global_base, 1024);
   Config->MaxMemory = args::getInteger(Args, OPT_max_memory, 0);
   Config->ZStackSize =
       args::getZOptionValue(Args, OPT_z, "stack-size", WasmPageSize);
 
   if (auto *Arg = Args.getLastArg(OPT_allow_undefined_file))

lld/trunk/wasm/Writer.cpp

void Writer::createGlobalSection() {
   raw_ostream &OS = Section->getStream();
 
   writeUleb128(OS, NumGlobals, "global count");
   for (auto &Pair : Config->SyntheticGlobals) {
     WasmGlobal &Global = Pair.second;
     writeGlobal(OS, Global);
   }
 
-  if (Config->Relocatable || Config->EmitRelocs) {
+  if (Config->EmitRelocs) {
     for (ObjFile *File : Symtab->ObjectFiles) {
       uint32_t GlobalIndex = File->NumGlobalImports();
       for (const WasmGlobal &Global : File->getWasmObj()->globals()) {
         WasmGlobal RelocatedGlobal(Global);
         if (Global.Type != WASM_TYPE_I32)
           fatal("unsupported global type: " + Twine(Global.Type));
         if (Global.InitExpr.Opcode != WASM_OPCODE_I32_CONST)
           fatal("unsupported global init opcode: " +
void Writer::createSections() {
   createGlobalSection();
   createExportSection();
   createStartSection();
   createElemSection();
   createCodeSection();
   createDataSection();
 
   // Custom sections
-  if (Config->EmitRelocs || Config->Relocatable)
+  if (Config->EmitRelocs)
     createRelocSections();
   createLinkingSection();
   if (!Config->StripDebug && !Config->StripAll)
     createNameSection();
 
   for (OutputSection *S : OutputSections) {
     S->setOffset(FileSize);
     S->finalizeContents();
for (ObjFile *File : Symtab->ObjectFiles) {
     const WasmObjectFile *WasmFile = File->getWasmObj();
 
     // Function Index
     File->FunctionIndexOffset =
         FunctionImports.size() - File->NumFunctionImports() + NumFunctions;
     NumFunctions += WasmFile->functions().size();
 
     // Global Index
-    if (Config->Relocatable || Config->EmitRelocs) {
+    if (Config->EmitRelocs) {
       File->GlobalIndexOffset =
           GlobalImports.size() - File->NumGlobalImports() + NumGlobals;
       NumGlobals += WasmFile->globals().size();
     }
 
     // Memory
     if (WasmFile->memories().size()) {
       if (WasmFile->memories().size() > 1) {