gold plugin: move target initialization to the top of the onload function.

[pcc]

Summary

On at least my machine, ar does not register an all symbols read hook (which
previously triggered target initialization), but it does register a claim
files hook, which depends on the targets being initialized.

[• rafael]

LGTM, thanks!

[pcc]

Closed by commit rL212303 (authored by @pcc).

llvm/trunk/tools/gold/gold-plugin.cpp

 
 static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
                                         int *claimed);
 static ld_plugin_status all_symbols_read_hook(void);
 static ld_plugin_status cleanup_hook(void);
 
 extern "C" ld_plugin_status onload(ld_plugin_tv *tv);
 ld_plugin_status onload(ld_plugin_tv *tv) {
+  InitializeAllTargetInfos();
+  InitializeAllTargets();
+  InitializeAllTargetMCs();
+  InitializeAllAsmParsers();
+  InitializeAllAsmPrinters();
+
   // We're given a pointer to the first transfer vector. We read through them
   // until we find one where tv_tag == LDPT_NULL. The REGISTER_* tagged values
   // contain pointers to functions that we need to call to register our own
   // hooks. The others are addresses of functions we can use to call into gold
   // for services.
 
   bool registeredClaimFile = false;
   bool RegisteredAllSymbolsRead = false;
ld_plugin_status onload(ld_plugin_tv *tv) {
   if (!add_symbols) {
     (*message)(LDPL_ERROR, "add_symbols not passed to LLVMgold.");
     return LDPS_ERR;
   }
 
   if (!RegisteredAllSymbolsRead)
     return LDPS_OK;
 
-  InitializeAllTargetInfos();
-  InitializeAllTargets();
-  InitializeAllTargetMCs();
-  InitializeAllAsmParsers();
-  InitializeAllAsmPrinters();
   CodeGen = new LTOCodeGenerator();
 
   // Pass through extra options to the code generator.
   if (!options::extra.empty()) {
     for (std::vector<std::string>::iterator it = options::extra.begin();
          it != options::extra.end(); ++it) {
       CodeGen->setCodeGenDebugOptions((*it).c_str());
     }