From 480fa7c00e477dc2bdad1f7750b57c128e78f491 Mon Sep 17 00:00:00 2001
From: Zack Corr <zack@z0w0.me>
Date: Sat, 21 Jul 2012 17:20:45 +1000
Subject: [PATCH] Only initialize targets that are actually supported / linked
 to in RustWrapper

---
 src/rustllvm/RustWrapper.cpp | 20 ++++++++++++++++----
 src/rustllvm/rustllvm.def.in |  2 ++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/rustllvm/RustWrapper.cpp b/src/rustllvm/RustWrapper.cpp
index 6c19a299757..8135465b30d 100644
--- a/src/rustllvm/RustWrapper.cpp
+++ b/src/rustllvm/RustWrapper.cpp
@@ -75,6 +75,12 @@ extern "C" bool LLVMLinkModules(LLVMModuleRef Dest, LLVMModuleRef Src) {
   return true;
 }
 
+void LLVMInitializeX86TargetInfo();
+void LLVMInitializeX86Target();
+void LLVMInitializeX86TargetMC();
+void LLVMInitializeX86AsmPrinter();
+void LLVMInitializeX86AsmParser();
+
 extern "C" bool
 LLVMRustWriteOutputFile(LLVMPassManagerRef PMR,
                         LLVMModuleRef M,
@@ -84,10 +90,16 @@ LLVMRustWriteOutputFile(LLVMPassManagerRef PMR,
                         CodeGenOpt::Level OptLevel,
 			bool EnableSegmentedStacks) {
 
-  InitializeAllTargets();
-  InitializeAllTargetMCs();
-  InitializeAllAsmPrinters();
-  InitializeAllAsmParsers();
+  // Only initialize the platforms supported by Rust here,
+  // because using --llvm-root will have multiple platforms
+  // that rustllvm doesn't actually link to and it's pointless to put target info
+  // into the registry that Rust can not generate machine code for.
+
+  LLVMInitializeX86TargetInfo();
+  LLVMInitializeX86Target();
+  LLVMInitializeX86TargetMC();
+  LLVMInitializeX86AsmPrinter();
+  LLVMInitializeX86AsmParser();
 
   TargetOptions Options;
   Options.NoFramePointerElim = true;
diff --git a/src/rustllvm/rustllvm.def.in b/src/rustllvm/rustllvm.def.in
index 8d82d930fd6..ed3799028d4 100644
--- a/src/rustllvm/rustllvm.def.in
+++ b/src/rustllvm/rustllvm.def.in
@@ -390,6 +390,8 @@ LLVMInitializeX86Disassembler
 LLVMInitializeX86Disassembler
 LLVMInitializeX86Target
 LLVMInitializeX86Target
+LLVMInitializeX86TargetMC
+LLVMInitializeX86TargetMC
 LLVMInitializeX86TargetInfo
 LLVMInitializeX86TargetInfo
 LLVMInsertBasicBlock