From 2c02f34fccee563e22db70cbfb03fb2cc7da30f9 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Jos=C3=A9=20Fonseca?= <jfonseca@vmware.com>
Date: Wed, 14 May 2014 12:20:14 +0100
Subject: [PATCH] gallivm: Support MCJIT on Windows.

It works fine, though it requires using ELF objects.

With this change there is nothing preventing us to switch exclusively
to MCJIT, everywhere.  It's still off though.
---
 scons/llvm.py                                 | 8 +++-----
 src/gallium/auxiliary/gallivm/lp_bld_misc.cpp | 9 +++++++++
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/scons/llvm.py b/scons/llvm.py
index cdfbe43708f..288a0806f2a 100644
--- a/scons/llvm.py
+++ b/scons/llvm.py
@@ -104,7 +104,7 @@ def generate(env):
                 'LLVMBitWriter', 'LLVMX86Disassembler', 'LLVMX86AsmParser',
                 'LLVMX86CodeGen', 'LLVMX86Desc', 'LLVMSelectionDAG',
                 'LLVMAsmPrinter', 'LLVMMCParser', 'LLVMX86AsmPrinter',
-                'LLVMX86Utils', 'LLVMX86Info', 'LLVMJIT',
+                'LLVMX86Utils', 'LLVMX86Info', 'LLVMMCJIT', 'LLVMJIT',
                 'LLVMExecutionEngine', 'LLVMCodeGen', 'LLVMScalarOpts',
                 'LLVMInstCombine', 'LLVMTransformUtils', 'LLVMipa',
                 'LLVMAnalysis', 'LLVMTarget', 'LLVMMC', 'LLVMCore',
@@ -116,7 +116,7 @@ def generate(env):
                 'LLVMBitWriter', 'LLVMX86Disassembler', 'LLVMX86AsmParser',
                 'LLVMX86CodeGen', 'LLVMX86Desc', 'LLVMSelectionDAG',
                 'LLVMAsmPrinter', 'LLVMMCParser', 'LLVMX86AsmPrinter',
-                'LLVMX86Utils', 'LLVMX86Info', 'LLVMJIT',
+                'LLVMX86Utils', 'LLVMX86Info', 'LLVMMCJIT', 'LLVMJIT',
                 'LLVMExecutionEngine', 'LLVMCodeGen', 'LLVMScalarOpts',
                 'LLVMInstCombine', 'LLVMTransformUtils', 'LLVMipa',
                 'LLVMAnalysis', 'LLVMTarget', 'LLVMMC', 'LLVMCore',
@@ -165,9 +165,7 @@ def generate(env):
             if '-fno-rtti' in cxxflags:
                 env.Append(CXXFLAGS = ['-fno-rtti'])
 
-            components = ['engine', 'bitwriter', 'x86asmprinter']
-
-            components.append('mcjit')
+            components = ['engine', 'mcjit', 'bitwriter', 'x86asmprinter']
 
             env.ParseConfig('llvm-config --libs ' + ' '.join(components))
             env.ParseConfig('llvm-config --ldflags')
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
index d03680fc67d..d1cc9b67b6c 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
+++ b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
@@ -57,6 +57,7 @@
 #include <llvm/ADT/Triple.h>
 #include <llvm/ExecutionEngine/JITMemoryManager.h>
 #include <llvm/Support/CommandLine.h>
+#include <llvm/Support/Host.h>
 #include <llvm/Support/PrettyStackTrace.h>
 
 #include <llvm/Support/TargetSelect.h>
@@ -452,6 +453,14 @@ lp_build_create_jit_compiler_for_module(LLVMExecutionEngineRef *OutJIT,
 
    if (useMCJIT) {
        builder.setUseMCJIT(true);
+#ifdef _WIN32
+       /*
+        * MCJIT works on Windows, but currently only through ELF object format.
+        */
+       std::string targetTriple = llvm::sys::getProcessTriple();
+       targetTriple.append("-elf");
+       unwrap(M)->setTargetTriple(targetTriple);
+#endif
    }
 
    llvm::SmallVector<std::string, 1> MAttrs;
-- 
2.30.2