From 3b30a6e92d1da79674451879d4112a8f83cc12a4 Mon Sep 17 00:00:00 2001
From: Anton Korobeynikov <asl@math.spbu.ru>
Date: Mon, 30 Jul 2007 20:02:02 +0000
Subject: [PATCH] Add detection of __dso_handle presence during configure. Use
 this information in the JITer (short path is added for darwin). This is
 needed to properly JIT llvm-gcc-4.2-built binaries, since cxa_atexit is
 enabled by default on much more targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40600 91177308-0d34-0410-b5e6-96231b3b80d8
---
 autoconf/configure.ac           |  3 +++
 include/llvm/Config/config.h.in |  3 +++
 lib/ExecutionEngine/JIT/JIT.cpp | 35 +++++++++++++++++++--------------
 3 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index 23897d5fd8a..5ba07c830a2 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -766,6 +766,9 @@ dnl=== SECTION 9: Additional checks, variables, etc.
 dnl===
 dnl===-----------------------------------------------------------------------===
 
+dnl Check, whether __dso_handle is present
+AC_CHECK_FUNCS([__dso_handle])
+
 dnl See if the llvm-gcc executable can compile to LLVM assembly
 AC_CACHE_CHECK([whether llvm-gcc is sane],[llvm_cv_llvmgcc_sanity],
 [llvm_cv_llvmgcc_sanity="no"
diff --git a/include/llvm/Config/config.h.in b/include/llvm/Config/config.h.in
index 80b443f6c7c..ae4116a9325 100644
--- a/include/llvm/Config/config.h.in
+++ b/include/llvm/Config/config.h.in
@@ -437,6 +437,9 @@
 /* Define to 1 if you have the <windows.h> header file. */
 #undef HAVE_WINDOWS_H
 
+/* Define to 1 if you have the `__dso_handle' function. */
+#undef HAVE___DSO_HANDLE
+
 /* Installation directory for binary executables */
 #undef LLVM_BINDIR
 
diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
index 603f8ec14ad..926142f4637 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -27,17 +27,29 @@
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetJITInfo.h"
+
+#include "llvm/Config/config.h"
+
 using namespace llvm;
 
 #ifdef __APPLE__ 
-#include <AvailabilityMacros.h>
-#if defined(MAC_OS_X_VERSION_10_4) && \
-    ((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \
-     (MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \
-      __APPLE_CC__ >= 5330))
-// __dso_handle is resolved by Mac OS X dynamic linker.
-extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
+// Apple gcc defaults to -fuse-cxa-atexit (i.e. calls __cxa_atexit instead
+// of atexit). It passes the address of linker generated symbol __dso_handle
+// to the function.
+// This configuration change happened at version 5330.
+# include <AvailabilityMacros.h>
+# if defined(MAC_OS_X_VERSION_10_4) && \
+     ((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \
+      (MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \
+       __APPLE_CC__ >= 5330))
+#  ifndef HAVE___DSO_HANDLE
+#   define HAVE___DSO_HANDLE 1
+#  endif
+# endif
 #endif
+
+#if HAVE___DSO_HANDLE
+extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
 #endif
 
 static struct RegisterJIT {
@@ -302,14 +314,7 @@ void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) {
 
   // If the global is external, just remember the address.
   if (GV->isDeclaration()) {
-#if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_4) && \
-    ((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \
-     (MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \
-      __APPLE_CC__ >= 5330))
-    // Apple gcc defaults to -fuse-cxa-atexit (i.e. calls __cxa_atexit instead
-    // of atexit). It passes the address of linker generated symbol __dso_handle
-    // to the function.
-    // This configuration change happened at version 5330.
+#if HAVE___DSO_HANDLE
     if (GV->getName() == "__dso_handle")
       return (void*)&__dso_handle;
 #endif