From 0069d72c053accc3e3c1713f6faa8ee6e9ee135e Mon Sep 17 00:00:00 2001
From: Jeffrey Yasskin <jyasskin@google.com>
Date: Thu, 11 Mar 2010 06:14:32 +0000
Subject: [PATCH] Make clang bootstrap happier on OSX 10.5 by reducing the
 number of headers included when using global symbols to ask the linker for
 the addresses of various functions.  One of the symbols was actually getting
 declared by a header included in DynamicLibrary.cpp, which conflicted with
 the "extern void*" declaration in SearchForAddressOfSpecialSymbol().

llvm-svn: 98243
---
 llvm/lib/System/DynamicLibrary.cpp            | 42 +-----------
 .../SearchForAddressOfSpecialSymbol.cpp       | 64 +++++++++++++++++++
 2 files changed, 67 insertions(+), 39 deletions(-)
 create mode 100644 llvm/lib/System/SearchForAddressOfSpecialSymbol.cpp

diff --git a/llvm/lib/System/DynamicLibrary.cpp b/llvm/lib/System/DynamicLibrary.cpp
index 63baa6d787c2..d6f3140a88e8 100644
--- a/llvm/lib/System/DynamicLibrary.cpp
+++ b/llvm/lib/System/DynamicLibrary.cpp
@@ -69,44 +69,8 @@ bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
   return false;
 }
 
-static void *SearchForAddressOfSpecialSymbol(const char* symbolName) {
-#define EXPLICIT_SYMBOL(SYM) \
-   extern void *SYM; if (!strcmp(symbolName, #SYM)) return &SYM
-
-  // If this is darwin, it has some funky issues, try to solve them here.  Some
-  // important symbols are marked 'private external' which doesn't allow
-  // SearchForAddressOfSymbol to find them.  As such, we special case them here,
-  // there is only a small handful of them.
-
-#ifdef __APPLE__
-  {
-    EXPLICIT_SYMBOL(__ashldi3);
-    EXPLICIT_SYMBOL(__ashrdi3);
-    EXPLICIT_SYMBOL(__cmpdi2);
-    EXPLICIT_SYMBOL(__divdi3);
-    EXPLICIT_SYMBOL(__eprintf);
-    EXPLICIT_SYMBOL(__fixdfdi);
-    EXPLICIT_SYMBOL(__fixsfdi);
-    EXPLICIT_SYMBOL(__fixunsdfdi);
-    EXPLICIT_SYMBOL(__fixunssfdi);
-    EXPLICIT_SYMBOL(__floatdidf);
-    EXPLICIT_SYMBOL(__floatdisf);
-    EXPLICIT_SYMBOL(__lshrdi3);
-    EXPLICIT_SYMBOL(__moddi3);
-    EXPLICIT_SYMBOL(__udivdi3);
-    EXPLICIT_SYMBOL(__umoddi3);
-  }
-#endif
-
-#ifdef __CYGWIN__
-  {
-    EXPLICIT_SYMBOL(_alloca);
-    EXPLICIT_SYMBOL(__main);
-  }
-#endif
-
-#undef EXPLICIT_SYMBOL
-  return 0;
+namespace llvm {
+void *SearchForAddressOfSpecialSymbol(const char* symbolName);
 }
 
 void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
@@ -132,7 +96,7 @@ void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
     }
   }
 
-  if (void *Result = SearchForAddressOfSpecialSymbol(symbolName))
+  if (void *Result = llvm::SearchForAddressOfSpecialSymbol(symbolName))
     return Result;
 
 // This macro returns the address of a well-known, explicit symbol
diff --git a/llvm/lib/System/SearchForAddressOfSpecialSymbol.cpp b/llvm/lib/System/SearchForAddressOfSpecialSymbol.cpp
new file mode 100644
index 000000000000..73b484c2e917
--- /dev/null
+++ b/llvm/lib/System/SearchForAddressOfSpecialSymbol.cpp
@@ -0,0 +1,64 @@
+//===- SearchForAddressOfSpecialSymbol.cpp - Function addresses -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file pulls the addresses of certain symbols out of the linker.  It must
+//  include as few header files as possible because it declares the symbols as
+//  void*, which would conflict with the actual symbol type if any header
+//  declared it.
+//
+//===----------------------------------------------------------------------===//
+
+#include <string.h>
+
+// Must declare the symbols in the global namespace.
+static void *DoSearch(const char* symbolName) {
+#define EXPLICIT_SYMBOL(SYM) \
+   extern void *SYM; if (!strcmp(symbolName, #SYM)) return &SYM
+
+  // If this is darwin, it has some funky issues, try to solve them here.  Some
+  // important symbols are marked 'private external' which doesn't allow
+  // SearchForAddressOfSymbol to find them.  As such, we special case them here,
+  // there is only a small handful of them.
+
+#ifdef __APPLE__
+  {
+    EXPLICIT_SYMBOL(__ashldi3);
+    EXPLICIT_SYMBOL(__ashrdi3);
+    EXPLICIT_SYMBOL(__cmpdi2);
+    EXPLICIT_SYMBOL(__divdi3);
+    EXPLICIT_SYMBOL(__eprintf);
+    EXPLICIT_SYMBOL(__fixdfdi);
+    EXPLICIT_SYMBOL(__fixsfdi);
+    EXPLICIT_SYMBOL(__fixunsdfdi);
+    EXPLICIT_SYMBOL(__fixunssfdi);
+    EXPLICIT_SYMBOL(__floatdidf);
+    EXPLICIT_SYMBOL(__floatdisf);
+    EXPLICIT_SYMBOL(__lshrdi3);
+    EXPLICIT_SYMBOL(__moddi3);
+    EXPLICIT_SYMBOL(__udivdi3);
+    EXPLICIT_SYMBOL(__umoddi3);
+  }
+#endif
+
+#ifdef __CYGWIN__
+  {
+    EXPLICIT_SYMBOL(_alloca);
+    EXPLICIT_SYMBOL(__main);
+  }
+#endif
+
+#undef EXPLICIT_SYMBOL
+  return 0;
+}
+
+namespace llvm {
+void *SearchForAddressOfSpecialSymbol(const char* symbolName) {
+  return DoSearch(symbolName);
+}
+}  // namespace llvm