Fix PR1798 - an error in the evaluation of SCEVAddRecExpr at an

[oota-llvm.git] / lib / System / DynamicLibrary.cpp

diff --git a/lib/System/DynamicLibrary.cpp b/lib/System/DynamicLibrary.cpp
index 0876d5deecdaab7a62d5f28e31db2c789de4f6de..a21f16ab327e71e45f68a4eb1cf35b8f882476c9 100644 (file)
--- a/lib/System/DynamicLibrary.cpp
+++ b/lib/System/DynamicLibrary.cpp
@@ -2,8 +2,8 @@
 //
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by Reid Spencer and is distributed under the
-// University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -13,6 +13,7 @@
 
 #include "llvm/System/DynamicLibrary.h"
 #include "llvm/Config/config.h"
+#include <cstring>
 #include <map>
 
 // Collection of symbol name/value pairs to be searched prior to any libraries.
@@ -49,6 +50,7 @@ static inline void check_ltdl_initialization() {
   static bool did_initialize_ltdl = false;
   if (!did_initialize_ltdl) {
     int Err = lt_dlinit();
+    Err = Err; // Silence warning.
     assert(0 == Err && "Can't init the ltdl library");
     did_initialize_ltdl = true;
   }
@@ -61,7 +63,7 @@ DynamicLibrary::DynamicLibrary() : handle(0) {
 
   lt_dlhandle a_handle = lt_dlopen(0);
 
-  assert(a_handle == 0 || "Can't open program as dynamic library");
+  assert(a_handle && "Can't open program as dynamic library");
 
   handle = a_handle;
   OpenedHandles.push_back(a_handle);
@@ -137,14 +139,16 @@ void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
       return ptr;
   }
 
+#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__
   {
-#define EXPLICIT_SYMBOL(SYM) \
-   extern void *SYM; if (!strcmp(symbolName, #SYM)) return &SYM
     EXPLICIT_SYMBOL(__ashldi3);
     EXPLICIT_SYMBOL(__ashrdi3);
     EXPLICIT_SYMBOL(__cmpdi2);
@@ -160,9 +164,46 @@ void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
     EXPLICIT_SYMBOL(__moddi3);
     EXPLICIT_SYMBOL(__udivdi3);
     EXPLICIT_SYMBOL(__umoddi3);
+  }
+#endif
+
+#ifdef __CYGWIN__
+  {
+    EXPLICIT_SYMBOL(_alloca);
+  }
+#endif
+
 #undef EXPLICIT_SYMBOL
+
+// This macro returns the address of a well-known, explicit symbol
+#define EXPLICIT_SYMBOL(SYM) \
+   if (!strcmp(symbolName, #SYM)) return &SYM
+
+// On linux we have a weird situation. The stderr/out/in symbols are both
+// macros and global variables because of standards requirements. So, we 
+// boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
+#if defined(__linux__)
+  {
+    EXPLICIT_SYMBOL(stderr);
+    EXPLICIT_SYMBOL(stdout);
+    EXPLICIT_SYMBOL(stdin);
+  }
+#else
+  // For everything else, we want to check to make sure the symbol isn't defined
+  // as a macro before using EXPLICIT_SYMBOL.
+  {
+#ifndef stdin
+    EXPLICIT_SYMBOL(stdin);
+#endif
+#ifndef stdout
+    EXPLICIT_SYMBOL(stdout);
+#endif
+#ifndef stderr
+    EXPLICIT_SYMBOL(stderr);
+#endif
   }
 #endif
+#undef EXPLICIT_SYMBOL
 
   return 0;
 }