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 0c179fc2f7eb4045e21f9526afd089191102d5fe..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.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -13,12 +13,14 @@
 
 #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.
 static std::map<std::string, void *> g_symbols;
 
-void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName, void *symbolValue) {
+void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName,
+                                          void *symbolValue) {
   g_symbols[symbolName] = symbolValue;
 }
 
@@ -44,12 +46,12 @@ using namespace llvm::sys;
 //===          independent code.
 //===----------------------------------------------------------------------===//
 
-static bool did_initialize_ltdl = false;
-
 static inline void check_ltdl_initialization() {
+  static bool did_initialize_ltdl = false;
   if (!did_initialize_ltdl) {
-    if (0 != lt_dlinit())
-      throw std::string(lt_dlerror());
+    int Err = lt_dlinit();
+    Err = Err; // Silence warning.
+    assert(0 == Err && "Can't init the ltdl library");
     did_initialize_ltdl = true;
   }
 }
@@ -61,13 +63,13 @@ DynamicLibrary::DynamicLibrary() : handle(0) {
 
   lt_dlhandle a_handle = lt_dlopen(0);
 
-  if (a_handle == 0)
-    throw std::string("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);
 }
 
+/*
 DynamicLibrary::DynamicLibrary(const char*filename) : handle(0) {
   check_ltdl_initialization();
 
@@ -82,6 +84,7 @@ DynamicLibrary::DynamicLibrary(const char*filename) : handle(0) {
   handle = a_handle;
   OpenedHandles.push_back(a_handle);
 }
+*/
 
 DynamicLibrary::~DynamicLibrary() {
   lt_dlhandle a_handle = (lt_dlhandle) handle;
@@ -93,24 +96,31 @@ DynamicLibrary::~DynamicLibrary() {
       if (*I == a_handle) {
         // Note: don't use the swap/pop_back trick here. Order is important.
         OpenedHandles.erase(I);
+        return;
       }
     }
   }
 }
 
-void DynamicLibrary::LoadLibraryPermanently(const char* filename) {
+bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
+                                            std::string *ErrMsg) {
   check_ltdl_initialization();
-  lt_dlhandle a_handle = lt_dlopen(filename);
+  lt_dlhandle a_handle = lt_dlopen(Filename);
 
   if (a_handle == 0)
-    a_handle = lt_dlopenext(filename);
+    a_handle = lt_dlopenext(Filename);
 
-  if (a_handle == 0)
-    throw std::string("Can't open :") + filename + ": " + lt_dlerror();
+  if (a_handle == 0) {
+    if (ErrMsg)
+      *ErrMsg = std::string("Can't open :") +
+          (Filename ? Filename : "<current process>") + ": " + lt_dlerror();
+    return true;
+  }
 
   lt_dlmakeresident(a_handle);
 
   OpenedHandles.push_back(a_handle);
+  return false;
 }
 
 void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
@@ -129,14 +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);
@@ -152,9 +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;
 }
@@ -165,3 +214,5 @@ void *DynamicLibrary::GetAddressOfSymbol(const char *symbolName) {
 }
 
 #endif // LLVM_ON_WIN32
+
+DEFINING_FILE_FOR(SystemDynamicLibrary)