From 50f19a906a9d5e42d7707b54a11c0f0c9265fc1f Mon Sep 17 00:00:00 2001
From: Filip Pizlo <fpizlo@apple.com>
Date: Tue, 21 May 2013 20:17:14 +0000
Subject: Roll out r182411 and 182412 because it's still broken.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182415 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/ExecutionEngine/MCJIT/SectionMemoryManager.cpp | 94 ++++++++++++++++++++++
 1 file changed, 94 insertions(+)

(limited to 'lib/ExecutionEngine/MCJIT')

diff --git a/lib/ExecutionEngine/MCJIT/SectionMemoryManager.cpp b/lib/ExecutionEngine/MCJIT/SectionMemoryManager.cpp
index 650832e129..1bb0103f08 100644
--- a/lib/ExecutionEngine/MCJIT/SectionMemoryManager.cpp
+++ b/lib/ExecutionEngine/MCJIT/SectionMemoryManager.cpp
@@ -14,8 +14,19 @@
 
 #include "llvm/Config/config.h"
 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
+#include "llvm/Support/DynamicLibrary.h"
 #include "llvm/Support/MathExtras.h"
 
+#ifdef __linux__
+  // These includes used by SectionMemoryManager::getPointerToNamedFunction()
+  // for Glibc trickery. See comments in this function for more information.
+  #ifdef HAVE_SYS_STAT_H
+    #include <sys/stat.h>
+  #endif
+  #include <fcntl.h>
+  #include <unistd.h>
+#endif
+
 namespace llvm {
 
 uint8_t *SectionMemoryManager::allocateDataSection(uintptr_t Size,
@@ -135,6 +146,38 @@ bool SectionMemoryManager::finalizeMemory(std::string *ErrMsg)
   return false;
 }
 
+// Determine whether we can register EH tables.
+#if (defined(__GNUC__) && !defined(__ARM_EABI__) && \
+     !defined(__USING_SJLJ_EXCEPTIONS__))
+#define HAVE_EHTABLE_SUPPORT 1
+#else
+#define HAVE_EHTABLE_SUPPORT 0
+#endif
+
+#if HAVE_EHTABLE_SUPPORT
+extern "C" void __register_frame(void*);
+
+static const char *processFDE(const char *Entry) {
+  const char *P = Entry;
+  uint32_t Length = *((uint32_t*)P);
+  P += 4;
+  uint32_t Offset = *((uint32_t*)P);
+  if (Offset != 0)
+    __register_frame((void*)Entry);
+  return P + Length;
+}
+#endif
+
+void SectionMemoryManager::registerEHFrames(StringRef SectionData) {
+#if HAVE_EHTABLE_SUPPORT
+  const char *P = SectionData.data();
+  const char *End = SectionData.data() + SectionData.size();
+  do  {
+    P = processFDE(P);
+  } while(P != End);
+#endif
+}
+
 error_code SectionMemoryManager::applyMemoryGroupPermissions(MemoryGroup &MemGroup,
                                                              unsigned Permissions) {
 
@@ -156,6 +199,57 @@ void SectionMemoryManager::invalidateInstructionCache() {
                                             CodeMem.AllocatedMem[i].size());
 }
 
+static int jit_noop() {
+  return 0;
+}
+
+void *SectionMemoryManager::getPointerToNamedFunction(const std::string &Name,
+                                                       bool AbortOnFailure) {
+#if defined(__linux__)
+  //===--------------------------------------------------------------------===//
+  // Function stubs that are invoked instead of certain library calls
+  //
+  // Force the following functions to be linked in to anything that uses the
+  // JIT. This is a hack designed to work around the all-too-clever Glibc
+  // strategy of making these functions work differently when inlined vs. when
+  // not inlined, and hiding their real definitions in a separate archive file
+  // that the dynamic linker can't see. For more info, search for
+  // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
+  if (Name == "stat") return (void*)(intptr_t)&stat;
+  if (Name == "fstat") return (void*)(intptr_t)&fstat;
+  if (Name == "lstat") return (void*)(intptr_t)&lstat;
+  if (Name == "stat64") return (void*)(intptr_t)&stat64;
+  if (Name == "fstat64") return (void*)(intptr_t)&fstat64;
+  if (Name == "lstat64") return (void*)(intptr_t)&lstat64;
+  if (Name == "atexit") return (void*)(intptr_t)&atexit;
+  if (Name == "mknod") return (void*)(intptr_t)&mknod;
+#endif // __linux__
+
+  // We should not invoke parent's ctors/dtors from generated main()!
+  // On Mingw and Cygwin, the symbol __main is resolved to
+  // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
+  // (and register wrong callee's dtors with atexit(3)).
+  // We expect ExecutionEngine::runStaticConstructorsDestructors()
+  // is called before ExecutionEngine::runFunctionAsMain() is called.
+  if (Name == "__main") return (void*)(intptr_t)&jit_noop;
+
+  const char *NameStr = Name.c_str();
+  void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
+  if (Ptr) return Ptr;
+
+  // If it wasn't found and if it starts with an underscore ('_') character,
+  // try again without the underscore.
+  if (NameStr[0] == '_') {
+    Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
+    if (Ptr) return Ptr;
+  }
+
+  if (AbortOnFailure)
+    report_fatal_error("Program used external function '" + Name +
+                      "' which could not be resolved!");
+  return 0;
+}
+
 SectionMemoryManager::~SectionMemoryManager() {
   for (unsigned i = 0, e = CodeMem.AllocatedMem.size(); i != e; ++i)
     sys::Memory::releaseMappedMemory(CodeMem.AllocatedMem[i]);
-- 
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