[MCJIT] Fix PR20656 by teaching MCJIT to honor ExecutionEngine's global mapping.

This is important for users of the C API who can't supply custom symbol
resolvers yet.

llvm-svn: 243589

2 files changed, 15 insertions, 2 deletions

diff --git a/llvm/lib/ExecutionEngine/ExecutionEngine.cpp b/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
index 67b843737cd..1fc6bb5fe16 100644
--- a/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/llvm/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -189,10 +189,17 @@ uint64_t ExecutionEngineState::RemoveMapping(StringRef Name) {
 }
 
 std::string ExecutionEngine::getMangledName(const GlobalValue *GV) {
+  assert(GV->hasName() && "Global must have name.");
+
   MutexGuard locked(lock);
-  Mangler Mang;
   SmallString<128> FullName;
-  Mang.getNameWithPrefix(FullName, GV, false);
+
+  const DataLayout &DL =
+    GV->getParent()->getDataLayout().isDefault()
+      ? getDataLayout()
+      : GV->getParent()->getDataLayout();
+
+  Mangler::getNameWithPrefix(FullName, GV->getName(), DL);
   return FullName.str();
 }
 
diff --git a/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp b/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp
index 492478da89f..c201f39a375 100644
--- a/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp
+++ b/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp
@@ -270,6 +270,12 @@ void MCJIT::finalizeModule(Module *M) {
 RuntimeDyld::SymbolInfo MCJIT::findExistingSymbol(const std::string &Name) {
   SmallString<128> FullName;
   Mangler::getNameWithPrefix(FullName, Name, getDataLayout());
+
+  if (void *Addr = getPointerToGlobalIfAvailable(FullName))
+    return RuntimeDyld::SymbolInfo(static_cast<uint64_t>(
+                                     reinterpret_cast<uintptr_t>(Addr)),
+                                   JITSymbolFlags::Exported);
+
   return Dyld.getSymbol(FullName);
 }