[RuntimeDyld] Track symbol visibility in RuntimeDyld.

RuntimeDyld symbol info previously consisted of just a Section/Offset pair. This
patch replaces that pair type with a SymbolInfo class that also tracks symbol
visibility. A new method, RuntimeDyld::getExportedSymbolLoadAddress, is
introduced which only returns a non-zero result for exported symbols. For
non-exported or non-existant symbols this method will return zero. The
RuntimeDyld::getSymbolAddress method retains its current behavior, returning
non-zero results for all symbols regardless of visibility.

No in-tree clients of RuntimeDyld are changed. The newly introduced
functionality will be used by the Orc APIs.

No test case: Since this patch doesn't modify the behavior for any in-tree
clients we don't have a good tool to test this with yet. Once Orc is in we can
use it to write regression tests that test these changes.

llvm-svn: 226341

1 files changed, 5 insertions, 4 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index 2664a10ece5..0f3ca0f2f39 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -920,15 +920,16 @@ relocation_iterator RuntimeDyldELF::processRelocationRef(
   SymbolRef::Type SymType = SymbolRef::ST_Unknown;
 
   // Search for the symbol in the global symbol table
-  SymbolTableMap::const_iterator gsi = GlobalSymbolTable.end();
+  RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
   if (Symbol != Obj.symbol_end()) {
     gsi = GlobalSymbolTable.find(TargetName.data());
     Symbol->getType(SymType);
   }
   if (gsi != GlobalSymbolTable.end()) {
-    Value.SectionID = gsi->second.first;
-    Value.Offset = gsi->second.second;
-    Value.Addend = gsi->second.second + Addend;
+    const auto &SymInfo = gsi->second;
+    Value.SectionID = SymInfo.getSectionID();
+    Value.Offset = SymInfo.getOffset();
+    Value.Addend = SymInfo.getOffset() + Addend;
   } else {
     switch (SymType) {
     case SymbolRef::ST_Debug: {