[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, 11 insertions, 8 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
index f3e5c77..309a9b4 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
@@ -850,14 +850,16 @@ std::pair<uint64_t, std::string> RuntimeDyldCheckerImpl::getStubAddrFor(
 
 StringRef
 RuntimeDyldCheckerImpl::getSubsectionStartingAt(StringRef Name) const {
-  RuntimeDyldImpl::SymbolTableMap::const_iterator pos =
+  RTDyldSymbolTable::const_iterator pos =
       getRTDyld().GlobalSymbolTable.find(Name);
   if (pos == getRTDyld().GlobalSymbolTable.end())
     return StringRef();
-  RuntimeDyldImpl::SymbolLoc Loc = pos->second;
-  uint8_t *SectionAddr = getRTDyld().getSectionAddress(Loc.first);
-  return StringRef(reinterpret_cast<const char *>(SectionAddr) + Loc.second,
-                   getRTDyld().Sections[Loc.first].Size - Loc.second);
+  const auto &SymInfo = pos->second;
+  uint8_t *SectionAddr = getRTDyld().getSectionAddress(SymInfo.getSectionID());
+  return StringRef(reinterpret_cast<const char *>(SectionAddr) +
+                     SymInfo.getOffset(),
+                   getRTDyld().Sections[SymInfo.getSectionID()].Size -
+                     SymInfo.getOffset());
 }
 
 void RuntimeDyldCheckerImpl::registerSection(
@@ -887,9 +889,10 @@ void RuntimeDyldCheckerImpl::registerStubMap(
       // If this is a (Section, Offset) pair, do a reverse lookup in the
       // global symbol table to find the name.
       for (auto &GSTEntry : getRTDyld().GlobalSymbolTable) {
-        if (GSTEntry.second.first == StubMapEntry.first.SectionID &&
-            GSTEntry.second.second ==
-                static_cast<uint64_t>(StubMapEntry.first.Offset)) {
+        const auto &SymInfo = GSTEntry.second;
+        if (SymInfo.getSectionID() == StubMapEntry.first.SectionID &&
+            SymInfo.getOffset() ==
+              static_cast<uint64_t>(StubMapEntry.first.Offset)) {
           SymbolName = GSTEntry.first();
           break;
         }