[llvm-commits] [llvm] r155819 - in /llvm/trunk/lib/ExecutionEngine/RuntimeDyld: RuntimeDyld.cpp RuntimeDyldImpl.h

[Eli Bendersky]

Author: eliben
Date: Mon Apr 30 07:15:58 2012
New Revision: 155819

URL: http://llvm.org/viewvc/llvm-project?rev=155819&view=rev
Log:
It doesn't make sense to move symbol relocations to section relocations when
relocations are resolved.  It's much more reasonable to do this decision when
relocations are just being added - we have all the information at that point.

Also a bit of renaming and extra comments to clarify extensions.


Modified:
    llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
    llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h

Modified: llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp?rev=155819&r1=155818&r2=155819&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp (original)
+++ llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp Mon Apr 30 07:15:58 2012
@@ -39,7 +39,7 @@
 // Resolve the relocations for all symbols we currently know about.
 void RuntimeDyldImpl::resolveRelocations() {
   // First, resolve relocations associated with external symbols.
-  resolveSymbols();
+  resolveExternalSymbols();
 
   // Just iterate over the sections we have and resolve all the relocations
   // in them. Gross overkill, but it gets the job done.
@@ -324,12 +324,20 @@
       Offset,
       RelType,
       Value.Addend));
-  } else
-    SymbolRelocations[Value.SymbolName].push_back(RelocationEntry(
-      SectionID,
-      Offset,
-      RelType,
-      Value.Addend));
+  } else {
+    // Relocation by symbol.  If the symbol is found in the global symbol table,
+    // create an appropriate section relocation.  Otherwise, add it to
+    // ExternalSymbolRelocations.
+    RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
+
+    StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(Value.SymbolName);
+    if (Loc == SymbolTable.end()) {
+      ExternalSymbolRelocations[Value.SymbolName].push_back(RE);
+    } else {
+      RE.Addend += Loc->second.second;
+      Relocations[Loc->second.first].push_back(RE);
+    }
+  }
 }
 
 uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr) {
@@ -386,11 +394,9 @@
   }
 }
 
-// resolveSymbols - Resolve any relocations to the specified symbols if
-// we know where it lives.
-void RuntimeDyldImpl::resolveSymbols() {
-  StringMap<RelocationList>::iterator i = SymbolRelocations.begin(),
-                                      e = SymbolRelocations.end();
+void RuntimeDyldImpl::resolveExternalSymbols() {
+  StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin(),
+                                      e = ExternalSymbolRelocations.end();
   for (; i != e; i++) {
     StringRef Name = i->first();
     RelocationList &Relocs = i->second;
@@ -405,15 +411,7 @@
               << "\n");
       resolveRelocationList(Relocs, (uintptr_t)Addr);
     } else {
-      // Change the relocation to be section relative rather than symbol
-      // relative and move it to the resolved relocation list.
-      DEBUG(dbgs() << "Resolving symbol '" << Name << "'\n");
-      for (int i = 0, e = Relocs.size(); i != e; ++i) {
-        RelocationEntry Entry = Relocs[i];
-        Entry.Addend += Loc->second.second;
-        Relocations[Loc->second.first].push_back(Entry);
-      }
-      Relocs.clear();
+      report_fatal_error("Expected external symbol");
     }
   }
 }

Modified: llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h?rev=155819&r1=155818&r2=155819&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h (original)
+++ llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h Mon Apr 30 07:15:58 2012
@@ -129,7 +129,7 @@
   // references it.
   typedef std::map<SectionRef, unsigned> ObjSectionToIDMap;
 
-  // Master symbol table. As modules are loaded and external symbols are
+  // Master symbol table. As modules are loaded and symbols are
   // resolved, their addresses are stored here as a SectionID/Offset pair.
   typedef std::pair<unsigned, uintptr_t> SymbolLoc;
   StringMap<SymbolLoc> SymbolTable;
@@ -148,9 +148,11 @@
   // source of the address. The target where the address will be writen is
   // SectionID/Offset in the relocation itself.
   DenseMap<unsigned, RelocationList> Relocations;
-  // Relocations to external symbols that are not yet resolved.
-  // Indexed by symbol name.
-  StringMap<RelocationList> SymbolRelocations;
+
+  // Relocations to external symbols that are not yet resolved.  Symbols are
+  // external when they aren't found in the global symbol table of all loaded
+  // modules.  This map is indexed by symbol name.
+  StringMap<RelocationList> ExternalSymbolRelocations;
 
   typedef std::map<RelocationValueRef, uintptr_t> StubMap;
 
@@ -235,7 +237,8 @@
                                     LocalSymbolMap &Symbols,
                                     StubMap &Stubs) = 0;
 
-  void resolveSymbols();
+  /// \brief Resolve relocations to external symbols.
+  void resolveExternalSymbols();
   virtual ObjectImage *createObjectImage(const MemoryBuffer *InputBuffer);
   virtual void handleObjectLoaded(ObjectImage *Obj)
   {