Simplify the TableManager class and move it into a public header.

Moves visitEdge into the TableManager derivatives, replacing the fixEdgeKind
methods in those classes. The visitEdge method takes on responsibility for
updating the edge target, as well as its kind.

llvm/include/llvm/ExecutionEngine/JITLink/TableManager.h

@@ -21,19 +21,13 @@
 namespace llvm {
 namespace jitlink {
 
-/// Table like section manager
+/// A CRTP base for tables that are built on demand, e.g. Global Offset Tables
+/// and Procedure Linkage Tables.
+/// The getEntyrForTarget function returns the table entry corresponding to the
+/// given target, calling down to the implementation class to build an entry if
+/// one does not already exist.
 template <typename TableManagerImplT> class TableManager {
 public:
-  /// Visit edge, return true if the edge was dealt with, otherwise return
-  /// false(let other managers to visit).
-  bool visitEdge(LinkGraph &G, Block *B, Edge &E) {
-    if (impl().fixEdgeKind(G, B, E)) {
-      fixTarget(G, E);
-      return true;
-    }
-    return false;
-  }
-
   /// Return the constructed entry
   ///
   /// Use parameter G to construct the entry for target symbol
@@ -61,10 +55,6 @@ public:
   }
 
 private:
-  void fixTarget(LinkGraph &G, Edge &E) {
-    E.setTarget(getEntryForTarget(G, E.getTarget()));
-  }
-
   TableManagerImplT &impl() { return static_cast<TableManagerImplT &>(*this); }
   DenseMap<StringRef, Symbol *> Entries;
 };

llvm/lib/ExecutionEngine/JITLink/ELF_x86_64.cpp

@@ -12,6 +12,7 @@
 
 #include "llvm/ExecutionEngine/JITLink/ELF_x86_64.h"
 #include "llvm/ExecutionEngine/JITLink/JITLink.h"
+#include "llvm/ExecutionEngine/JITLink/TableManager.h"
 #include "llvm/ExecutionEngine/JITLink/x86_64.h"
 #include "llvm/Object/ELFObjectFile.h"
 #include "llvm/Support/Endian.h"
@@ -21,7 +22,6 @@
 #include "ELFLinkGraphBuilder.h"
 #include "JITLinkGeneric.h"
 #include "PerGraphGOTAndPLTStubsBuilder.h"
-#include "TableManager.h"
 
 #define DEBUG_TYPE "jitlink"
 
@@ -43,8 +43,8 @@ public:
   // Nice name for table
   StringRef getTableName() { return "GOT"; }
 
-  bool fixEdgeKind(LinkGraph &G, Block *B, Edge &E) {
-    Edge::Kind KindToSet = E.getKind();
+  bool visitEdge(LinkGraph &G, Block *B, Edge &E) {
+    Edge::Kind KindToSet = Edge::Invalid;
     switch (E.getKind()) {
     case x86_64::Delta64FromGOT: {
       // we need to make sure that the GOT section exists, but don't otherwise
@@ -70,6 +70,8 @@ public:
     default:
       return false;
     }
+    assert(KindToSet != Edge::Invalid &&
+           "Fell through switch, but no new kind to set");
     LLVM_DEBUG({
       dbgs() << "  Fixing " << G.getEdgeKindName(E.getKind()) << " edge at "
              << formatv("{0:x}", B->getFixupAddress(E)) << " ("
@@ -77,6 +79,7 @@ public:
              << formatv("{0:x}", E.getOffset()) << ")\n";
     });
     E.setKind(KindToSet);
+    E.setTarget(getEntryForTarget(G, E.getTarget()));
     return true;
   }
 
@@ -111,7 +114,7 @@ public:
   StringRef getTableName() { return "PLT"; }
 
   static const uint8_t StubContent[6];
-  bool fixEdgeKind(LinkGraph &G, Block *B, Edge &E) {
+  bool visitEdge(LinkGraph &G, Block *B, Edge &E) {
     if (E.getKind() == x86_64::BranchPCRel32 && !E.getTarget().isDefined()) {
       LLVM_DEBUG({
         dbgs() << "  Fixing " << G.getEdgeKindName(E.getKind()) << " edge at "
@@ -122,6 +125,7 @@ public:
       // Set the edge kind to Branch32ToPtrJumpStubBypassable to enable it to
       // be optimized when the target is in-range.
       E.setKind(x86_64::BranchPCRel32ToPtrJumpStubBypassable);
+      E.setTarget(getEntryForTarget(G, E.getTarget()));
       return true;
     }
     return false;
@@ -161,7 +165,7 @@ public:
 
   StringRef getTableName() { return "TLSInfo"; }
 
-  bool fixEdgeKind(LinkGraph &G, Block *B, Edge &E) {
+  bool visitEdge(LinkGraph &G, Block *B, Edge &E) {
     if (E.getKind() == x86_64::RequestTLSDescInGOTAndTransformToDelta32) {
       LLVM_DEBUG({
         dbgs() << "  Fixing " << G.getEdgeKindName(E.getKind()) << " edge at "
@@ -170,6 +174,7 @@ public:
                << formatv("{0:x}", E.getOffset()) << ")\n";
       });
       E.setKind(x86_64::Delta32);
+      E.setTarget(getEntryForTarget(G, E.getTarget()));
       return true;
     }
     return false;