[Orc] Add a JITSymbol class to the Orc APIs, refactor APIs, update clients.

This patch refactors a key piece of the Orc APIs: It removes the
*::getSymbolAddress and *::lookupSymbolAddressIn methods, which returned target
addresses (uint64_ts), and replaces them with *::findSymbol and *::findSymbolIn
respectively, which return instances of the new JITSymbol type. Unlike the old
methods, calling findSymbol or findSymbolIn does not cause the symbol to be
immediately materialized when found. Instead, the symbol will be materialized
if/when the getAddress method is called on the returned JITSymbol. This allows
us to query for the existence of symbols without actually materializing them. In
the future I expect more information to be attached to the JITSymbol class, for
example whether the returned symbol is a weak or strong definition. This will
allow us to properly handle weak symbols and multiple definitions.

llvm-svn: 228557

1 files changed, 10 insertions, 10 deletions

diff --git a/llvm/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp b/llvm/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
index 2963f30e2ed..11a17dd9aee 100644
--- a/llvm/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
+++ b/llvm/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
@@ -1174,8 +1174,8 @@ public:
     auto MM = createLookasideRTDyldMM<SectionMemoryManager>(
                 [&](const std::string &Name) -> uint64_t {
                   // First try to find 'Name' within the JIT.
-                  if (uint64_t Addr = getMangledSymbolAddress(Name))
-                    return Addr;
+                  if (auto Symbol = findMangledSymbol(Name))
+                    return Symbol.getAddress();
 
                   // If we don't find 'Name' in the JIT, see if we have some AST
                   // for it.
@@ -1192,8 +1192,8 @@ public:
                   // finished with it.
                   Session.FunctionDefs.erase(DefI);
 
-                  return getMangledSymbolAddress(Name);
-                }, 
+                  return findMangledSymbol(Name).getAddress();
+                },
                 [](const std::string &S) { return 0; } );
 
     return LazyEmitLayer.addModuleSet(std::move(S), std::move(MM));
@@ -1201,12 +1201,12 @@ public:
 
   void removeModule(ModuleHandleT H) { LazyEmitLayer.removeModuleSet(H); }
 
-  uint64_t getMangledSymbolAddress(const std::string &Name) {
-    return LazyEmitLayer.getSymbolAddress(Name, false);
+  JITSymbol findMangledSymbol(const std::string &Name) {
+    return LazyEmitLayer.findSymbol(Name, false);
   }
 
-  uint64_t getSymbolAddress(const std::string &Name) {
-    return getMangledSymbolAddress(Mangle(Name));
+  JITSymbol findSymbol(const std::string &Name) {
+    return findMangledSymbol(Mangle(Name));
   }
 
 private:
@@ -1253,11 +1253,11 @@ static void HandleTopLevelExpression(SessionContext &S, KaleidoscopeJIT &J) {
       auto H = J.addModule(C.takeM());
 
       // Get the address of the JIT'd function in memory.
-      uint64_t ExprFuncAddr = J.getSymbolAddress("__anon_expr");
+      auto ExprSymbol = J.findSymbol("__anon_expr");
       
       // Cast it to the right type (takes no arguments, returns a double) so we
       // can call it as a native function.
-      double (*FP)() = (double (*)())(intptr_t)ExprFuncAddr;
+      double (*FP)() = (double (*)())(intptr_t)ExprSymbol.getAddress();
 #ifdef MINIMAL_STDERR_OUTPUT
       FP();
 #else