[ORC] Add findSymbolIn() wrapper to C bindings.

In many cases JIT users will know in which module a symbol
resides. Avoiding to search other modules can be more efficient. It
also allows to handle duplicate symbol names between modules.

Reviewed By: lhames

Differential Revision: https://reviews.llvm.org/D44889

llvm-svn: 333147

llvm/include/llvm-c/OrcBindings.h

@@ -140,6 +140,15 @@ LLVMOrcErrorCode LLVMOrcGetSymbolAddress(LLVMOrcJITStackRef JITStack,
                                          LLVMOrcTargetAddress *RetAddr,
                                          const char *SymbolName);
 
+/**
+ * Get symbol address from JIT instance, searching only the specified
+ * handle.
+ */
+LLVMOrcErrorCode LLVMOrcGetSymbolAddressIn(LLVMOrcJITStackRef JITStack,
+                                           LLVMOrcTargetAddress *RetAddr,
+                                           LLVMOrcModuleHandle H,
+                                           const char *SymbolName);
+
 /**
  * Dispose of an ORC JIT stack.
  */

llvm/lib/ExecutionEngine/Orc/OrcCBindings.cpp

@@ -112,6 +112,14 @@ LLVMOrcErrorCode LLVMOrcGetSymbolAddress(LLVMOrcJITStackRef JITStack,
   return J.findSymbolAddress(*RetAddr, SymbolName, true);
 }
 
+LLVMOrcErrorCode LLVMOrcGetSymbolAddressIn(LLVMOrcJITStackRef JITStack,
+                                           LLVMOrcTargetAddress *RetAddr,
+                                           LLVMOrcModuleHandle H,
+                                           const char *SymbolName) {
+  OrcCBindingsStack &J = *unwrap(JITStack);
+  return J.findSymbolAddressIn(*RetAddr, H, SymbolName, true);
+}
+
 LLVMOrcErrorCode LLVMOrcDisposeInstance(LLVMOrcJITStackRef JITStack) {
   auto *J = unwrap(JITStack);
   auto Err = J->shutdown();

llvm/lib/ExecutionEngine/Orc/OrcCBindingsStack.h

@@ -380,6 +380,7 @@ class OrcCBindingsStack {
 
   JITSymbol findSymbolIn(orc::VModuleKey K, const std::string &Name,
                          bool ExportedSymbolsOnly) {
+    assert(KeyLayers.count(K) && "looking up symbol in unknown module");
     return KeyLayers[K]->findSymbolIn(K, Name, ExportedSymbolsOnly);
   }
 
@@ -403,6 +404,27 @@ class OrcCBindingsStack {
     return LLVMOrcErrSuccess;
   }
 
+  LLVMOrcErrorCode findSymbolAddressIn(JITTargetAddress &RetAddr,
+                                       orc::VModuleKey K,
+                                       const std::string &Name,
+                                       bool ExportedSymbolsOnly) {
+    RetAddr = 0;
+    if (auto Sym = findSymbolIn(K, Name, ExportedSymbolsOnly)) {
+      // Successful lookup, non-null symbol:
+      if (auto AddrOrErr = Sym.getAddress()) {
+        RetAddr = *AddrOrErr;
+        return LLVMOrcErrSuccess;
+      } else
+        return mapError(AddrOrErr.takeError());
+    } else if (auto Err = Sym.takeError()) {
+      // Lookup failure - report error.
+      return mapError(std::move(Err));
+    }
+    // Otherwise we had a successful lookup but got a null result. We already
+    // set RetAddr to '0' above, so just return success.
+    return LLVMOrcErrSuccess;
+  }
+
   const std::string &getErrorMessage() const { return ErrMsg; }
 
 private:

llvm/unittests/ExecutionEngine/Orc/OrcCAPITest.cpp

@@ -98,12 +98,26 @@ TEST_F(OrcCAPIExecutionTest, TestEagerIRCompilation) {
 
   LLVMOrcModuleHandle H;
   LLVMOrcAddEagerlyCompiledIR(JIT, &H, wrap(M.release()), myResolver, nullptr);
-  LLVMOrcTargetAddress MainAddr;
-  LLVMOrcGetSymbolAddress(JIT, &MainAddr, "main");
-  MainFnTy MainFn = (MainFnTy)MainAddr;
-  int Result = MainFn();
-  EXPECT_EQ(Result, 42)
-    << "Eagerly JIT'd code did not return expected result";
+
+  // get symbol address searching the entire stack
+  {
+    LLVMOrcTargetAddress MainAddr;
+    LLVMOrcGetSymbolAddress(JIT, &MainAddr, "main");
+    MainFnTy MainFn = (MainFnTy)MainAddr;
+    int Result = MainFn();
+    EXPECT_EQ(Result, 42)
+      << "Eagerly JIT'd code did not return expected result";
+  }
+
+  // and then just searching a single handle
+  {
+    LLVMOrcTargetAddress MainAddr;
+    LLVMOrcGetSymbolAddressIn(JIT, &MainAddr, H, "main");
+    MainFnTy MainFn = (MainFnTy)MainAddr;
+    int Result = MainFn();
+    EXPECT_EQ(Result, 42)
+      << "Eagerly JIT'd code did not return expected result";
+  }
 
   LLVMOrcRemoveModule(JIT, H);