[MCJIT] Fix PR20656 by teaching MCJIT to honor ExecutionEngine's global mapping.

This is important for users of the C API who can't supply custom symbol
resolvers yet.

llvm-svn: 243589

1 files changed, 33 insertions, 0 deletions

diff --git a/llvm/unittests/ExecutionEngine/MCJIT/MCJITCAPITest.cpp b/llvm/unittests/ExecutionEngine/MCJIT/MCJITCAPITest.cpp
index c7d4dd757cf..16530293270 100644
--- a/llvm/unittests/ExecutionEngine/MCJIT/MCJITCAPITest.cpp
+++ b/llvm/unittests/ExecutionEngine/MCJIT/MCJITCAPITest.cpp
@@ -488,3 +488,36 @@ TEST_F(MCJITCAPITest, yield) {
   EXPECT_TRUE(didCallYield);
 }
 
+static int localTestFunc() {
+  return 42;
+}
+
+TEST_F(MCJITCAPITest, addGlobalMapping) {
+  SKIP_UNSUPPORTED_PLATFORM;
+
+  Module = LLVMModuleCreateWithName("testModule");
+  LLVMTypeRef FunctionType = LLVMFunctionType(LLVMInt32Type(), NULL, 0, 0);
+  LLVMValueRef MappedFn = LLVMAddFunction(Module, "mapped_fn", FunctionType);
+
+  Function = LLVMAddFunction(Module, "test_fn", FunctionType);
+  LLVMBasicBlockRef Entry = LLVMAppendBasicBlock(Function, "");
+  LLVMBuilderRef Builder = LLVMCreateBuilder();
+  LLVMPositionBuilderAtEnd(Builder, Entry);
+  LLVMValueRef RetVal = LLVMBuildCall(Builder, MappedFn, NULL, 0, "");
+  LLVMBuildRet(Builder, RetVal);
+
+  LLVMVerifyModule(Module, LLVMAbortProcessAction, &Error);
+  LLVMDisposeMessage(Error);
+
+  buildMCJITOptions();
+  buildMCJITEngine();
+
+  LLVMAddGlobalMapping(Engine, MappedFn, reinterpret_cast<void*>(&localTestFunc));
+
+  buildAndRunPasses();
+
+  uint64_t raw = LLVMGetFunctionAddress(Engine, "test_fn");
+  int (*usable)() = (int (*)()) raw;
+
+  EXPECT_EQ(42, usable());
+}