Stackmaps are used for OSR exits, which is a custom kind of unwinding. Hence, they

should not be marked nounwind.

Marking them nounwind caused crashes in the WebKit FTL JIT, because if we enable
sufficient optimizations, LLVM starts eliding compact_unwind sections (or any unwind
data for that matter), making deoptimization via stackmaps impossible.

This changes the stackmap intrinsic to be may-throw, adds a test for exactly the
sympton that WebKit saw, and fixes TableGen to handle un-attributed intrinsics.

Thanks to atrick and philipreames for reviewing this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201826 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/IR/Intrinsics.td b/include/llvm/IR/Intrinsics.td
index ca05db4982ac771cc3f7c19087b2b334e0620af6..f8d8e79c9afdcceab0f6ae6b3c4026876c6355ff 100644 (file)
--- a/include/llvm/IR/Intrinsics.td
+++ b/include/llvm/IR/Intrinsics.td
@@ -458,7 +458,8 @@ def int_invariant_end   : Intrinsic<[],
 //===------------------------ Stackmap Intrinsics -------------------------===//
 //
 def int_experimental_stackmap : Intrinsic<[],
-                                  [llvm_i64_ty, llvm_i32_ty, llvm_vararg_ty]>;
+                                  [llvm_i64_ty, llvm_i32_ty, llvm_vararg_ty],
+                                  [Throws]>;
 def int_experimental_patchpoint_void : Intrinsic<[],
                                                  [llvm_i64_ty, llvm_i32_ty,
                                                   llvm_ptr_ty, llvm_i32_ty,

diff --git a/unittests/ExecutionEngine/MCJIT/CMakeLists.txt b/unittests/ExecutionEngine/MCJIT/CMakeLists.txt
index a425b2478ac6b10a59bf39cdae9c1206f888ae3b..afa3f2a6f66b5ad3d4dfbe3f84efcff9cb0dcadd 100644 (file)
--- a/unittests/ExecutionEngine/MCJIT/CMakeLists.txt
+++ b/unittests/ExecutionEngine/MCJIT/CMakeLists.txt
@@ -2,6 +2,7 @@ set(LLVM_LINK_COMPONENTS
   Analysis
   Core
   ExecutionEngine
+  IPO
   JIT
   MCJIT
   ScalarOpts

diff --git a/unittests/ExecutionEngine/MCJIT/MCJITCAPITest.cpp b/unittests/ExecutionEngine/MCJIT/MCJITCAPITest.cpp
index a56d9c7b9c054bd0b843ca33ea3200c16fb17036..7a7d178623d87397a5bd3a97b933bad11c115d2c 100644 (file)
--- a/unittests/ExecutionEngine/MCJIT/MCJITCAPITest.cpp
+++ b/unittests/ExecutionEngine/MCJIT/MCJITCAPITest.cpp
@@ -18,6 +18,7 @@
 #include "llvm-c/ExecutionEngine.h"
 #include "llvm-c/Target.h"
 #include "llvm-c/Transforms/Scalar.h"
+#include "llvm-c/Transforms/PassManagerBuilder.h"
 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
 #include "llvm/Support/Host.h"
 #include "gtest/gtest.h"
@@ -26,6 +27,7 @@
 using namespace llvm;
 
 static bool didCallAllocateCodeSection;
+static bool didAllocateCompactUnwindSection;
 
 static uint8_t *roundTripAllocateCodeSection(void *object, uintptr_t size,
                                              unsigned alignment,
@@ -41,6 +43,8 @@ static uint8_t *roundTripAllocateDataSection(void *object, uintptr_t size,
                                              unsigned sectionID,
                                              const char *sectionName,
                                              LLVMBool isReadOnly) {
+  if (!strcmp(sectionName, "__compact_unwind"))
+    didAllocateCompactUnwindSection = true;
   return static_cast<SectionMemoryManager*>(object)->allocateDataSection(
     size, alignment, sectionID, sectionName, isReadOnly);
 }
@@ -135,6 +139,7 @@ protected:
   
   virtual void SetUp() {
     didCallAllocateCodeSection = false;
+    didAllocateCompactUnwindSection = false;
     Module = 0;
     Function = 0;
     Engine = 0;
@@ -168,6 +173,36 @@ protected:
     LLVMDisposeBuilder(builder);
   }
   
+  void buildFunctionThatUsesStackmap() {
+    Module = LLVMModuleCreateWithName("simple_module");
+    
+    LLVMSetTarget(Module, HostTriple.c_str());
+    
+    LLVMTypeRef stackmapParamTypes[] = { LLVMInt64Type(), LLVMInt32Type() };
+    LLVMValueRef stackmap = LLVMAddFunction(
+      Module, "llvm.experimental.stackmap",
+      LLVMFunctionType(LLVMVoidType(), stackmapParamTypes, 2, 1));
+    LLVMSetLinkage(stackmap, LLVMExternalLinkage);
+    
+    Function = LLVMAddFunction(
+      Module, "simple_function", LLVMFunctionType(LLVMInt32Type(), 0, 0, 0));
+    
+    LLVMBasicBlockRef entry = LLVMAppendBasicBlock(Function, "entry");
+    LLVMBuilderRef builder = LLVMCreateBuilder();
+    LLVMPositionBuilderAtEnd(builder, entry);
+    LLVMValueRef stackmapArgs[] = {
+      LLVMConstInt(LLVMInt64Type(), 0, 0), LLVMConstInt(LLVMInt32Type(), 5, 0),
+      LLVMConstInt(LLVMInt32Type(), 42, 0)
+    };
+    LLVMBuildCall(builder, stackmap, stackmapArgs, 3, "");
+    LLVMBuildRet(builder, LLVMConstInt(LLVMInt32Type(), 42, 0));
+    
+    LLVMVerifyModule(Module, LLVMAbortProcessAction, &Error);
+    LLVMDisposeMessage(Error);
+    
+    LLVMDisposeBuilder(builder);
+  }
+  
   void buildModuleWithCodeAndData() {
     Module = LLVMModuleCreateWithName("simple_module");
     
@@ -248,6 +283,38 @@ protected:
     LLVMDisposePassManager(pass);
   }
   
+  void buildAndRunOptPasses() {
+    LLVMPassManagerBuilderRef passBuilder;
+    
+    passBuilder = LLVMPassManagerBuilderCreate();
+    LLVMPassManagerBuilderSetOptLevel(passBuilder, 2);
+    LLVMPassManagerBuilderSetSizeLevel(passBuilder, 0);
+    
+    LLVMPassManagerRef functionPasses =
+      LLVMCreateFunctionPassManagerForModule(Module);
+    LLVMPassManagerRef modulePasses =
+      LLVMCreatePassManager();
+    
+    LLVMAddTargetData(LLVMGetExecutionEngineTargetData(Engine), modulePasses);
+    
+    LLVMPassManagerBuilderPopulateFunctionPassManager(passBuilder,
+                                                      functionPasses);
+    LLVMPassManagerBuilderPopulateModulePassManager(passBuilder, modulePasses);
+    
+    LLVMPassManagerBuilderDispose(passBuilder);
+    
+    LLVMInitializeFunctionPassManager(functionPasses);
+    for (LLVMValueRef value = LLVMGetFirstFunction(Module);
+         value; value = LLVMGetNextFunction(value))
+      LLVMRunFunctionPassManager(functionPasses, value);
+    LLVMFinalizeFunctionPassManager(functionPasses);
+    
+    LLVMRunPassManager(modulePasses, Module);
+    
+    LLVMDisposePassManager(functionPasses);
+    LLVMDisposePassManager(modulePasses);
+  }
+  
   LLVMModuleRef Module;
   LLVMValueRef Function;
   LLVMValueRef Function2;
@@ -293,6 +360,29 @@ TEST_F(MCJITCAPITest, custom_memory_manager) {
   EXPECT_TRUE(didCallAllocateCodeSection);
 }
 
+TEST_F(MCJITCAPITest, stackmap_creates_compact_unwind_on_darwin) {
+  SKIP_UNSUPPORTED_PLATFORM;
+  
+  buildFunctionThatUsesStackmap();
+  buildMCJITOptions();
+  useRoundTripSectionMemoryManager();
+  buildMCJITEngine();
+  buildAndRunOptPasses();
+  
+  union {
+    void *raw;
+    int (*usable)();
+  } functionPointer;
+  functionPointer.raw = LLVMGetPointerToGlobal(Engine, Function);
+  
+  EXPECT_EQ(42, functionPointer.usable());
+  EXPECT_TRUE(didCallAllocateCodeSection);
+  
+  EXPECT_TRUE(
+    Triple(HostTriple).getOS() != Triple::Darwin ||
+    didAllocateCompactUnwindSection);
+}
+
 TEST_F(MCJITCAPITest, reserve_allocation_space) {
   SKIP_UNSUPPORTED_PLATFORM;
   

diff --git a/unittests/ExecutionEngine/MCJIT/Makefile b/unittests/ExecutionEngine/MCJIT/Makefile
index 454f83099d4b4e5338297c63aef3566482806884..c4dd740e05751a524a43aebb790281e049d90324 100644 (file)
--- a/unittests/ExecutionEngine/MCJIT/Makefile
+++ b/unittests/ExecutionEngine/MCJIT/Makefile
@@ -9,7 +9,7 @@
 
 LEVEL = ../../..
 TESTNAME = MCJIT
-LINK_COMPONENTS := core jit mcjit native support
+LINK_COMPONENTS := core ipo jit mcjit native support
 
 include $(LEVEL)/Makefile.config
 include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest

diff --git a/utils/TableGen/IntrinsicEmitter.cpp b/utils/TableGen/IntrinsicEmitter.cpp
index 173e50653274154483a2be8299d617ad89cbb11d..d366861992d587cc9e983a45991a17eeb10dc8e6 100644 (file)
--- a/utils/TableGen/IntrinsicEmitter.cpp
+++ b/utils/TableGen/IntrinsicEmitter.cpp
@@ -666,6 +666,7 @@ EmitAttributes(const std::vector<CodeGenIntrinsic> &Ints, raw_ostream &OS) {
       OS << "      }\n";
     } else {
       OS << "      return AttributeSet();\n";
+      OS << "      }\n";
     }
   }