lib/RSAddDebugInfoPass.cpp - platform/frameworks/compile/libbcc - Git at Google

 /*
  * Copyright 2015, The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "Assert.h"
 #include "Log.h"
 #include "RSTransforms.h"

 #include "bcinfo/MetadataExtractor.h"

 #include <string>

 #include <llvm/Pass.h>
 #include <llvm/IR/DIBuilder.h>
 #include <llvm/IR/Function.h>
 #include <llvm/IR/InstIterator.h>
 #include <llvm/IR/Instructions.h>
 #include <llvm/IR/IRBuilder.h>
 #include <llvm/IR/Module.h>
 #include <llvm/ADT/SetVector.h>

 namespace {

 const char DEBUG_SOURCE_PATH[] = "/opt/renderscriptdebugger/1";
 const char DEBUG_GENERATED_FILE[] = "generated.rs";
 const char DEBUG_PROTOTYPE_VAR_NAME[] = "rsDebugOuterForeachT";
 const char DEBUG_COMPILE_UNIT_MDNAME[] = "llvm.dbg.cu";

 /*
  * LLVM pass to attach debug information to the bits of code
  * generated by the compiler.
  */
 class RSAddDebugInfoPass : public llvm::ModulePass {

 public:
   // Pass ID
   static char ID;

   RSAddDebugInfoPass() : ModulePass(ID), kernelTypeMD(nullptr),
       sourceFileName(nullptr), emptyExpr(nullptr), abiMetaCU(nullptr),
       indexVarType(nullptr) {
   }

   virtual bool runOnModule(llvm::Module &Module) {
     // Gather information about this bcc module.
     bcinfo::MetadataExtractor me(&Module);
     if (!me.extract()) {
       ALOGE("Could not extract metadata from module!");
       return false;
     }

     const size_t nForEachKernels = me.getExportForEachSignatureCount();
     const char **forEachKernels = me.getExportForEachNameList();
     const bcinfo::MetadataExtractor::Reduce *reductions =
         me.getExportReduceList();
     const size_t nReductions = me.getExportReduceCount();

     llvm::SmallSetVector<llvm::Function *, 16> expandFuncs{};
     auto pushExpanded = [&](const char *const name) -> void {
       bccAssert(name && *name && (::strcmp(name, ".") != 0));

       const std::string expandName = std::string(name) + ".expand";
       if (llvm::Function *const func = Module.getFunction(expandName))
         expandFuncs.insert(func);
     };

     for (size_t i = 0; i < nForEachKernels; ++i)
       pushExpanded(forEachKernels[i]);

     for (size_t i = 0; i < nReductions; ++i) {
       const bcinfo::MetadataExtractor::Reduce &reduction = reductions[i];
       pushExpanded(reduction.mAccumulatorName);
     }

     // Set up the debug info builder.
     llvm::DIBuilder DebugInfo(Module);
     initializeDebugInfo(DebugInfo, Module);

     for (const auto &expandFunc : expandFuncs) {
       // Attach DI metadata to each generated function.
       // No inlining has occurred at this point so it's safe to name match
       // without worrying about inlined function bodies.
       attachDebugInfo(DebugInfo, *expandFunc);
     }

     DebugInfo.finalize();

     cleanupDebugInfo(Module);

     return true;
   }

 private:

   // @brief Initialize the debug info generation.
   //
   // This method does a couple of things:
   // * Look up debug metadata for kernel ABI and store it if present.
   // * Store a couple of useful pieces of debug metadata in member
   //   variables so they do not have to be created multiple times.
   void initializeDebugInfo(llvm::DIBuilder &DebugInfo,
                            const llvm::Module &Module) {
     llvm::LLVMContext &ctx = Module.getContext();

     // Start generating debug information for bcc-generated code.
     DebugInfo.createCompileUnit(llvm::dwarf::DW_LANG_GOOGLE_RenderScript,
                                 DEBUG_GENERATED_FILE, DEBUG_SOURCE_PATH,
                                 "RS", false, "", 0);

     // Pre-generate and save useful pieces of debug metadata.
     sourceFileName = DebugInfo.createFile(DEBUG_GENERATED_FILE, DEBUG_SOURCE_PATH);
     emptyExpr = DebugInfo.createExpression();

     // Lookup compile unit with kernel ABI debug metadata.
     llvm::NamedMDNode *mdCompileUnitList =
         Module.getNamedMetadata(DEBUG_COMPILE_UNIT_MDNAME);
     bccAssert(mdCompileUnitList != nullptr &&
         "DebugInfo pass could not find any existing compile units.");

     llvm::DIGlobalVariable *kernelPrototypeVarMD = nullptr;
     for (llvm::MDNode* CUNode : mdCompileUnitList->operands()) {
       if (auto *CU = llvm::dyn_cast<llvm::DICompileUnit>(CUNode)) {
         for (llvm::DIGlobalVariable* GV : CU->getGlobalVariables()) {
           if (GV->getDisplayName() == DEBUG_PROTOTYPE_VAR_NAME) {
             kernelPrototypeVarMD = GV;
             abiMetaCU = CU;
             break;
           }
         }
         if (kernelPrototypeVarMD != nullptr)
           break;
       }
     }

     // Lookup the expanded function interface type metadata.
     llvm::MDTuple *kernelPrototypeMD = nullptr;
     if (kernelPrototypeVarMD != nullptr) {
       // Dig into the metadata to look for function prototype.
       llvm::DIDerivedType *DT = nullptr;
       DT = llvm::cast<llvm::DIDerivedType>(kernelPrototypeVarMD->getType());
       DT = llvm::cast<llvm::DIDerivedType>(DT->getBaseType());
       llvm::DISubroutineType *ST = llvm::cast<llvm::DISubroutineType>(DT->getBaseType());
       kernelPrototypeMD = llvm::cast<llvm::MDTuple>(ST->getRawTypeArray());

       indexVarType = llvm::dyn_cast_or_null<llvm::DIType>(
           kernelPrototypeMD->getOperand(2));
     }
     // Fall back to the function type of void() if there is no proper debug info.
     if (kernelPrototypeMD == nullptr)
       kernelPrototypeMD = llvm::MDTuple::get(ctx, {nullptr});
     // Fall back to unspecified type if we don't have a proper index type.
     if (indexVarType == nullptr)
       indexVarType = DebugInfo.createBasicType("uint32_t", 32, 32,
           llvm::dwarf::DW_ATE_unsigned);

     // Capture the expanded kernel type debug info.
     kernelTypeMD = DebugInfo.createSubroutineType(kernelPrototypeMD);
   }

   /// @brief Add debug information to a generated function.
   ///
   /// This procedure adds the following pieces of debug information
   /// to the function specified by Func:
   /// * Entry for the function to the current compile unit.
   /// * Adds debug info entries for each function argument.
   /// * Adds debug info entry for the rsIndex local variable.
   /// * File/line information to each instruction set to generates.rs:1.
   void attachDebugInfo(llvm::DIBuilder &DebugInfo, llvm::Function &Func) {
     // Lookup the current thread coordinate variable.
     llvm::AllocaInst* indexVar = nullptr;
     for (llvm::Instruction &inst : llvm::instructions(Func)) {
       if (auto *allocaInst = llvm::dyn_cast<llvm::AllocaInst>(&inst)) {
         if (allocaInst->getName() == bcc::BCC_INDEX_VAR_NAME) {
           indexVar = allocaInst;
           break;
         }
       }
     }

     // Create function-level debug metadata.
     llvm::DISubprogram *ExpandedFunc = DebugInfo.createFunction(
         sourceFileName, // scope
         Func.getName(), Func.getName(),
         sourceFileName, 1, kernelTypeMD,
         false, true, 1, 0, false
     );
     Func.setSubprogram(ExpandedFunc);

     // IRBuilder for allocating variables for arguments.
     llvm::IRBuilder<> ir(&*Func.getEntryBlock().begin());

     // Walk through the argument list and expanded function prototype
     // debuginfo in lockstep to create debug entries for
     // the expanded function arguments.
     unsigned argIdx = 1;
     llvm::MDTuple *argTypes = kernelTypeMD->getTypeArray().get();
     for (llvm::Argument &arg : Func.getArgumentList()) {
       // Stop processing arguments if we run out of debug info.
       if (argIdx >= argTypes->getNumOperands())
         break;

       // Create debuginfo entry for the argument and advance.
       llvm::DILocalVariable *argVarDI = DebugInfo.createParameterVariable(
           ExpandedFunc, arg.getName(), argIdx, sourceFileName, 1,
           llvm::cast<llvm::DIType>(argTypes->getOperand(argIdx).get()),
           true, 0
       );

       // Annotate the argument variable in the IR.
       llvm::AllocaInst *argVar =
           ir.CreateAlloca(arg.getType(), nullptr, arg.getName() + ".var");
       llvm::StoreInst *argStore = ir.CreateStore(&arg, argVar);
       llvm::LoadInst *loadedVar = ir.CreateLoad(argVar, arg.getName() + ".l");
       DebugInfo.insertDeclare(argVar, argVarDI, emptyExpr,
           llvm::DebugLoc::get(1, 1, ExpandedFunc), loadedVar);
       for (llvm::Use &u : arg.uses())
         if (u.getUser() != argStore)
           u.set(loadedVar);
       argIdx++;
     }

     // Annotate the index variable with metadata.
     if (indexVar) {
       // Debug information for loop index variable.
       llvm::DILocalVariable *indexVarDI = DebugInfo.createAutoVariable(
           ExpandedFunc, bcc::BCC_INDEX_VAR_NAME, sourceFileName, 1,
           indexVarType, true
       );

       // Insert declaration annotation in the instruction stream.
       llvm::Instruction *decl = DebugInfo.insertDeclare(
           indexVar, indexVarDI, emptyExpr,
           llvm::DebugLoc::get(1, 1, ExpandedFunc), indexVar);
       indexVar->moveBefore(decl);
     }

     // Attach location information to each instruction in the function.
     for (llvm::Instruction &inst : llvm::instructions(Func)) {
       inst.setDebugLoc(llvm::DebugLoc::get(1, 1, ExpandedFunc));
     }
   }

   // @brief Clean up the debug info.
   //
   // At the moment, it only finds the compile unit for the expanded function
   // metadata generated by clang and removes it.
   void cleanupDebugInfo(llvm::Module& Module) {
     if (abiMetaCU == nullptr)
       return;

     // Remove the compile unit with the runtime interface DI.
     llvm::SmallVector<llvm::MDNode*, 4> unitsTmp;
     llvm::NamedMDNode *debugMD =
         Module.getNamedMetadata(DEBUG_COMPILE_UNIT_MDNAME);
     for (llvm::MDNode *cu : debugMD->operands())
       if (cu != abiMetaCU)
         unitsTmp.push_back(cu);
     debugMD->eraseFromParent();
     debugMD = Module.getOrInsertNamedMetadata(DEBUG_COMPILE_UNIT_MDNAME);
     for (llvm::MDNode *cu : unitsTmp)
       debugMD->addOperand(cu);
   }

 private:
   // private attributes
   llvm::DISubroutineType* kernelTypeMD;
   llvm::DIFile *sourceFileName;
   llvm::DIExpression *emptyExpr;
   llvm::DICompileUnit *abiMetaCU;
   llvm::DIType *indexVarType;

 }; // end class RSAddDebugInfoPass

 char RSAddDebugInfoPass::ID = 0;
 static llvm::RegisterPass<RSAddDebugInfoPass> X("addrsdi", "Add RS DebugInfo Pass");

 } // end anonymous namespace

 namespace bcc {

 llvm::ModulePass * createRSAddDebugInfoPass() {
   return new RSAddDebugInfoPass();
 }

 } // end namespace bcc
	/*
	* Copyright 2015, The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "Assert.h"
	#include "Log.h"
	#include "RSTransforms.h"

	#include "bcinfo/MetadataExtractor.h"

	#include <string>

	#include <llvm/Pass.h>
	#include <llvm/IR/DIBuilder.h>
	#include <llvm/IR/Function.h>
	#include <llvm/IR/InstIterator.h>
	#include <llvm/IR/Instructions.h>
	#include <llvm/IR/IRBuilder.h>
	#include <llvm/IR/Module.h>
	#include <llvm/ADT/SetVector.h>

	namespace {

	const char DEBUG_SOURCE_PATH[] = "/opt/renderscriptdebugger/1";
	const char DEBUG_GENERATED_FILE[] = "generated.rs";
	const char DEBUG_PROTOTYPE_VAR_NAME[] = "rsDebugOuterForeachT";
	const char DEBUG_COMPILE_UNIT_MDNAME[] = "llvm.dbg.cu";

	/*
	* LLVM pass to attach debug information to the bits of code
	* generated by the compiler.
	*/
	class RSAddDebugInfoPass : public llvm::ModulePass {

	public:
	// Pass ID
	static char ID;

	RSAddDebugInfoPass() : ModulePass(ID), kernelTypeMD(nullptr),
	sourceFileName(nullptr), emptyExpr(nullptr), abiMetaCU(nullptr),
	indexVarType(nullptr) {
	}

	virtual bool runOnModule(llvm::Module &Module) {
	// Gather information about this bcc module.
	bcinfo::MetadataExtractor me(&Module);
	if (!me.extract()) {
	ALOGE("Could not extract metadata from module!");
	return false;
	}

	const size_t nForEachKernels = me.getExportForEachSignatureCount();
	const char **forEachKernels = me.getExportForEachNameList();
	const bcinfo::MetadataExtractor::Reduce *reductions =
	me.getExportReduceList();
	const size_t nReductions = me.getExportReduceCount();

	llvm::SmallSetVector<llvm::Function *, 16> expandFuncs{};
	auto pushExpanded = [&](const char *const name) -> void {
	bccAssert(name && *name && (::strcmp(name, ".") != 0));

	const std::string expandName = std::string(name) + ".expand";
	if (llvm::Function *const func = Module.getFunction(expandName))
	expandFuncs.insert(func);
	};

	for (size_t i = 0; i < nForEachKernels; ++i)
	pushExpanded(forEachKernels[i]);

	for (size_t i = 0; i < nReductions; ++i) {
	const bcinfo::MetadataExtractor::Reduce &reduction = reductions[i];
	pushExpanded(reduction.mAccumulatorName);
	}

	// Set up the debug info builder.
	llvm::DIBuilder DebugInfo(Module);
	initializeDebugInfo(DebugInfo, Module);

	for (const auto &expandFunc : expandFuncs) {
	// Attach DI metadata to each generated function.
	// No inlining has occurred at this point so it's safe to name match
	// without worrying about inlined function bodies.
	attachDebugInfo(DebugInfo, *expandFunc);
	}

	DebugInfo.finalize();

	cleanupDebugInfo(Module);

	return true;
	}

	private:

	// @brief Initialize the debug info generation.
	//
	// This method does a couple of things:
	// * Look up debug metadata for kernel ABI and store it if present.
	// * Store a couple of useful pieces of debug metadata in member
	// variables so they do not have to be created multiple times.
	void initializeDebugInfo(llvm::DIBuilder &DebugInfo,
	const llvm::Module &Module) {
	llvm::LLVMContext &ctx = Module.getContext();

	// Start generating debug information for bcc-generated code.
	DebugInfo.createCompileUnit(llvm::dwarf::DW_LANG_GOOGLE_RenderScript,
	DEBUG_GENERATED_FILE, DEBUG_SOURCE_PATH,
	"RS", false, "", 0);

	// Pre-generate and save useful pieces of debug metadata.
	sourceFileName = DebugInfo.createFile(DEBUG_GENERATED_FILE, DEBUG_SOURCE_PATH);
	emptyExpr = DebugInfo.createExpression();

	// Lookup compile unit with kernel ABI debug metadata.
	llvm::NamedMDNode *mdCompileUnitList =
	Module.getNamedMetadata(DEBUG_COMPILE_UNIT_MDNAME);
	bccAssert(mdCompileUnitList != nullptr &&
	"DebugInfo pass could not find any existing compile units.");

	llvm::DIGlobalVariable *kernelPrototypeVarMD = nullptr;
	for (llvm::MDNode* CUNode : mdCompileUnitList->operands()) {
	if (auto *CU = llvm::dyn_cast<llvm::DICompileUnit>(CUNode)) {
	for (llvm::DIGlobalVariable* GV : CU->getGlobalVariables()) {
	if (GV->getDisplayName() == DEBUG_PROTOTYPE_VAR_NAME) {
	kernelPrototypeVarMD = GV;
	abiMetaCU = CU;
	break;
	}
	}
	if (kernelPrototypeVarMD != nullptr)
	break;
	}
	}

	// Lookup the expanded function interface type metadata.
	llvm::MDTuple *kernelPrototypeMD = nullptr;
	if (kernelPrototypeVarMD != nullptr) {
	// Dig into the metadata to look for function prototype.
	llvm::DIDerivedType *DT = nullptr;
	DT = llvm::cast<llvm::DIDerivedType>(kernelPrototypeVarMD->getType());
	DT = llvm::cast<llvm::DIDerivedType>(DT->getBaseType());
	llvm::DISubroutineType *ST = llvm::cast<llvm::DISubroutineType>(DT->getBaseType());
	kernelPrototypeMD = llvm::cast<llvm::MDTuple>(ST->getRawTypeArray());

	indexVarType = llvm::dyn_cast_or_null<llvm::DIType>(
	kernelPrototypeMD->getOperand(2));
	}
	// Fall back to the function type of void() if there is no proper debug info.
	if (kernelPrototypeMD == nullptr)
	kernelPrototypeMD = llvm::MDTuple::get(ctx, {nullptr});
	// Fall back to unspecified type if we don't have a proper index type.
	if (indexVarType == nullptr)
	indexVarType = DebugInfo.createBasicType("uint32_t", 32, 32,
	llvm::dwarf::DW_ATE_unsigned);

	// Capture the expanded kernel type debug info.
	kernelTypeMD = DebugInfo.createSubroutineType(kernelPrototypeMD);
	}

	/// @brief Add debug information to a generated function.
	///
	/// This procedure adds the following pieces of debug information
	/// to the function specified by Func:
	/// * Entry for the function to the current compile unit.
	/// * Adds debug info entries for each function argument.
	/// * Adds debug info entry for the rsIndex local variable.
	/// * File/line information to each instruction set to generates.rs:1.
	void attachDebugInfo(llvm::DIBuilder &DebugInfo, llvm::Function &Func) {
	// Lookup the current thread coordinate variable.
	llvm::AllocaInst* indexVar = nullptr;
	for (llvm::Instruction &inst : llvm::instructions(Func)) {
	if (auto *allocaInst = llvm::dyn_cast<llvm::AllocaInst>(&inst)) {
	if (allocaInst->getName() == bcc::BCC_INDEX_VAR_NAME) {
	indexVar = allocaInst;
	break;
	}
	}
	}

	// Create function-level debug metadata.
	llvm::DISubprogram *ExpandedFunc = DebugInfo.createFunction(
	sourceFileName, // scope
	Func.getName(), Func.getName(),
	sourceFileName, 1, kernelTypeMD,
	false, true, 1, 0, false
	);
	Func.setSubprogram(ExpandedFunc);

	// IRBuilder for allocating variables for arguments.
	llvm::IRBuilder<> ir(&*Func.getEntryBlock().begin());

	// Walk through the argument list and expanded function prototype
	// debuginfo in lockstep to create debug entries for
	// the expanded function arguments.
	unsigned argIdx = 1;
	llvm::MDTuple *argTypes = kernelTypeMD->getTypeArray().get();
	for (llvm::Argument &arg : Func.getArgumentList()) {
	// Stop processing arguments if we run out of debug info.
	if (argIdx >= argTypes->getNumOperands())
	break;

	// Create debuginfo entry for the argument and advance.
	llvm::DILocalVariable *argVarDI = DebugInfo.createParameterVariable(
	ExpandedFunc, arg.getName(), argIdx, sourceFileName, 1,
	llvm::cast<llvm::DIType>(argTypes->getOperand(argIdx).get()),
	true, 0
	);

	// Annotate the argument variable in the IR.
	llvm::AllocaInst *argVar =
	ir.CreateAlloca(arg.getType(), nullptr, arg.getName() + ".var");
	llvm::StoreInst *argStore = ir.CreateStore(&arg, argVar);
	llvm::LoadInst *loadedVar = ir.CreateLoad(argVar, arg.getName() + ".l");
	DebugInfo.insertDeclare(argVar, argVarDI, emptyExpr,
	llvm::DebugLoc::get(1, 1, ExpandedFunc), loadedVar);
	for (llvm::Use &u : arg.uses())
	if (u.getUser() != argStore)
	u.set(loadedVar);
	argIdx++;
	}

	// Annotate the index variable with metadata.
	if (indexVar) {
	// Debug information for loop index variable.
	llvm::DILocalVariable *indexVarDI = DebugInfo.createAutoVariable(
	ExpandedFunc, bcc::BCC_INDEX_VAR_NAME, sourceFileName, 1,
	indexVarType, true
	);

	// Insert declaration annotation in the instruction stream.
	llvm::Instruction *decl = DebugInfo.insertDeclare(
	indexVar, indexVarDI, emptyExpr,
	llvm::DebugLoc::get(1, 1, ExpandedFunc), indexVar);
	indexVar->moveBefore(decl);
	}

	// Attach location information to each instruction in the function.
	for (llvm::Instruction &inst : llvm::instructions(Func)) {
	inst.setDebugLoc(llvm::DebugLoc::get(1, 1, ExpandedFunc));
	}
	}

	// @brief Clean up the debug info.
	//
	// At the moment, it only finds the compile unit for the expanded function
	// metadata generated by clang and removes it.
	void cleanupDebugInfo(llvm::Module& Module) {
	if (abiMetaCU == nullptr)
	return;

	// Remove the compile unit with the runtime interface DI.
	llvm::SmallVector<llvm::MDNode*, 4> unitsTmp;
	llvm::NamedMDNode *debugMD =
	Module.getNamedMetadata(DEBUG_COMPILE_UNIT_MDNAME);
	for (llvm::MDNode *cu : debugMD->operands())
	if (cu != abiMetaCU)
	unitsTmp.push_back(cu);
	debugMD->eraseFromParent();
	debugMD = Module.getOrInsertNamedMetadata(DEBUG_COMPILE_UNIT_MDNAME);
	for (llvm::MDNode *cu : unitsTmp)
	debugMD->addOperand(cu);
	}

	private:
	// private attributes
	llvm::DISubroutineType* kernelTypeMD;
	llvm::DIFile *sourceFileName;
	llvm::DIExpression *emptyExpr;
	llvm::DICompileUnit *abiMetaCU;
	llvm::DIType *indexVarType;

	}; // end class RSAddDebugInfoPass

	char RSAddDebugInfoPass::ID = 0;
	static llvm::RegisterPass<RSAddDebugInfoPass> X("addrsdi", "Add RS DebugInfo Pass");

	} // end anonymous namespace

	namespace bcc {

	llvm::ModulePass * createRSAddDebugInfoPass() {
	return new RSAddDebugInfoPass();
	}

	} // end namespace bcc