From 5d82919adc6c9e4ecd17eebe799863d5e5017d4a Mon Sep 17 00:00:00 2001 From: Lang Hames Date: Mon, 23 May 2016 20:34:19 +0000 Subject: [PATCH] [Kaleidoscope] Add an initial "Building an ORC JIT" tutorial chapter. This is a work in progress - the chapter text is incomplete, though the example code compiles and runs. Feedback and patches are, as usual, most welcome. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270487 91177308-0d34-0410-b5e6-96231b3b80d8 --- docs/tutorial/BuildingAJIT1.rst | 281 ++++ docs/tutorial/index.rst | 10 + .../Kaleidoscope/BuildingAJIT/CMakeLists.txt | 1 + .../BuildingAJIT/Chapter1/CMakeLists.txt | 17 + .../BuildingAJIT/Chapter1/KaleidoscopeJIT.h | 83 ++ .../BuildingAJIT/Chapter1/toy.cpp | 1219 +++++++++++++++++ examples/Kaleidoscope/CMakeLists.txt | 1 + 7 files changed, 1612 insertions(+) create mode 100644 docs/tutorial/BuildingAJIT1.rst create mode 100644 examples/Kaleidoscope/BuildingAJIT/CMakeLists.txt create mode 100644 examples/Kaleidoscope/BuildingAJIT/Chapter1/CMakeLists.txt create mode 100644 examples/Kaleidoscope/BuildingAJIT/Chapter1/KaleidoscopeJIT.h create mode 100644 examples/Kaleidoscope/BuildingAJIT/Chapter1/toy.cpp diff --git a/docs/tutorial/BuildingAJIT1.rst b/docs/tutorial/BuildingAJIT1.rst new file mode 100644 index 00000000000..545451c139a --- /dev/null +++ b/docs/tutorial/BuildingAJIT1.rst @@ -0,0 +1,281 @@ +======================================================= +Kaleidoscope: Building an ORC-based JIT in LLVM +======================================================= + +.. contents:: + :local: + +**This tutorial is under active development. It is incomplete and details may +change frequently.** Nonetheless we invite you to try it out as it stands, and +we welcome any feedback. + +Chapter 1 Introduction +====================== + +Welcome to Chapter 1 of the "Building an ORC-based JIT in LLVM" tutorial. This +tutorial runs through the implementation of a JIT compiler using LLVM's +On-Request-Compilation (ORC) APIs. It begins with a simplified version of the +KaleidoscopeJIT class used in the +`Implementing a language with LLVM `_ tutorials and then +introduces new features like optimization, lazy compilation and remote +execution. + +The goal of this tutorial is to introduce you to LLVM's ORC JIT APIs, show how +these APIs interact with other parts of LLVM, and to teach you how to recombine +them to build a custom JIT that is suited to your use-case. + +The structure of the tutorial is: + +- Chapter #1: Investigate the simple KaleidoscopeJIT class. This will + introduce some of the basic concepts of the ORC JIT APIs, including the + idea of an ORC *Layer*. + +- `Chapter #2 `_: Extend the basic KaleidoscopeJIT by adding + a new layer that will optimize IR and generated code. + +- `Chapter #3 `_: Further extend the JIT by adding a + Compile-On-Demand layer to lazily compile IR. + +- `Chapter #4 `_: Improve the laziness of our JIT by + replacing the Compile-On-Demand layer with a custom layer that uses the ORC + Compile Callbacks API directly to defer IR-generation until functions are + called. + +- `Chapter #5 `_: Add process isolation by JITing code into + a remote process with reduced privileges using the JIT Remote APIs. + +To provide input for our JIT we will use the Kaleidoscope REPL from +`Chapter 7 `_ of the "Implementing a language in LLVM tutorial", +with one minor modification: We will remove the FunctionPassManager from the +code for that chapter and replace it with optimization support in our JIT class +in Chapter #2. + +Finally, a word on API generations: ORC is the 3rd generation of LLVM JIT API. +It was preceeded by MCJIT, and before that by the (now deleted) legacy JIT. +These tutorials don't assume any experience with these earlier APIs, but +readers acquainted with them will see many familiar elements. Where appropriate +we will make this connection with the earlier APIs explicit to help people who +are transitioning from them to ORC. + +JIT API Basics +============== + +The purpose of a JIT compiler is to compile code "on-the-fly" as it is needed, +rather than compiling whole programs to disk ahead of time as a traditional +compiler does. To support that aim our initial, bare-bones JIT API will be: + +1. Handle addModule(Module &M) -- Make the given IR module available for + execution. +2. JITSymbol findSymbol(const std::string &Name) -- Search for pointers to + symbols (functions or variables) that have been added to the JIT. +3. void removeModule(Handle H) -- Remove a module from the JIT, releasing any + memory that had been used for the compiled code. + +A basic use-case for this API, executing the 'main' function from a module, +will look like: + +.. code-block:: c++ + + std::unique_ptr M = buildModule(); + JIT J; + Handle H = J.addModule(*M); + int (*Main)(int, char*[]) = + (int(*)(int, char*[])J.findSymbol("main").getAddress(); + int Result = Main(); + J.removeModule(H); + +The APIs that we build in these tutorials will all be variations on this simple +theme. Behind the API we will refine the implementation of the JIT to add +support for optimization and lazy compilation. Eventually we will extend the +API itself to allow higher-level program representations (e.g. ASTs) to be +added to the JIT. + +KaleidoscopeJIT +=============== + +In the previous section we described our API, now we examine a simple +implementation of it: The KaleidoscopeJIT class [1]_ that was used in the +`Implementing a language with LLVM `_ tutorials. We will use +the REPL code from `Chapter 7 `_ of that tutorial to supply the +input for our JIT: Each time the user enters an expression the REPL will add a +new IR module containing the code for that expression to the JIT. If the +expression is a top-level expression like '1+1' or 'sin(x)', the REPL will also +use the findSymbol method of our JIT class find and execute the code for the +expression, and then use the removeModule method to remove the code again +(since there's no way to re-invoke an anonymous expression). In later chapters +of this tutorial we'll modify the REPL to enable new interactions with our JIT +class, but for now we will take this setup for granted and focus our attention on +the implementation of our JIT itself. + +Our KaleidoscopeJIT class is defined in the KaleidoscopeJIT.h header. After the +usual include guards and #includes [2]_, we get to the definition of our class: + +.. code-block:: c++ + + #ifndef LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H + #define LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H + + #include "llvm/ExecutionEngine/ExecutionEngine.h" + #include "llvm/ExecutionEngine/RTDyldMemoryManager.h" + #include "llvm/ExecutionEngine/Orc/CompileUtils.h" + #include "llvm/ExecutionEngine/Orc/IRCompileLayer.h" + #include "llvm/ExecutionEngine/Orc/LambdaResolver.h" + #include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h" + #include "llvm/IR/Mangler.h" + #include "llvm/Support/DynamicLibrary.h" + + namespace llvm { + namespace orc { + + class KaleidoscopeJIT { + private: + + std::unique_ptr TM; + const DataLayout DL; + ObjectLinkingLayer<> ObjectLayer; + IRCompileLayer CompileLayer; + + public: + + typedef decltype(CompileLayer)::ModuleSetHandleT ModuleHandleT; + +Our class begins with four members: A TargetMachine, TM, which will be used +to build our LLVM compiler instance; A DataLayout, DL, which will be used for +symbol mangling (more on that later), and two ORC *layers*: An +ObjectLinkingLayer, and an IRCompileLayer. The ObjectLinkingLayer is the +foundation of our JIT: it takes in-memory object files produced by a +compiler and links them on the fly to make them executable. This +JIT-on-top-of-a-linker design was introduced in MCJIT, where the linker was +hidden inside the MCJIT class itself. In ORC we expose the linker as a visible, +reusable component so that clients can access and configure it directly +if they need to. In this tutorial our ObjectLinkingLayer will just be used to +support the next layer in our stack: the IRCompileLayer, which will be +responsible for taking LLVM IR, compiling it, and passing the resulting +in-memory object files down to the object linking layer below. + +After our member variables comes typedef: ModuleHandle. This is the handle +type that will be returned from our JIT's addModule method, and which can be +used to remove a module again using the removeModule method. The IRCompileLayer +class already provides a convenient handle type +(IRCompileLayer::ModuleSetHandleT), so we will just provide a type-alias for +this. + +.. code-block:: c++ + + KaleidoscopeJIT() + : TM(EngineBuilder().selectTarget()), DL(TM->createDataLayout()), + CompileLayer(ObjectLayer, SimpleCompiler(*TM)) { + llvm::sys::DynamicLibrary::LoadLibraryPermanently(nullptr); + } + + TargetMachine &getTargetMachine() { return *TM; } + +Next up we have our class constructor. We begin by initializing TM using the +EngineBuilder::selectTarget helper method, which constructs a TargetMachine for +the current process. Next we use our newly created TargetMachine to initialize +DL, our DataLayout. Then we initialize our IRCompileLayer. Our IRCompile layer +needs two things: (1) A reference to our object linking layer, and (2) a +compiler instance to use to perform the actual compilation from IR to object +files. We use the off-the-shelf SimpleCompiler instance for now, but in later +chapters we will substitute our own configurable compiler classes. Finally, in +the body of the constructor, we call the DynamicLibrary::LoadLibraryPermanently +method with a nullptr argument. Normally the LoadLibraryPermanently method is +called with the path of a dynamic library to load, but when passed a null +pointer it will 'load' the host process itself, making its exported symbols +available for execution. + +.. code-block:: c++ + + ModuleHandleT addModule(std::unique_ptr M) { + // We need a memory manager to allocate memory and resolve symbols for this + // new module. Create one that resolves symbols by looking back into the + // JIT. + auto Resolver = createLambdaResolver( + [&](const std::string &Name) { + if (auto Sym = CompileLayer.findSymbol(Name, false)) + return RuntimeDyld::SymbolInfo(Sym.getAddress(), Sym.getFlags()); + return RuntimeDyld::SymbolInfo(nullptr); + }, + [](const std::string &S) { return nullptr; }); + std::vector> Ms; + Ms.push_back(std::move(M)); + return CompileLayer.addModuleSet(singletonSet(std::move(M)), + make_unique(), + std::move(Resolver)); + } + +*To be done: describe addModule -- createLambdaResolver, resolvers, memory +managers, why 'module set' rather than a single module...* + +.. code-block:: c++ + + JITSymbol findSymbol(const std::string Name) { + std::string MangledName; + raw_string_ostream MangledNameStream(MangledName); + Mangler::getNameWithPrefix(MangledNameStream, Name, DL); + return CompileLayer.findSymbol(MangledNameStream.str(), true); + } + + void removeModule(ModuleHandle H) { + CompileLayer.removeModuleSet(H); + } + +*To be done: describe findSymbol and removeModule -- why do we mangle? what's +the relationship between findSymbol and resolvers, why remove modules...* + +*To be done: Conclusion, exercises (maybe a utility for a standalone IR JIT, +like a mini-LLI), feed to next chapter.* + +Full Code Listing +================= + +Here is the complete code listing for our running example, enhanced with +mutable variables and var/in support. To build this example, use: + +.. code-block:: bash + + # Compile + clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core orc native` -O3 -o toy + # Run + ./toy + +Here is the code: + +.. literalinclude:: ../../examples/Kaleidoscope/BuildingAJIT/Chapter1/KaleidoscopeJIT.h + :language: c++ + +`Next: Extending the KaleidoscopeJIT `_ + +.. [1] Actually we use a cut-down version of KaleidoscopeJIT that makes a + simplifying assumption: symbols cannot be re-defined. This will make it + impossible to re-define symbols in the REPL, but will make our symbol + lookup logic simpler. Re-introducing support for symbol redefinition is + left as an exercise for the reader. (The KaleidoscopeJIT.h used in the + original tutorials will be a helpful reference). + +.. [2] +-----------------------+-----------------------------------------------+ + | File | Reason for inclusion | + +=======================+===============================================+ + | ExecutionEngine.h | Access to the EngineBuilder::selectTarget | + | | method. | + +-----------------------+-----------------------------------------------+ + | | Access to the | + | RTDyldMemoryManager.h | RTDyldMemoryManager::getSymbolAddressInProcess| + | | method. | + +-----------------------+-----------------------------------------------+ + | CompileUtils.h | Provides the SimpleCompiler class. | + +-----------------------+-----------------------------------------------+ + | IRCompileLayer.h | Provides the IRCompileLayer class. | + +-----------------------+-----------------------------------------------+ + | | Access the createLambdaResolver function, | + | LambdaResolver.h | which provides easy construction of symbol | + | | resolvers. | + +-----------------------+-----------------------------------------------+ + | ObjectLinkingLayer.h | Provides the ObjectLinkingLayer class. | + +-----------------------+-----------------------------------------------+ + | Mangler.h | Provides the Mangler class for platform | + | | specific name-mangling. | + +-----------------------+-----------------------------------------------+ + | DynamicLibrary.h | Provides the DynamicLibrary class, which | + | | makes symbols in the host process searchable. | + +-----------------------+-----------------------------------------------+ diff --git a/docs/tutorial/index.rst b/docs/tutorial/index.rst index dde53badd3a..08efdee43cc 100644 --- a/docs/tutorial/index.rst +++ b/docs/tutorial/index.rst @@ -22,6 +22,16 @@ Kaleidoscope: Implementing a Language with LLVM in Objective Caml OCamlLangImpl* +Kaleidoscope: Building an ORC-based JIT in LLVM +=============================================== + +.. toctree:: + :titlesonly: + :glob: + :numbered: + + BuildingAJIT* + External Tutorials ================== diff --git a/examples/Kaleidoscope/BuildingAJIT/CMakeLists.txt b/examples/Kaleidoscope/BuildingAJIT/CMakeLists.txt new file mode 100644 index 00000000000..53e861a8295 --- /dev/null +++ b/examples/Kaleidoscope/BuildingAJIT/CMakeLists.txt @@ -0,0 +1 @@ +add_subdirectory(Chapter1) diff --git a/examples/Kaleidoscope/BuildingAJIT/Chapter1/CMakeLists.txt b/examples/Kaleidoscope/BuildingAJIT/Chapter1/CMakeLists.txt new file mode 100644 index 00000000000..657a14be87d --- /dev/null +++ b/examples/Kaleidoscope/BuildingAJIT/Chapter1/CMakeLists.txt @@ -0,0 +1,17 @@ +set(LLVM_LINK_COMPONENTS + Analysis + Core + ExecutionEngine + InstCombine + Object + RuntimeDyld + ScalarOpts + Support + native + ) + +add_kaleidoscope_chapter(BuildingAJIT-Ch1 + toy.cpp + ) + +export_executable_symbols(BuildingAJIT-Ch1) diff --git a/examples/Kaleidoscope/BuildingAJIT/Chapter1/KaleidoscopeJIT.h b/examples/Kaleidoscope/BuildingAJIT/Chapter1/KaleidoscopeJIT.h new file mode 100644 index 00000000000..bc97400978b --- /dev/null +++ b/examples/Kaleidoscope/BuildingAJIT/Chapter1/KaleidoscopeJIT.h @@ -0,0 +1,83 @@ +//===----- KaleidoscopeJIT.h - A simple JIT for Kaleidoscope ----*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Contains a simple JIT definition for use in the kaleidoscope tutorials. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H +#define LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H + +#include "llvm/ExecutionEngine/ExecutionEngine.h" +#include "llvm/ExecutionEngine/RTDyldMemoryManager.h" +#include "llvm/ExecutionEngine/Orc/CompileUtils.h" +#include "llvm/ExecutionEngine/Orc/IRCompileLayer.h" +#include "llvm/ExecutionEngine/Orc/LambdaResolver.h" +#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h" +#include "llvm/IR/Mangler.h" +#include "llvm/Support/DynamicLibrary.h" + +namespace llvm { +namespace orc { + +class KaleidoscopeJIT { +private: + + std::unique_ptr TM; + const DataLayout DL; + ObjectLinkingLayer<> ObjectLayer; + IRCompileLayer CompileLayer; + +public: + + typedef decltype(CompileLayer)::ModuleSetHandleT ModuleHandle; + + KaleidoscopeJIT() + : TM(EngineBuilder().selectTarget()), DL(TM->createDataLayout()), + CompileLayer(ObjectLayer, SimpleCompiler(*TM)) { + llvm::sys::DynamicLibrary::LoadLibraryPermanently(nullptr); + } + + TargetMachine &getTargetMachine() { return *TM; } + + ModuleHandle addModule(std::unique_ptr M) { + // We need a memory manager to allocate memory and resolve symbols for this + // new module. Create one that resolves symbols by looking back into the + // JIT. + auto Resolver = createLambdaResolver( + [&](const std::string &Name) { + if (auto Sym = CompileLayer.findSymbol(Name, false)) + return RuntimeDyld::SymbolInfo(Sym.getAddress(), Sym.getFlags()); + return RuntimeDyld::SymbolInfo(nullptr); + }, + [](const std::string &S) { return nullptr; }); + std::vector> Ms; + Ms.push_back(std::move(M)); + return CompileLayer.addModuleSet(std::move(Ms), + make_unique(), + std::move(Resolver)); + } + + JITSymbol findSymbol(const std::string Name) { + std::string MangledName; + raw_string_ostream MangledNameStream(MangledName); + Mangler::getNameWithPrefix(MangledNameStream, Name, DL); + return CompileLayer.findSymbol(MangledNameStream.str(), true); + } + + void removeModule(ModuleHandle H) { + CompileLayer.removeModuleSet(H); + } + +}; + +} // End namespace orc. +} // End namespace llvm + +#endif // LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H diff --git a/examples/Kaleidoscope/BuildingAJIT/Chapter1/toy.cpp b/examples/Kaleidoscope/BuildingAJIT/Chapter1/toy.cpp new file mode 100644 index 00000000000..22b0819cd71 --- /dev/null +++ b/examples/Kaleidoscope/BuildingAJIT/Chapter1/toy.cpp @@ -0,0 +1,1219 @@ +#include "llvm/ADT/APFloat.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/IR/BasicBlock.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/LegacyPassManager.h" +#include "llvm/IR/Module.h" +#include "llvm/IR/Type.h" +#include "llvm/IR/Verifier.h" +#include "llvm/Support/TargetSelect.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Transforms/Scalar.h" +#include "llvm/Transforms/Scalar/GVN.h" +#include "KaleidoscopeJIT.h" +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +using namespace llvm; +using namespace llvm::orc; + +//===----------------------------------------------------------------------===// +// Lexer +//===----------------------------------------------------------------------===// + +// The lexer returns tokens [0-255] if it is an unknown character, otherwise one +// of these for known things. +enum Token { + tok_eof = -1, + + // commands + tok_def = -2, + tok_extern = -3, + + // primary + tok_identifier = -4, + tok_number = -5, + + // control + tok_if = -6, + tok_then = -7, + tok_else = -8, + tok_for = -9, + tok_in = -10, + + // operators + tok_binary = -11, + tok_unary = -12, + + // var definition + tok_var = -13 +}; + +static std::string IdentifierStr; // Filled in if tok_identifier +static double NumVal; // Filled in if tok_number + +/// gettok - Return the next token from standard input. +static int gettok() { + static int LastChar = ' '; + + // Skip any whitespace. + while (isspace(LastChar)) + LastChar = getchar(); + + if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]* + IdentifierStr = LastChar; + while (isalnum((LastChar = getchar()))) + IdentifierStr += LastChar; + + if (IdentifierStr == "def") + return tok_def; + if (IdentifierStr == "extern") + return tok_extern; + if (IdentifierStr == "if") + return tok_if; + if (IdentifierStr == "then") + return tok_then; + if (IdentifierStr == "else") + return tok_else; + if (IdentifierStr == "for") + return tok_for; + if (IdentifierStr == "in") + return tok_in; + if (IdentifierStr == "binary") + return tok_binary; + if (IdentifierStr == "unary") + return tok_unary; + if (IdentifierStr == "var") + return tok_var; + return tok_identifier; + } + + if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+ + std::string NumStr; + do { + NumStr += LastChar; + LastChar = getchar(); + } while (isdigit(LastChar) || LastChar == '.'); + + NumVal = strtod(NumStr.c_str(), nullptr); + return tok_number; + } + + if (LastChar == '#') { + // Comment until end of line. + do + LastChar = getchar(); + while (LastChar != EOF && LastChar != '\n' && LastChar != '\r'); + + if (LastChar != EOF) + return gettok(); + } + + // Check for end of file. Don't eat the EOF. + if (LastChar == EOF) + return tok_eof; + + // Otherwise, just return the character as its ascii value. + int ThisChar = LastChar; + LastChar = getchar(); + return ThisChar; +} + +//===----------------------------------------------------------------------===// +// Abstract Syntax Tree (aka Parse Tree) +//===----------------------------------------------------------------------===// +namespace { +/// ExprAST - Base class for all expression nodes. +class ExprAST { +public: + virtual ~ExprAST() {} + virtual Value *codegen() = 0; +}; + +/// NumberExprAST - Expression class for numeric literals like "1.0". +class NumberExprAST : public ExprAST { + double Val; + +public: + NumberExprAST(double Val) : Val(Val) {} + Value *codegen() override; +}; + +/// VariableExprAST - Expression class for referencing a variable, like "a". +class VariableExprAST : public ExprAST { + std::string Name; + +public: + VariableExprAST(const std::string &Name) : Name(Name) {} + const std::string &getName() const { return Name; } + Value *codegen() override; +}; + +/// UnaryExprAST - Expression class for a unary operator. +class UnaryExprAST : public ExprAST { + char Opcode; + std::unique_ptr Operand; + +public: + UnaryExprAST(char Opcode, std::unique_ptr Operand) + : Opcode(Opcode), Operand(std::move(Operand)) {} + Value *codegen() override; +}; + +/// BinaryExprAST - Expression class for a binary operator. +class BinaryExprAST : public ExprAST { + char Op; + std::unique_ptr LHS, RHS; + +public: + BinaryExprAST(char Op, std::unique_ptr LHS, + std::unique_ptr RHS) + : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {} + Value *codegen() override; +}; + +/// CallExprAST - Expression class for function calls. +class CallExprAST : public ExprAST { + std::string Callee; + std::vector> Args; + +public: + CallExprAST(const std::string &Callee, + std::vector> Args) + : Callee(Callee), Args(std::move(Args)) {} + Value *codegen() override; +}; + +/// IfExprAST - Expression class for if/then/else. +class IfExprAST : public ExprAST { + std::unique_ptr Cond, Then, Else; + +public: + IfExprAST(std::unique_ptr Cond, std::unique_ptr Then, + std::unique_ptr Else) + : Cond(std::move(Cond)), Then(std::move(Then)), Else(std::move(Else)) {} + Value *codegen() override; +}; + +/// ForExprAST - Expression class for for/in. +class ForExprAST : public ExprAST { + std::string VarName; + std::unique_ptr Start, End, Step, Body; + +public: + ForExprAST(const std::string &VarName, std::unique_ptr Start, + std::unique_ptr End, std::unique_ptr Step, + std::unique_ptr Body) + : VarName(VarName), Start(std::move(Start)), End(std::move(End)), + Step(std::move(Step)), Body(std::move(Body)) {} + Value *codegen() override; +}; + +/// VarExprAST - Expression class for var/in +class VarExprAST : public ExprAST { + std::vector>> VarNames; + std::unique_ptr Body; + +public: + VarExprAST( + std::vector>> VarNames, + std::unique_ptr Body) + : VarNames(std::move(VarNames)), Body(std::move(Body)) {} + Value *codegen() override; +}; + +/// PrototypeAST - This class represents the "prototype" for a function, +/// which captures its name, and its argument names (thus implicitly the number +/// of arguments the function takes), as well as if it is an operator. +class PrototypeAST { + std::string Name; + std::vector Args; + bool IsOperator; + unsigned Precedence; // Precedence if a binary op. + +public: + PrototypeAST(const std::string &Name, std::vector Args, + bool IsOperator = false, unsigned Prec = 0) + : Name(Name), Args(std::move(Args)), IsOperator(IsOperator), + Precedence(Prec) {} + Function *codegen(); + const std::string &getName() const { return Name; } + + bool isUnaryOp() const { return IsOperator && Args.size() == 1; } + bool isBinaryOp() const { return IsOperator && Args.size() == 2; } + + char getOperatorName() const { + assert(isUnaryOp() || isBinaryOp()); + return Name[Name.size() - 1]; + } + + unsigned getBinaryPrecedence() const { return Precedence; } +}; + +/// FunctionAST - This class represents a function definition itself. +class FunctionAST { + std::unique_ptr Proto; + std::unique_ptr Body; + +public: + FunctionAST(std::unique_ptr Proto, + std::unique_ptr Body) + : Proto(std::move(Proto)), Body(std::move(Body)) {} + Function *codegen(); +}; +} // end anonymous namespace + +//===----------------------------------------------------------------------===// +// Parser +//===----------------------------------------------------------------------===// + +/// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current +/// token the parser is looking at. getNextToken reads another token from the +/// lexer and updates CurTok with its results. +static int CurTok; +static int getNextToken() { return CurTok = gettok(); } + +/// BinopPrecedence - This holds the precedence for each binary operator that is +/// defined. +static std::map BinopPrecedence; + +/// GetTokPrecedence - Get the precedence of the pending binary operator token. +static int GetTokPrecedence() { + if (!isascii(CurTok)) + return -1; + + // Make sure it's a declared binop. + int TokPrec = BinopPrecedence[CurTok]; + if (TokPrec <= 0) + return -1; + return TokPrec; +} + +/// LogError* - These are little helper functions for error handling. +std::unique_ptr LogError(const char *Str) { + fprintf(stderr, "Error: %s\n", Str); + return nullptr; +} + +std::unique_ptr LogErrorP(const char *Str) { + LogError(Str); + return nullptr; +} + +static std::unique_ptr ParseExpression(); + +/// numberexpr ::= number +static std::unique_ptr ParseNumberExpr() { + auto Result = llvm::make_unique(NumVal); + getNextToken(); // consume the number + return std::move(Result); +} + +/// parenexpr ::= '(' expression ')' +static std::unique_ptr ParseParenExpr() { + getNextToken(); // eat (. + auto V = ParseExpression(); + if (!V) + return nullptr; + + if (CurTok != ')') + return LogError("expected ')'"); + getNextToken(); // eat ). + return V; +} + +/// identifierexpr +/// ::= identifier +/// ::= identifier '(' expression* ')' +static std::unique_ptr ParseIdentifierExpr() { + std::string IdName = IdentifierStr; + + getNextToken(); // eat identifier. + + if (CurTok != '(') // Simple variable ref. + return llvm::make_unique(IdName); + + // Call. + getNextToken(); // eat ( + std::vector> Args; + if (CurTok != ')') { + while (true) { + if (auto Arg = ParseExpression()) + Args.push_back(std::move(Arg)); + else + return nullptr; + + if (CurTok == ')') + break; + + if (CurTok != ',') + return LogError("Expected ')' or ',' in argument list"); + getNextToken(); + } + } + + // Eat the ')'. + getNextToken(); + + return llvm::make_unique(IdName, std::move(Args)); +} + +/// ifexpr ::= 'if' expression 'then' expression 'else' expression +static std::unique_ptr ParseIfExpr() { + getNextToken(); // eat the if. + + // condition. + auto Cond = ParseExpression(); + if (!Cond) + return nullptr; + + if (CurTok != tok_then) + return LogError("expected then"); + getNextToken(); // eat the then + + auto Then = ParseExpression(); + if (!Then) + return nullptr; + + if (CurTok != tok_else) + return LogError("expected else"); + + getNextToken(); + + auto Else = ParseExpression(); + if (!Else) + return nullptr; + + return llvm::make_unique(std::move(Cond), std::move(Then), + std::move(Else)); +} + +/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression +static std::unique_ptr ParseForExpr() { + getNextToken(); // eat the for. + + if (CurTok != tok_identifier) + return LogError("expected identifier after for"); + + std::string IdName = IdentifierStr; + getNextToken(); // eat identifier. + + if (CurTok != '=') + return LogError("expected '=' after for"); + getNextToken(); // eat '='. + + auto Start = ParseExpression(); + if (!Start) + return nullptr; + if (CurTok != ',') + return LogError("expected ',' after for start value"); + getNextToken(); + + auto End = ParseExpression(); + if (!End) + return nullptr; + + // The step value is optional. + std::unique_ptr Step; + if (CurTok == ',') { + getNextToken(); + Step = ParseExpression(); + if (!Step) + return nullptr; + } + + if (CurTok != tok_in) + return LogError("expected 'in' after for"); + getNextToken(); // eat 'in'. + + auto Body = ParseExpression(); + if (!Body) + return nullptr; + + return llvm::make_unique(IdName, std::move(Start), std::move(End), + std::move(Step), std::move(Body)); +} + +/// varexpr ::= 'var' identifier ('=' expression)? +// (',' identifier ('=' expression)?)* 'in' expression +static std::unique_ptr ParseVarExpr() { + getNextToken(); // eat the var. + + std::vector>> VarNames; + + // At least one variable name is required. + if (CurTok != tok_identifier) + return LogError("expected identifier after var"); + + while (true) { + std::string Name = IdentifierStr; + getNextToken(); // eat identifier. + + // Read the optional initializer. + std::unique_ptr Init = nullptr; + if (CurTok == '=') { + getNextToken(); // eat the '='. + + Init = ParseExpression(); + if (!Init) + return nullptr; + } + + VarNames.push_back(std::make_pair(Name, std::move(Init))); + + // End of var list, exit loop. + if (CurTok != ',') + break; + getNextToken(); // eat the ','. + + if (CurTok != tok_identifier) + return LogError("expected identifier list after var"); + } + + // At this point, we have to have 'in'. + if (CurTok != tok_in) + return LogError("expected 'in' keyword after 'var'"); + getNextToken(); // eat 'in'. + + auto Body = ParseExpression(); + if (!Body) + return nullptr; + + return llvm::make_unique(std::move(VarNames), std::move(Body)); +} + +/// primary +/// ::= identifierexpr +/// ::= numberexpr +/// ::= parenexpr +/// ::= ifexpr +/// ::= forexpr +/// ::= varexpr +static std::unique_ptr ParsePrimary() { + switch (CurTok) { + default: + return LogError("unknown token when expecting an expression"); + case tok_identifier: + return ParseIdentifierExpr(); + case tok_number: + return ParseNumberExpr(); + case '(': + return ParseParenExpr(); + case tok_if: + return ParseIfExpr(); + case tok_for: + return ParseForExpr(); + case tok_var: + return ParseVarExpr(); + } +} + +/// unary +/// ::= primary +/// ::= '!' unary +static std::unique_ptr ParseUnary() { + // If the current token is not an operator, it must be a primary expr. + if (!isascii(CurTok) || CurTok == '(' || CurTok == ',') + return ParsePrimary(); + + // If this is a unary operator, read it. + int Opc = CurTok; + getNextToken(); + if (auto Operand = ParseUnary()) + return llvm::make_unique(Opc, std::move(Operand)); + return nullptr; +} + +/// binoprhs +/// ::= ('+' unary)* +static std::unique_ptr ParseBinOpRHS(int ExprPrec, + std::unique_ptr LHS) { + // If this is a binop, find its precedence. + while (true) { + int TokPrec = GetTokPrecedence(); + + // If this is a binop that binds at least as tightly as the current binop, + // consume it, otherwise we are done. + if (TokPrec < ExprPrec) + return LHS; + + // Okay, we know this is a binop. + int BinOp = CurTok; + getNextToken(); // eat binop + + // Parse the unary expression after the binary operator. + auto RHS = ParseUnary(); + if (!RHS) + return nullptr; + + // If BinOp binds less tightly with RHS than the operator after RHS, let + // the pending operator take RHS as its LHS. + int NextPrec = GetTokPrecedence(); + if (TokPrec < NextPrec) { + RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS)); + if (!RHS) + return nullptr; + } + + // Merge LHS/RHS. + LHS = + llvm::make_unique(BinOp, std::move(LHS), std::move(RHS)); + } +} + +/// expression +/// ::= unary binoprhs +/// +static std::unique_ptr ParseExpression() { + auto LHS = ParseUnary(); + if (!LHS) + return nullptr; + + return ParseBinOpRHS(0, std::move(LHS)); +} + +/// prototype +/// ::= id '(' id* ')' +/// ::= binary LETTER number? (id, id) +/// ::= unary LETTER (id) +static std::unique_ptr ParsePrototype() { + std::string FnName; + + unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary. + unsigned BinaryPrecedence = 30; + + switch (CurTok) { + default: + return LogErrorP("Expected function name in prototype"); + case tok_identifier: + FnName = IdentifierStr; + Kind = 0; + getNextToken(); + break; + case tok_unary: + getNextToken(); + if (!isascii(CurTok)) + return LogErrorP("Expected unary operator"); + FnName = "unary"; + FnName += (char)CurTok; + Kind = 1; + getNextToken(); + break; + case tok_binary: + getNextToken(); + if (!isascii(CurTok)) + return LogErrorP("Expected binary operator"); + FnName = "binary"; + FnName += (char)CurTok; + Kind = 2; + getNextToken(); + + // Read the precedence if present. + if (CurTok == tok_number) { + if (NumVal < 1 || NumVal > 100) + return LogErrorP("Invalid precedecnce: must be 1..100"); + BinaryPrecedence = (unsigned)NumVal; + getNextToken(); + } + break; + } + + if (CurTok != '(') + return LogErrorP("Expected '(' in prototype"); + + std::vector ArgNames; + while (getNextToken() == tok_identifier) + ArgNames.push_back(IdentifierStr); + if (CurTok != ')') + return LogErrorP("Expected ')' in prototype"); + + // success. + getNextToken(); // eat ')'. + + // Verify right number of names for operator. + if (Kind && ArgNames.size() != Kind) + return LogErrorP("Invalid number of operands for operator"); + + return llvm::make_unique(FnName, ArgNames, Kind != 0, + BinaryPrecedence); +} + +/// definition ::= 'def' prototype expression +static std::unique_ptr ParseDefinition() { + getNextToken(); // eat def. + auto Proto = ParsePrototype(); + if (!Proto) + return nullptr; + + if (auto E = ParseExpression()) + return llvm::make_unique(std::move(Proto), std::move(E)); + return nullptr; +} + +/// toplevelexpr ::= expression +static std::unique_ptr ParseTopLevelExpr() { + if (auto E = ParseExpression()) { + // Make an anonymous proto. + auto Proto = llvm::make_unique("__anon_expr", + std::vector()); + return llvm::make_unique(std::move(Proto), std::move(E)); + } + return nullptr; +} + +/// external ::= 'extern' prototype +static std::unique_ptr ParseExtern() { + getNextToken(); // eat extern. + return ParsePrototype(); +} + +//===----------------------------------------------------------------------===// +// Code Generation +//===----------------------------------------------------------------------===// + +static LLVMContext TheContext; +static IRBuilder<> Builder(TheContext); +static std::unique_ptr TheModule; +static std::map NamedValues; +static std::unique_ptr TheJIT; +static std::map> FunctionProtos; + +Value *LogErrorV(const char *Str) { + LogError(Str); + return nullptr; +} + +Function *getFunction(std::string Name) { + // First, see if the function has already been added to the current module. + if (auto *F = TheModule->getFunction(Name)) + return F; + + // If not, check whether we can codegen the declaration from some existing + // prototype. + auto FI = FunctionProtos.find(Name); + if (FI != FunctionProtos.end()) + return FI->second->codegen(); + + // If no existing prototype exists, return null. + return nullptr; +} + +/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of +/// the function. This is used for mutable variables etc. +static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction, + const std::string &VarName) { + IRBuilder<> TmpB(&TheFunction->getEntryBlock(), + TheFunction->getEntryBlock().begin()); + return TmpB.CreateAlloca(Type::getDoubleTy(TheContext), nullptr, VarName); +} + +Value *NumberExprAST::codegen() { + return ConstantFP::get(TheContext, APFloat(Val)); +} + +Value *VariableExprAST::codegen() { + // Look this variable up in the function. + Value *V = NamedValues[Name]; + if (!V) + return LogErrorV("Unknown variable name"); + + // Load the value. + return Builder.CreateLoad(V, Name.c_str()); +} + +Value *UnaryExprAST::codegen() { + Value *OperandV = Operand->codegen(); + if (!OperandV) + return nullptr; + + Function *F = getFunction(std::string("unary") + Opcode); + if (!F) + return LogErrorV("Unknown unary operator"); + + return Builder.CreateCall(F, OperandV, "unop"); +} + +Value *BinaryExprAST::codegen() { + // Special case '=' because we don't want to emit the LHS as an expression. + if (Op == '=') { + // Assignment requires the LHS to be an identifier. + // This assume we're building without RTTI because LLVM builds that way by + // default. If you build LLVM with RTTI this can be changed to a + // dynamic_cast for automatic error checking. + VariableExprAST *LHSE = static_cast(LHS.get()); + if (!LHSE) + return LogErrorV("destination of '=' must be a variable"); + // Codegen the RHS. + Value *Val = RHS->codegen(); + if (!Val) + return nullptr; + + // Look up the name. + Value *Variable = NamedValues[LHSE->getName()]; + if (!Variable) + return LogErrorV("Unknown variable name"); + + Builder.CreateStore(Val, Variable); + return Val; + } + + Value *L = LHS->codegen(); + Value *R = RHS->codegen(); + if (!L || !R) + return nullptr; + + switch (Op) { + case '+': + return Builder.CreateFAdd(L, R, "addtmp"); + case '-': + return Builder.CreateFSub(L, R, "subtmp"); + case '*': + return Builder.CreateFMul(L, R, "multmp"); + case '<': + L = Builder.CreateFCmpULT(L, R, "cmptmp"); + // Convert bool 0/1 to double 0.0 or 1.0 + return Builder.CreateUIToFP(L, Type::getDoubleTy(TheContext), "booltmp"); + default: + break; + } + + // If it wasn't a builtin binary operator, it must be a user defined one. Emit + // a call to it. + Function *F = getFunction(std::string("binary") + Op); + assert(F && "binary operator not found!"); + + Value *Ops[] = {L, R}; + return Builder.CreateCall(F, Ops, "binop"); +} + +Value *CallExprAST::codegen() { + // Look up the name in the global module table. + Function *CalleeF = getFunction(Callee); + if (!CalleeF) + return LogErrorV("Unknown function referenced"); + + // If argument mismatch error. + if (CalleeF->arg_size() != Args.size()) + return LogErrorV("Incorrect # arguments passed"); + + std::vector ArgsV; + for (unsigned i = 0, e = Args.size(); i != e; ++i) { + ArgsV.push_back(Args[i]->codegen()); + if (!ArgsV.back()) + return nullptr; + } + + return Builder.CreateCall(CalleeF, ArgsV, "calltmp"); +} + +Value *IfExprAST::codegen() { + Value *CondV = Cond->codegen(); + if (!CondV) + return nullptr; + + // Convert condition to a bool by comparing equal to 0.0. + CondV = Builder.CreateFCmpONE( + CondV, ConstantFP::get(TheContext, APFloat(0.0)), "ifcond"); + + Function *TheFunction = Builder.GetInsertBlock()->getParent(); + + // Create blocks for the then and else cases. Insert the 'then' block at the + // end of the function. + BasicBlock *ThenBB = BasicBlock::Create(TheContext, "then", TheFunction); + BasicBlock *ElseBB = BasicBlock::Create(TheContext, "else"); + BasicBlock *MergeBB = BasicBlock::Create(TheContext, "ifcont"); + + Builder.CreateCondBr(CondV, ThenBB, ElseBB); + + // Emit then value. + Builder.SetInsertPoint(ThenBB); + + Value *ThenV = Then->codegen(); + if (!ThenV) + return nullptr; + + Builder.CreateBr(MergeBB); + // Codegen of 'Then' can change the current block, update ThenBB for the PHI. + ThenBB = Builder.GetInsertBlock(); + + // Emit else block. + TheFunction->getBasicBlockList().push_back(ElseBB); + Builder.SetInsertPoint(ElseBB); + + Value *ElseV = Else->codegen(); + if (!ElseV) + return nullptr; + + Builder.CreateBr(MergeBB); + // Codegen of 'Else' can change the current block, update ElseBB for the PHI. + ElseBB = Builder.GetInsertBlock(); + + // Emit merge block. + TheFunction->getBasicBlockList().push_back(MergeBB); + Builder.SetInsertPoint(MergeBB); + PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(TheContext), 2, "iftmp"); + + PN->addIncoming(ThenV, ThenBB); + PN->addIncoming(ElseV, ElseBB); + return PN; +} + +// Output for-loop as: +// var = alloca double +// ... +// start = startexpr +// store start -> var +// goto loop +// loop: +// ... +// bodyexpr +// ... +// loopend: +// step = stepexpr +// endcond = endexpr +// +// curvar = load var +// nextvar = curvar + step +// store nextvar -> var +// br endcond, loop, endloop +// outloop: +Value *ForExprAST::codegen() { + Function *TheFunction = Builder.GetInsertBlock()->getParent(); + + // Create an alloca for the variable in the entry block. + AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName); + + // Emit the start code first, without 'variable' in scope. + Value *StartVal = Start->codegen(); + if (!StartVal) + return nullptr; + + // Store the value into the alloca. + Builder.CreateStore(StartVal, Alloca); + + // Make the new basic block for the loop header, inserting after current + // block. + BasicBlock *LoopBB = BasicBlock::Create(TheContext, "loop", TheFunction); + + // Insert an explicit fall through from the current block to the LoopBB. + Builder.CreateBr(LoopBB); + + // Start insertion in LoopBB. + Builder.SetInsertPoint(LoopBB); + + // Within the loop, the variable is defined equal to the PHI node. If it + // shadows an existing variable, we have to restore it, so save it now. + AllocaInst *OldVal = NamedValues[VarName]; + NamedValues[VarName] = Alloca; + + // Emit the body of the loop. This, like any other expr, can change the + // current BB. Note that we ignore the value computed by the body, but don't + // allow an error. + if (!Body->codegen()) + return nullptr; + + // Emit the step value. + Value *StepVal = nullptr; + if (Step) { + StepVal = Step->codegen(); + if (!StepVal) + return nullptr; + } else { + // If not specified, use 1.0. + StepVal = ConstantFP::get(TheContext, APFloat(1.0)); + } + + // Compute the end condition. + Value *EndCond = End->codegen(); + if (!EndCond) + return nullptr; + + // Reload, increment, and restore the alloca. This handles the case where + // the body of the loop mutates the variable. + Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str()); + Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar"); + Builder.CreateStore(NextVar, Alloca); + + // Convert condition to a bool by comparing equal to 0.0. + EndCond = Builder.CreateFCmpONE( + EndCond, ConstantFP::get(TheContext, APFloat(0.0)), "loopcond"); + + // Create the "after loop" block and insert it. + BasicBlock *AfterBB = + BasicBlock::Create(TheContext, "afterloop", TheFunction); + + // Insert the conditional branch into the end of LoopEndBB. + Builder.CreateCondBr(EndCond, LoopBB, AfterBB); + + // Any new code will be inserted in AfterBB. + Builder.SetInsertPoint(AfterBB); + + // Restore the unshadowed variable. + if (OldVal) + NamedValues[VarName] = OldVal; + else + NamedValues.erase(VarName); + + // for expr always returns 0.0. + return Constant::getNullValue(Type::getDoubleTy(TheContext)); +} + +Value *VarExprAST::codegen() { + std::vector OldBindings; + + Function *TheFunction = Builder.GetInsertBlock()->getParent(); + + // Register all variables and emit their initializer. + for (unsigned i = 0, e = VarNames.size(); i != e; ++i) { + const std::string &VarName = VarNames[i].first; + ExprAST *Init = VarNames[i].second.get(); + + // Emit the initializer before adding the variable to scope, this prevents + // the initializer from referencing the variable itself, and permits stuff + // like this: + // var a = 1 in + // var a = a in ... # refers to outer 'a'. + Value *InitVal; + if (Init) { + InitVal = Init->codegen(); + if (!InitVal) + return nullptr; + } else { // If not specified, use 0.0. + InitVal = ConstantFP::get(TheContext, APFloat(0.0)); + } + + AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName); + Builder.CreateStore(InitVal, Alloca); + + // Remember the old variable binding so that we can restore the binding when + // we unrecurse. + OldBindings.push_back(NamedValues[VarName]); + + // Remember this binding. + NamedValues[VarName] = Alloca; + } + + // Codegen the body, now that all vars are in scope. + Value *BodyVal = Body->codegen(); + if (!BodyVal) + return nullptr; + + // Pop all our variables from scope. + for (unsigned i = 0, e = VarNames.size(); i != e; ++i) + NamedValues[VarNames[i].first] = OldBindings[i]; + + // Return the body computation. + return BodyVal; +} + +Function *PrototypeAST::codegen() { + // Make the function type: double(double,double) etc. + std::vector Doubles(Args.size(), Type::getDoubleTy(TheContext)); + FunctionType *FT = + FunctionType::get(Type::getDoubleTy(TheContext), Doubles, false); + + Function *F = + Function::Create(FT, Function::ExternalLinkage, Name, TheModule.get()); + + // Set names for all arguments. + unsigned Idx = 0; + for (auto &Arg : F->args()) + Arg.setName(Args[Idx++]); + + return F; +} + +Function *FunctionAST::codegen() { + // Transfer ownership of the prototype to the FunctionProtos map, but keep a + // reference to it for use below. + auto &P = *Proto; + FunctionProtos[Proto->getName()] = std::move(Proto); + Function *TheFunction = getFunction(P.getName()); + if (!TheFunction) + return nullptr; + + // If this is an operator, install it. + if (P.isBinaryOp()) + BinopPrecedence[P.getOperatorName()] = P.getBinaryPrecedence(); + + // Create a new basic block to start insertion into. + BasicBlock *BB = BasicBlock::Create(TheContext, "entry", TheFunction); + Builder.SetInsertPoint(BB); + + // Record the function arguments in the NamedValues map. + NamedValues.clear(); + for (auto &Arg : TheFunction->args()) { + // Create an alloca for this variable. + AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, Arg.getName()); + + // Store the initial value into the alloca. + Builder.CreateStore(&Arg, Alloca); + + // Add arguments to variable symbol table. + NamedValues[Arg.getName()] = Alloca; + } + + if (Value *RetVal = Body->codegen()) { + // Finish off the function. + Builder.CreateRet(RetVal); + + // Validate the generated code, checking for consistency. + verifyFunction(*TheFunction); + + return TheFunction; + } + + // Error reading body, remove function. + TheFunction->eraseFromParent(); + + if (P.isBinaryOp()) + BinopPrecedence.erase(Proto->getOperatorName()); + return nullptr; +} + +//===----------------------------------------------------------------------===// +// Top-Level parsing and JIT Driver +//===----------------------------------------------------------------------===// + +static void InitializeModule() { + // Open a new module. + TheModule = llvm::make_unique("my cool jit", TheContext); + TheModule->setDataLayout(TheJIT->getTargetMachine().createDataLayout()); +} + +static void HandleDefinition() { + if (auto FnAST = ParseDefinition()) { + if (auto *FnIR = FnAST->codegen()) { + fprintf(stderr, "Read function definition:"); + FnIR->dump(); + TheJIT->addModule(std::move(TheModule)); + InitializeModule(); + } + } else { + // Skip token for error recovery. + getNextToken(); + } +} + +static void HandleExtern() { + if (auto ProtoAST = ParseExtern()) { + if (auto *FnIR = ProtoAST->codegen()) { + fprintf(stderr, "Read extern: "); + FnIR->dump(); + FunctionProtos[ProtoAST->getName()] = std::move(ProtoAST); + } + } else { + // Skip token for error recovery. + getNextToken(); + } +} + +static void HandleTopLevelExpression() { + // Evaluate a top-level expression into an anonymous function. + if (auto FnAST = ParseTopLevelExpr()) { + if (FnAST->codegen()) { + // JIT the module containing the anonymous expression, keeping a handle so + // we can free it later. + auto H = TheJIT->addModule(std::move(TheModule)); + InitializeModule(); + + // Search the JIT for the __anon_expr symbol. + auto ExprSymbol = TheJIT->findSymbol("__anon_expr"); + assert(ExprSymbol && "Function not found"); + + // Get the symbol's address and 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)ExprSymbol.getAddress(); + fprintf(stderr, "Evaluated to %f\n", FP()); + + // Delete the anonymous expression module from the JIT. + TheJIT->removeModule(H); + } + } else { + // Skip token for error recovery. + getNextToken(); + } +} + +/// top ::= definition | external | expression | ';' +static void MainLoop() { + while (true) { + fprintf(stderr, "ready> "); + switch (CurTok) { + case tok_eof: + return; + case ';': // ignore top-level semicolons. + getNextToken(); + break; + case tok_def: + HandleDefinition(); + break; + case tok_extern: + HandleExtern(); + break; + default: + HandleTopLevelExpression(); + break; + } + } +} + +//===----------------------------------------------------------------------===// +// "Library" functions that can be "extern'd" from user code. +//===----------------------------------------------------------------------===// + +/// putchard - putchar that takes a double and returns 0. +extern "C" double putchard(double X) { + fputc((char)X, stderr); + return 0; +} + +/// printd - printf that takes a double prints it as "%f\n", returning 0. +extern "C" double printd(double X) { + fprintf(stderr, "%f\n", X); + return 0; +} + +//===----------------------------------------------------------------------===// +// Main driver code. +//===----------------------------------------------------------------------===// + +int main() { + InitializeNativeTarget(); + InitializeNativeTargetAsmPrinter(); + InitializeNativeTargetAsmParser(); + + // Install standard binary operators. + // 1 is lowest precedence. + BinopPrecedence['='] = 2; + BinopPrecedence['<'] = 10; + BinopPrecedence['+'] = 20; + BinopPrecedence['-'] = 20; + BinopPrecedence['*'] = 40; // highest. + + // Prime the first token. + fprintf(stderr, "ready> "); + getNextToken(); + + TheJIT = llvm::make_unique(); + + InitializeModule(); + + // Run the main "interpreter loop" now. + MainLoop(); + + return 0; +} diff --git a/examples/Kaleidoscope/CMakeLists.txt b/examples/Kaleidoscope/CMakeLists.txt index 32664aa2a22..61a6a8c2eac 100644 --- a/examples/Kaleidoscope/CMakeLists.txt +++ b/examples/Kaleidoscope/CMakeLists.txt @@ -6,6 +6,7 @@ macro(add_kaleidoscope_chapter name) add_llvm_example(${name} ${ARGN}) endmacro(add_kaleidoscope_chapter name) +add_subdirectory(BuildingAJIT) add_subdirectory(Chapter2) add_subdirectory(Chapter3) add_subdirectory(Chapter4)