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| author | 2016-09-03 22:46:54 +0000 | |
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| committer | 2016-09-03 22:46:54 +0000 | |
| commit | b5500b9ca0102f1ccaf32f0e77e96d0739aded9b (patch) | |
| tree | e1b7ebb5a0231f9e6d8d3f6f719582cebd64dc98 /gnu/llvm/examples/Kaleidoscope/Chapter2/toy.cpp | |
| parent | clarify purpose of src/gnu/ directory. (diff) | |
| download | wireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.tar.xz wireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.zip | |
Use the space freed up by sparc and zaurus to import LLVM.
ok hackroom@
Diffstat (limited to 'gnu/llvm/examples/Kaleidoscope/Chapter2/toy.cpp')
| -rw-r--r-- | gnu/llvm/examples/Kaleidoscope/Chapter2/toy.cpp | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/gnu/llvm/examples/Kaleidoscope/Chapter2/toy.cpp b/gnu/llvm/examples/Kaleidoscope/Chapter2/toy.cpp new file mode 100644 index 00000000000..69f35996129 --- /dev/null +++ b/gnu/llvm/examples/Kaleidoscope/Chapter2/toy.cpp @@ -0,0 +1,451 @@ +#include <cctype> +#include <cstdio> +#include <map> +#include <memory> +#include <string> +#include <vector> + +namespace helper { +// Cloning make_unique here until it's standard in C++14. +// Using a namespace to avoid conflicting with MSVC's std::make_unique (which +// ADL can sometimes find in unqualified calls). +template <class T, class... Args> +static + typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type + make_unique(Args &&... args) { + return std::unique_ptr<T>(new T(std::forward<Args>(args)...)); +} +} + +//===----------------------------------------------------------------------===// +// 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 +}; + +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; + 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() {} +}; + +/// NumberExprAST - Expression class for numeric literals like "1.0". +class NumberExprAST : public ExprAST { + double Val; + +public: + NumberExprAST(double Val) : Val(Val) {} +}; + +/// VariableExprAST - Expression class for referencing a variable, like "a". +class VariableExprAST : public ExprAST { + std::string Name; + +public: + VariableExprAST(const std::string &Name) : Name(Name) {} +}; + +/// BinaryExprAST - Expression class for a binary operator. +class BinaryExprAST : public ExprAST { + char Op; + std::unique_ptr<ExprAST> LHS, RHS; + +public: + BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS, + std::unique_ptr<ExprAST> RHS) + : Op(Op), LHS(std::move(LHS)), RHS(std::move(RHS)) {} +}; + +/// CallExprAST - Expression class for function calls. +class CallExprAST : public ExprAST { + std::string Callee; + std::vector<std::unique_ptr<ExprAST>> Args; + +public: + CallExprAST(const std::string &Callee, + std::vector<std::unique_ptr<ExprAST>> Args) + : Callee(Callee), Args(std::move(Args)) {} +}; + +/// 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). +class PrototypeAST { + std::string Name; + std::vector<std::string> Args; + +public: + PrototypeAST(const std::string &Name, std::vector<std::string> Args) + : Name(Name), Args(std::move(Args)) {} +}; + +/// FunctionAST - This class represents a function definition itself. +class FunctionAST { + std::unique_ptr<PrototypeAST> Proto; + std::unique_ptr<ExprAST> Body; + +public: + FunctionAST(std::unique_ptr<PrototypeAST> Proto, + std::unique_ptr<ExprAST> Body) + : Proto(std::move(Proto)), Body(std::move(Body)) {} +}; +} // 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<char, int> 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; +} + +/// Error* - These are little helper functions for error handling. +std::unique_ptr<ExprAST> Error(const char *Str) { + fprintf(stderr, "Error: %s\n", Str); + return nullptr; +} +std::unique_ptr<PrototypeAST> ErrorP(const char *Str) { + Error(Str); + return nullptr; +} + +static std::unique_ptr<ExprAST> ParseExpression(); + +/// numberexpr ::= number +static std::unique_ptr<ExprAST> ParseNumberExpr() { + auto Result = helper::make_unique<NumberExprAST>(NumVal); + getNextToken(); // consume the number + return std::move(Result); +} + +/// parenexpr ::= '(' expression ')' +static std::unique_ptr<ExprAST> ParseParenExpr() { + getNextToken(); // eat (. + auto V = ParseExpression(); + if (!V) + return nullptr; + + if (CurTok != ')') + return Error("expected ')'"); + getNextToken(); // eat ). + return V; +} + +/// identifierexpr +/// ::= identifier +/// ::= identifier '(' expression* ')' +static std::unique_ptr<ExprAST> ParseIdentifierExpr() { + std::string IdName = IdentifierStr; + + getNextToken(); // eat identifier. + + if (CurTok != '(') // Simple variable ref. + return helper::make_unique<VariableExprAST>(IdName); + + // Call. + getNextToken(); // eat ( + std::vector<std::unique_ptr<ExprAST>> Args; + if (CurTok != ')') { + while (1) { + if (auto Arg = ParseExpression()) + Args.push_back(std::move(Arg)); + else + return nullptr; + + if (CurTok == ')') + break; + + if (CurTok != ',') + return Error("Expected ')' or ',' in argument list"); + getNextToken(); + } + } + + // Eat the ')'. + getNextToken(); + + return helper::make_unique<CallExprAST>(IdName, std::move(Args)); +} + +/// primary +/// ::= identifierexpr +/// ::= numberexpr +/// ::= parenexpr +static std::unique_ptr<ExprAST> ParsePrimary() { + switch (CurTok) { + default: + return Error("unknown token when expecting an expression"); + case tok_identifier: + return ParseIdentifierExpr(); + case tok_number: + return ParseNumberExpr(); + case '(': + return ParseParenExpr(); + } +} + +/// binoprhs +/// ::= ('+' primary)* +static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec, + std::unique_ptr<ExprAST> LHS) { + // If this is a binop, find its precedence. + while (1) { + 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 primary expression after the binary operator. + auto RHS = ParsePrimary(); + 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 = helper::make_unique<BinaryExprAST>(BinOp, std::move(LHS), + std::move(RHS)); + } +} + +/// expression +/// ::= primary binoprhs +/// +static std::unique_ptr<ExprAST> ParseExpression() { + auto LHS = ParsePrimary(); + if (!LHS) + return nullptr; + + return ParseBinOpRHS(0, std::move(LHS)); +} + +/// prototype +/// ::= id '(' id* ')' +static std::unique_ptr<PrototypeAST> ParsePrototype() { + if (CurTok != tok_identifier) + return ErrorP("Expected function name in prototype"); + + std::string FnName = IdentifierStr; + getNextToken(); + + if (CurTok != '(') + return ErrorP("Expected '(' in prototype"); + + std::vector<std::string> ArgNames; + while (getNextToken() == tok_identifier) + ArgNames.push_back(IdentifierStr); + if (CurTok != ')') + return ErrorP("Expected ')' in prototype"); + + // success. + getNextToken(); // eat ')'. + + return helper::make_unique<PrototypeAST>(FnName, std::move(ArgNames)); +} + +/// definition ::= 'def' prototype expression +static std::unique_ptr<FunctionAST> ParseDefinition() { + getNextToken(); // eat def. + auto Proto = ParsePrototype(); + if (!Proto) + return nullptr; + + if (auto E = ParseExpression()) + return helper::make_unique<FunctionAST>(std::move(Proto), std::move(E)); + return nullptr; +} + +/// toplevelexpr ::= expression +static std::unique_ptr<FunctionAST> ParseTopLevelExpr() { + if (auto E = ParseExpression()) { + // Make an anonymous proto. + auto Proto = helper::make_unique<PrototypeAST>("__anon_expr", + std::vector<std::string>()); + return helper::make_unique<FunctionAST>(std::move(Proto), std::move(E)); + } + return nullptr; +} + +/// external ::= 'extern' prototype +static std::unique_ptr<PrototypeAST> ParseExtern() { + getNextToken(); // eat extern. + return ParsePrototype(); +} + +//===----------------------------------------------------------------------===// +// Top-Level parsing +//===----------------------------------------------------------------------===// + +static void HandleDefinition() { + if (ParseDefinition()) { + fprintf(stderr, "Parsed a function definition.\n"); + } else { + // Skip token for error recovery. + getNextToken(); + } +} + +static void HandleExtern() { + if (ParseExtern()) { + fprintf(stderr, "Parsed an extern\n"); + } else { + // Skip token for error recovery. + getNextToken(); + } +} + +static void HandleTopLevelExpression() { + // Evaluate a top-level expression into an anonymous function. + if (ParseTopLevelExpr()) { + fprintf(stderr, "Parsed a top-level expr\n"); + } else { + // Skip token for error recovery. + getNextToken(); + } +} + +/// top ::= definition | external | expression | ';' +static void MainLoop() { + while (1) { + 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; + } + } +} + +//===----------------------------------------------------------------------===// +// Main driver code. +//===----------------------------------------------------------------------===// + +int main() { + // Install standard binary operators. + // 1 is lowest precedence. + BinopPrecedence['<'] = 10; + BinopPrecedence['+'] = 20; + BinopPrecedence['-'] = 20; + BinopPrecedence['*'] = 40; // highest. + + // Prime the first token. + fprintf(stderr, "ready> "); + getNextToken(); + + // Run the main "interpreter loop" now. + MainLoop(); + + return 0; +} |
