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[原创]入门编译原理之前端对接LLVM IR
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发表于: 2023-9-5 21:30
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接上篇[原创]入门编译原理之前端体验，本篇将前端解析到的AST对接到LLVM IR。本文目标明确，就直贴代码了。
输出结果:
下篇就是将IR转成汇编语言了... ...
import llvmlite.ir as ir
import llvmlite.binding as llvm
# 初始化LLVMllvm.initialize()llvm.initialize_native_target()llvm.initialize_native_asmprinter()# 创建LLVM模块module = ir.Module(name="my_module")
# 创建一个LLVM上下文和函数context = ir.Context()
function = None
# 创建LLVM IR构建器builder = None
# 创建一个LLVM上下文和函数# context = llvm.getGlobalContext()# function = None# Token 类用于表示词法分析器生成的令牌class Token:
def __init__(self, type, value=None):
self.type = type
self.value = value
# Lexer 类负责将输入文本解析成令牌流class Lexer:
def __init__(self, text):
self.text = text # 要解析的文本
self.pos = 0 # 当前解析位置
# 获取下一个令牌
def get_next_token(self):
if self.pos >= len(self.text):
return Token("EOF") # 如果已经到达文本末尾，返回一个表示结束的令牌
current_char = self.text[self.pos]
# 如果当前字符是字母，则解析标识符
if current_char.isalpha():
identifier = ""
while self.pos < len(self.text) and self.text[self.pos].isalnum():
identifier += self.text[self.pos]
self.pos += 1
return Token("IDENTIFIER", identifier)
# 如果当前字符是数字，则解析数字
if current_char.isdigit():
self.pos += 1
return Token("NUMBER", int(current_char))
# 如果当前字符是运算符，则解析运算符
if current_char in "+-*/":
self.pos += 1
return Token("OPERATOR", current_char)
# 如果当前字符是等号，则解析为赋值符号
if current_char == "=":
self.pos += 1
return Token("ASSIGN", "=")
# 如果当前字符是分号，则解析为分号
if current_char == ";":
self.pos += 1
return Token("SEMICOLON", ";")
# 如果当前字符是左括号，则解析为左括号
if current_char == "(":
self.pos += 1
return Token("LPAREN", "(")
# 如果当前字符是右括号，则解析为右括号
if current_char == ")":
self.pos += 1
return Token("RPAREN", ")")
# 如果当前字符是空格或制表符，则忽略并获取下一个令牌
if current_char in " \t":
self.pos += 1
return self.get_next_token()
raise ValueError("Invalid character") # 如果遇到无法识别的字符，引发异常
# Parser 类负责解析令牌流并计算结果class Parser:
def __init__(self, lexer):
self.lexer = lexer # 词法分析器
self.current_token = self.lexer.get_next_token() # 当前令牌
self.variables = {} # 存储变量名和值的字典
# 解析整个表达式并生成LLVM IR
def parse(self):
global builder, function
results = []
# 创建主函数
main_function_type = ir.FunctionType(ir.IntType(32), ())
function = ir.Function(module, main_function_type, name="main")
block = function.append_basic_block(name="entry")
builder = ir.IRBuilder(block)
while self.current_token.type != "EOF":
result = self.parse_statement()
results.append(result)
if self.current_token.type == "SEMICOLON":
self.eat("SEMICOLON")
builder.ret(results[-1])
return results
# 解析表达式并生成LLVM IR
def parse_expression(self, min_precedence=0):
left = self.parse_atom()
while self.current_token.type == "OPERATOR" and self.precedence(self.current_token.value) >= min_precedence:
operator = self.current_token.value
self.eat("OPERATOR")
right = self.parse_expression(self.precedence(operator) + 1)
if operator == "+":
result = builder.add(left, right, name="addtmp")
elif operator == "-":
result = builder.sub(left, right, name="subtmp")
elif operator == "*":
result = builder.mul(left, right, name="multmp")
elif operator == "/":
result = builder.sdiv(left, right, name="divtmp")
left = result
return left
# 解析原子表达式并生成LLVM IR
def parse_atom(self):
if self.current_token.type == "NUMBER":
value = self.current_token.value
self.eat("NUMBER")
return ir.Constant(ir.IntType(32), value)
elif self.current_token.type == "IDENTIFIER":
variable_name = self.current_token.value
self.eat("IDENTIFIER")
if variable_name in self.variables:
return self.variables[variable_name]
else:
raise ValueError(f"Undefined variable: {variable_name}")
elif self.current_token.type == "LPAREN":
self.eat("LPAREN")
expression = self.parse_expression()
self.eat("RPAREN")
return expression
else:
raise ValueError("Invalid syntax")
def parse_statement(self):
if self.current_token.type == "IDENTIFIER":
variable_name = self.current_token.value
self.eat("IDENTIFIER")
self.eat("ASSIGN")
expression_value = self.parse_expression()
self.eat("SEMICOLON")
self.variables[variable_name] = expression_value
return expression_value
else:
return self.parse_expression()
def eat(self, token_type):
if self.current_token.type == token_type:
self.current_token = self.lexer.get_next_token()
else:
raise ValueError("Unexpected token")
def precedence(self, operator):
precedence = {"+": 1, "-": 1, "*": 2, "/": 2}
return precedence.get(operator, 0)
def apply_operator(self, left, operator, right):
if operator == "+":
return left + right
elif operator == "-":
return left - right
elif operator == "*":
return left * right
elif operator == "/":
return left / right
# 计算函数，接受一个表达式并返回计算结果def calculate(expression):
lexer = Lexer(expression)
parser = Parser(lexer)
results = parser.parse()
# 使用 str 方法将 LLVM IR 内部表示转换为格式化的LLVM IR 汇编代码
formatted_ir = str(module)
# 打印格式化的 LLVM IR 汇编代码
# print(formatted_ir)
return results, formatted_ir
'''# 测试代码expression = "x = 3 * (4-1); y = 2*x + 2;"# expression = "7"results = calculate(expression)print(results) # 输出结果为 [12, 14, None]'''# 测试代码expression = "x = 3 * (4-1); y = 2*x + 2;"
llvm_ir = calculate(expression)
print("\n------------------------------------------")
print("LLVM IR的内部表示:\n", llvm_ir[0])
print("\n------------------------------------------")
print("LLVM IR的内部表示格式化和排版的LLVM IR汇编代码:\n", llvm_ir[1])
import llvmlite.ir as ir
import llvmlite.binding as llvm
# 初始化LLVMllvm.initialize()llvm.initialize_native_target()llvm.initialize_native_asmprinter()# 创建LLVM模块module = ir.Module(name="my_module")
# 创建一个LLVM上下文和函数context = ir.Context()
function = None
# 创建LLVM IR构建器builder = None
# 创建一个LLVM上下文和函数# context = llvm.getGlobalContext()# function = None# Token 类用于表示词法分析器生成的令牌class Token:
def __init__(self, type, value=None):
self.type = type
self.value = value
# Lexer 类负责将输入文本解析成令牌流class Lexer:
def __init__(self, text):
self.text = text # 要解析的文本
self.pos = 0 # 当前解析位置
# 获取下一个令牌
def get_next_token(self):
if self.pos >= len(self.text):
return Token("EOF") # 如果已经到达文本末尾，返回一个表示结束的令牌
current_char = self.text[self.pos]
# 如果当前字符是字母，则解析标识符
if current_char.isalpha():
identifier = ""
while self.pos < len(self.text) and self.text[self.pos].isalnum():
identifier += self.text[self.pos]
self.pos += 1
return Token("IDENTIFIER", identifier)
# 如果当前字符是数字，则解析数字
if current_char.isdigit():
self.pos += 1
return Token("NUMBER", int(current_char))
# 如果当前字符是运算符，则解析运算符
if current_char in "+-*/":
self.pos += 1
return Token("OPERATOR", current_char)
# 如果当前字符是等号，则解析为赋值符号
if current_char == "=":
self.pos += 1
return Token("ASSIGN", "=")
# 如果当前字符是分号，则解析为分号
if current_char == ";":
self.pos += 1
return Token("SEMICOLON", ";")
# 如果当前字符是左括号，则解析为左括号
if current_char == "(":
self.pos += 1
return Token("LPAREN", "(")
# 如果当前字符是右括号，则解析为右括号
if current_char == ")":
self.pos += 1
return Token("RPAREN", ")")
# 如果当前字符是空格或制表符，则忽略并获取下一个令牌
if current_char in " \t":
self.pos += 1
return self.get_next_token()
raise ValueError("Invalid character") # 如果遇到无法识别的字符，引发异常
# Parser 类负责解析令牌流并计算结果class Parser:
def __init__(self, lexer):
self.lexer = lexer # 词法分析器
self.current_token = self.lexer.get_next_token() # 当前令牌
self.variables = {} # 存储变量名和值的字典
# 解析整个表达式并生成LLVM IR
def parse(self):
global builder, function
results = []
# 创建主函数
main_function_type = ir.FunctionType(ir.IntType(32), ())
function = ir.Function(module, main_function_type, name="main")
block = function.append_basic_block(name="entry")
builder = ir.IRBuilder(block)
while self.current_token.type != "EOF":
result = self.parse_statement()
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最后于 2023-9-5 21:37
被_THINCT编辑
，原因：
