142 lines
5.1 KiB
Python
142 lines
5.1 KiB
Python
import t, c
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from stdint import *
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import ast
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import llvmlite
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import memhub
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import string
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import stdio
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import viperlib
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import lib.core.Handles.HandlesBase as HandlesBase
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import lib.core.Handles.HandlesTranslator as HT
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import lib.core.Handles.HandlesExpr as HandlesExpr
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import lib.core.Handles.HandlesBody as HandlesBody
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# ============================================================
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# HandlesIf - if/elif/else 语句处理（Mixin 继承模式）
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#
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# 翻译 if 语句为 LLVM IR 控制流:
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# br i1 %cond, label %then, label %else
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# then:
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# ... body ...
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# br label %end
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# else:
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# ... orelse ...
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# br label %end
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# end:
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# ============================================================
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@t.NoVTable
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class IfHandle(HandlesBase.Mixin):
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"""if/elif/else 语句处理器：继承 Mixin 获得 Trans 回指针"""
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def __init__(self, trans: HT.Translator | t.CPtr):
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self.Trans = trans
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# ============================================================
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# Handle - 处理 if 语句，返回新增变量数
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# ============================================================
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def Handle(self, node: ast.AST | t.CPtr) -> int:
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"""翻译 if/elif/else 语句"""
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if node is None:
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return 0
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trans: HT.Translator | t.CPtr = self.Trans
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pool: memhub.MemBuddy | t.CPtr = trans.Pool
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builder: llvmlite.IRBuilder | t.CPtr = trans._cur_builder
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func: llvmlite.Function | t.CPtr = trans._cur_func
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if builder is None or func is None:
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return 0
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if_node: ast.If | t.CPtr = (ast.If | t.CPtr)(node)
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# 1. 求值条件表达式
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cond_val: llvmlite.Value | t.CPtr = HandlesExpr.translate_value(
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builder, pool, trans.Module, if_node.test,
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trans._funcs, trans._func_count, trans)
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# 2. 转换为 i1 条件
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# Compare/Not 表达式已返回 i1，直接使用；其他类型与 0 比较
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if cond_val is None:
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cond_val = llvmlite.const_int32(pool, 0)
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cond_bits: int = HandlesExpr.get_llvm_type_bits(cond_val.Ty)
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if cond_bits == 1:
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cond_i1: llvmlite.Value | t.CPtr = cond_val
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else:
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zero: llvmlite.Value | t.CPtr = llvmlite.const_int32(pool, 0)
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cond_i1 = llvmlite.build_icmp(
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builder, llvmlite.ICMP_NE, cond_val, zero)
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# 3. 创建基本块（使用 trans._label_counter 生成唯一标签名，不与 SSA 名共享）
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cnt: int = trans._label_counter
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trans._label_counter = cnt + 1
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name_buf: t.CChar | t.CPtr = pool.alloc(32)
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viperlib.snprintf(name_buf, 32, "if.then.%d", cnt)
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then_bb: llvmlite.BasicBlock | t.CPtr = llvmlite.create_block(pool, func, name_buf)
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viperlib.snprintf(name_buf, 32, "if.end.%d", cnt)
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merge_bb: llvmlite.BasicBlock | t.CPtr = llvmlite.create_block(pool, func, name_buf)
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# 检查是否有 else 分支
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has_else: int = 0
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orelse_list: list[ast.AST | t.CPtr] | t.CPtr = if_node.orelse
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if orelse_list is not None:
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if orelse_list.__len__() > 0:
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has_else = 1
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else_bb: llvmlite.BasicBlock | t.CPtr = None
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if has_else == 1:
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viperlib.snprintf(name_buf, 32, "if.else.%d", cnt)
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else_bb = llvmlite.create_block(pool, func, name_buf)
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# 4. 发射条件分支
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if has_else == 1:
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llvmlite.build_cond_br(builder, cond_i1, then_bb, else_bb)
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else:
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llvmlite.build_cond_br(builder, cond_i1, then_bb, merge_bb)
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# 5. 翻译 then body
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llvmlite.position_at_end(builder, then_bb)
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body: list[ast.AST | t.CPtr] | t.CPtr = if_node.children
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if body is not None:
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body_count: t.CSizeT = body.__len__()
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for bi in range(body_count):
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stmt: ast.AST | t.CPtr = body.get(bi)
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if stmt is not None:
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HandlesBody.translate_stmt(trans, stmt)
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# then 块未终止则跳到 merge
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if llvmlite.builder_cur_block_is_terminated(builder) == 0:
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llvmlite.build_br(builder, merge_bb)
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# 6. 翻译 else body（若有）
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if has_else == 1:
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llvmlite.position_at_end(builder, else_bb)
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else_count: t.CSizeT = orelse_list.__len__()
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for ei in range(else_count):
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stmt: ast.AST | t.CPtr = orelse_list.get(ei)
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if stmt is not None:
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HandlesBody.translate_stmt(trans, stmt)
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if llvmlite.builder_cur_block_is_terminated(builder) == 0:
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llvmlite.build_br(builder, merge_bb)
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# 7. 定位到 merge 块继续后续代码
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llvmlite.position_at_end(builder, merge_bb)
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return 0
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# ============================================================
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# NewIfHandle - 工厂函数
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# ============================================================
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def NewIfHandle(pool: memhub.MemBuddy | t.CPtr,
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trans: HT.Translator | t.CPtr) -> IfHandle | t.CPtr:
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h: IfHandle | t.CPtr = pool.alloc(IfHandle.__sizeof__())
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if h is None:
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return None
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string.memset(h, 0, IfHandle.__sizeof__())
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h.Trans = trans
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return h
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