swiftlang/swift

[SR-2403] Recognize __builtin_{huge_val,inf,nan}() macros

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#45,010 创建于 2016年8月18日

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 (0 评论) (0 反应) (0 负责人)Swift (69,989 star) (10,719 fork)batch import
bugc interopc/c++ macroscompilergood first issue

描述
Previous ID SR-2403
Radar rdar://problem/19051485
Original Reporter @belkadan
Type Bug
Votes 0
Component/s Compiler
Labels Bug, ClangImporter, Macros, StarterBug
Assignee None
Priority Medium

md5: c8e64f9c66f50b498cedbe9171dcc5a6

Issue Description:

__builtin_huge_val(), __builtin_nan(""), and __builtin_inf() are often used to define macros that evaluate to IEEE infinity or NaN. We could recognize these patterns and import them as aliases for Double.infinity/nan (or mark them unavailable in favor of the native Swift type properties).

贡献者指南

技术栈
无
领域
backend
议题类型
bug
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
3
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
1-3 hours
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
stale
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
SwiftClang importerMacro handling
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
70
研究方向
Investigate the ClangImporter source code in the Swift repository to understand how built in functions are currently recognized and imported. Look for existing handling of similar builtin * functions and determine the best approach to map the three macros (` builtin huge val`, ` builtin inf`, ` builtin nan`) to Swift's Double.infinity and Double.nan. Consider whether to import them as aliases or mark them unavailable in favor of the native Swift types. Check the relevant Swift evolution discussions or comments for any previous attempts.