swiftlang/swift

[SR-7148] Compile-time conditionalization of endianness in the compiler should be done by target checking

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#49,696 建立於 2018年3月8日

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 (5 留言) (0 反應) (0 負責人)Swift (69,989 star) (10,719 fork)batch import
bugcompilergood first issue

描述
Previous ID SR-7148
Radar None
Original Reporter @jckarter
Type Bug
Votes 0
Component/s Compiler
Labels Bug, StarterBug
Assignee None
Priority Medium

md5: 7f26b7e8c0700431c7bacc1871180f85

Issue Description:

IRGen appears to have grown compile-time conditionalizations on host properties, e.g.:

https://github.com/apple/swift/blob/master/lib/IRGen/GenEnum.cpp#L3892

This is not correct if cross-compiling for a target with different endianness than the compiler host. This should check the properties of the target instead of being a #if

貢獻者指南

技術棧
cpp
領域
backend
議題類型
bug
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
3
預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。
1-3 hours
活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。
fresh
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
clear
前置要求
C++compiler internalscross compilationendianness
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
65
研究方向
Examine GenEnum.cpp line 3892 to see the compile time conditional on endianness. Investigate how the target's endianness can be accessed in IRGen. Look for examples in the codebase where target properties are used instead of host conditionals. Implement a change to use target endianness check.