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The Swift Programming Language
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[SR-5457] Specific error message when user tries to compile Swift executable #48029

Open swift-ci opened 7 years ago

swift-ci commented 7 years ago
Previous ID SR-5457
Radar None
Original Reporter carlb (JIRA User)
Type Improvement
Additional Detail from JIRA | | | |------------------|-----------------| |Votes | 0 | |Component/s | Compiler | |Labels | Improvement, Parser, StarterBug | |Assignee | None | |Priority | Medium | md5: 111feeb80ab569e4bee27d9d511be231

Issue Description:

I was talking to a new Swift programmer who came from the ruby/python world. He had this output:

$ swift .build/debug/helloWorld
.build/debug/helloWorld:1:1: error: invalid UTF-8 found in source file
�����x� H__PAGEZERO8__TEXT@@__text__TEXT Ͷ �__stubs__TEXT��
.build/debug/helloWorld:1:2: error: invalid UTF-8 found in source file
�����x� H__PAGEZERO8__TEXT@@__text__TEXT Ͷ �__stubs__TEXT��
.build/debug/helloWorld:1:3: error: invalid UTF-8 found in source file
�����x� H__PAGEZERO8__TEXT@@__text__TEXT Ͷ �__stubs__TEXT��
.build/debug/helloWorld:1:4: error: input files must be encoded as UTF-8 instead of UTF-16
�����x� H__PAGEZERO8__TEXT@@__text__TEXT Ͷ �__stubs__TEXT��

Because he had started with Swift scripts, where you put swift in front of the file.swift name.

The error message above is perfectly valid, but unhelpful in this case. I would guess enough new programmers would make this mistake that it's worth discussing a special-case error message if the file to be run is already a Swift executable.

belkadan commented 7 years ago

Interesting! I think the best way to do this would be to check for various executable formats' "magic numbers" at the start of a source buffer. "\xCA\xFE\xBA\xBE" and "\x7fELF" would handle both Mach-O and ELF executables (Darwin and Linux/BSD).

belkadan commented 5 years ago

Resetting assignee on all Starter Bugs not modified since 2018.