Here is one to consider:
I get this warning on compile in Pelles version 10 ... yes I know upgrade soon! :)
-
C:\Program Files\PellesC\Files\vCardz\vCardz\search.c(1006): warning #1044: Trigraph '??!' converted to '|'.
due to this source line
{ startrec = 0;} // back to the start (what about loop when doing directory??!!)
I would not think the compiler would care what is in a comment... even though Level 2 and C11
Smallest program is not included since you can just paste the comment. BUT if that doesn't work I'll post.
John Z
Hello John,
this behavior is fully compliant with the standard, apart the warning that is just informational to advice you that a trigraph has been found and translated.
The C standards, from C89 up to C20, specify the the first phase of a 'unit translation' (read source file compilation), is the mapping of source file to source character set and the translations of trigraphs.
From C17 standard draft:
Quote5.1.1.2 Translation phases
.1 The precedence among the syntax rules of translation is specified by the following phases.
1. Physical source file multibyte characters are mapped, in an implementation-defined manner, to
the source character set (introducing new-line characters for end-of-line indicators) if necessary.
Trigraph sequences are replaced by corresponding single-character internal representations.
2. Each instance of a backslash character (\) immediately followed by a new-line character is
deleted, splicing physical source lines (... omissis ...)
So in the very first phase trigraphs are translated to the internal representation, and a warning showed for each of them. This happens before the comment is stripped out from translation process.
Thanks for the great explanation, especially the
Quote from: frankie on April 16, 2022, 04:29:55 PMThis happens before the comment is stripped out from translation process
Got it!
Thank you,
John Z
Anyway I have to admit that the warning is very annoying! >:( ;D ;D
From Pelle's help file:
QuoteC trigraph sequences
All occurrences in a source file of the following sequences of three characters (called trigraph sequences) are replaced with the corresponding single character. They are meant for computers with limited character sets.
| Trigraph | Character |
| ??= | # |
| ??( | [ |
| ??/ | \ |
| ??) | ] |
| ??' | ^ |
| ??< | { |
| ??! | | |
| ??> | } |
| ??- | ~
|