CVS commit: src/usr.bin/make

["Roland Illig" <rillig%netbsd.org@localhost>]

Module Name:    src
Committed By:   rillig
Date:           Tue Feb 16 16:14:27 UTC 2021

Modified Files:
        src/usr.bin/make: var.c

Log Message:
make: sync comment about duplicated code with reality

There are only very few places in var.c that contain really duplicate
code anymore.

There is still lots of _almost_ duplicate, for example the code for
parsing variable modifiers.  It differs subtly in behavior:

*   The modifiers ':M' and ':N' use '$$' to escape a '$' sign, while
    almost all other modifiers use '\$' for this purpose.

*   The modifiers ':M', ':N', ':S', ':@' and several others parse
    balanced parentheses and braces, allowing '(' to '}' to match.
    The modifiers ':D' and ':U' only treat the end character special but
    not the other 3 of '(){}'.

*   When parsing the modifier ':S' but not evaluating it, the code for
    nested variable expressions is parsed differently from when it is in
    evaluation mode (VARE_WANTRES).  This applies to an outer ':S'
    modifier and an inner ':D' or ':M' modifier.

Since these inconsistencies affect the behavior in edge cases and some
users of make might depend on it, they cannot be fixed by
behavior-preserving refactorings.


To generate a diff of this commit:
cvs rdiff -u -r1.826 -r1.827 src/usr.bin/make/var.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.