CVS commit: src/usr.bin/make

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

Module Name:    src
Committed By:   rillig
Date:           Mon Apr 12 18:48:00 UTC 2021

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

Log Message:
make: reduce memory allocation and strlen calls in modifier ':from=to'

Previously, SysVMatch was quite verbose and felt like hand-optimized
assembler code, which made it difficult to discover the underlying idea
of the code.

All this code was replaced with two simple calls to Substring_HasPrefix
and Substring_HasSuffix.  Now that the operands of that modifier are no
longer passed as C strings, there is no need to collect all information
in a single scan through the word and the pattern.

It was not necessary to call Var_Subst unconditionally.  Calling it only
when the string contains a '$' saves another memory allocation and two
string copies (because of the Buf_DoneDataCompact).

No functional change.


To generate a diff of this commit:
cvs rdiff -u -r1.5 -r1.6 src/usr.bin/make/str.h
cvs rdiff -u -r1.924 -r1.925 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.