Module Name: src
Committed By: rillig
Date: Mon Dec 13 05:25:04 UTC 2021
Modified Files:
src/usr.bin/make: main.c make.h parse.c str.c str.h
Log Message:
make: fix memory leak for filenames in .for loops (since 2013-06-18)
Previously, each time a .for directive pushed its buffer on the input
file stack, the current filename was duplicated. This was a waste of
memory.
The name of a file is typically only used while it is read in. There is
one situation when the filename is needed for longer, which is when a
target is defined.
Since .for loops are implemented as a special form of included files,
each .for loop duplicated the current filename as well.
$ cat << EOF > for.mk
.for i in 1 2 3 4 5 6 7 8 9 0
.for i in 1 2 3 4 5 6 7 8 9 0
.for i in 1 2 3 4 5 6 7 8 9 0
.for i in 1 2 3 4 5 6 7 8 9 0
.for i in 1 2 3 4 5 6 7 8 9 0
.for i in 1 2 3 4 5 6 7 8 9 0
.for i in 1 2 3 4 5 6 7 8 9 0
.endfor
.endfor
.endfor
.endfor
.endfor
.endfor
.endfor
all:
@ps -o rsz -p ${.MAKE.PID}
EOF
$ make-2021.12.13.03.55.16 -r -f for.mk
RSZ
10720
$ ./make -r -f for.mk
RSZ
1716
The difference is 8 MB, which amounts to 1 million .for loops.
To generate a diff of this commit:
cvs rdiff -u -r1.541 -r1.542 src/usr.bin/make/main.c
cvs rdiff -u -r1.270 -r1.271 src/usr.bin/make/make.h
cvs rdiff -u -r1.575 -r1.576 src/usr.bin/make/parse.c
cvs rdiff -u -r1.86 -r1.87 src/usr.bin/make/str.c
cvs rdiff -u -r1.13 -r1.14 src/usr.bin/make/str.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
