On Tue, 20 Nov 2012, Bruce Evans wrote:
On Tue, 20 Nov 2012, Eitan Adler wrote:
Log:
Remove unneeded includes.
Tested with "make universe"; there are no conditional features.
"make universe" can't find such features. Except inversely -- when it
doesn't find them, it usually means that there is a bug in the headers.
[... oops; I wrote a lot about sys/stat.h, but removing it was correct]
To remove a single header, you must know all the standard pollutions and
check cc -E -MM output to verify that no nonstandard pollutions are
depended on.
My unused includes checking utility doesn't do much better with the
pollution, but it finds better includes to remove: (it tends to
find pollution problems by generating large output that is not quite
so large as cc -E -MM output). It gives:
%%%
trying /home/bde/r/edquota/edquota.c
line 55 in source /home/bde/r/edquota/edquota.c seems to be unnecessary:
#include <sys/mount.h>
line 53 in source /home/bde/r/edquota/edquota.c seems to be unnecessary:
#include <sys/stat.h>
line 52 in source /home/bde/r/edquota/edquota.c seems to be unnecessary:
#include <sys/param.h>
%%%
Removing all 3 headers doesn't work, and shows that some ufs header depends
on sys/param.h> But removing sys/stat.h like you did and also sys/mount.h
works, and checking .depend (which is equivalent to checking cc -E -MM)
shows that neither sys/stat.h nor sys/mount.h is used. Except I didn't
check with a universe-wide set of variations of options.
Removing the include of sys/mount.h instead of the include of sys/param.h
is correct. In the current version, the ufs header is satisfying its
dependency on sys/param.h accidentally by getting sufficient pollution
from sys/mount.h, which it otherwise doesn't use. Pollution in headers
makes this bug too easy to write, and dependencies on accidental pollution
make cleaning the pollution harder.
@ #!/bin/sh
@
@ # unusedinc - find unused `#include' lines in almost (?) any directory with
@ # a makefile. Usage: `unusedinc' or `unusedinc file.o ...'.
@ #
@ # Known bugs:
@ # - scribbles in current directory
@ # - copying files to the current directory tends to break #include "foo.h",
@ # e.g., in src/usr.bin/w.
@ # - doesn't handle undocumented nested includes properly. E.g., including
@ # <sys/time.h> to get `struct timeval' gives a free include of <time.h>,
@ # but it is not correct to depend on this pollution. We should run gcc -M
@ # to separate these unused but necessary includes from the completely
@ # unused ones.
@ # - slow.
@
@ # XXX removed -Wconversion since it was too painful.
@ # XXX removed -Wshadow since it was too painful.
@ # XXX removed -Wwrite-strings since it was too painful.
@ MAKEOBJDIR=/ make -n "$@" | grep '^cc .*-c ' | sed 's/cc/cc -Wall
-Wbad-function-cast -Wcast-align -Wcast-qual -Wchar-subscripts -Winline
-Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wredundant-decls
-Wstrict-prototypes -fno-builtin/' |
@ while :;
@ do
@ read line
@ if [ -z "$line" ]
@ then
@ rm -f 1 2 1.o 2.o z.c
@ exit
@ fi
@ line=`echo "$line" | sed 's; -o [^ ]*;;'`
@ cmd=`echo "$line" | sed 's;[ ][^ ]*$;;'`
@ src=`echo "$line" | sed 's;.* ;;'`
@ echo "trying $src"
@ cat $src >z.c
@ $cmd z.c >/dev/null 2>1
@ if test -f z.o
@ then
@ mv z.o 1.o
@ else
@ echo "original build of $src failed!"
@ $cmd z.c
@ exit 1
@ fi
@ for i in `grep -n '^[ ]*#include' $src | sed 's/:.*//' | sort -nr`
@ do
@ sed -e "$i""s/.*//" $src >z.c
@ $cmd z.c >/dev/null 2>2
@ if test -f z.o
@ then
@ mv z.o 2.o
@ if cmp -s 1 2 && cmp -s 1.o 2.o
@ then
@ echo "line $i in source $src seems to be unnecessary:"
@ head -$i $src | tail -1
@ # exit 1
@ fi
@ fi
@ done
@ done
unusedinc is not very good in different ways than
/usr/src/tools/tools/kerninclude/kerninclude.sh. The latter is smarter
about annulling includes (IIRC, it builds a new include tree and
replaces 1 include at a time with an empty file, where the above removes
#include lines 1 at a time). This gives many fewer false positives,
but makes the checking too heavyweight to use on 1 small program at a
time. It is only implemented for the kernel, while the above works
in any reasonably- structured source directory (no subdirectories or
.PATH's pointing elsewhere), or on a single source file at a time in
such a directory. kerninclude.sh is also unusable because its globality
and the kernel size generates more output than anyone wants to see.
Bruce
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