Messages in this thread | | | From | "" <> | Subject | Re: Extern variables in *.c files (maintainers pls read this) | Date | Thu, 3 Jan 2002 22:28:55 -0200 |
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> So, you have a choice: > 1. Enable -fno-common > - detect variables that should be marked static which aren't > - don't detect size differences > 2. Disable -fno-common > - don't detect variables that should be marked static > - detect size differences as long as the variables aren't marked extern > > As soon as someone has int foo in one file, and extern char foo in another, > you've lost no matter which option you take. > > The header file approach is the most reliable (and imho correct) method to > solve this problem.
And this method is traditional for C. We have struct declarations and fn propotypes in *.h, we should place extern vars there too. Always.
If you are a kernel subsystem or driver maintainer, you may wish to check whether *your* part of kernel has any extern variable defs. Just run this hunter script in top dir of kernel source: ----------------------- #!/bin/sh
function do_grep() { pattern="$1" dir="$2" shift;shift for i in $dir/$*; do if ! test -d "$i"; then if test -e "$i"; then grep -E "$pattern" "$i" /dev/null fi fi done for i in $dir/*; do if test -d "$i"; then do_grep "$pattern" "$i" $* fi done }
do_grep 'extern [^()]*;' . "*.c" 2>&1 | tee ../extern.log ---------------------------------
Output is not attached here, it's too big: ~100 KB, ~1500 lines for 2.5.1-pre8 -- vda - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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