Current tree handling of initializers is rather incomplete
and in many cases broken. Patchset rewrites that stuff pretty much
from scratch; AFAICS it works.
Fixed:
* proper walking into subobjects, with warnings about missing
braces. Current tree doesn't handle that and in the best case we
get a warning when initializer hits the wrong subobject and gets a type
mismatch; in the worst case we get nothing.
* excess of initializer list elements is reported
* unnamed bitfields are skipped as the should be; the current tree
doesn't do that
* fixed handling of string literals; current tree is inconsistent
in that area, especially when they come from inlined functions
(evaluate_expression() changes expr->type, so it's not recognized as string
literal the next time aroung).
* fixed handling of struct/union assignment-style initializers.
* fixed handling of gccisms (unnamed union as a member, empty struct
as a member) to match gcc behaviour; gcc extension allowing ("a") to be
treated as "a" is handled, with a warning conditional on -Wparen-string
(default is off). BTW, several places in the kernel have that sort of
idiocy.
Areas still missing:
* wide string literals. We don't support wide char anyway, so...
* expand doesn't care for order of initializers. For overlapping
ones that becomes a problem, especially when mixed with gcc range
designators (e.g. [20 ... 100] = {1, 2}, [0 ... 30].a = 15, [49] = {15, 20})
* expand still leaves EXPR_POS -> EXPR_POS -> EXPR_VALUE for
[0 ... 1][0] = 1, which makes compile-i386.c rather unhappy (segfaults).
While we are at it, compile-i386.c apparently is unaware of range designators
at all - it ignores the count. Probably best fixed in compile-i386.c...
* calculation of array size by initializer is still broken; at least
now we get warnings about missing braces in the cases that trigger that
crap; struct {int a, b;} a[] = {1,2,3,4,5}; should give a 3-element array,
not 5-element one. New code warns about missing braces and puts the values
in right places, but it still doesn't fix the array size calculation - it's
done too early. Since evaluate_initializer() can work with array of
unknown size, perhaps the best solution would be to call it from the
count_array_initializer() and look for maximal index in the results if
we have EXPR_INITIALIZER / look for string size otherwise (no other
variants are possible for arrays). Objections?
Have fun... The tree is in branch 'initializers' of
git://git.kernel.org//pub/scm/linux/kernel/git/viro/sparse/
Al Viro (4):
make copying of EXPR_INDEX non-lazy
tie the fields of struct in simple list
rewrite of initializer handling
fix handling of typeof on structs
evaluate.c | 569 ++++++++++++++++++++++++++++++++++++++++------------------
expression.h | 1 +
inline.c | 2 -
lib.c | 2 +
lib.h | 1 +
parse.c | 20 ++-
symbol.c | 7 +-
symbol.h | 6 +-
8 files changed, 428 insertions(+), 180 deletions(-)
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