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2023-01-09use DUP_ARRAYRené Scharfe
Add a semantic patch for replace ALLOC_ARRAY+COPY_ARRAY with DUP_ARRAY to reduce code duplication and apply its results. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-10cocci: avoid normalization rules for memcpyRené Scharfe
Some of the rules for using COPY_ARRAY instead of memcpy with sizeof are intended to reduce the number of sizeof variants to deal with. They can have unintended side effects if only they match, but not the one for the COPY_ARRAY conversion at the end. Avoid these side effects by instead using a self-contained rule for each combination of array and pointer for source and destination which lists all sizeof variants inline. This lets "make contrib/coccinelle/array.cocci.patch" take 15% longer on my machine, but gives peace of mind that no incomplete transformation will be generated. Suggested-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-16cocci: allow xcalloc(1, size)Junio C Hamano
Allocating a pre-cleared single element is quite common and it is misleading to use CALLOC_ARRAY(); these allocations that would be affected without this change are not allocating an array. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-14use CALLOC_ARRAYRené Scharfe
Add and apply a semantic patch for converting code that open-codes CALLOC_ARRAY to use it instead. It shortens the code and infers the element size automatically. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-18coccinelle: use COPY_ARRAY for copying arraysRené Scharfe
The current semantic patch for COPY_ARRAY transforms memcpy(3) calls on pointers, but Coccinelle distinguishes them from arrays. It already contains three rules to handle the options for sizeof (i.e. source, destination and type), and handling arrays as source and destination would require four times as many rules if we enumerated all cases. We also don't handle array subscripts, and supporting that would increase the number of rules by another factor of four. (An isomorphism telling Coccinelle that "sizeof x[...]" is equivalent to "sizeof *x" would be nice..) Support arrays and array subscripts, but keep the number of rules down by adding normalization steps: First turn array subscripts into derefences, then determine the types of expressions used with sizeof and replace them with these types, and then convert the different possible combinations of arrays and pointers with memcpy(3) to COPY_ARRAY. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-02coccinelle: remove parentheses that become unnecessaryRené Scharfe
Transformations that hide multiplications can end up with an pair of parentheses that is no longer needed. E.g. with a rule like this: @@ expression E; @@ - E * 2 + double(E) ... we might get a patch like this: - x = (a + b) * 2; + x = double((a + b)); Add a pair of parentheses to the preimage side of such rules. Coccinelle will generate patches that remove them if they are present, and it will still match expressions that lack them. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-07-17add MOVE_ARRAYRené Scharfe
Similar to COPY_ARRAY (introduced in 60566cbb58), add a safe and convenient helper for moving potentially overlapping ranges of array entries. It infers the element size, multiplies automatically and safely to get the size in bytes, does a basic type safety check by comparing element sizes and unlike memmove(3) it supports NULL pointers iff 0 elements are to be moved. Also add a semantic patch to demonstrate the helper's intended usage. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-27cocci: use ALLOC_ARRAYRené Scharfe
Add a semantic patch for using ALLOC_ARRAY to allocate arrays and apply the transformation on the current source tree. The macro checks for multiplication overflow and infers the element size automatically; the result is shorter and safer code. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-25use COPY_ARRAYRené Scharfe
Add a semantic patch for converting certain calls of memcpy(3) to COPY_ARRAY() and apply that transformation to the code base. The result is shorter and safer code. For now only consider calls where source and destination have the same type, or in other words: easy cases. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>