git/xdiff, branch v2.45.2

xdiff: mark unused parameter in xdl_call_hunk_func()

2022-12-13T13:16:23Z

This function is used interchangeably with xdl_emit via a function pointer, so we can't just drop the unused parameter. Mark it to silence -Wunused-parameter. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

xdiff: drop unused parameter in def_ff()

2022-12-13T13:16:23Z

The def_ff() function is the default "find_func" for finding hunk headers. It has never used its "priv" argument since it was introduced in f258475a6e (Per-path attribute based hunk header selection., 2007-07-06). But back then we used a function pointer to switch between a caller-provided function and the default, so the two had to conform to the same interface. In ff2981f724 (xdiff: factor out match_func_rec(), 2016-05-28), that pointer indirection went away in favor of code which directly calls either of the two functions. So there's no need for def_ff() to retain this unused parameter. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

xdiff: drop unused mmfile parameters from xdl_do_patience_diff()

2022-08-20T21:14:55Z

The entry point to the patience-diff algorithm takes two mmfile_t structs with the original file contents, but it doesn't actually do anything useful with them. This is similar to the case recently cleaned up in the histogram code via f1d019071e (xdiff: drop unused mmfile parameters from xdl_do_histogram_diff(), 2022-08-19), but there's a bit more subtlety going on. We pass them into the recursive patience_diff(), which in turn passes them into fill_hashmap(), which stuffs the pointers into a struct. But the only thing which reads the struct fields is our recursion into patience_diff()! So it's unlikely that something like -Wunused-parameter could find this case: it would have to detect the circular dependency caused by the recursion (not to mention tracing across struct field assignments). But once found, it's easy to have the compiler confirm what's going on: 1. Drop the "file1" and "file2" fields from the hashmap struct definition. Remove the assignments in fill_hashmap(), and temporarily substitute NULL in the recursive call to patience_diff(). Compiling shows that no other code touched those fields. 2. Now fill_hashmap() will trigger -Wunused-parameter. Drop "file1" and "file2" from its definition and callsite. 3. Now patience_diff() will trigger -Wunused-parameter. Drop them there, too. One of the callsites is the recursion with our NULL values, so those temporary values go away. 4. Now xdl_do_patience_diff() will trigger -Wunused-parameter. Drop them there. And we're done. Suggested-by: Phillip Wood Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

xdiff: drop unused mmfile parameters from xdl_do_histogram_diff()

2022-08-19T19:20:24Z

These are no longer used since 9df0fc3d57 (xdiff: fix a memory leak, 2022-02-16), as the caller is expected to call xdl_prepare_env() itself. After that change the histogram code only examines the prepared xdfenv_t, not the original buffers. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

xdiff: introduce XDL_ALLOC_GROW()

2022-07-08T16:34:30Z

Add a helper to grow an array. This is analogous to ALLOC_GROW() in the rest of the codebase but returns −1 on allocation failure to accommodate other users of libxdiff such as libgit2. It will also return a error if the multiplication overflows while calculating the new allocation size. Note that this keeps doubling on reallocation like the code it is replacing rather than increasing the existing size by half like ALLOC_GROW(). It does however copy ALLOC_GROW()'s trick of adding a small amount to the new allocation to avoid a lot of reallocations at small sizes. Note that xdl_alloc_grow_helper() uses long rather than size_t for `nr` and `alloc` to match the existing code. Signed-off-by: Phillip Wood Signed-off-by: Junio C Hamano

xdiff: introduce XDL_CALLOC_ARRAY()

2022-07-08T16:34:30Z

Add a helper for allocating an array and initialize the elements to zero. This is analogous to CALLOC_ARRAY() in the rest of the codebase but it returns NULL on allocation failures rather than dying to accommodate other users of libxdiff such as libgit2. Signed-off-by: Phillip Wood Signed-off-by: Junio C Hamano

xdiff: introduce xdl_calloc

2022-07-08T16:34:30Z

In preparation for introducing XDL_CALLOC_ARRAY() use calloc() to obtain zeroed out memory rather than malloc() followed by memset(). To try and keep the lines a reasonable length this commit also stops casting the pointer returned by calloc() as this is unnecessary. Signed-off-by: Phillip Wood Signed-off-by: Junio C Hamano

xdiff: introduce XDL_ALLOC_ARRAY()

2022-07-08T16:34:30Z

Add a helper to allocate an array that automatically calculates the allocation size. This is analogous to ALLOC_ARRAY() in the rest of the codebase but returns NULL if the allocation fails to accommodate other users of libxdiff such as libgit2. The helper will also return NULL if the multiplication in the allocation calculation overflows. Signed-off-by: Phillip Wood Signed-off-by: Junio C Hamano

Merge branch 'ep/maint-equals-null-cocci'

2022-05-20T22:26:59Z

Introduce and apply coccinelle rule to discourage an explicit comparison between a pointer and NULL, and applies the clean-up to the maintenance track. * ep/maint-equals-null-cocci: tree-wide: apply equals-null.cocci tree-wide: apply equals-null.cocci contrib/coccinnelle: add equals-null.cocci

Merge branch 'ep/maint-equals-null-cocci' for maint-2.35

2022-05-02T17:06:04Z

* ep/maint-equals-null-cocci: tree-wide: apply equals-null.cocci contrib/coccinnelle: add equals-null.cocci