git/hashmap.h, branch v2.29.2

hashmap_for_each_entry(): workaround MSVC's runtime check failure #3

2020-09-30T20:26:54Z

The OFFSETOF_VAR(var, member) macro is implemented in terms of offsetof(typeof(*var), member) with compilers that know typeof(), but its fallback implemenation compares &(var->member) and (var) and count the distance in bytes, i.e. ((uintptr_t)&(var)->member - (uintptr_t)(var)) MSVC's runtime check, when fed an uninitialized 'var', flags this as a use of an uninitialized variable (and that is legit---uninitialized contents of 'var' is subtracted) in a debug build. After auditing all 6 uses of OFFSETOF_VAR(), 1 of them does feed a potentially uninitialized 'var' to the macro in the beginning of the for() loop: #define hashmap_for_each_entry(map, iter, var, member) \ for (var = hashmap_iter_first_entry_offset(map, iter, \ OFFSETOF_VAR(var, member)); \ var; \ var = hashmap_iter_next_entry_offset(iter, \ OFFSETOF_VAR(var, member))) We can work around this by making sure that var has _some_ value when OFFSETOF_VAR() is called. Strictly speaking, it invites undefined behaviour to use NULL here if we end up with pointer comparison, but MSVC runtime seems to be happy with it, and most other systems have typeof() and don't even need pointer comparison fallback code. Signed-off-by: Junio C Hamano Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

hashmap: fix typo in usage docs

2020-07-28T21:28:15Z

Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

Merge branch 'en/doc-typofix'

2019-12-01T17:04:35Z

Docfix. * en/doc-typofix: Fix spelling errors in no-longer-updated-from-upstream modules multimail: fix a few simple spelling errors sha1dc: fix trivial comment spelling error Fix spelling errors in test commands Fix spelling errors in messages shown to users Fix spelling errors in names of tests Fix spelling errors in comments of testcases Fix spelling errors in code comments Fix spelling errors in documentation outside of Documentation/ Documentation: fix a bunch of typos, both old and new

Fix spelling errors in code comments

2019-11-10T07:00:54Z

Reported-by: Jens Schleusener Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

hashmap: fix documentation misuses of -> versus .

2019-11-07T05:40:56Z

Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

hashmap_entry: remove first member requirement from docs

2019-10-07T01:20:12Z

Comments stating that "struct hashmap_entry" must be the first member in a struct are no longer valid. Suggested-by: Phillip Wood Signed-off-by: Eric Wong Signed-off-by: Junio C Hamano

hashmap: remove type arg from hashmap_{get,put,remove}_entry

2019-10-07T01:20:12Z

Since these macros already take a `keyvar' pointer of a known type, we can rely on OFFSETOF_VAR to get the correct offset without relying on non-portable `__typeof__' and `offsetof'. Argument order is also rearranged, so `keyvar' and `member' are sequential as they are used as: `keyvar->member' Signed-off-by: Eric Wong Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano

OFFSETOF_VAR macro to simplify hashmap iterators

2019-10-07T01:20:11Z

While we cannot rely on a `__typeof__' operator being portable to use with `offsetof'; we can calculate the pointer offset using an existing pointer and the address of a member using pointer arithmetic for compilers without `__typeof__'. This allows us to simplify usage of hashmap iterator macros by not having to specify a type when a pointer of that type is already given. In the future, list iterator macros (e.g. list_for_each_entry) may also be implemented using OFFSETOF_VAR to save hackers the trouble of using container_of/list_entry macros and without relying on non-portable `__typeof__'. v3: use `__typeof__' to avoid clang warnings Signed-off-by: Eric Wong Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano

hashmap: introduce hashmap_free_entries

2019-10-07T01:20:11Z

`hashmap_free_entries' behaves like `container_of' and passes the offset of the hashmap_entry struct to the internal `hashmap_free_' function, allowing the function to free any struct pointer regardless of where the hashmap_entry field is located. `hashmap_free' no longer takes any arguments aside from the hashmap itself. Signed-off-by: Eric Wong Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano

hashmap: hashmap_{put,remove} return hashmap_entry *

2019-10-07T01:20:11Z

And add *_entry variants to perform container_of as necessary to simplify most callers. Signed-off-by: Eric Wong Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano