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10 daysdiff: consult oid-only hunk providers via diff.<driver>.processMichael Montalbo1-0/+9
The provider chain so far holds the diff-hunks store in front of the terminal builtin computation. Open it to external processes: a pair on a path whose driver configures diff.<driver>.process is answered by a long-running process speaking a pkt-line protocol (following the filter process protocol), registered at the head of the chain and consulted before the store and before any blob is loaded. The protocol starts with the smallest request that can carry an answer: object names alone. A request is the pathname and the pair's old-oid/new-oid, with no content. The process answers with hunk lines, with a zero-hunk success that asserts the blobs equivalent (trailing newlines included), or with status=need-content, on which the pair falls through to the builtin answer. This serves the two shapes that need no content pushed to them: a cache keyed on the blob pair, and a process that fetches the blobs itself (for example over "git cat-file --batch"). A pair whose side is not a stored blob carries a NULL id; the provider sends no request and passes it. Because Git holds no content for the exchange, the answer is used as sent: hunks are validated for order, overlap, lockstep alignment, and magnitude, then replayed without the normalization xdiff applies to diffs it computes itself. The magnitude bound is the blobs' sizes, read from the object database without loading content: a blob of N bytes holds at most N lines. Because the process's answer is authoritative, it outranks the store, and its head-of-chain position says so. A pair the process answers never reaches the store and is never recorded, so nothing it produces enters the store, which holds the builtin answer only. A request it does not answer, whether need-content, a missing capability, or a missing id, passes down the chain to the builtin answer, which is what the store serves, so the store may serve such a pair and a warming run may record it. Entries recorded before a process was configured are not purged; a pair the process answers ignores them, and "git diff-hunks clear" discards them. The provider gates itself per request. The driver is looked up by the old-side path, so a renamed file resolves to the same driver, and by the repository-relative path, so a diff.relative run from a subdirectory names the pair the same way. Options the process is never told about select no process: the whitespace-ignoring options, -I, --anchored, and an algorithm forced by option or configuration (blame routes its algorithm through xdl_opts, so --histogram is covered). The request gains its last field, the path; the consumers change only by filling it, and neither names the process. The provider's state is its repository's pool of running processes, keyed by the configured command, so drivers sharing a command share a process, a submodule speaks to its own, and releasing the provider (from repo_clear()) stops them. The pool owns a copy of each command string, so an entry outlives a config re-read. A command that fails stays as an entry that is not retried: its request and every later one pass, so the store may serve the path for the rest of the command. A protocol error in a response never kills the command. The response is read through a packet reader gentle about framing, so an error takes one path: a single warning, the process stopped and marked failed, and the builtin diff for the rest of the command. That covers garbage bytes, a truncated response, an empty packet, a bare status, and an unrecognized status. Semantically invalid coordinates cost only their pair: the response is drained, the pair is computed, and the process stays alive. A path the protocol cannot carry (an embedded newline, or one too long for a packet) falls back per path rather than costing the command its process. The handshake keeps one fatal check: a process that announces a capability Git did not request aborts the command, as the long-running filter protocol does. Consulting is allowed per command, following the allow_textconv precedent. "git diff", "git log" and "git show", and "git blame" set allow_diff_process; the plumbing diff commands and the interactive-patch machinery never set it, so scripted and staging output stays builtin. The options adjust the flag: - --no-ext-diff clears it and --ext-diff sets it; - --diff-process and --no-diff-process set and clear it alone, leaving external diff drivers as they were; - format-patch clears it unconditionally, so a generated patch applies for recipients without the process; - range-diff passes --no-ext-diff to the "git log" it compares. git blame and the summary formats consult the process. For blame, a pair reported equivalent emits no hunks, so the whole commit passes to its parent. In the stat formats such a pair sums to a zero-count entry, which the "nothing changed" rule omits, as under -w. The subprocess is long-running: one startup cost across a traversal, one round-trip per consulted pair. Answers travel in struct xdl_hunk, new in xdiff-interface.h, holding xdiff's 1-based coordinates; nothing feeds them back to xdiff, since only coordinate consumers consult. A content-carrying request is the natural extension: it would serve sides that are not stored blobs and processes that want content pushed to them, and bring patch output and log -L's range tracking to the same answer. As it stands, a process's answers show in blame and the summary formats while patch output stays builtin. t4080 exercises the protocol, the per-command gate, and the error paths: - each adversarial response shape warns and falls back to builtin, the request log proving which failures disable the process and which keep it alive (a malformed hunk line, coordinates past the blob size, a count overflowing strtol(), overlapping or misaligned hunks, an unrecognized status, a bare status, an empty packet, a mid-response crash, and raw garbage); - a capability-less process and status=abort degrade without noise, and a failed start warns once and returns the path to the store; - a trailing token on a hunk line is ignored, pinning field appendability; - positive consults for git diff, git show, and diff-tree under --ext-diff and --diff-process; textconv output and gitlink sides are never identified; a diff.relative run consults by the repo-relative path; - the equivalence answer is pinned from both consumers, and a warming run past a deferring process records the pair for a later read. Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
10 daysblame: read precomputed hunksMichael Montalbo1-0/+11
Before diffing a target blob against a parent, offer the pair's identity to the hunk provider interface. Blame's requests have gone through diff_provider_emit_hunks() since the interface arrived, but carried no identity, so nothing could answer them. Now blame fills in the pair's blob object ids and its diff options, and the chain serves the pair from the store, keyed by the ids and the request's xdiff flags, before the terminal provider falls back to fill-and-compute. Blame diffs at zero context, which is not part of the key. An answer replays the recorded hunks through blame_chunk_cb without loading either blob; a request carrying -I patterns or anchors is outside the key and always computes. Blame withholds the identity where its diff is not the plain blob-pair diff the key describes: reverse blame, ignored revisions, textconv paths, and the working-tree or --contents pseudo-commit, whose blob is not a stored object. Those requests always compute. Whitespace and algorithm options such as -w instead change blame's xdl_opts, so the consult keys a different entry and misses a store warmed without them. Blame's default xdl_opts now come from DIFF_HUNKS_DEFAULT_XDL_OPTS, new here, which records the key-relevant defaults a diff_options-based consumer already carries (today the indent heuristic), so a default blame run and a default "log --stat" warming run share keys by construction. "--show-stats" reports how many pairs the store served and how many consultations it could not, read from diff_hunks_read_stats(); the store counts its own consultations, so blame keeps no tally. Extend t4220 with the blame side: - parity for plain, --porcelain, and --incremental output, and hit and miss accounting across warming runs; - the blame inputs that must bypass or miss the store: -w, indent heuristics, --reverse, textconv, -M/-C, and the --ignore-rev pass; - rename and merge handling, and --contents; - reading a truncated or corrupt store as absent, and a crafted zero-hunk record as a miss that verify flags. Add p4218, measuring the cost of a warming run and the read speedups. Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
10 daysdiff: read precomputed hunks for stat outputMichael Montalbo1-5/+15
Teach builtin_diffstat() to consult the hunk provider interface through diff_provider_consult(), new here: the consult-only entry that answers without loading content or computing, so it never returns DIFF_PROVIDER_ERROR. On an answer, the summing callback accumulates the provided counts directly into the diffstat entry; the blobs were already loaded for the binary check, so an answer saves the diff run, not the content load (blame, taught next, skips its loads too). On an unanswered outcome it computes as before and, with a writer attached, records what it computed; on unanswered-no-record it computes without recording. The provider behind the consult is the diff-hunks store, registered in front of the terminal builtin computation. Its consult serves a recorded pair through diff_hunks_replay(), which validates the sequence before any hunk reaches the callback, so direct accumulation is safe. The request gains the pair's object ids and the diff options read by the exclusions below. A side whose bytes are not a stored blob, such as a working-tree file or a gitlink, has a NULL id; the store passes it by and the terminal provider computes it. diff_provider_emit_hunks() walks the same chain, so blame's requests follow these rules the moment blame supplies identity. The walk also insists, as a BUG check, that a request's diff options belong to the repository whose chain it walks. Each exclusion lives with the provider whose key cannot express it. -I patterns and --anchored shape the diff outside the store key, and break detection (-B) rescores the pair outside it; the store's consult maps all three to stop-no-record, so such a request is neither served nor recorded for any consumer. The consumer-side guard the recording commit carried for those three comes out here. The compile-time assert on xpparam_t's layout sits next to that decision, forcing an explicit keying decision whenever a diff parameter is added. The stat consumer keeps only the exclusion that is not about the key: --ignore-blank-lines is part of the key but coalesces hunks differently between the text-emitting and coordinate-callback paths, so the consumer returns before consulting. A "log -L" range-scoped stat neither reads nor records; the line-range filter computes it as before. "git diff", "git log", "git show", and "git diff-tree" with the --stat, --numstat, and --shortstat formats consult the interface. Reading is controlled by core.diffHunks. An answer is invisible in the output, so the store counts the pairs it serves and the consultations it cannot, and diff_hunks_read_stats() reports both; the stat path emits the hits as a trace2 "read-hits" datum for tests and tuning. The counters live on the store because only the store knows whether a consultation reached it, and none of its exclusion legs reaches the replay, so none counts as a miss. Extend t4220 with the read half: - output parity with and without the store, at several context lengths and both directions, and reversed pairs keying apart; - the consultation made visible through the read-hits datum, and the trim-divergent pair correct at every context; - the settings that must bypass the store doing so in both directions (-I, -B, --anchored, --ignore-blank-lines), asserted through the trace rather than output parity alone, which a coincidentally equal count could satisfy; - a driver-forced algorithm keying apart rather than bypassing: it is part of the key, so a read under it misses the default entries and a warm records under its own. A "log -L" range-scoped stat neither reads nor records. Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
10 daysdiff: record precomputed hunks during stat outputMichael Montalbo1-0/+17
The diff-hunks store has a writer, but nothing fills it. Teach builtin_diffstat() to do so: on a warming run (a writer is attached), a modified pair's stat is produced by collecting the pair's hunk coordinates instead of emitting text, the counts are summed from those hunks, and the pair is recorded. A run without a writer is unchanged, and nothing reads the store yet; the read side arrives next. The store records one context-free entry per pair, and only for a trim-stable pair: one whose zero-context trimmed diff (what blame will read) and untrimmed diff (whose counts a nonzero-context stat matches) are identical. The warming path computes both and hands them to diff_hunks_writer_record_stable(), new here, which records only when they agree; a divergent pair is never recorded and every consumer computes it. The warming run displays the counts it shows a store-less run: the trimmed ones, since xdi_diff trims at zero context, while the untrimmed counts serve only the stability comparison. Not everything the stat path computes may be recorded. --ignore-blank-lines is part of the key, but it coalesces hunks differently between the text-emitting and coordinate-callback paths, so a recorded entry would not match a store-less run's --stat. -I patterns, --anchored, and break detection (-B) shape the diff outside the key entirely; the guard for those three sits in this consumer for now and moves into the store's own provider when it registers, next. A "log -L" range-scoped stat is not the whole-pair diff the key describes, so it does not record. Recording also requires both sides to be valid regular files whose blobs the key can name: a working-tree side, textconv output, or a gitlink has no usable id. "git diff", "git log", "git show", and "git diff-tree" with the --stat, --numstat, and --shortstat formats attach a writer when writing is enabled and flush it when the traversal finishes, so a warming run such as GIT_DIFF_HUNKS_WRITE=1 git log --all --stat >/dev/null fills the cache as a side effect of the diff work the command already does. Writing is controlled by diffHunks.write and GIT_DIFF_HUNKS_WRITE. Add the write half of t4220: - ordinary commands never create the store, and creation is gated off by default, the environment overriding the config; - a warming run builds a store that verifies, and a second refreshes it in place; - a warming run displays parity at zero context on a trim-divergent pair, committed as a fixture (small synthetic pairs cannot diverge: minimal diffs add and delete equal counts, and trimming preserves that); - binary and mode-only pairs do not break the writer; - a corrupt store is discarded at seed; - verify and clear run against the files a warming run builds. Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-05-13diff: reject negative values for -U/--unifiedMichael Montalbo1-1/+1
Passing a negative value to -U is silently accepted and produces corrupt unified diff output with malformed hunk headers: $ git log -1 -p -U-500 -- GIT-VERSION-GEN | grep '^@@' @@ -503,999- +503,999- @@ Line 503 of a 106-line file, count "999-" is not a valid integer. The config variable diff.context already rejects negative values, but the command line callback diff_opt_unified() uses strtol() with no range check. Change the type of diff_options.context and its static default from int to unsigned int, matching the change to interhunkcontext in the previous commit. The type change requires reworking the callback and config parsing to validate in a local variable before assigning to the now-unsigned field. Unlike --inter-hunk-context which could be converted to OPT_UNSIGNED, -U needs OPT_CALLBACK_F for PARSE_OPT_OPTARG (bare -U with no value enables patch output). Add a range check in the callback instead. Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-05-13diff: reject negative values for --inter-hunk-contextMichael Montalbo1-1/+1
Negative values for --inter-hunk-context produce structurally invalid diff output with overlapping hunks: $ git log -1 -p -U3 --inter-hunk-context=-100 791aeddfa2 \ -- git-compat-util.h | grep '^@@' @@ -110,6 +110,9 @@ @@ -115,6 +118,9 @@ @@ -116,6 +122,7 @@ Hunk 1 covers lines 110-115, hunk 2 starts at 115 (overlap), hunk 3 starts at 116 (overlaps both). The resulting patch cannot be applied. The config variable diff.interHunkContext already rejects negative values, but the command line option does not. Change the type of diff_options.interhunkcontext and its static default from int to unsigned int, and switch the option parser from OPT_INTEGER_F to OPT_UNSIGNED. This rejects negative values at parse time via git_parse_unsigned() and enforces the correct type at compile time via BARF_UNLESS_UNSIGNED. Signed-off-by: Michael Montalbo <mmontalbo@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-12-14Merge branch 'rs/diff-index-find-copies-harder-optim'Junio C Hamano1-0/+5
Halve the memory consumed by artificial filepairs created during "git diff --find-copioes-harder", also making the operation run faster. * rs/diff-index-find-copies-harder-optim: diff-index: don't queue unchanged filepairs with diff_change()
2025-11-30Merge branch 'jc/whitespace-incomplete-line'Junio C Hamano1-3/+3
Both "git apply" and "git diff" learn a new whitespace error class, "incomplete-line". * jc/whitespace-incomplete-line: attr: enable incomplete-line whitespace error for this project diff: highlight and error out on incomplete lines apply: check and fix incomplete lines whitespace: allocate a few more bits and define WS_INCOMPLETE_LINE apply: revamp the parsing of incomplete lines diff: update the way rewrite diff handles incomplete lines diff: call emit_callback ecbdata everywhere diff: refactor output of incomplete line diff: keep track of the type of the last line seen diff: correct suppress_blank_empty hack diff: emit_line_ws_markup() if/else style fix whitespace: correct bit assignment comments
2025-11-30diff-index: don't queue unchanged filepairs with diff_change()René Scharfe1-0/+5
diff_cache() queues unchanged filepairs if the flag find_copies_harder is set, and uses diff_change() for that. This function allocates a filespec for each side, does a few other things that are unnecessary for unchanged filepairs and always sets the diff_flag has_changes, which is simply misleading in this case. Add a new streamlined function for queuing unchanged filepairs and use it in show_modified(), which is called by diff_cache() via oneway_diff() and do_oneway_diff(). It allocates only a single filespec for each filepair and uses it twice with reference counting. This has a measurable effect if there are a lot of them, like in the Linux repo: Benchmark 1: ./git_v2.52.0 -C ../linux diff --cached --find-copies-harder Time (mean ± σ): 31.8 ms ± 0.2 ms [User: 24.2 ms, System: 6.3 ms] Range (min … max): 31.5 ms … 32.3 ms 85 runs Benchmark 2: ./git -C ../linux diff --cached --find-copies-harder Time (mean ± σ): 23.9 ms ± 0.2 ms [User: 18.1 ms, System: 4.6 ms] Range (min … max): 23.5 ms … 24.4 ms 111 runs Summary ./git -C ../linux diff --cached --find-copies-harder ran 1.33 ± 0.01 times faster than ./git_v2.52.0 -C ../linux diff --cached --find-copies-harder Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12whitespace: allocate a few more bits and define WS_INCOMPLETE_LINEJunio C Hamano1-3/+3
Reserve a few more bits in the diff flags word to be used for future whitespace rules. Add WS_INCOMPLETE_LINE without implementing the behaviour (yet). Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-12whitespace: correct bit assignment commentsJunio C Hamano1-3/+3
A comment in diff.c claimed that bits up to 12th (counting from 0th) are whitespace rules, and 13th thru 15th are for new/old/context, but it turns out it was miscounting. Correct them, and clarify where the whitespace rule bits come from in the comment. Extend bit assignment comments to cover bits used for color-moved, which weren't described. Also update the way these bit constants are defined to use (1 << N) notation, instead of octal constants, as it tends to make it easier to notice a breakage like this. Sprinkle a few blank lines between logically distinct groups of CPP macro definitions to make them easier to read. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-24diff: replace diff_options.dry_run flag with NULL fileJeff King1-2/+0
We introduced a dry_run flag to diff_options in b55e6d36eb (diff: ensure consistent diff behavior with ignore options, 2025-08-08), with the idea that the lower-level diff code could skip output when it is set. As we saw with the bugs fixed by 3ed5d8bd73 (diff: stop output garbled message in dry run mode, 2025-10-20), it is easy to miss spots. In the end, we located all of them by checking where diff_options.file is used. That suggests another possible approach: we can replace the dry_run boolean with a NULL pointer for "file", as we know that using "file" in dry_run mode would always be an error. This turns any missed spots from producing extra output[1] into a segfault. Which is less forgiving, but that is the point: this is indicative of a programming error, and complaining loudly and immediately is good. [1] We protect ourselves against garbled output as a separate step, courtesy of 623f7af284 (diff: restore redirection to /dev/null for diff_from_contents, 2025-10-17). So in that sense this patch can only introduce user-visible errors (since any "bugs" were going to /dev/null before), but the idea is to catch them rather than quietly send garbage to /dev/null. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-29Merge branch 'tc/last-modified-recursive-fix'Junio C Hamano1-0/+7
"git last-modified" operating in non-recursive mode used to trigger a BUG(), which has been corrected. * tc/last-modified-recursive-fix: last-modified: fix bug when some paths remain unhandled
2025-09-29Merge branch 'jk/color-variable-fixes'Junio C Hamano1-2/+3
Some places in the code confused a variable that is *not* a boolean to enable color but is an enum that records what the user requested to do about color. A couple of bugs of this sort have been fixed, while the code has been cleaned up to prevent similar bugs in the future. * jk/color-variable-fixes: config: store want_color() result in a separate bool add-interactive: retain colorbool values longer color: return bool from want_color() color: use git_colorbool enum type to store colorbools pretty: use format_commit_context.auto_color as colorbool diff: stop passing ecbdata->use_color as boolean diff: pass o->use_color directly to fill_metainfo() diff: don't use diff_options.use_color as a strict bool diff: simplify color_moved check when flushing grep: don't treat grep_opt.color as a strict bool color: return enum from git_config_colorbool() color: use GIT_COLOR_* instead of numeric constants
2025-09-18last-modified: fix bug when some paths remain unhandledToon Claes1-0/+7
The recently introduced new subcommand git-last-modified(1) runs into an error in some scenarios. It then would exit with the message: BUG: paths remaining beyond boundary in last-modified This seems to happens for example when criss-cross merges are involved. In that scenario, the function diff_tree_combined() gets called. The function diff_tree_combined() copies the `struct diff_options` from the input `struct rev_info` to override some flags. One flag is `recursive`, which is always set to 1. This has been the case since the inception of this function in af3feefa1d (diff-tree -c: show a merge commit a bit more sensibly., 2006-01-24). This behavior is incompatible with git-last-modified(1), when called non-recursive (which is the default). The last-modified machinery uses a hashmap for all the paths it wants to get the last-modified commit for. Through log_tree_commit() the callback mark_path() is called. The diff machinery uses diff_tree_combined() internally, and due to it's recursive behavior the callback receives entries inside subtrees, but not the subtree entries themselves. So a directory is never expelled from the hashmap, and the BUG() statement gets hit. Because there are many callers calling into diff_tree_combined(), both directly and indirectly, we cannot simply change it's behavior. Instead, add a flag `no_recursive_diff_tree_combined` which supresses the behavior of diff_tree_combined() to override `recursive` and set this flag in builtin/last-modified.c. Signed-off-by: Toon Claes <toon@iotcl.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-16color: use git_colorbool enum type to store colorboolsJeff King1-2/+3
We traditionally used "int" to store and pass around the values defined by "enum git_colorbool" (which were originally just #define macros). Using an int doesn't produce incorrect results, but using the actual enum makes the intent of the code more clear. It would be nice if the compiler could catch cases where we used the enum and an int interchangeably, since it's very easy to accidentally check the boolean true/false of a colorbool like: if (branch_use_color) This is wrong because GIT_COLOR_UNKNOWN and GIT_COLOR_AUTO evaluate to true in C, even though we may ultimately decide not to use color. But C is pretty happy to convert between ints and enums (even with various -Wenum-* warnings). So this sadly doesn't protect us from such mistakes, but it hopefully does make the code easier to read. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-08-25Merge branch 'tc/diff-tree-max-depth'Junio C Hamano1-0/+8
"git diff-tree" learned "--max-depth" option. * tc/diff-tree-max-depth: diff: teach tree-diff a max-depth parameter within_depth: fix return for empty path combine-diff: zero memory used for callback filepairs
2025-08-08diff: ensure consistent diff behavior with ignore optionsLidong Yan1-0/+2
In git-diff, options like `-w` and `-I<regex>`, two files are considered equivalent under the specified "ignore" rules, even when they are not bit-for-bit identical. For options like `--raw`, `--name-status`, and `--name-only`, git-diff deliberately compares only the SHA values to determine whether two files are equivalent, for performance reasons. As a result, a file shown in `git diff --name-status` may not appear in `git diff --patch`. To quickly determine whether two files are equivalent, add a helper function diff_flush_patch_quietly() in diff.c. Add `.dry_run` field in `struct diff_options`. When `.dry_run` is true, builtin_diff() returns immediately upon finding any change. Call diff_flush_patch_quietly() to determine if we should flush `--raw`, `--name-only` or `--name-status` output. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Lidong Yan <yldhome2d2@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-08-07diff: teach tree-diff a max-depth parameterJeff King1-0/+8
When you are doing a tree-diff, there are basically two options: do not recurse into subtrees at all, or recurse indefinitely. While most callers would want to always recurse and see full pathnames, some may want the efficiency of looking only at a particular level of the tree. This is currently easy to do for the top-level (just turn off recursion), but you cannot say "show me what changed in subdir/, but do not recurse". This patch adds a max-depth parameter which is measured from the closest pathspec match, so that you can do: git log --raw --max-depth=1 -- a/b/c and see the raw output for a/b/c/, but not those of a/b/c/d/ (instead of the raw output you would see for a/b/c/d). Co-authored-by: Toon Claes <toon@iotcl.com> Signed-off-by: Toon Claes <toon@iotcl.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-15Merge branch 'ps/object-wo-the-repository'Junio C Hamano1-1/+1
The object layer has been updated to take an explicit repository instance as a parameter in more code paths. * ps/object-wo-the-repository: hash: stop depending on `the_repository` in `null_oid()` hash: fix "-Wsign-compare" warnings object-file: split out logic regarding hash algorithms delta-islands: stop depending on `the_repository` object-file-convert: stop depending on `the_repository` pack-bitmap-write: stop depending on `the_repository` pack-revindex: stop depending on `the_repository` pack-check: stop depending on `the_repository` environment: move access to "core.bigFileThreshold" into repo settings pack-write: stop depending on `the_repository` and `the_hash_algo` object: stop depending on `the_repository` csum-file: stop depending on `the_repository`
2025-03-26Merge branch 'jt/diff-pairs'Junio C Hamano1-0/+33
A post-processing filter for "diff --raw" output has been introduced. * jt/diff-pairs: builtin/diff-pairs: allow explicit diff queue flush builtin: introduce diff-pairs command diff: add option to skip resolving diff statuses diff: return diff_filepair from diff queue helpers
2025-03-10hash: stop depending on `the_repository` in `null_oid()`Patrick Steinhardt1-1/+1
The `null_oid()` function returns the object ID that only consists of zeroes. Naturally, this ID also depends on the hash algorithm used, as the number of zeroes is different between SHA1 and SHA256. Consequently, the function returns the hash-algorithm-specific null object ID. This is currently done by depending on `the_hash_algo`, which implicitly makes us depend on `the_repository`. Refactor the function to instead pass in the hash algorithm for which we want to retrieve the null object ID. Adapt callsites accordingly by passing in `the_repository`, thus bubbling up the dependency on that global variable by one layer. There are a couple of trivial exceptions for subsystems that already got rid of `the_repository`. These subsystems instead use the repository that is available via the calling context: - "builtin/grep.c" - "grep.c" - "refs/debug.c" There are also two non-trivial exceptions: - "diff-no-index.c": Here we know that we may not have a repository initialized at all, so we cannot rely on `the_repository`. Instead, we adapt `diff_no_index()` to get a `struct git_hash_algo` as parameter. The only caller is located in "builtin/diff.c", where we know to call `repo_set_hash_algo()` in case we're running outside of a Git repository. Consequently, it is fine to continue passing `the_repository->hash_algo` even in this case. - "builtin/ls-files.c": There is an in-flight patch series that drops `USE_THE_REPOSITORY_VARIABLE` in this file, which causes a semantic conflict because we use `null_oid()` in `show_submodule()`. The value is passed to `repo_submodule_init()`, which may use the object ID to resolve a tree-ish in the superproject from which we want to read the submodule config. As such, the object ID should refer to an object in the superproject, and consequently we need to use its hash algorithm. This means that we could in theory just not bother about this edge case at all and just use `the_repository` in "diff-no-index.c". But doing so would feel misdesigned. Remove the `USE_THE_REPOSITORY_VARIABLE` preprocessor define in "hash.c". Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03diff.h: *.txt -> *.adoc fixesTodd Zullinger1-1/+1
Signed-off-by: Todd Zullinger <tmz@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03diff: add option to skip resolving diff statusesJustin Tobler1-0/+8
By default, `diffcore_std()` resolves the statuses for queued diff file pairs by calling `diff_resolve_rename_copy()`. If status information is already manually set, invoking `diffcore_std()` may change the status value. Introduce the `skip_resolving_statuses` diff option that prevents `diffcore_std()` from resolving file pair statuses when enabled. Signed-off-by: Justin Tobler <jltobler@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03diff: return diff_filepair from diff queue helpersJustin Tobler1-0/+25
The `diff_addremove()` and `diff_change()` functions set up and queue diffs, but do not return the `diff_filepair` added to the queue. In a subsequent commit, modifications to `diff_filepair` need to occur in certain cases after being queued. Since the existing `diff_addremove()` and `diff_change()` are also used for callbacks in `diff_options` as types `add_remove_fn_t` and `change_fn_t`, modifying the existing function signatures requires further changes. The diff options for pruning use `file_add_remove()` and `file_change()` where file pairs do not even get queued. Thus, separate functions are implemented instead. Split out the queuing operations into `diff_queue_addremove()` and `diff_queue_change()` which also return a handle to the queued `diff_filepair`. Both `diff_addremove()` and `diff_change()` are reimplemented as thin wrappers around the new functions. Signed-off-by: Justin Tobler <jltobler@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-10Merge branch 'ps/hash-cleanup'Junio C Hamano1-1/+1
Further code clean-up on the use of hash functions. Now the context object knows what hash function it is working with. * ps/hash-cleanup: global: adapt callers to use generic hash context helpers hash: provide generic wrappers to update hash contexts hash: stop typedeffing the hash context hash: convert hashing context to a structure
2025-01-31hash: stop typedeffing the hash contextPatrick Steinhardt1-1/+1
We generally avoid using `typedef` in the Git codebase. One exception though is the `git_hash_ctx`, likely because it used to be a union rather than a struct until the preceding commit refactored it. But now that it is a normal `struct` there isn't really a need for a typedef anymore. Drop the typedef and adapt all callers accordingly. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-09tree-diff: drop list-tail argument to diff_tree_paths()Jeff King1-1/+1
The internals of the path diffing code, including ll_diff_tree_paths(), all take an extra combine_diff_path parameter which they use as the tail of a list of results, appending any new entries to it. The public-facing diff_tree_paths() takes the same argument, but it just makes the callers more awkward. They always start with a clean list, and have to set up a fake head struct to pass in. Let's keep the public API clean by always returning a new list. That keeps the fake struct as an implementation detail of tree-diff.c. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-09combine-diff: drop public declaration of combine_diff_path_size()Jeff King1-3/+0
We want callers to use combine_diff_path_new() to allocate structs, rather than using combine_diff_path_size() and xmalloc(). That gives us more consistency over the initialization of the fields. Now that the final external user of combine_diff_path_size() is gone, we can stop declaring it publicly. And since our constructor is the only caller, we can just inline it there. Breaking the size computation into two parts also lets us reuse the intermediate multiplication result of the parent length, since we need to know it to perform our memset(). The result is a little easier to read. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-09diff: add a comment about combine_diff_path.parent.pathJeff King1-0/+6
We only fill in the per-parent "path" field when it differs from what's in combine_diff_path.path (and even then only when the option is appropriate). Let's document that. Suggested-by: Wink Saville <wink@saville.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-09combine-diff: use pointer for parent pathsJeff King1-1/+1
Commit d76ce4f734 (log,diff-tree: add --combined-all-paths option, 2019-02-07) added a "path" field to each combine_diff_parent struct. It's defined as a strbuf, but this is overkill. We never manipulate the buffer beyond inserting a single string into it. And in fact there's a small bug: we zero the parent structs, including the path strbufs. For the 0th parent, we strbuf_init() the strbuf before adding to it. But for subsequent parents, we never do the init. This is technically violating the strbuf API, though the code there is resilient enough to handle this zero'd state. This patch switches us to just store an allocated string pointer. Zeroing it is enough to properly initialize it there (modulo the usual assumption we make that a NULL pointer is all-zeroes). And as a bonus, we can just check for a non-NULL value to see if it is present, rather than repeating the combined_all_paths logic at each site. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-09combine-diff: add combine_diff_path_new()Jeff King1-0/+5
The combine_diff_path struct has variable size, since it embeds both the memory allocation for the path field as well as a variable-sized parent array. This makes allocating one a bit tricky. We have a helper to compute the required size, but it's up to individual sites to actually initialize all of the fields. Let's provide a constructor function to make that a little nicer. Besides being shorter, it also hides away tricky bits like the computation of the "path" pointer (which is right after the "parent" flex array). As a bonus, using the same constructor everywhere means that we'll consistently initialize all parts of the struct. A few code paths left the parent array unitialized. This didn't cause any bugs, but we'll be able to simplify some code in the next few patches knowing that the parent fields have all been zero'd. This also gets rid of some questionable uses of "int" to store buffer lengths. Though we do use them to allocate, I don't think there are any integer overflow vulnerabilities here (the allocation helper promotes them to size_t and checks arithmetic for overflow, and the actual memcpy of the bytes is done using the possibly-truncated "int" value). Sadly we can't use the FLEX_* macros to simplify the allocation here, because there are two variable-sized parts to the struct (and those macros only handle one). Nor can we get stop publicly declaring combine_diff_path_size(). This patch does not touch the code in path_appendnew() at all, which is not ready to be moved to our new constructor for a few reasons: - path_appendnew() has a memory-reuse optimization where it tries to reuse combine_diff_path structs rather than freeing and reallocating. - path_appendnew() does not create the struct from a single path string, but rather allocates and copies into the buffer from multiple sources. These can be addressed by some refactoring, but let's leave it as-is for now. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-06diff.h: fix index used to loop through unsigned integerPatrick Steinhardt1-2/+1
The `struct diff_flags` structure is essentially an array of flags, all of which have the same type. We can thus use `sizeof()` to iterate through all of the flags, which we do in `diff_flags_or()`. But while the statement returns an unsigned integer, we used a signed integer to iterate through the flags, which generates a warning. Fix this by using `size_t` for the index instead. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-10-10Merge branch 'jk/output-prefix-cleanup'Junio C Hamano1-2/+1
Code clean-up. * jk/output-prefix-cleanup: diff: store graph prefix buf in git_graph struct diff: return line_prefix directly when possible diff: return const char from output_prefix callback diff: drop line_prefix_length field line-log: use diff_line_prefix() instead of custom helper
2024-10-03diff: return const char from output_prefix callbackJeff King1-1/+1
The diff_options structure has an output_prefix callback for returning a prefix string, but it does so by returning a pointer to a strbuf. This makes the interface awkward. There's no reason the callback should need to use a strbuf, and it creates questions about whether the ownership of the resulting buffer should be transferred to the caller (it should not be, but a recent attempt to clean up this code led to a double-free in some cases). The one advantage we get is that the strbuf contains a ptr/len pair, so we could in theory have a prefix with embedded NULs. But we can observe that none of the existing callbacks would ever produce such a NUL (they are usually just indentation or graph symbols, and even the "--line-prefix" option takes a NUL-terminated string). And anyway, only one caller (the one in log_tree_diff_flush) actually looks at the strbuf length. In every other case we use a helper function which discards the length and just returns the NUL-terminated string. So let's just have the callback return a "const char *" pointer. It's up to the callbacks themselves if they want to use a strbuf under the hood. And now the caller in log_tree_diff_flush() can just use the helper function along with everybody else. That lets us even simplify out the function pointer check, since the helper returns an empty string (technically this does mean we'll sometimes issue an empty fputs() call, but I don't think this code path is hot enough to care about that). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-10-03diff: drop line_prefix_length fieldJeff King1-1/+0
The diff_options structure holds a line_prefix string and an associated length. But the length is always just the strlen() of the NUL-terminated string. Let's simplify the code by just storing the string pointer and assuming it is NUL-terminated when we use it. This will cause us to compute the string length in a few extra spots, but I don't think any of these are particularly hot code paths. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-10-02Merge branch 'ps/leakfixes-part-7'Junio C Hamano1-1/+1
More leak-fixes. * ps/leakfixes-part-7: (23 commits) diffcore-break: fix leaking filespecs when merging broken pairs revision: fix leaking parents when simplifying commits builtin/maintenance: fix leak in `get_schedule_cmd()` builtin/maintenance: fix leaking config string promisor-remote: fix leaking partial clone filter grep: fix leaking grep pattern submodule: fix leaking submodule ODB paths trace2: destroy context stored in thread-local storage builtin/difftool: plug several trivial memory leaks builtin/repack: fix leaking configuration diffcore-order: fix leaking buffer when parsing orderfiles parse-options: free previous value of `OPTION_FILENAME` diff: fix leaking orderfile option builtin/pull: fix leaking "ff" option dir: fix off by one errors for ignored and untracked entries builtin/submodule--helper: fix leaking remote ref on errors t/helper: fix leaking subrepo in nested submodule config helper builtin/submodule--helper: fix leaking error buffer builtin/submodule--helper: clear child process when not running it submodule: fix leaking update strategy ...
2024-09-27diff: fix leaking orderfile optionPatrick Steinhardt1-1/+1
The `orderfile` diff option is being assigned via `OPT_FILENAME()`, which assigns an allocated string to the variable. We never free it though, causing a memory leak. Change the type of the string to `char *` and free it to plug the leak. This also requires us to use `xstrdup()` to assign the global config to it in case it is set. This leak is being hit in t7621, but plugging it alone does not make the test suite pass. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-16Merge branch 'jc/range-diff-lazy-setup'Junio C Hamano1-1/+1
Code clean-up. * jc/range-diff-lazy-setup: remerge-diff: clean up temporary objdir at a central place remerge-diff: lazily prepare temporary objdir on demand
2024-08-09remerge-diff: clean up temporary objdir at a central placeJunio C Hamano1-1/+1
After running a diff between two things, or a series of diffs while walking the history, the diff computation is concluded by a call to diff_result_code() to extract the exit status of the diff machinery. The function can work on "struct diffopt", but all the callers historically and currently pass "struct diffopt" that is embedded in the "struct rev_info" that is used to hold the remerge_diff bit and the remerge_objdir variable that points at the temporary object directory in use. Redefine diff_result_code() to take the whole "struct rev_info" to give it an access to these members related to remerge-diff, so that it can get rid of the temporary object directory for any and all callers that used the feature. We can lose the equivalent code to do so from the code paths for individual commands, diff-tree, diff, and log. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14hash-ll: merge with "hash.h"Patrick Steinhardt1-1/+1
The "hash-ll.h" header was introduced via d1cbe1e6d8 (hash-ll.h: split out of hash.h to remove dependency on repository.h, 2023-04-22) to make explicit the split between hash-related functions that rely on the global `the_repository`, and those that don't. This split is no longer necessary now that we we have removed the reliance on `the_repository`. Merge "hash-ll.h" back into "hash.h". This causes some code units to not include "repository.h" anymore, which requires us to add some forward declarations. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-09-29diff --stat: set the width defaults in a helper functionDragan Simic1-0/+1
Extract the commonly used initialization of the --stat-width=<width>, --stat-name-width=<width> and --stat-graph-with=<width> parameters to their internal default values into a helper function, to avoid repeating the same initialization code in a few places. Add a couple of tests to additionally cover existing configuration options diff.statNameWidth=<width> and diff.statGraphWidth=<width> when used by git-merge to generate --stat outputs. This closes the gap that existed previously in the --stat tests, and reduces the chances for having any regressions introduced by this commit. While there, perform a small bunch of minor wording tweaks in the improved unit test, to improve its test-level consistency a bit. Signed-off-by: Dragan Simic <dsimic@manjaro.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-21diff: drop useless "status" parameter from diff_result_code()Jeff King1-1/+1
Many programs use diff_result_code() to get a user-visible program exit code from a diff result (e.g., checking opts.found_changes if --exit-code was requested). This function also takes a "status" parameter, which seems at first glance that it could be used to propagate an error encountered when computing the diff. But it doesn't work that way: - negative values are passed through as-is, but are not appropriate as program exit codes - when --exit-code or --check is in effect, we _ignore_ the passed-in status completely. So a failed diff which did not have a chance to set opts.found_changes would erroneously report "success, no changes" instead of propagating the error. After recent cleanups, neither of these bugs is possible to trigger, as every caller just passes in "0". So rather than fixing them, we can simply drop the useless parameter instead. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-21diff: drop useless return from run_diff_{files,index} functionsJeff King1-2/+2
Neither of these functions ever returns a value other than zero. Instead, they expect unrecoverable errors to exit immediately, and things like "--exit-code" are stored inside the diff_options struct to be handled later via diff_result_code(). Some callers do check the return values, but many don't bother. Let's drop the useless return values, which are misleading callers about how the functions work. This could be seen as a step in the wrong direction, as we might want to eventually "lib-ify" these to more cleanly return errors up the stack, in which case we'd have to add the return values back in. But there are some benefits to doing this now: 1. In the current code, somebody could accidentally add a "return -1" to one of the functions, which would be erroneously ignored by many callers. By removing the return code, the compiler can notice the mismatch and force the developer to decide what to do. Obviously the other option here is that we could start consistently checking the error code in every caller. But it would be dead code, and we wouldn't get any compile-time help in catching new cases. 2. It communicates the situation to callers, who may want to choose a different function. These functions are really thin wrappers for doing git-diff-files and git-diff-index within the process. But callers who care about recovering from an error here are probably better off using the underlying library functions, many of which do return errors. If somebody eventually wants to teach these functions to propagate errors, they'll have to switch back to returning a value, effectively reverting this patch. But at least then they will be starting with a level playing field: they know that they will need to inspect each caller to see how it should handle the error. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-06Merge branch 'gc/config-context'Junio C Hamano1-2/+5
Reduce reliance on a global state in the config reading API. * gc/config-context: config: pass source to config_parser_event_fn_t config: add kvi.path, use it to evaluate includes config.c: remove config_reader from configsets config: pass kvi to die_bad_number() trace2: plumb config kvi config.c: pass ctx with CLI config config: pass ctx with config files config.c: pass ctx in configsets config: add ctx arg to config_fn_t urlmatch.h: use config_fn_t type config: inline git_color_default_config
2023-06-28config: add ctx arg to config_fn_tGlen Choo1-2/+5
Add a new "const struct config_context *ctx" arg to config_fn_t to hold additional information about the config iteration operation. config_context has a "struct key_value_info kvi" member that holds metadata about the config source being read (e.g. what kind of config source it is, the filename, etc). In this series, we're only interested in .kvi, so we could have just used "struct key_value_info" as an arg, but config_context makes it possible to add/adjust members in the future without changing the config_fn_t signature. We could also consider other ways of organizing the args (e.g. moving the config name and value into config_context or key_value_info), but in my experiments, the incremental benefit doesn't justify the added complexity (e.g. a config_fn_t will sometimes invoke another config_fn_t but with a different config value). In subsequent commits, the .kvi member will replace the global "struct config_reader" in config.c, making config iteration a global-free operation. It requires much more work for the machinery to provide meaningful values of .kvi, so for now, merely change the signature and call sites, pass NULL as a placeholder value, and don't rely on the arg in any meaningful way. Most of the changes are performed by contrib/coccinelle/config_fn_ctx.pending.cocci, which, for every config_fn_t: - Modifies the signature to accept "const struct config_context *ctx" - Passes "ctx" to any inner config_fn_t, if needed - Adds UNUSED attributes to "ctx", if needed Most config_fn_t instances are easily identified by seeing if they are called by the various config functions. Most of the remaining ones are manually named in the .cocci patch. Manual cleanups are still needed, but the majority of it is trivial; it's either adjusting config_fn_t that the .cocci patch didn't catch, or adding forward declarations of "struct config_context ctx" to make the signatures make sense. The non-trivial changes are in cases where we are invoking a config_fn_t outside of config machinery, and we now need to decide what value of "ctx" to pass. These cases are: - trace2/tr2_cfg.c:tr2_cfg_set_fl() This is indirectly called by git_config_set() so that the trace2 machinery can notice the new config values and update its settings using the tr2 config parsing function, i.e. tr2_cfg_cb(). - builtin/checkout.c:checkout_main() This calls git_xmerge_config() as a shorthand for parsing a CLI arg. This might be worth refactoring away in the future, since git_xmerge_config() can call git_default_config(), which can do much more than just parsing. Handle them by creating a KVI_INIT macro that initializes "struct key_value_info" to a reasonable default, and use that to construct the "ctx" arg. Signed-off-by: Glen Choo <chooglen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21diff.h: remove unnecessary include of oidset.hElijah Newren1-1/+3
This also made it clear that several .c files depended upon various things that oidset included, but had omitted the direct #include for those headers. Add those now. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21diff.h: move declaration for global in diff.c from cache.hElijah Newren1-0/+2
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-20Merge branch 'jk/log-follow-with-non-literal-pathspec'Junio C Hamano1-0/+7
"git [-c log.follow=true] log [--follow] ':(glob)f**'" used to barf. * jk/log-follow-with-non-literal-pathspec: diff: detect pathspec magic not supported by --follow diff: factor out --follow pathspec check pathspec: factor out magic-to-name function
2023-06-03diff: factor out --follow pathspec checkJeff King1-0/+7
In --follow mode, we require exactly one pathspec. We check this condition in two places: - in diff_setup_done(), we complain if --follow is used with an inapropriate pathspec - in git-log's revision "tweak" function, we enable log.follow only if the pathspec allows it The duplication isn't a big deal right now, since the logic is so simple. But in preparation for it becoming more complex, let's pull it into a shared function. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>