diff options
Diffstat (limited to 'third_party/git/Documentation/revisions.txt')
| -rw-r--r-- | third_party/git/Documentation/revisions.txt | 380 |
1 files changed, 0 insertions, 380 deletions
diff --git a/third_party/git/Documentation/revisions.txt b/third_party/git/Documentation/revisions.txt deleted file mode 100644 index d9169c062eb1..000000000000 --- a/third_party/git/Documentation/revisions.txt +++ /dev/null @@ -1,380 +0,0 @@ -SPECIFYING REVISIONS --------------------- - -A revision parameter '<rev>' typically, but not necessarily, names a -commit object. It uses what is called an 'extended SHA-1' -syntax. Here are various ways to spell object names. The -ones listed near the end of this list name trees and -blobs contained in a commit. - -NOTE: This document shows the "raw" syntax as seen by git. The shell -and other UIs might require additional quoting to protect special -characters and to avoid word splitting. - -'<sha1>', e.g. 'dae86e1950b1277e545cee180551750029cfe735', 'dae86e':: - The full SHA-1 object name (40-byte hexadecimal string), or - a leading substring that is unique within the repository. - E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both - name the same commit object if there is no other object in - your repository whose object name starts with dae86e. - -'<describeOutput>', e.g. 'v1.7.4.2-679-g3bee7fb':: - Output from `git describe`; i.e. a closest tag, optionally - followed by a dash and a number of commits, followed by a dash, a - 'g', and an abbreviated object name. - -'<refname>', e.g. 'master', 'heads/master', 'refs/heads/master':: - A symbolic ref name. E.g. 'master' typically means the commit - object referenced by 'refs/heads/master'. If you - happen to have both 'heads/master' and 'tags/master', you can - explicitly say 'heads/master' to tell Git which one you mean. - When ambiguous, a '<refname>' is disambiguated by taking the - first match in the following rules: - - . If '$GIT_DIR/<refname>' exists, that is what you mean (this is usually - useful only for `HEAD`, `FETCH_HEAD`, `ORIG_HEAD`, `MERGE_HEAD` - and `CHERRY_PICK_HEAD`); - - . otherwise, 'refs/<refname>' if it exists; - - . otherwise, 'refs/tags/<refname>' if it exists; - - . otherwise, 'refs/heads/<refname>' if it exists; - - . otherwise, 'refs/remotes/<refname>' if it exists; - - . otherwise, 'refs/remotes/<refname>/HEAD' if it exists. -+ -`HEAD` names the commit on which you based the changes in the working tree. -`FETCH_HEAD` records the branch which you fetched from a remote repository -with your last `git fetch` invocation. -`ORIG_HEAD` is created by commands that move your `HEAD` in a drastic -way, to record the position of the `HEAD` before their operation, so that -you can easily change the tip of the branch back to the state before you ran -them. -`MERGE_HEAD` records the commit(s) which you are merging into your branch -when you run `git merge`. -`CHERRY_PICK_HEAD` records the commit which you are cherry-picking -when you run `git cherry-pick`. -+ -Note that any of the 'refs/*' cases above may come either from -the `$GIT_DIR/refs` directory or from the `$GIT_DIR/packed-refs` file. -While the ref name encoding is unspecified, UTF-8 is preferred as -some output processing may assume ref names in UTF-8. - -'@':: - '@' alone is a shortcut for `HEAD`. - -'[<refname>]@{<date>}', e.g. 'master@\{yesterday\}', 'HEAD@{5 minutes ago}':: - A ref followed by the suffix '@' with a date specification - enclosed in a brace - pair (e.g. '\{yesterday\}', '{1 month 2 weeks 3 days 1 hour 1 - second ago}' or '{1979-02-26 18:30:00}') specifies the value - of the ref at a prior point in time. This suffix may only be - used immediately following a ref name and the ref must have an - existing log ('$GIT_DIR/logs/<ref>'). Note that this looks up the state - of your *local* ref at a given time; e.g., what was in your local - 'master' branch last week. If you want to look at commits made during - certain times, see `--since` and `--until`. - -'<refname>@{<n>}', e.g. 'master@\{1\}':: - A ref followed by the suffix '@' with an ordinal specification - enclosed in a brace pair (e.g. '\{1\}', '\{15\}') specifies - the n-th prior value of that ref. For example 'master@\{1\}' - is the immediate prior value of 'master' while 'master@\{5\}' - is the 5th prior value of 'master'. This suffix may only be used - immediately following a ref name and the ref must have an existing - log ('$GIT_DIR/logs/<refname>'). - -'@{<n>}', e.g. '@\{1\}':: - You can use the '@' construct with an empty ref part to get at a - reflog entry of the current branch. For example, if you are on - branch 'blabla' then '@\{1\}' means the same as 'blabla@\{1\}'. - -'@{-<n>}', e.g. '@{-1}':: - The construct '@{-<n>}' means the <n>th branch/commit checked out - before the current one. - -'[<branchname>]@\{upstream\}', e.g. 'master@\{upstream\}', '@\{u\}':: - The suffix '@\{upstream\}' to a branchname (short form '<branchname>@\{u\}') - refers to the branch that the branch specified by branchname is set to build on - top of (configured with `branch.<name>.remote` and - `branch.<name>.merge`). A missing branchname defaults to the - current one. These suffixes are also accepted when spelled in uppercase, and - they mean the same thing no matter the case. - -'[<branchname>]@\{push\}', e.g. 'master@\{push\}', '@\{push\}':: - The suffix '@\{push}' reports the branch "where we would push to" if - `git push` were run while `branchname` was checked out (or the current - `HEAD` if no branchname is specified). Since our push destination is - in a remote repository, of course, we report the local tracking branch - that corresponds to that branch (i.e., something in `refs/remotes/`). -+ -Here's an example to make it more clear: -+ ------------------------------- -$ git config push.default current -$ git config remote.pushdefault myfork -$ git switch -c mybranch origin/master - -$ git rev-parse --symbolic-full-name @{upstream} -refs/remotes/origin/master - -$ git rev-parse --symbolic-full-name @{push} -refs/remotes/myfork/mybranch ------------------------------- -+ -Note in the example that we set up a triangular workflow, where we pull -from one location and push to another. In a non-triangular workflow, -'@\{push}' is the same as '@\{upstream}', and there is no need for it. -+ -This suffix is also accepted when spelled in uppercase, and means the same -thing no matter the case. - -'<rev>{caret}[<n>]', e.g. 'HEAD{caret}, v1.5.1{caret}0':: - A suffix '{caret}' to a revision parameter means the first parent of - that commit object. '{caret}<n>' means the <n>th parent (i.e. - '<rev>{caret}' - is equivalent to '<rev>{caret}1'). As a special rule, - '<rev>{caret}0' means the commit itself and is used when '<rev>' is the - object name of a tag object that refers to a commit object. - -'<rev>{tilde}[<n>]', e.g. 'HEAD{tilde}, master{tilde}3':: - A suffix '{tilde}' to a revision parameter means the first parent of - that commit object. - A suffix '{tilde}<n>' to a revision parameter means the commit - object that is the <n>th generation ancestor of the named - commit object, following only the first parents. I.e. '<rev>{tilde}3' is - equivalent to '<rev>{caret}{caret}{caret}' which is equivalent to - '<rev>{caret}1{caret}1{caret}1'. See below for an illustration of - the usage of this form. - -'<rev>{caret}{<type>}', e.g. 'v0.99.8{caret}\{commit\}':: - A suffix '{caret}' followed by an object type name enclosed in - brace pair means dereference the object at '<rev>' recursively until - an object of type '<type>' is found or the object cannot be - dereferenced anymore (in which case, barf). - For example, if '<rev>' is a commit-ish, '<rev>{caret}\{commit\}' - describes the corresponding commit object. - Similarly, if '<rev>' is a tree-ish, '<rev>{caret}\{tree\}' - describes the corresponding tree object. - '<rev>{caret}0' - is a short-hand for '<rev>{caret}\{commit\}'. -+ -'<rev>{caret}\{object\}' can be used to make sure '<rev>' names an -object that exists, without requiring '<rev>' to be a tag, and -without dereferencing '<rev>'; because a tag is already an object, -it does not have to be dereferenced even once to get to an object. -+ -'<rev>{caret}\{tag\}' can be used to ensure that '<rev>' identifies an -existing tag object. - -'<rev>{caret}{}', e.g. 'v0.99.8{caret}{}':: - A suffix '{caret}' followed by an empty brace pair - means the object could be a tag, - and dereference the tag recursively until a non-tag object is - found. - -'<rev>{caret}{/<text>}', e.g. 'HEAD^{/fix nasty bug}':: - A suffix '{caret}' to a revision parameter, followed by a brace - pair that contains a text led by a slash, - is the same as the ':/fix nasty bug' syntax below except that - it returns the youngest matching commit which is reachable from - the '<rev>' before '{caret}'. - -':/<text>', e.g. ':/fix nasty bug':: - A colon, followed by a slash, followed by a text, names - a commit whose commit message matches the specified regular expression. - This name returns the youngest matching commit which is - reachable from any ref, including HEAD. - The regular expression can match any part of the - commit message. To match messages starting with a string, one can use - e.g. ':/^foo'. The special sequence ':/!' is reserved for modifiers to what - is matched. ':/!-foo' performs a negative match, while ':/!!foo' matches a - literal '!' character, followed by 'foo'. Any other sequence beginning with - ':/!' is reserved for now. - Depending on the given text, the shell's word splitting rules might - require additional quoting. - -'<rev>:<path>', e.g. 'HEAD:README', 'master:./README':: - A suffix ':' followed by a path names the blob or tree - at the given path in the tree-ish object named by the part - before the colon. - A path starting with './' or '../' is relative to the current working directory. - The given path will be converted to be relative to the working tree's root directory. - This is most useful to address a blob or tree from a commit or tree that has - the same tree structure as the working tree. - -':[<n>:]<path>', e.g. ':0:README', ':README':: - A colon, optionally followed by a stage number (0 to 3) and a - colon, followed by a path, names a blob object in the - index at the given path. A missing stage number (and the colon - that follows it) names a stage 0 entry. During a merge, stage - 1 is the common ancestor, stage 2 is the target branch's version - (typically the current branch), and stage 3 is the version from - the branch which is being merged. - -Here is an illustration, by Jon Loeliger. Both commit nodes B -and C are parents of commit node A. Parent commits are ordered -left-to-right. - -........................................ -G H I J - \ / \ / - D E F - \ | / \ - \ | / | - \|/ | - B C - \ / - \ / - A -........................................ - - A = = A^0 - B = A^ = A^1 = A~1 - C = = A^2 - D = A^^ = A^1^1 = A~2 - E = B^2 = A^^2 - F = B^3 = A^^3 - G = A^^^ = A^1^1^1 = A~3 - H = D^2 = B^^2 = A^^^2 = A~2^2 - I = F^ = B^3^ = A^^3^ - J = F^2 = B^3^2 = A^^3^2 - - -SPECIFYING RANGES ------------------ - -History traversing commands such as `git log` operate on a set -of commits, not just a single commit. - -For these commands, -specifying a single revision, using the notation described in the -previous section, means the set of commits `reachable` from the given -commit. - -Specifying several revisions means the set of commits reachable from -any of the given commits. - -A commit's reachable set is the commit itself and the commits in -its ancestry chain. - - -Commit Exclusions -~~~~~~~~~~~~~~~~~ - -'{caret}<rev>' (caret) Notation:: - To exclude commits reachable from a commit, a prefix '{caret}' - notation is used. E.g. '{caret}r1 r2' means commits reachable - from 'r2' but exclude the ones reachable from 'r1' (i.e. 'r1' and - its ancestors). - -Dotted Range Notations -~~~~~~~~~~~~~~~~~~~~~~ - -The '..' (two-dot) Range Notation:: - The '{caret}r1 r2' set operation appears so often that there is a shorthand - for it. When you have two commits 'r1' and 'r2' (named according - to the syntax explained in SPECIFYING REVISIONS above), you can ask - for commits that are reachable from r2 excluding those that are reachable - from r1 by '{caret}r1 r2' and it can be written as 'r1..r2'. - -The '...' (three-dot) Symmetric Difference Notation:: - A similar notation 'r1\...r2' is called symmetric difference - of 'r1' and 'r2' and is defined as - 'r1 r2 --not $(git merge-base --all r1 r2)'. - It is the set of commits that are reachable from either one of - 'r1' (left side) or 'r2' (right side) but not from both. - -In these two shorthand notations, you can omit one end and let it default to HEAD. -For example, 'origin..' is a shorthand for 'origin..HEAD' and asks "What -did I do since I forked from the origin branch?" Similarly, '..origin' -is a shorthand for 'HEAD..origin' and asks "What did the origin do since -I forked from them?" Note that '..' would mean 'HEAD..HEAD' which is an -empty range that is both reachable and unreachable from HEAD. - -Other <rev>{caret} Parent Shorthand Notations -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Three other shorthands exist, particularly useful for merge commits, -for naming a set that is formed by a commit and its parent commits. - -The 'r1{caret}@' notation means all parents of 'r1'. - -The 'r1{caret}!' notation includes commit 'r1' but excludes all of its parents. -By itself, this notation denotes the single commit 'r1'. - -The '<rev>{caret}-[<n>]' notation includes '<rev>' but excludes the <n>th -parent (i.e. a shorthand for '<rev>{caret}<n>..<rev>'), with '<n>' = 1 if -not given. This is typically useful for merge commits where you -can just pass '<commit>{caret}-' to get all the commits in the branch -that was merged in merge commit '<commit>' (including '<commit>' -itself). - -While '<rev>{caret}<n>' was about specifying a single commit parent, these -three notations also consider its parents. For example you can say -'HEAD{caret}2{caret}@', however you cannot say 'HEAD{caret}@{caret}2'. - -Revision Range Summary ----------------------- - -'<rev>':: - Include commits that are reachable from <rev> (i.e. <rev> and its - ancestors). - -'{caret}<rev>':: - Exclude commits that are reachable from <rev> (i.e. <rev> and its - ancestors). - -'<rev1>..<rev2>':: - Include commits that are reachable from <rev2> but exclude - those that are reachable from <rev1>. When either <rev1> or - <rev2> is omitted, it defaults to `HEAD`. - -'<rev1>\...<rev2>':: - Include commits that are reachable from either <rev1> or - <rev2> but exclude those that are reachable from both. When - either <rev1> or <rev2> is omitted, it defaults to `HEAD`. - -'<rev>{caret}@', e.g. 'HEAD{caret}@':: - A suffix '{caret}' followed by an at sign is the same as listing - all parents of '<rev>' (meaning, include anything reachable from - its parents, but not the commit itself). - -'<rev>{caret}!', e.g. 'HEAD{caret}!':: - A suffix '{caret}' followed by an exclamation mark is the same - as giving commit '<rev>' and then all its parents prefixed with - '{caret}' to exclude them (and their ancestors). - -'<rev>{caret}-<n>', e.g. 'HEAD{caret}-, HEAD{caret}-2':: - Equivalent to '<rev>{caret}<n>..<rev>', with '<n>' = 1 if not - given. - -Here are a handful of examples using the Loeliger illustration above, -with each step in the notation's expansion and selection carefully -spelt out: - -.... - Args Expanded arguments Selected commits - D G H D - D F G H I J D F - ^G D H D - ^D B E I J F B - ^D B C E I J F B C - C I J F C - B..C = ^B C C - B...C = B ^F C G H D E B C - B^- = B^..B - = ^B^1 B E I J F B - C^@ = C^1 - = F I J F - B^@ = B^1 B^2 B^3 - = D E F D G H E F I J - C^! = C ^C^@ - = C ^C^1 - = C ^F C - B^! = B ^B^@ - = B ^B^1 ^B^2 ^B^3 - = B ^D ^E ^F B - F^! D = F ^I ^J D G H D F -.... |