diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/manual.cli | 52 |
1 files changed, 31 insertions, 21 deletions
diff --git a/doc/manual.cli b/doc/manual.cli index 6dd7002..f10e54f 100644 --- a/doc/manual.cli +++ b/doc/manual.cli @@ -343,8 +343,9 @@ increment \i{patch} when making binary-compatible changes, \i{minor} when making source-compatible changes, and \i{major} when making breaking changes. While the binary compatibility must be set in stone, the source compatibility rules can sometimes be bent. For example, you may decide to make a breaking -change in a rarely used interface as part of a minor release. Note also that -in the context of C++ deciding whether a change is binary-compatible is a +change in a rarely used interface as part of a minor release (though this is +probably still a bad idea if your library is widely depended upon). Note also +that in the context of C++ deciding whether a change is binary-compatible is a non-trivial task. There are resources that list the rules but no automated tooling yet. If unsure, increment \i{minor}. @@ -379,10 +380,11 @@ worse, from the final release. One way to remedy this is to increment the pre-release number before each publication. However, unless automated, this will be burdensome and error-prone. Also, there is a real possibility of running out of version numbers if, for example, we do continuous integration -by testing (and therefore publishing) each commit. +by publishing and testing each commit. To address this, the standard versioning scheme supports \i{snapshot -pre-releases} with the \i{prerel} component having the following form: +pre-releases} with the \i{prerel} component having the following extended +form: \ (a|b).<num>.<snapsn>[.<snapid>] @@ -391,13 +393,13 @@ pre-releases} with the \i{prerel} component having the following form: For example: \ -1.2.3-a.1.1422564055.340c0a26a5efed1f +1.2.3-a.1.20180319215815.26efe301f4a7 \ In essence, a snapshot pre-release is after the previous final release but before the next (\c{a.1} and, perhaps, \c{a.2} in the above example) and is uniquely identified by the snapshot sequence number (\i{snapsn}) and -snapshot id (\i{snapid}). +optional snapshot id (\i{snapid}). The \i{num} component has the same semantics as in the final pre-releases except that it can be \c{0}. The \i{snapsn} component should be either the @@ -408,12 +410,12 @@ uniquely identifies the snapshot. It is not required for version comparison (\i{snapsn} should be sufficient) and is included for reference. It must not be longer than 16 characters. -Where do the snapshot sn and id come from? Normally from the version control -system. For example, for \c{git}, \i{snapsn} is the commit date (as UNIX -timestamp in the UTC timezone) and \i{snapid} is a 16-character abbreviated -commit id. As discussed below, the \c{build2} \c{version} module extracts -and manages all this information automatically (the use of \c{git} commit -dates is not without limitations; see below for details). +Where do the snapshot number and id come from? Normally from the version +control system. For example, for \c{git}, \i{snapsn} is the commit date in the +\i{YYYYMMDDhhmmss} form and UTC timezone and \i{snapid} is a 12-character +abbreviated commit id. As discussed below, the \c{build2} \c{version} module +extracts and manages all this information automatically (but the use of +\c{git} commit dates is not without limitations; see below for details). The special '\c{z}' \i{snapsn} value identifies the \i{latest} or \i{uncommitted} snapshot. It is chosen to be greater than any other possible @@ -448,7 +450,7 @@ When it comes to the version control systems, the recommended workflow is as follows: The change to the final version should be the last commit in the (pre-)release. It is also a good idea to tag this commit with the project version. A commit immediately after that should change the version to a -snapshot essentially \"opening\" the repository for development. +snapshot, \"opening\" the repository for development. The project version without the snapshot part can be represented as a 64-bit decimal value comparable as integers (for example, in preprocessor @@ -517,6 +519,7 @@ as the following build system variables (which can be used in the buildfiles): [uint64] version.snapshot_sn # 1234567 [string] version.snapshot_id # deadbeef [string] version.snapshot_string # 1234567.deadbeef +[bool] version.snapshot_committed # true [uint64] version.revision # 3 \ @@ -537,11 +540,17 @@ control system used by the project. Currently only \c{git} is supported with the following semantics. If the project's source directory (\c{src_root}) is clean (that is, it does -not have any changed or untracked files), then the \c{HEAD} commit date and -id are used as the snapshot sn and id, respectively. Otherwise, the snapshot -is left in the \c{.z} form (which signals the latest/uncommitted -snapshot). While we can work with such a \c{.z} snapshot locally, preparing a -distribution of such an uncommitted snapshot is an error. +not have any changed or untracked files), then the \c{HEAD} commit date and id +are used as the snapshot number and id, respectively. + +Otherwise (that is, the project is between commits), the \c{HEAD} commit date +is incremented by one second and is used as the snapshot number with no id. +While we can work with such uncommitted snapshots locally, we should not +distribute or publish them since they are indistinguishable from each other. + +Finally, if the project does not have \c{HEAD} (that is, the project has +no commits yet), the special \c{19700101000000} (UNIX epoch) commit date is +used. The use of \c{git} commit dates for snapshot ordering has its limitations: they have one second resolution which means it is possible to create two @@ -555,9 +564,10 @@ option, nevertheless). When we prepare a distribution of a snapshot, the \c{version} module automatically adjusts the package name to include the snapshot information as -well as patches the manifest file in the distribution with the snapshot sn and -id (that is, replacing \c{.z} in the version value with the actual snapshot -information). The result is a package that is specific to this commit. +well as patches the manifest file in the distribution with the snapshot number +and id (that is, replacing \c{.z} in the version value with the actual +snapshot information). The result is a package that is specific to this +commit. Besides extracting the version information and making it available as individual components, the \c{version} module also provide rules for |