Fix generator metadata

[Shushe] / README.markdown

diff --git a/README.markdown b/README.markdown
index e0a143e5f5ea0fa823630038a616edf6496ec97f..6b865aeb07499008c86d550e253ae89cdcc51820 100644 (file)
--- a/README.markdown
+++ b/README.markdown
@@ -1,3 +1,7 @@
+<!--
+SPDX-FileCopyrightText: 2024 Lady <https://www.ladys.computer/about/#lady>
+SPDX-License-Identifier: CC0-1.0
+-->

 # ⛩️📰 书社
 
 <b>A make·file for X·M·L.</b>
 # ⛩️📰 书社
 
 <b>A make·file for X·M·L.</b>


@@ -17,16 +21,12 @@ It makes things easier by :⁠—
 - Enabling easy inclusion of source files within each other.
 
 It aims to do this with zero dependencies beyond the programs already
 - Enabling easy inclusion of source files within each other.
 
 It aims to do this with zero dependencies beyond the programs already

-  installed on your computer.
-(On Linux machines, you may need to install `libxml2-utils` to get the
-  commandline programs from `libxml2`.)
+  installed on your computer†.

 
 

-**Note:**
-⛩️📰 书社 requires functionality present in G·N·U Make 3.81 (or later)
-  and will not work in previous versions, or other implementations of
-  Make.
-Compatibility with later versions of G·N·U Make is assumed, but not
-  tested.
+† Assuming an operating system with a fairly featureful, and
+  Posix‐compliant, development setup (e·g, Macintosh ≥ version 10.8).
+In fact, on Linux you will probably need to install a few programs:
+  `libxml2-utils`, `xsltproc`, `sharutils`, and `pax`.

 
 ## Nomenclature
 
 
 ## Nomenclature
 


@@ -48,6 +48,98 @@ The name <i lang="cmn-Hans">书社</i> was chosen to play on this pun, as
 In Ascii environments, ⛩️📰 书社 should be written `Shushe`, following
   the pinyin transliteration.
 
 In Ascii environments, ⛩️📰 书社 should be written `Shushe`, following
   the pinyin transliteration.
 

+## Prerequisites
+
+In most cases, ⛩️📰 书社 aims to require only functionality which is
+  present in all Posix‐compliant (`POSIX.1-2001`) operating systems.
+There are a few exceptions.
+Details on particular programs are given below; if a program is not
+  listed, it is assumed that any Posix‐compliant implementation will
+  work.
+
+### `diff`
+
+This is a Posix utility, but ⛩️📰 书社 depends on functionality
+  introduced after `POSIX.1-2001` (the `-u` option, introduced in
+  `POSIX.1-2008`).
+Macintosh systems somewhat interestingly implement this option
+  correctly in legacy mode (`COMMAND_MODE=legacy`) but incorrectly by
+  default (despite claiming `POSIX.1-2008` conformance for this
+  utility).
+[Note this erroneous comment claiming nanosecond & timezone are
+  extensions rather than standardized.][rdar-92753335]
+Despite this, the default Macintosh implementation will still work with
+  ⛩️📰 书社, with the caveat that the timestamp will only include a
+  fractional component when a Posix⹀compliant (e·g, Macintosh legacy or
+  G·N·U) implementation is used.
+
+### `file`
+
+This is a Posix utility, but it was considered optional in
+  `POSIX.1-2001` (altho it was made mandatory in `POSIX.1-2008`) and
+  ⛩️📰 书社 currently depends on unspecified behaviour.
+It requires support for the following additional options :⁠—
+
+- **`-C`**, when supplied with `-m`, must be useable to compile a
+    `.mgc` magicfile for use with future invocations of `file`.
+
+- **`--files-from`** must be useable to provide a file that `file`
+    should read file·names from, and `-` must be useable in this
+    context to specify the standard input.
+
+- **`--mime-type`** must cause `file` to print the internet media type
+    of the file with no charset parameter.
+
+- **`--separator`** must be useable to set the separator that `file`
+    uses to separate file names from types.
+
+These options are implemented by the
+  [Fine Free File Command](https://darwinsys.com/file/), which is used
+  by most operating systems.
+
+### `git`
+
+This is not a Posix utility.
+Usage of `git` is optional, but recommended (and activated by default).
+To disable it, set `GIT=`.
+
+### `make`
+
+This is a Posix utility, but it is considered an optional Software
+  Development utility and ⛩️📰 书社 currently depends on unspecified
+  behaviour.
+⛩️📰 书社 requires specifically the G·N·U version of `make`, and
+  depends on functionality present in version 3.81 or later.
+It is not expected to work in previous versions, or with other
+  implementations of Make.
+
+### `pax`
+
+This is a Posix utility, but it is not included in the Linux Standard
+  Base or installed by default in many distributions.
+⛩️📰 书社 only requires support for the `ustar` format.
+
+### `uudecode` and `uuencode`
+
+These are Posix utilities, but they were considered optional in
+  `POSIX.1-2001` (altho they are made mandatory in `POSIX.1-2008`) and
+  they are not included in the Linux Standard Base or installed by
+  default in many distributions.
+The G·N·U [Sharutils](https://www.gnu.org/software/sharutils/) package
+  provides one implementation.
+
+### `xmlcatalog` and `xmllint`
+
+These are not a Posix utilities.
+They are a part of `libxml2`, but may need to be installed separately
+  on some platforms (e·g by the name `libxml2-utils`).
+
+### `xsltproc`
+
+This is not a Posix utility.
+It is a part of `libxslt`, but may need to be installed separately on
+  some platforms.
+

 ## Basic Usage
 
 Place source files in `sources/` and run `make install` to compile
 ## Basic Usage
 
 Place source files in `sources/` and run `make install` to compile


@@ -69,9 +161,13 @@ Compilation involves the following steps :⁠—
 5. ⛩️📰 书社 uses the dependency tree to establish prerequisites for
     each output file.
 
 5. ⛩️📰 书社 uses the dependency tree to establish prerequisites for
     each output file.
 

-6. ⛩️📰 书社 compiles each output file to `build/public`.
+6. ⛩️📰 书社 compiles each output file to `build/result`.

 
 

-7. ⛩️📰 书社 copies the output files to `public`.
+7. ⛩️📰 书社 copies most output files from `build/result` to
+     `build/public`, but it does some additional processing instead on
+     those which indicate a non‐X·M·L desired final output form.
+
+8. ⛩️📰 书社 copies the final resulting files to `public`.

 
 You can use `make list` to list each identified source file or include
   alongside its computed type and dependencies.
 
 You can use `make list` to list each identified source file or include
   alongside its computed type and dependencies.


@@ -79,19 +175,23 @@ As this is a Make‐based program, steps will only be run if the
   corresponding buildfile or output file is older than its
   prerequisites.
 
   corresponding buildfile or output file is older than its
   prerequisites.
 

-## Namespaces
+## Name·spaces

 
 

-The ⛩️📰 书社 namespace is `urn:fdc:ladys.computer:20231231:Shu1She4`.
+The ⛩️📰 书社 name·space is `urn:fdc:ladys.computer:20231231:Shu1She4`.

 
 

-This document uses a few namespace prefixes, with the following
+This document uses a few name·space prefixes, with the following

   meanings :⁠—
 
   meanings :⁠—
 

-|   Prefix | Expansion                                  |
-| -------: | :----------------------------------------- |
-|  `html:` | `http://www.w3.org/1999/xhtml`             |
-| `xlink:` | `http://www.w3.org/1999/xlink`             |
-|  `xslt:` | `http://www.w3.org/1999/XSL/Transform`     |
-|  `书社:` | `urn:fdc:ladys.computer:20231231:Shu1She4` |
+|     Prefix | Expansion                                     |
+| ---------: | :-------------------------------------------- |
+| `catalog:` | `urn:oasis:names:tc:entity:xmlns:xml:catalog` |
+|    `exsl:` | `http://exslt.org/common`                     |
+| `exslstr:` | `http://exslt.org/strings`                    |
+|    `html:` | `http://www.w3.org/1999/xhtml`                |
+|     `svg:` | `http://www.w3.org/2000/svg`                  |
+|   `xlink:` | `http://www.w3.org/1999/xlink`                |
+|    `xslt:` | `http://www.w3.org/1999/XSL/Transform`        |
+|    `书社:` | `urn:fdc:ladys.computer:20231231:Shu1She4`    |

 
 ## Setup and Configuration
 
 
 ## Setup and Configuration
 


@@ -102,27 +202,30 @@ In every case, you may supply your own implementation by overriding the
 
 - `awk`
 - `cat`
 
 - `awk`
 - `cat`

+- `cd`

 - `cksum`
 - `cp`
 - `date`
 - `cksum`
 - `cp`
 - `date`

-- `echo`
+- `diff`

 - `file`
 - `find`
 - `git` (optional; set `GIT=` to disable)
 - `file`
 - `find`
 - `git` (optional; set `GIT=` to disable)

+- `grep`

 - `ln`
 - `ln`

-- `mkdir` (requires support for `-p`)
+- `mkdir`

 - `mv`
 - `mv`

-- `od` (requires support for `-t x1`)
+- `od`
+- `pax` (only when generating archives)

 - `printf`
 - `rm`
 - `sed`
 - `sleep`
 - `printf`
 - `rm`
 - `sed`
 - `sleep`

-- `stat`

 - `test`
 - `touch`
 - `test`
 - `touch`

-- `tr` (requires support for `-d`)
-- `uuencode` (requires support for `-m` and `-r`)
-- `xargs` (requires support for `-0`)
+- `tr`
+- `uuencode`
+- `uudecode`
+- `xargs`

 - `xmlcatalog` (provided by `libxml2`)
 - `xmllint` (provided by `libxml2`)
 - `xsltproc` (provided by `libxslt`)
 - `xmlcatalog` (provided by `libxml2`)
 - `xmllint` (provided by `libxml2`)
 - `xsltproc` (provided by `libxslt`)


@@ -211,20 +314,31 @@ The following additional variables can be used to control the behaviour
     enable additional transforms without overriding the existing ones.
 
 - **`XMLTYPES`:**
     enable additional transforms without overriding the existing ones.
 
 - **`XMLTYPES`:**

-  A white·space‐separated list of media types to consider X·M·L
-    (default: `application/xml text/xml`).
+  A white·space‐separated list of media types or media type suffixes to
+    consider X·M·L (default: `application/xml text/xml +xml`).

 
 

-- **`GENERATOR`:**
-  The name of the generator program (default: `⛩️📰 书社`).
+- **`FINALIZE`:**
+  A program to run on (unspecial) X·M·L files after they are
+    transformed (default: `xmllint --nonet --nsclean`).
+  This variable can be used for postprocessing.

 
 

-- **`VERSION`:**
-  The current version of `GENERATOR` (default: derived from the current
+- **`THISREV`:**
+  The current version of ⛩️📰 书社 (default: derived from the current

     git tag/branch/commit).
 
 - **`SRCREV`:**
   The current version of the source files (default: derived from the
     current git tag/branch/commit).
 
     git tag/branch/commit).
 
 - **`SRCREV`:**
   The current version of the source files (default: derived from the
     current git tag/branch/commit).
 

+- **`QUIET`:**
+  If this variable has a value, informative messages will not be
+    printed (default: empty).
+  Informative messages print to stderr, not stdout, so disabling them
+    usually shouldn’t be necessary.
+  This does not (cannot) disable messages from Make itself, for which
+    the `-s`, `--silent` ∕ `--quiet` Make option is more likely to be
+    useful.
+

 - **`VERBOSE`:**
   If this variable has a value, every recipe instruction will be
     printed when it runs (default: empty).
 - **`VERBOSE`:**
   If this variable has a value, every recipe instruction will be
     printed when it runs (default: empty).


@@ -257,11 +371,11 @@ Source files whose media type does not have an associated X·S·L·T
   contain Ascii white·space, colons (`:`), semis (`;`), pipes (`|`),
   bucks (`$`), percents (`%`), hashes (`#`), asterisks (`*`), brackets
   (`[` or `]`), erotemes (`?`), backslashes (`\`), or control
   contain Ascii white·space, colons (`:`), semis (`;`), pipes (`|`),
   bucks (`$`), percents (`%`), hashes (`#`), asterisks (`*`), brackets
   (`[` or `]`), erotemes (`?`), backslashes (`\`), or control

-  characters, must not begin with a hyphen‐minus (`-`), and must not
-  end with a cloparen (`)`).**
+  characters, must not begin with a hyphen‐minus (`-`), and must not end
+  with a cloparen (`)`).**

 The former characters have the potential to conflict with make syntax,
 The former characters have the potential to conflict with make syntax,

-  a leading hyphen‐minus is confusable for a command‐line argument, and
-  a trailing cloparen [activates a bug in G·N·U Make
+  a leading hyphen‐minus is confusable for a commandline argument, and a
+  trailing cloparen [activates a bug in G·N·U Make

   3.81](https://stackoverflow.com/questions/17148468/capturing-filenames-including-parentheses-with-gnu-makes-wildcard-function#comment24825307_17148894).
 
 ## Parsers
   3.81](https://stackoverflow.com/questions/17148468/capturing-filenames-including-parentheses-with-gnu-makes-wildcard-function#comment24825307_17148894).
 
 ## Parsers


@@ -272,22 +386,21 @@ Parsers are used to convert plaintext files into X·M·L trees, as well
 ⛩️📰 书社 comes with some parsers; namely :⁠—
 
 - **`parsers/plain.xslt`:**
 ⛩️📰 书社 comes with some parsers; namely :⁠—
 
 - **`parsers/plain.xslt`:**

-  Wraps `text/plain` contents in a `<html:pre class="plain">` element.
+  Wraps `text/plain` contents in a `<html:pre>` element.

 
 - **`parsers/record-jar.xslt`:**
 
 - **`parsers/record-jar.xslt`:**

-  Converts `text/record-jar` contents into a
-    `<html:div class="record-jar">` of `<html:dl>` elements (one for
-    each record).
+  Converts `text/record-jar` contents into a `<html:div>` of
+    `<html:dl>` elements (one for each record).

 
 - **`parsers/tsv.xslt`:**
 
 - **`parsers/tsv.xslt`:**

-  Converts `text/tab-separated-values` contents into an
-    `<html:table class="tsv">` element.
+  Converts `text/tab-separated-values` contents into an `<html:table>`
+    element.

 
 New ⛩️📰 书社 parsers which target plaintext formats should have an
   `<xslt:template>` element with no `@name` or `@mode` and whose
   `@match` attribute…
 
 
 New ⛩️📰 书社 parsers which target plaintext formats should have an
   `<xslt:template>` element with no `@name` or `@mode` and whose
   `@match` attribute…
 

-- Starts with an appropriately‐namespaced qualified name for a
+- Starts with an appropriately‐name·spaced qualified name for a

     `<html:script>` element.
 
 - Follows this with the string `[@type=`.
     `<html:script>` element.
 
 - Follows this with the string `[@type=`.


@@ -344,9 +457,29 @@ Parsers are applied *prior* to embedding (and can be used to generate
   embeds); transforms are applied *after*.
 
 It is **strongly recommended** that auxillary templates in parsers be
   embeds); transforms are applied *after*.
 
 It is **strongly recommended** that auxillary templates in parsers be

-  namespaced (by `@name` or `@mode`) whenever possible, to avoid
+  name·spaced (by `@name` or `@mode`) whenever possible, to avoid

   conflicts between parsers.
 
   conflicts between parsers.
 

+### Attributes added during parsing
+
+⛩️📰 书社 will add a few attributes to the output of the parsing step,
+  namely :⁠—
+
+- A `@书社:cksum` attribute on toplevel result elements, giving the
+    `cksum` checksum of the corresponding source file.
+
+- For the elements which result from parsing plaintext `<html:script>`
+    elements :⁠—
+
+  - A `@书社:parsed-by` attribute, giving a space‐separated list of
+      parsers which parsed the node.
+    (Generally, this will be a list of one, but it is possible for the
+      result of a parse to be another plaintext node, which may be
+      parsed by a different parser.)
+
+  - A `@书社:media-type` attribute, giving the identified media type of
+      the plaintext node.
+

 ## Embedding
 
 Documents can be embedded in other documents using a `<书社:link>`
 ## Embedding
 
 Documents can be embedded in other documents using a `<书社:link>`


@@ -363,6 +496,8 @@ Embeds are replaced with the parsed contents of a file, unless the file
   is an asset, in which case an `<html:object>` element is produced
   instead (with the contents of the asset file provided as a base64
   `data:` u·r·i).
   is an asset, in which case an `<html:object>` element is produced
   instead (with the contents of the asset file provided as a base64
   `data:` u·r·i).

+Embed replacements will be given a `@书社:identifier` attribute whose
+  value will match the `@xlink:href` of the embed.

 
 Embedding takes place after parsing but before transformation, so
   parsers are able to generate their own embeds.
 
 Embedding takes place after parsing but before transformation, so
   parsers are able to generate their own embeds.


@@ -385,14 +520,6 @@ Transforms are used to convert X·M·L files into their final output,
   after all necessary parsing and embedding has taken place.
 ⛩️📰 书社 comes with some transforms; namely :⁠—
 
   after all necessary parsing and embedding has taken place.
 ⛩️📰 书社 comes with some transforms; namely :⁠—
 

-- **`transforms/attributes.xslt`:**
-  Applies transforms to the children of any `<书社:apply-attributes>`
-    elements, and then applies the attributes of the
-    `<书社:apply-attributes>` to each result child, replacing the
-    element with the result.
-  This is useful in combination with image embeds to apply alt‐text to
-    the resulting `<html:img>`.
-

 - **`transforms/asset.xslt`:**
   Converts `<html:object>` elements which correspond to recognized
     media types into the appropriate H·T·M·L elements, and deletes
 - **`transforms/asset.xslt`:**
   Converts `<html:object>` elements which correspond to recognized
     media types into the appropriate H·T·M·L elements, and deletes


@@ -407,11 +534,38 @@ Transforms are used to convert X·M·L files into their final output,
   - **`urn:fdc:ladys.computer:20231231:Shu1She4:title`:**
     Provides the title of the page.
 
   - **`urn:fdc:ladys.computer:20231231:Shu1She4:title`:**
     Provides the title of the page.
 

-  ⛩️📰 书社 automatically encapsulates embeds so that their metadata
-    does not propogate up to the embedding document.
+  ⛩️📰 书社 automatically encapsulates H·T·M·L embeds so that their
+    metadata does not propogate up to the embedding document.

   To undo this behaviour, remove the `@itemscope` and `@itemtype`
     attributes from the embed during the transformation phase.
 
   To undo this behaviour, remove the `@itemscope` and `@itemtype`
     attributes from the embed during the transformation phase.
 

+- **`transforms/serialization.xslt`:**
+  Replaces `<书社:serialize-xml>` elements with the (escaped)
+    serialized X·M·L of their contents.
+  This replacement happens during the application phase, after most
+    other transformations have taken place.
+
+  If a `@with-namespaces` attribute is provided, any name·space nodes
+    on the toplevel serialized elements whose U·R·I’s correspond to the
+    definitions of the provided prefixes, as defined for the
+    `<书社:serialize-xml>` element, will be declared using name·space
+    attributes on the serialized elements.
+  Otherwise, only name·space nodes which _differ_ from the definitions
+    on the `<书社:serialize-xml>` element will be declared.
+  The string `#default` may be used to represent the default
+    name·space.
+  Multiple prefixes may be provided, separated by white·space.
+
+  When it comes to name·spaces used internally by ⛩️📰 书社, the
+    prefix used by ⛩️📰 书社 may be declared _in addition to_ the
+    prefix(es) used in the source document(s).
+  It is not possible to selectively only declare one prefix for a
+    name·space to the exclusion of others.
+
+  `<书社:raw-output>` elements may be used inside of
+    `<书社:serialize-xml>` elements to inject raw output into the
+    serialized X·M·L.
+

 The following are recommendations on effective creation of
   transforms :⁠—
 
 The following are recommendations on effective creation of
   transforms :⁠—
 


@@ -419,10 +573,10 @@ The following are recommendations on effective creation of
   It is likely an error if two transforms have templates which match
     the same element (unless the templates have different priority).
 
   It is likely an error if two transforms have templates which match
     the same element (unless the templates have different priority).
 

-- Namespace templates (with `@name` or `@mode`) whenever possible.
+- Name·space templates (with `@name` or `@mode`) whenever possible.

 
 - Set `@exclude-result-prefixes` on the root `xslt:transform` element
 
 - Set `@exclude-result-prefixes` on the root `xslt:transform` element

-    to reduce the number of declared namespaces in the final result.
+    to reduce the number of declared name·spaces in the final result.

 
 ## Global Params
 
 
 ## Global Params
 


@@ -435,8 +589,9 @@ The following params are made available globally in parsers and
 - **`CKSUM`:**
   The checksum of the source file (⅌ `cksum`).
 
 - **`CKSUM`:**
   The checksum of the source file (⅌ `cksum`).
 

-- **`GENERATOR`:**
-  The value of the `GENERATOR` variable (if present).
+- **`IDENTIFIER`:**
+  The ⛩️📰 书社 identifier of the source file (a u·r·i beginning with
+    `about:shushe`).

 
 - **`SRCREV`:**
   The value of the `SRCREV` variable (if present).
 
 - **`SRCREV`:**
   The value of the `SRCREV` variable (if present).


@@ -444,8 +599,8 @@ The following params are made available globally in parsers and
 - **`SRCTIME`:**
   The time at which the source file was last modified.
 
 - **`SRCTIME`:**
   The time at which the source file was last modified.
 

-- **`VERSION`:**
-  The value of the `VERSION` variable (if present).
+- **`THISREV`:**
+  The value of the `THISREV` variable (if present).

 
 The following params are only available in transforms :⁠—
 
 
 The following params are only available in transforms :⁠—
 


@@ -507,11 +662,70 @@ This mechanism can be used to allow transforms to insert content
 Output wrapping can be entirely disabled by adding a
   `@书社:disable-output-wrapping` attribute to the top‐level element in
   the result tree.
 Output wrapping can be entirely disabled by adding a
   `@书社:disable-output-wrapping` attribute to the top‐level element in
   the result tree.

+It will not be performed on outputs whose root elements are
+  `<书社:archive>`, `<书社:base64-binary>`, or `<书社:raw-text>`
+  (described below).
+
+## Applying Attributes
+
+The `<书社:apply-attributes>` element will apply any attributes on the
+  element to the element(s) it wraps.
+It is especially useful in combination with embeds.
+
+The `<书社:apply-attributes-to-root>` element will apply any attributes
+  on the element to the root node of the final transformation result.
+It is especially useful in combination with output wrapping.
+
+In both cases, attributes from various sources are combined with
+  white·space between them.
+Attribute application takes place after all ordinary transforms have
+  completed.
+
+Both elements ignore attributes in the `xml:` name·space, except for
+  `@xml:lang`, which ignores all but the first definition (including
+  any already present on the root element).
+On H·T·M·L and S·V·G elements, `@lang` has the same behaviour as
+  `@xml:lang`.
+
+## Other Kinds of Output
+
+There are a few special elements in the `书社:` name·space which, if
+  they appear as the toplevel element in a transformation result, cause
+  ⛩️📰 书社 to produce something other than an X·M·L file.
+They are :⁠—
+
+- **`<书社:archive>`:**
+  Each child element with a `@书社:archived-as` attribute will be
+    archived as a separate file in a resulting tarball (this attribute
+    gives the file name).
+  These elements will be processed the same as the root elements of any
+    other file (e·g, they will be wrapped; they can themselves specify
+    non X·M·L output types, ⁊·c).
+  Other child elements will be ignored.
+
+  If the `<书社:archive>` element is given an `@书社:expanded`
+    attribute, rather than producing a tarball ⛩️📰 书社 will output
+    the directory which expanding the tarball would produce.
+  This mechanism can be used to generate multiple files from a single
+    source, provided all of the files are contained with·in the same
+    directory.
+
+- **`<书社:base64-binary>`:**
+  The text nodes in the transformation result will, after removing all
+    Ascii whitespace, be treated as a Base·64 string, which is then
+    decoded.
+
+- **`<书社:raw-text>`:**
+  A plaintext (U·T·F‐8) file will be produced from the text nodes in
+    the transformation result.

 
 ## License
 
 
 ## License
 

-Source files are licensed under the terms of the <cite>Mozilla Public
-  License, version 2.0</cite>.
-For more information, see [LICENSE](./LICENSE).
+This repository conforms to [REUSE][].
+
+Most source files are licensed under the terms of the <cite>Mozilla
+  Public License, version 2.0</cite>.

 
 

+[REUSE]: <https://reuse.software/spec/>

 [draft-phillips-record-jar-01]: <https://datatracker.ietf.org/doc/html/draft-phillips-record-jar-01>
 [draft-phillips-record-jar-01]: <https://datatracker.ietf.org/doc/html/draft-phillips-record-jar-01>

+[rdar-92753335]: <https://github.com/apple-oss-distributions/patch_cmds/blob/5084833f90df1b0e0924ea56f94c0199b3b8bbc6/diff/diffreg.c#L1800-L1808>