Document config options (PR digraphs#420)

Resolve Issue digraphs#320

README.md

@@ -85,12 +85,27 @@ If you installed GAP on several architectures, then you must execute the
 configure/make step for each of the architectures. You can either do this
 immediately after configuring and compiling GAP itself on this architecture, or
 alternatively set the environment variable `CONFIGNAME` to the name of the
-configuration you used when compiling GAPbefore running `./configure`.  Note
+configuration you used when compiling GAP before running `./configure`.  Note
 however that your compiler choice and flags (environment variables `CC` and
 `CFLAGS`) need to be chosen to match the setup of the original GAP compilation.
 For example, you have to specify 32-bit or 64-bit mode correctly!
 
-Digraphs vendors `bliss` and `planarity` libraries in the `extern` directory.
+### Configuration options
+
+In addition to the usual autoconf generated configuration flags, the following
+flags are provided.
+
+Option                        | Meaning
+----------------------------- | ------------------------------------------------
+--enable-code-coverage        | enable code coverage support
+--enable-compile-warnings     | enable compiler warnings
+--enable-debug                | enable debug mode
+--with-external-bliss         | use external `bliss`
+--with-external-planarity     | use external `planarity`
+--with-gaproot                | specify root of GAP installation
+--without-intrinsics          | do not use compiler intrinsics even if available
+
+Digraphs vendors the `bliss` and `planarity` libraries in the `extern` directory.
 If you wish to use your system copy of `bliss` or `planarity`, please use the
 configure options `--with-external-bliss` or `--with-external-planarity`, as
 appropriate.

doc/z-chap1.xml

@@ -94,6 +94,44 @@ make]]></Listing>
     If you want to check that the package is working correctly, you
     should run some of the tests described in Section
     <Ref Sect="Testing your installation"/>.
+    <Subsection Label="Configuration options">
+      <Heading>Configuration options</Heading>
+
+In addition to the usual autoconf generated configuration flags, the following
+flags are provided.
+
+<Table Align="|l|l|">
+ <Caption>Configuration flags</Caption>
+ <HorLine/>
+  <Row>
+   <Item>Option</Item><Item>Meaning</Item>
+  </Row>
+ <HorLine/>
+ <HorLine/>
+ <Row>
+   <Item><C>--enable-code-coverage</C></Item><Item> enable code coverage support</Item>
+ </Row>
+ <Row>
+   <Item><C>--enable-compile-warnings</C></Item><Item> enable compiler warnings</Item>
+ </Row>
+ <Row>
+   <Item><C>--enable-debug</C></Item><Item> enable debug mode</Item>
+ </Row>
+ <Row>
+   <Item><C>--with-external-bliss</C></Item><Item> use external &bliss;</Item>
+ </Row>
+ <Row>
+   <Item><C>--with-external-planarity</C></Item><Item> use external &edge-addition-planarity-suite;</Item>
+ </Row>
+ <Row>
+   <Item><C>--with-gaproot</C></Item><Item> specify root of GAP installation</Item>
+ </Row>
+ <Row>
+   <Item><C>--without-intrinsics</C></Item><Item> do not use compiler intrinsics even if available</Item>
+ </Row>
+ <HorLine/>
+</Table>
+</Subsection>
   </Section>
 
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