a short form…). You can get all of these at once
(<emphasis>lots</emphasis> of output) by using
<option>-v5</option>, or most of them with
- <option>-v4</option>. Some of the most useful ones
- are:</para>
+ <option>-v4</option>. You can prevent them from clogging up
+ your standard output by passing <option>-ddump-to-file</option>.
+ Some of the most useful ones are:</para>
<variablelist>
<varlistentry>
style.</para>
</listitem>
</varlistentry>
+ </variablelist>
+ </sect2>
+
+ <sect2 id="formatting dumps">
+ <title>Formatting dumps</title>
+
+ <indexterm><primary>formatting dumps</primary></indexterm>
+
+ <variablelist>
+ <varlistentry>
+ <term>
+ <option>-dppr-user-length</option>
+ <indexterm><primary><option>-dppr-user-length</option></primary></indexterm>
+ </term>
+ <listitem>
+ <para>In error messages, expressions are printed to a
+ certain “depth”, with subexpressions beyond the
+ depth replaced by ellipses. This flag sets the
+ depth. Its default value is 5.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>
+ <option>-dppr-colsNNN</option>
+ <indexterm><primary><option>-dppr-colsNNN</option></primary></indexterm>
+ </term>
+ <listitem>
+ <para>Set the width of debugging output. Use this if your code is wrapping too much.
+ For example: <option>-dppr-cols200</option>.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>
+ <option>-dppr-case-as-let</option>
+ <indexterm><primary><option>-dppr-case-as-let</option></primary></indexterm>
+ </term>
+ <listitem>
+ <para>Print single alternative case expressions as though they were strict
+ let expressions. This is helpful when your code does a lot of unboxing.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>
+ <option>-dno-debug-output</option>
+ <indexterm><primary><option>-dno-debug-output</option></primary></indexterm>
+ </term>
+ <listitem>
+ <para>Suppress any unsolicited debugging output. When GHC
+ has been built with the <literal>DEBUG</literal> option it
+ occasionally emits debug output of interest to developers.
+ The extra output can confuse the testing framework and
+ cause bogus test failures, so this flag is provided to
+ turn it off.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+
+ </sect2>
+
+ <sect2 id="supression">
+ <title>Suppressing unwanted information</title>
+
+ <indexterm><primary>suppression</primary></indexterm>
+
+ Core dumps contain a large amount of information. Depending on what you are doing, not all of it will be useful.
+ Use these flags to suppress the parts that you are not interested in.
+
+ <variablelist>
+ <varlistentry>
+ <term>
+ <option>-dsuppress-all</option>
+ <indexterm><primary><option>-dsuppress-all</option></primary></indexterm>
+ </term>
+ <listitem>
+ <para>Suppress everything that can be suppressed, except for unique ids as this often
+ makes the printout ambiguous. If you just want to see the overall structure of
+ the code, then start here.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term>
<indexterm><primary><option>-dsuppress-uniques</option></primary></indexterm>
</term>
<listitem>
- <para>Suppress the printing of uniques in debugging output. This may make
+ <para>Suppress the printing of uniques. This may make
the printout ambiguous (e.g. unclear where an occurrence of 'x' is bound), but
it makes the output of two compiler runs have many fewer gratuitous differences,
so you can realistically apply <command>diff</command>. Once <command>diff</command>
<varlistentry>
<term>
- <option>-dsuppress-coercions</option>
- <indexterm><primary><option>-dsuppress-coercions</option></primary></indexterm>
+ <option>-dsuppress-idinfo</option>
+ <indexterm><primary><option>-dsuppress-idinfo</option></primary></indexterm>
</term>
<listitem>
- <para>Suppress the printing of coercions in Core dumps to make them
-shorter.</para>
+ <para>Suppress extended information about identifiers where they are bound. This includes
+ strictness information and inliner templates. Using this flag can cut the size
+ of the core dump in half, due to the lack of inliner templates</para>
</listitem>
</varlistentry>
<indexterm><primary><option>-dsuppress-module-prefixes</option></primary></indexterm>
</term>
<listitem>
- <para>Suppress the printing of module qualification prefixes in Core dumps to make them easier to read.</para>
+ <para>Suppress the printing of module qualification prefixes.
+ This is the <constant>Data.List</constant> in <constant>Data.List.length</constant>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
- <option>-dppr-user-length</option>
- <indexterm><primary><option>-dppr-user-length</option></primary></indexterm>
+ <option>-dsuppress-type-signatures</option>
+ <indexterm><primary><option>-dsuppress-type-signatures</option></primary></indexterm>
</term>
<listitem>
- <para>In error messages, expressions are printed to a
- certain “depth”, with subexpressions beyond the
- depth replaced by ellipses. This flag sets the
- depth. Its default value is 5.</para>
+ <para>Suppress the printing of type signatures.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term>
- <option>-dno-debug-output</option>
- <indexterm><primary><option>-dno-debug-output</option></primary></indexterm>
+ <term>
+ <option>-dsuppress-type-applications</option>
+ <indexterm><primary><option>-dsuppress-type-applications</option></primary></indexterm>
</term>
- <listitem>
- <para>Suppress any unsolicited debugging output. When GHC
- has been built with the <literal>DEBUG</literal> option it
- occasionally emits debug output of interest to developers.
- The extra output can confuse the testing framework and
- cause bogus test failures, so this flag is provided to
- turn it off.</para>
- </listitem>
+ <listitem>
+ <para>Suppress the printing of type applications.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>
+ <option>-dsuppress-coercions</option>
+ <indexterm><primary><option>-dsuppress-coercions</option></primary></indexterm>
+ </term>
+ <listitem>
+ <para>Suppress the printing of type coercions.</para>
+ </listitem>
</varlistentry>
</variablelist>
</sect2>
projects / ghc-hetmet.git / blobdiff