docs: wine-devel [8/16]
Dimitrie O. Paun
dpaun at rogers.com
Sun Sep 21 11:52:05 CDT 2003
It still needs work, but it will have to do for now.
ChangeLog
Big update to the debug logging section.
Index: documentation/debugging.sgml
===================================================================
RCS file: /var/cvs/wine/documentation/debugging.sgml,v
retrieving revision 1.11
diff -u -r1.11 debugging.sgml
--- documentation/debugging.sgml 21 Jul 2003 22:42:50 -0000 1.11
+++ documentation/debugging.sgml 20 Sep 2003 06:52:43 -0000
@@ -1,33 +1,36 @@
<chapter id="debugging">
<title>Debug Logging</title>
- <para>
- Written by &name-dimitrie-paun; <email>&email-dimitrie-paun;</email>, 28 Mar 1998
- </para>
- <para>
- (Extracted from <filename>wine/documentation/debug-msgs</filename>)
- </para>
-
- <note>
- <para>
- It is possible to turn on and of debugging output from
- within the debugger using the set command. Please see the
- WineDbg Command Reference section for how to do this.
- </para>
- </note>
-
- <important>
<para>
- At the end of the document, there is a "Style Guide" for
- debugging messages. Please read it.
+ To better manage the large volume of debugging messages that
+ Wine can generate, we divide the messages on a component basis,
+ and classify them based on the severity of the reported problem.
+ Therefore a message belongs to a <emphasis>channel</emphasis>
+ and a <emphasis>class</emphasis> respectively.
+ </para>
+ <para>
+ This section will describe the debugging classes, how you can
+ create a new debugging channel, what the debugging API is,
+ and how you can control the debugging output. A picture is
+ worth a thousand words, so here are a few examples of the
+ debugging API in action:
+ <screen>
+ERR("lock_count == 0 ... please report\n");
+FIXME("Unsupported RTL style!\n");
+WARN(": file seems to be truncated!\n");
+TRACE("[%p]: new horz extent = %d\n", hwnd, extent );
+MESSAGE( "Could not create graphics driver '%s'\n", buffer );
+ </screen>
</para>
- </important>
<sect1 id="dbg-classes">
<title>Debugging classes</title>
<para>
- There are 4 types (or classes) of messages:
+ A debugging class categorizes a message based on the severity
+ of the reported problem. There is a fixed set of classes, and
+ you must carefuly choose the appropriate one for your messages.
+ There are five classes of messages:
</para>
<variablelist>
<varlistentry>
@@ -38,22 +41,15 @@
features, known bugs, etc. They serve as a constant and
active reminder of what needs to be done.
</para>
- <para>
- Examples: stubs, semi-implemented features, etc.
- </para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>ERR</literal></term>
<listitem>
<para>
- Messages in this class relate to serious errors in
- Wine. This sort of messages signal an inconsistent
- internal state, or more general, a condition which
- should never happen by design.
- </para>
- <para>
- Examples: unexpected change in internal state, etc.
+ Messages in this class indicate serious errors in
+ Wine, such as as conditions that should never happen
+ by design.
</para>
</listitem>
</varlistentry>
@@ -62,15 +58,11 @@
<listitem>
<para>
These are warning messages. You should report a
- warning when something unwanted happen but the
- function behaves properly. That is, output a warning
- when you encounter something unexpected (ex: could not
- open a file) but the function deals correctly with the
- situation (that is, according to the docs). If you do
- not deal correctly with it, output a fixme.
- </para>
- <para>
- Examples: fail to access a resource required by the app.
+ warning when something unwanted happens, and the
+ function can not deal with the condition. This
+ is seldomly used since proper functions can usually
+ report failures back to the caller. Think twice before
+ making the message a warning.
</para>
</listitem>
</varlistentry>
@@ -79,13 +71,18 @@
<listitem>
<para>
These are detailed debugging messages that are mainly
- useful to debug a component. These are usually turned
- off.
+ useful to debug a component. These are turned off unless
+ explicitly enabled.
</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><literal>MESSAGE</literal></term>
+ <listitem>
<para>
- Examples: everything else that does not fall in one of
- the above mentioned categories and the user does not
- need to know about it.
+ There messages are intended for the end user. They do not
+ belong to any channel. As with warnings, you will seldomly
+ need to output such messages.
</para>
</listitem>
</varlistentry>
@@ -96,35 +93,18 @@
<title>Debugging channels</title>
<para>
- To better manage the large volume of debugging messages that
- Wine can generate, we divide them also on a component basis.
Each component is assigned a debugging channel. The
- identifier of the channel must be a valid C identifier but
- note that it may also be a reserved word like
- <type>int</type> or <type>static</type>.
- </para>
- <para>
- Examples of debugging channels:
- <simplelist type="inline">
- <member><literal>reg</literal></member>
- <member><literal>updown</literal></member>
- <member><literal>string</literal></member>
- </simplelist>
- </para>
- <para>
- We will refer to a generic channel as <literal>xxx</literal>.
+ identifier of the channel must be a valid C identifier
+ (reserved word like <type>int</type> or <type>static</type>
+ are premitted). To use a new channel, simply use it in
+ your code. It will be picked up automatically by the build process.
</para>
- </sect1>
-
- <sect1 id="dbg-using">
- <title>How to use it</title>
<para>
Typically, a file contains code pertaining to only one component,
- and as such, there is only one channel to output to. To simplify
- usage, you can declare that channel at the beginning of the file,
- and simply write FIXMEs, ERRs, etc. as such:
-
+ and as such, there is only one channel to output to. You can declare
+ a default chanel for the file using the
+ <symbol>WINE_DEFAULT_DEBUG_CHANNEL()</symbol> macro:
<programlisting>
#include "wine/debug.h"
@@ -160,48 +140,29 @@
</programlisting>
</para>
- <para>
- If you need to declare a new debugging channel, simply use it in
- your code. It will be picked up automatically by the build process.
- </para>
-
</sect1>
<sect1 id="dbg-checking">
<title>Are we debugging?</title>
<para>
- To test whether the debugging output of class
- <literal>yyy</literal> on channel <literal>xxx</literal> is
- enabled, use:
- </para>
- <screen>
-TRACE_ON to test if TRACE is enabled
-WARN_ON to test if WARN is enabled
-FIXME_ON to test if FIXME is enabled
-ERR_ON to test if ERR is enabled
- </screen>
- <para>
- Examples:
- </para>
+ To test whether the debugging channel <literal>xxx</literal> is
+ enabled, use the <symbol>TRACE_ON</symbol>, <symbol>WARN_ON</symbol>,
+ <symbol>FIXME_ON</symbol>, or <symbol>ERR_ON</symbol> macros. For
+ example:
<programlisting>
if(TRACE_ON(atom)){
- ...blah...
+ ...blah...
}
</programlisting>
-
- <note>
- <para>
- You should normally need to test only if
- <literal>TRACE_ON</literal>. At present, none of the other
- 3 tests (except for <literal>ERR_ON</literal> which is
- used only once!) are used in Wine.
- </para>
- </note>
+ You should normally need to test only if <literal>TRACE_ON</literal>,
+ all the others are very seldomly used. With careful coding, you
+ can avoid the use of these macros, which is generally desired.
+ </para>
</sect1>
- <sect1 id="dbg-resource-ids">
- <title>Resource identifiers</title>
+ <sect1 id="dbg-helpers">
+ <title>Helper functions</title>
<para>
Resource identifiers can be either strings or numbers. To
@@ -241,10 +202,32 @@
TRACE("resource is %s", debugres(myresource));
</programlisting>
+
+ <para>
+ Many times strings need to be massaged before output:
+ they may be <literal>NULL</literal>, contain control
+ characters, or they may be too long. Similarly, Unicode
+ strings need to be converted to ASCII for usage with
+ the debugging API. For all this, you can use the
+ <function>debugstr_[aw]n?</function> familly of functions:
+ <programlisting>
+HANDLE32 WINAPI YourFunc(LPCSTR s)
+{
+ FIXME("(%s): stub\n", debugstr_a(s));
+}
+ </programlisting>
+ </para>
+
</sect1>
- <sect1 id="dbg-param">
- <title>The <parameter>--debugmsg</parameter> command line option</title>
+ <sect1 id="dbg-control">
+ <title>Controlling the debugging output</title>
+
+ <para>
+ It is possible to turn on and off debugging output from
+ within the debugger using the set command. Please see the
+ WineDbg Command Reference section for how to do this.
+ </para>
<para>
The <parameter>--debugmsg</parameter> command line
@@ -385,7 +368,7 @@
<itemizedlist>
<listitem>
<para>
- do NOT include the name of the function: it is included automatically
+ do not include the name of the function: it is included automatically
</para>
</listitem>
<listitem>
@@ -418,99 +401,10 @@
</listitem>
<listitem>
<para>
- if you want to name a value, use <literal>=</literal> and
- NOT <literal>:</literal>. That is, instead of saying:
- <programlisting>
-FIXME("(fd: %d, file: %s): stub\n", fd, name);
- </programlisting>
- say:
+ if you want to name a parameter, use <literal>=</literal> :
<programlisting>
FIXME("(fd=%d, file=%s): stub\n", fd, name);
</programlisting>
- use <literal>:</literal> to separate categories.
- </para>
- </listitem>
- <listitem>
- <para>
- try to avoid the style:
- <programlisting>
-FIXME(xxx, "(fd=%d, file=%s)\n", fd, name);
- </programlisting>
- instead use:
- <programlisting>
-FIXME(xxx, "(fd=%d, file=%s): stub\n", fd, name);
- </programlisting>
- The reason is that if you want to <command>grep</command>
- for things, you would search for <literal>FIXME</literal>
- but in the first case there is no additional information
- available, where in the second one, there is (e.g. the word
- stub)
- </para>
- </listitem>
- <listitem>
- <para>
- if you output a string s that might contain control
- characters, or if <parameter>s</parameter> may be
- <literal>NULL</literal>, use
- <function>debugstr_a</function> (for ASCII strings, or
- <function>debugstr_w</function> for Unicode strings) to
- convert <parameter>s</parameter> to a C string, like this:
- <programlisting>
-HANDLE32 WINAPI YourFunc(LPCSTR s)
-{
- FIXME("(%s): stub\n", debugstr_a(s));
-}
- </programlisting>
- </para>
- </listitem>
- <listitem>
- <para>
- if you want to output a resource identifier, use debugres to
- convert it to a string first, like this:
- <programlisting>
-HANDLE32 WINAPI YourFunc(LPCSTR res)
-{
- FIXME("(res=%s): stub\n", debugres(s));
-}
- </programlisting>
- if the resource identifier is a <type>SEGPTR</type>, use
- <function>PTR_SEG_TO_LIN</function> to get a
- liner pointer first:
- <programlisting>
-HRSRC16 WINAPI FindResource16( HMODULE16 hModule, SEGPTR name, SEGPTR type )
-{
-[...]
- TRACE(resource, "module=%04x name=%s type=%s\n",
- hModule, debugres(PTR_SEG_TO_LIN(name)),
- debugres(PTR_SEG_TO_LIN(type)) );
-[...]
-}
- </programlisting>
- </para>
- </listitem>
- <listitem>
- <para>
- for messages intended for the user (specifically those that
- report errors in the wine config file), use the
- <literal>MSG</literal> macro. Use it like a
- <function>printf</function>:
- <programlisting>
-MSG( "Definition of drive %d is incorrect!\n", drive );
- </programlisting>
- However, note that there are <emphasis>very</emphasis> few
- valid uses of this macro. Most messages are debugging
- messages, so chances are you will not need to use this
- macro. Grep the source to get an idea where it is
- appropriate to use it.
- </para>
- </listitem>
- <listitem>
- <para>
- For structure dumps, use the <function>DUMP</function>
- macro. Use it like a <function>printf</function>, just like
- the <literal>MSG</literal> macro. Similarly, there are only
- a few valid uses of this macro. Grep the source to see when
- to use it.
</para>
</listitem>
</itemizedlist>
--
Dimi.
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