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Re: [RFC]: pending break support
Eli Zaretskii wrote:
Date: Tue, 02 Dec 2003 20:35:01 -0500
From: "J. Johnston" <jjohnstn@redhat.com>
I have added documentation on the pending breakpoint per Eli's request.
Thanks. The documentation patch is approved, but please take care of
these minor problems:
+Where the breakpoint is in your program, as a memory address. If the
+breakpoint is pending on a future load of a shared library, the address
+will be listed as <PENDING>.
First, please add something like "(see below)" after "If the
breakpoint is pending", since this is the first time the reader meets
this term. Second, please say @samp{<PENDING>} to make this stand out.
+@cindex pending breakpoints
+If a specified breakpoint location cannot be found, you will be prompted
+as to whether you want to make the breakpoint pending on a future shared
+library load. This is useful for setting breakpoints at the start of your
+@value{GDBN} session for locations that you know will be dynamically loaded
+later by the program being debugged.
+You may specify
+a condition for a pending breakpoint, however, the
+condition will only be parsed for correctness after the breakpoint location
+is resolved by a future shared library load. A pending breakpoint can be
+enabled or disabled. A disabled pending breakpoint will not be resolved
+on subsequent shared library loads. Enabling a disabled pending breakpoint
+will cause @value{GDBN} to attempt to resolve the breakpoint in the event
+that the required shared library has already been loaded.
+Once a shared library load resolves a pending breakpoint location, the
+pending breakpoint is removed and a real breakpoint is created.
I think this text should be divided into several paragraphs, as it
describes several not-so-related aspects of a pending breakpoint.
TIA
How about the following updated patch? I tied together why I was talking about
the various operations on pending breakpoints which makes the grouping of the
information make more sense.
-- Jeff J.
Index: gdb.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/gdb.texinfo,v
retrieving revision 1.185
diff -u -r1.185 gdb.texinfo
--- gdb.texinfo 28 Oct 2003 22:04:47 -0000 1.185
+++ gdb.texinfo 3 Dec 2003 19:44:55 -0000
@@ -2600,16 +2600,23 @@
Enabled breakpoints are marked with @samp{y}. @samp{n} marks breakpoints
that are not enabled.
@item Address
-Where the breakpoint is in your program, as a memory address.
+Where the breakpoint is in your program, as a memory address. If the
+breakpoint is pending (see below for details) on a future load of a shared library, the address
+will be listed as @samp{<PENDING>}.
@item What
Where the breakpoint is in the source for your program, as a file and
-line number.
+line number. For a pending breakpoint, the original string passed to
+the breakpoint command will be listed as it cannot be resolved until
+the appropriate shared library is loaded in the future.
@end table
@noindent
If a breakpoint is conditional, @code{info break} shows the condition on
the line following the affected breakpoint; breakpoint commands, if any,
-are listed after that.
+are listed after that. A pending breakpoint is allowed to have a condition
+specified for it. The condition is not parsed for validity until a shared
+library is loaded that allows the pending breakpoint to resolve to a
+valid location.
@noindent
@code{info break} with a breakpoint
@@ -2631,6 +2638,30 @@
your program. There is nothing silly or meaningless about this. When
the breakpoints are conditional, this is even useful
(@pxref{Conditions, ,Break conditions}).
+
+@cindex pending breakpoints
+If a specified breakpoint location cannot be found, you will be prompted
+as to whether you want to make the breakpoint pending on a future shared
+library load. This is useful for setting breakpoints at the start of your
+@value{GDBN} session for locations that you know will be dynamically loaded
+later by the program being debugged. When shared libraries are loaded,
+a check is made to see if the load resoloves any pending breakpoint locations.
+If a pending breakpoint location has been resolved,
+a real breakpoint is created and the original pending breakpoint is removed.
+
+@cindex operations allowed on pending breakpoints
+Normal breakpoint operations apply to pending breakpoints as well. You may
+specify, a condition for a pending breakpoint, commands to run when the
+breakpoint is reached, and you can also enable or disable
+the pending breakpoint. When you specify a condition for a pending breakpoint,
+the parsing of the condition will be deferred until the point where the
+pending breakpoint location is resolved. Disabling a pending breakpoint
+tells @value{GDBN} to not attempt to resolve the breakpoint on any subsequent
+shared library load. When a pending breakpoint is re-enabled,
+@value{GDBN} checks to see if the location is already resolved.
+This is done because any number of shared library loads could have
+occurred since the time the breakpoint was disabled and one or more
+of these loads could resolve the location.
@cindex negative breakpoint numbers
@cindex internal @value{GDBN} breakpoints