gdb

[deliverable/binutils-gdb.git] / gdb / doc / gdb.texinfo

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index cd3ac0f0e987fcd906a3f802228f52fb6b50902e..fa50761ffabf6070043bf930327db1a51acc1f7c 100644 (file)
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -3711,7 +3711,7 @@ watchpoints, which do not slow down the running of your program.
 
 @table @code
 @kindex watch
-@item watch @var{expr} @r{[}thread @var{threadnum}@r{]}
+@item watch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]}
 Set a watchpoint for an expression.  @value{GDBN} will break when the
 expression @var{expr} is written into by the program and its value
 changes.  The simplest (and the most popular) use of this command is
@@ -3728,13 +3728,22 @@ change the value of @var{expr}, @value{GDBN} will not break.  Note
 that watchpoints restricted to a single thread in this way only work
 with Hardware Watchpoints.
 
+Ordinarily a watchpoint respects the scope of variables in @var{expr}
+(see below).  The @code{-location} argument tells @value{GDBN} to
+instead watch the memory referred to by @var{expr}.  In this case,
+@value{GDBN} will evaluate @var{expr}, take the address of the result,
+and watch the memory at that address.  The type of the result is used
+to determine the size of the watched memory.  If the expression's
+result does not have an address, then @value{GDBN} will print an
+error.
+
 @kindex rwatch
-@item rwatch @var{expr} @r{[}thread @var{threadnum}@r{]}
+@item rwatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]}
 Set a watchpoint that will break when the value of @var{expr} is read
 by the program.
 
 @kindex awatch
-@item awatch @var{expr} @r{[}thread @var{threadnum}@r{]}
+@item awatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]}
 Set a watchpoint that will break when @var{expr} is either read from
 or written into by the program.