From ab1adacd8a1980a5af7fecb6ac3ee85f41ce94bd Mon Sep 17 00:00:00 2001 From: Eli Zaretskii Date: Sat, 27 Aug 2005 12:51:30 +0000 Subject: [PATCH] (Variables, Symbols): Document the "" message and its reasons. --- gdb/doc/ChangeLog | 2 ++ gdb/doc/gdb.texinfo | 29 +++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index ce69cf1804c..7d94de776d5 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -3,6 +3,8 @@ * gdb.texinfo (File Options): Don't document --mapped, it's gone since 19-Jan-2004. (Files): Likewise. + (Variables, Symbols): Document the "" message and + its reasons. 2005-08-01 Fred Fish diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 79a924b99a1..45cc16fbf43 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -5179,6 +5179,11 @@ for Debugging Your Program or @sc{gnu} CC, gcc.info, Using @sc{gnu} CC}. @xref{C, , Debugging C++}, for more info about debug info formats that are best suited to C@t{++} programs. +If you ask to print an object whose contents are unknown to +@value{GDBN}, e.g., because its data type is not completely specified +by the debug information, @value{GDBN} will say @samp{}. @xref{Symbols, incomplete type}, for more about this. + @node Arrays @section Artificial arrays @@ -10008,6 +10013,30 @@ type = struct complex @{ As with @code{whatis}, using @code{ptype} without an argument refers to the type of @code{$}, the last value in the value history. +@cindex incomplete type +Sometimes, programs use opaque data types or incomplete specifications +of complex data structure. If the debug information included in the +program does not allow @value{GDBN} to display a full declaration of +the data type, it will say @samp{}. For example, +given these declarations: + +@smallexample + struct foo; + struct foo *fooptr; +@end smallexample + +@noindent +but no definition for @code{struct foo} itself, @value{GDBN} will say: + +@smallexample + (gdb) ptype foo + $1 = +@end smallexample + +@noindent +``Incomplete type'' is C terminology for data types that are not +completely specified. + @kindex info types @item info types @var{regexp} @itemx info types -- 2.30.2