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The forward-search and reverse-search commands were broken by this commit: commita75cd9a2c1Date: Thu Nov 14 16:11:15 2019 -0700 Add observable to watch current source symtab while builds on the work in this commit: commit1dd5885077Date: Thu Aug 1 09:34:40 2019 -0600 Make current_source_* per-program-space both of these commits went into GDB 10. The documentation for these commands is pretty clear: 'forward-search REGEXP' 'search REGEXP' The command 'forward-search REGEXP' checks each line, starting with the one following the last line listed, for a match for REGEXP. It lists the line that is found. You can use the synonym 'search REGEXP' or abbreviate the command name as 'fo'. 'reverse-search REGEXP' The command 'reverse-search REGEXP' checks each line, starting with the one before the last line listed and going backward, for a match for REGEXP. It lists the line that is found. You can abbreviate this command as 'rev'. Both searches should start searching based on the last line listed. But currently: (gdb) list 3 1 int 2 main (void) 3 { 4 /* Line 4 */ 5 /* Line 5 */ 6 /* Line 6 */ 7 /* Line 7 */ 8 /* Line 8 */ 9 /* Line 9 */ 10 /* Line 10 */ (gdb) forward-search Line 4 /* Line 4 */ (gdb) This should have found line 11. And for reverse-search: (gdb) list 3 1 int 2 main (void) 3 { 4 /* Line 4 */ 5 /* Line 5 */ 6 /* Line 6 */ 7 /* Line 7 */ 8 /* Line 8 */ 9 /* Line 9 */ 10 /* Line 10 */ (gdb) reverse-search Line Expression not found (gdb) The reverse-search should have returned line 9. This new behaviour started with the above commits in GDB 10. On GDB 9 we see behaviour that matches the documentation. Where the forward and reverse searches start from is controlled by a global, last_line_listed, found in source.c. Before commit1dd5885077, in print_source_lines_base, the last_line_listed variable was updated as each source line was printed, and it was updated with the current line being printed. After commit1dd5885077, the current symtab and line are moved into a current_source_location object, but the symtab and line member variables are public. The last_line_listed is still set based on the value held in the current_source_location object, and this object is updated each time around the source printing loop. So despite the restructure, the logic, and behaviour, is unchanged. After commita75cd9a2c1, the member variables of current_source_location are now private. The source printing loop in print_source_lines_base uses a local variable, new_lineno, to track the current source line number, and updates the current_source_location at the end of print_source_lines_base. However, last_line_listed is still updated inside the loop, using the original line value within current_source_location, which is no longer being updated each time around the loop. As a result, last_line_listed is now just the first line listed! This didn't show up in testing because, as far as I can tell, the last_line_listed is _only_ used for forward and reverse searching, and the testing for these commands is minimal. In this commit I move the setting of last_line_listed outside of the source printing loop, this only needs to be updated once, when we have finished printing the source lines. I've also done a couple of other cleanups in the same area, I moved 'buf' a local variable into the most inner scope where it is required, and I converted the 'while' loop into a 'for' loop, moving the increment out of the loop body. There's now a test which does some more detailed checks of the forward and reverse search commands. Approved-By: Tom Tromey <tom@tromey.com>
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.