From 67f3ed6afef86d08ef9989cc251eac585e9ef9cf Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Sun, 8 Sep 2019 00:05:22 +0100 Subject: [PATCH] gdb: Catch exceptions when accessing source cache The source_cache::get_line_charpos function can currently throw an exception if the source file is missing, which doesn't match the expected behaviour documented in the functions header file. The documented behaviour is to return false on failure, and this is how the function appears to be used throughout GDB. I spotted this in the 'info source' command, currently for a missing source file you'll see something like this: (gdb) info source Current source file is /path/to/src/file.c Compilation directory is /path/to/build/ /path/to/src/file.c: No such file or directory. (gdb) After this patch we see this: (gdb) info source Current source file is /path/to/src/file.c Compilation directory is /path/to/build/ Source language is c. Producer is COMPILER VERSION AND FLAGS. Compiled with DWARF 2 debugging format. Does not include preprocessor macro info. We don't currently indicate that the source file can't be found, and maybe that would be something worth adding in the future. gdb/ChangeLog: * source-cache.c (source_cache::get_line_charpos): Catch exceptions and return false, this matches the behaviour documented in the header file. gdb/testsuite/ChangeLog: * gdb.base/list-missing-source.exp: New file. --- gdb/ChangeLog | 6 ++ gdb/source-cache.c | 27 +++++--- gdb/testsuite/ChangeLog | 4 ++ .../gdb.base/list-missing-source.exp | 63 +++++++++++++++++++ 4 files changed, 90 insertions(+), 10 deletions(-) create mode 100644 gdb/testsuite/gdb.base/list-missing-source.exp diff --git a/gdb/ChangeLog b/gdb/ChangeLog index c564fcecc0..c9be686c26 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2019-09-17 Andrew Burgess + + * source-cache.c (source_cache::get_line_charpos): Catch + exceptions and return false, this matches the behaviour documented + in the header file. + 2019-09-17 Joel Brobecker * ada-tasks.c (info_task): Remove quoting of the task's name. diff --git a/gdb/source-cache.c b/gdb/source-cache.c index 18e2be989b..7a52ce9458 100644 --- a/gdb/source-cache.c +++ b/gdb/source-cache.c @@ -231,19 +231,26 @@ bool source_cache::get_line_charpos (struct symtab *s, const std::vector **offsets) { - std::string fullname = symtab_to_fullname (s); + try + { + std::string fullname = symtab_to_fullname (s); + + auto iter = m_offset_cache.find (fullname); + if (iter == m_offset_cache.end ()) + { + ensure (s); + iter = m_offset_cache.find (fullname); + /* cache_source_text ensured this was entered. */ + gdb_assert (iter != m_offset_cache.end ()); + } - auto iter = m_offset_cache.find (fullname); - if (iter == m_offset_cache.end ()) + *offsets = &iter->second; + return true; + } + catch (const gdb_exception_error &e) { - ensure (s); - iter = m_offset_cache.find (fullname); - /* cache_source_text ensured this was entered. */ - gdb_assert (iter != m_offset_cache.end ()); + return false; } - - *offsets = &iter->second; - return true; } /* A helper function that extracts the desired source lines from TEXT, diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index d04cff15b8..b9060ef5d0 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2019-09-17 Andrew Burgess + + * gdb.base/list-missing-source.exp: New file. + 2019-09-14 Tom de Vries PR teststuite/24599 diff --git a/gdb/testsuite/gdb.base/list-missing-source.exp b/gdb/testsuite/gdb.base/list-missing-source.exp new file mode 100644 index 0000000000..703603e7cb --- /dev/null +++ b/gdb/testsuite/gdb.base/list-missing-source.exp @@ -0,0 +1,63 @@ +# Copyright 2019 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +# This test checks how GDB handles missing source files around the +# 'list' and 'info source' commands. + +standard_testfile + +# Create a source file in the output directory. +set srcfile [standard_output_file main.c] +set fd [open "$srcfile" w] +puts $fd { +int +main () +{ + return 0; +} +} +close $fd + +# Compile the source file. +set options "debug" +if { [gdb_compile "${srcfile}" "${binfile}" \ + executable $options] != "" } { + untested "failed to compile" + return -1 +} + +# Now delete the source file. +file delete $srcfile + +# Now start GDB, run to main and try to list the source. +clean_restart ${binfile} + +if ![runto_main] then { + fail "can't run to main" + return 0 +} + +gdb_test "list" "1\[ \t\]+in\[ \t\]+$srcfile" + +gdb_test "info source" \ + [multi_line \ + "info source" \ + "Current source file is $srcfile" \ + "Compilation directory is \[^\n\r\]+" \ + "Source language is c." \ + "Producer is \[^\n\r\]+" \ + "Compiled with DWARF $decimal debugging format." \ + "Does not include preprocessor macro info." ] + -- 2.34.1