0dce428051
Initially, gdb sets the language to auto/c: ... $ gdb -q (gdb) show language The current source language is "auto; currently c". ... And after loading a c++ executable, that changes to auto/c++: ... (gdb) file a.out Reading symbols from a.out... (gdb) show language The current source language is "auto; currently c++". ... Now consider setting the language manually to c: ... $ gdb -q (gdb) show language The current source language is "auto; currently c". (gdb) set language c (gdb) show language The current source language is "c". ... The resulting language is manual/c. Surprisingly, a subsequent load of the c++ executable: ... (gdb) file a.out Reading symbols from a.out... (gdb) show language The current source language is "c++". ... gets us language manual/c++. Loading the file should get us either: - auto/c++, or - manual/c. That is, either the manual setting should be reset by loading, or the manual setting should persist. Fix this in the manual/c fashion. [ Though we could make some gdb setting to choose one or the other. ] Build and reg-tested on x86_64-linux. [ Note: In PR23710 comment 1 a cc1 binary is attached for which gdb is slow when loading and settting a breakpoint on do_rpo_vn: ... $ time.sh gdb cc1 -batch -ex "b do_rpo_vn" Breakpoint 1 at 0xd40e30: do_rpo_vn. (2 locations) maxmem: 1463496 real: 8.88 user: 8.59 system: 0.35 ... This fix enables a speedup by manually setting the language before loading, reducing executing time with ~17%, due to not having to load the full symtab containing main: ... $ time.sh gdb -iex "set language c++" cc1 -batch -ex "b do_rpo_vn" Breakpoint 1 at 0xd40e30: do_rpo_vn. (2 locations) maxmem: 1067308 real: 7.36 user: 7.14 system: 0.28 ... ] gdb/ChangeLog: 2020-02-26 Tom de Vries <tdevries@suse.de> PR gdb/25603 * symfile.c (set_initial_language): Exit-early if language_mode == language_mode_manual. gdb/testsuite/ChangeLog: 2020-02-26 Tom de Vries <tdevries@suse.de> PR gdb/25603 * gdb.base/persistent-lang.cc: New test. * gdb.base/persistent-lang.exp: New file.
22 lines
777 B
C++
22 lines
777 B
C++
/* This testcase is part of GDB, the GNU debugger.
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Copyright 2020 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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int
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main ()
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{
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return 0;
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}
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