From 38899f16e1560ce3020bab8a6a0b3a0c017d7925 Mon Sep 17 00:00:00 2001 From: Iain Buclaw Date: Sun, 28 Feb 2016 10:25:55 +0100 Subject: [PATCH] Don't recursively look for a symbol in all imports of imported modules. Given two or more modules that import each other's scope, the current symbol lookup routines would go round in circles looking through each import from each module, possibly checking the same module twice or more until all possible paths are marked as "searched". Given enough modules, this causes an exponential slowdown in time taken to find symbols that do exist, and infinite recursion when they don't. gdb/ChangeLog: * d-namespace.c (d_lookup_symbol_imports): Avoid recursive lookups from cyclic imports. gdb/testsuite/ChangeLog: * gdb.dlang/circular.c: New file. * gdb.dlang/circular.exp: New file. --- gdb/ChangeLog | 5 + gdb/d-namespace.c | 10 +- gdb/testsuite/ChangeLog | 5 + gdb/testsuite/gdb.dlang/circular.c | 33 ++++++ gdb/testsuite/gdb.dlang/circular.exp | 149 +++++++++++++++++++++++++++ 5 files changed, 197 insertions(+), 5 deletions(-) create mode 100644 gdb/testsuite/gdb.dlang/circular.c create mode 100644 gdb/testsuite/gdb.dlang/circular.exp diff --git a/gdb/ChangeLog b/gdb/ChangeLog index bcbaacfe224..bc6a713d01a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2016-02-28 Iain Buclaw + + * d-namespace.c (d_lookup_symbol_imports): Avoid recursive lookups from + cyclic imports. + 2016-02-26 Keith Seitz * rs6000-tdep.c (rs6000_frame_cache): Explicitly cast return result diff --git a/gdb/d-namespace.c b/gdb/d-namespace.c index 6399ef012f3..8b8c3cc96c7 100644 --- a/gdb/d-namespace.c +++ b/gdb/d-namespace.c @@ -483,9 +483,9 @@ d_lookup_symbol_imports (const char *scope, const char *name, { /* Skip the '.' */ name_scope++; - sym = d_lookup_symbol_imports (current->import_src, - name + name_scope, - block, domain); + sym = d_lookup_symbol_in_module (current->import_src, + name + name_scope, + block, domain, 1); } } } @@ -494,8 +494,8 @@ d_lookup_symbol_imports (const char *scope, const char *name, /* If this import statement creates no alias, pass current->import_src as MODULE to direct the search towards the imported module. */ - sym = d_lookup_symbol_imports (current->import_src, - name, block, domain); + sym = d_lookup_symbol_in_module (current->import_src, + name, block, domain, 1); } current->searched = 0; discard_cleanups (searched_cleanup); diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 23489ae2c00..6aa071341cd 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-02-28 Iain Buclaw + + * gdb.dlang/circular.c: New file. + * gdb.dlang/circular.exp: New file. + 2016-02-26 Yao Qi * gdb.reverse/insn-reverse.c [__arm__] (ext_reg_load): New. diff --git a/gdb/testsuite/gdb.dlang/circular.c b/gdb/testsuite/gdb.dlang/circular.c new file mode 100644 index 00000000000..a946e3fcc70 --- /dev/null +++ b/gdb/testsuite/gdb.dlang/circular.c @@ -0,0 +1,33 @@ +/* Copyright 2016 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 . */ + +asm ("circular1_found_start: .globl circular1_found_start"); + +/* DWARF will describe this function as being inside a D module. */ + +void +found (void) +{ +} + +asm ("circular1_found_end: .globl circular1_found_end"); + +int +main (void) +{ + found (); + return 0; +} + diff --git a/gdb/testsuite/gdb.dlang/circular.exp b/gdb/testsuite/gdb.dlang/circular.exp new file mode 100644 index 00000000000..c6eb789579a --- /dev/null +++ b/gdb/testsuite/gdb.dlang/circular.exp @@ -0,0 +1,149 @@ +# Copyright (C) 2016 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 . + +# Test symbol lookup when there are multiple circular imports. + +load_lib "d-support.exp" +load_lib "dwarf.exp" + +if { [skip_d_tests] } { continue } + +# This test can only be run on targets which support DWARF-2 and use gas. +if {![dwarf2_support]} { + return 0 +} + +standard_testfile circular.c circular-dw.S + +# Make some DWARF for the test. +set asm_file [standard_output_file $srcfile2] +Dwarf::assemble $asm_file { + cu {} { + compile_unit { + {language @DW_LANG_D} + } { + declare_labels circular1_label circular2_label circular3_label + declare_labels circular4_label circular5_label + + extern circular1_found_start circular1_found_end + + circular1_label: module { + {name circular1} + } { + imported_module { + {import :$circular2_label} + } + imported_module { + {import :$circular3_label} + } + imported_module { + {import :$circular4_label} + } + imported_module { + {import :$circular5_label} + } + + subprogram { + {name found} + {external 1 flag_present} + {low_pc circular1_found_start addr} + {high_pc circular1_found_end addr} + } + } + + circular2_label: module { + {name circular2} + } { + imported_module { + {import :$circular1_label} + } + imported_module { + {import :$circular3_label} + } + imported_module { + {import :$circular4_label} + } + imported_module { + {import :$circular5_label} + } + } + + circular3_label: module { + {name circular3} + } { + imported_module { + {import :$circular1_label} + } + imported_module { + {import :$circular2_label} + } + imported_module { + {import :$circular4_label} + } + imported_module { + {import :$circular5_label} + } + } + + circular4_label: module { + {name circular4} + } { + imported_module { + {import :$circular1_label} + } + imported_module { + {import :$circular2_label} + } + imported_module { + {import :$circular3_label} + } + imported_module { + {import :$circular5_label} + } + } + + circular5_label: module { + {name circular5} + } { + imported_module { + {import :$circular1_label} + } + imported_module { + {import :$circular2_label} + } + imported_module { + {import :$circular3_label} + } + imported_module { + {import :$circular4_label} + } + } + } + } +} + +if { [prepare_for_testing ${testfile}.exp ${testfile} \ + [list $srcfile $asm_file] {nodebug}] } { + return -1 +} + +gdb_test_no_output "set language d" + +if {![runto "circular1.found"]} { + return -1 +} + +# This last test shouldn't timeout. +gdb_test "print notfound" "No symbol \"notfound\" in current context." -- 2.39.2