[binutils-gdb] [gdb] Fix range loop index in find_method

[Tom de Vries <vries@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ea90f2278cee318976c66bf82284046214fb30af

commit ea90f2278cee318976c66bf82284046214fb30af
Author: Tom de Vries <tdevries@suse.de>
Date:   Wed Apr 29 11:39:36 2020 +0200

    [gdb] Fix range loop index in find_method
    
    With target board debug-types, we have:
    ...
    FAIL: gdb.cp/cpexprs.exp: list policy1::function
    ...
    
    This is a regression triggered by commit 770479f223e "gdb: Fix toplevel types
    with -fdebug-types-section".
    
    However, the FAIL is caused by commit 4dedf84da98 "Change
    decode_compound_collector to use std::vector" which changes a VEC_iterate loop
    into a range loop:
    ...
    -  for (ix = 0; VEC_iterate (symbolp, sym_classes, ix, sym); ++ix)
    +  unsigned int ix = 0;
    +  for (const auto &sym : *sym_classes)
    ...
    but fails to ensure that the increment of ix happens every iteration.
    
    Fix this by calculating the index variable at the start of the loop body:
    ...
      for (const auto &elt : *sym_classes)
        {
          unsigned int ix = &elt - &*sym_classes->begin ();
    ...
    
    Tested on x86_64-linux, with native and target board debug-types.
    
    gdb/ChangeLog:
    
    2020-04-29  Tom de Vries  <tdevries@suse.de>
    
            PR symtab/25889
            * linespec.c (find_method): Fix ix calculation.
    
    gdb/testsuite/ChangeLog:
    
    2020-04-29  Tom de Vries  <tdevries@suse.de>
    
            PR symtab/25889
            * gdb.cp/cpexprs.exp: Adapt for inclusion.
            * gdb.cp/cpexprs-debug-types.exp: New file.  Set -fdebug-types-section
            and include cpexprs.exp.

Diff:
---
 gdb/ChangeLog                                |  5 +++++
 gdb/linespec.c                               |  3 +--
 gdb/testsuite/ChangeLog                      |  7 +++++++
 gdb/testsuite/gdb.cp/cpexprs-debug-types.exp | 20 ++++++++++++++++++++
 gdb/testsuite/gdb.cp/cpexprs.exp             | 14 ++++++++++++--
 5 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3313f156c94..ef605655999 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-04-29  Tom de Vries  <tdevries@suse.de>
+
+	PR symtab/25889
+	* linespec.c (find_method): Fix ix calculation.
+
 2020-04-28  Kamil Rytarowski  <n54@gmx.com>
 
 	* syscalls/update-netbsd.sh: New file.
diff --git a/gdb/linespec.c b/gdb/linespec.c
index 0eb3bc5b8d4..6e4fe6cb771 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -3670,12 +3670,12 @@ find_method (struct linespec_state *self, std::vector<symtab *> *file_symtabs,
      because we collect data across the program space before deciding
      what to do.  */
   last_result_len = 0;
-  unsigned int ix = 0;
   for (const auto &elt : *sym_classes)
     {
       struct type *t;
       struct program_space *pspace;
       struct symbol *sym = elt.symbol;
+      unsigned int ix = &elt - &*sym_classes->begin ();
 
       /* Program spaces that are executing startup should have
 	 been filtered out earlier.  */
@@ -3706,7 +3706,6 @@ find_method (struct linespec_state *self, std::vector<symtab *> *file_symtabs,
 
 	  superclass_vec.clear ();
 	  last_result_len = result_names.size ();
-	  ++ix;
 	}
     }
 
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 129b9697598..761fe30535e 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2020-04-29  Tom de Vries  <tdevries@suse.de>
+
+	PR symtab/25889
+	* gdb.cp/cpexprs.exp: Adapt for inclusion.
+	* gdb.cp/cpexprs-debug-types.exp: New file.  Set -fdebug-types-section
+	and include cpexprs.exp.
+
 2020-04-28 Mark Williams <mark@myosotissp.com>
 
 	PR gdb/24480
diff --git a/gdb/testsuite/gdb.cp/cpexprs-debug-types.exp b/gdb/testsuite/gdb.cp/cpexprs-debug-types.exp
new file mode 100644
index 00000000000..9499aecf4c6
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/cpexprs-debug-types.exp
@@ -0,0 +1,20 @@
+# Copyright 2020 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 <http://www.gnu.org/licenses/>.
+
+# This file is part of the gdb testsuite.
+
+# Run cpexprs.exp with -fdebug-types-section.
+set flags {additional_flags=-fdebug-types-section}
+source $srcdir/$subdir/cpexprs.exp
diff --git a/gdb/testsuite/gdb.cp/cpexprs.exp b/gdb/testsuite/gdb.cp/cpexprs.exp
index e8b898fa111..383def9fb64 100644
--- a/gdb/testsuite/gdb.cp/cpexprs.exp
+++ b/gdb/testsuite/gdb.cp/cpexprs.exp
@@ -685,13 +685,23 @@ if {[skip_cplus_tests]} { continue }
 # test running programs
 #
 
-standard_testfile .cc
+standard_testfile cpexprs.cc
 
 if {[get_compiler_info "c++"]} {
     return -1
 }
 
-if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug c++}]} {
+if { [info exists flags] } {
+    # Already set externally.
+} else {
+    # Initialize to empty.
+    set flags {}
+}
+
+# Include required flags.
+set flags "$flags debug c++"
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile "$flags"]} {
     return -1
 }