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Re: [RFA/linespec] wrong line number in breakpoint location
[with the patch, this time...]
On Thu, Dec 21, 2017 at 03:31:27PM +0400, Joel Brobecker wrote:
> > > /* The following function's implementation starts by including a file
> > > (break-include.inc) which contains a copyright header followed by
> > > a single C statement. When we break on the line where the function
> >
> > I would say "place a breakpoint" instead of break. For me "to break" is the
> > action of the program stopping on a breakpoint (though maybe it
>
> Sounds good.
>
> Here is a new version :). I also noticed I forgot the gdb.base/
> subdir in the name of the new files in the testsuite, so I fixed
> that up too.
>
> gdb/ChangeLog:
>
> * linespec.c (create_sals_line_offset): Remove code that preserved
> the symtab_and_line's line number.
>
> gdb/testsuite/ChangeLog:
>
> * gdb.base/break-include.c, gdb.base/break-include.inc,
> gdb.base/break-include.exp: New files.
> * gdb.base/ending-run.exp: Minor adaptations due to the breakpoint's
> line number now being the actual line number where the breakpoint
> was inserted.
> * gdb.mi/mi-break.exp: Likewise.
> * gdb.mi/mi-reverse.exp: Likewise.
> * gdb.mi/mi-simplerun.exp: Ditto.
>
> Thanks,
> --
> Joel
--
Joel
>From ff9cb05d65753f870ec58691cef8596e92c060ff Mon Sep 17 00:00:00 2001
From: Joel Brobecker <brobecker@adacore.com>
Date: Thu, 9 Jun 2016 15:41:47 -0700
Subject: [PATCH] wrong line number in breakpoint location
Consider the following situation, where we have one file containing...
$ cat -n body.inc
1 i = i + 1;
... we include that file from some code, like so:
$ cat -n cat -n small.c
[...]
17 int
18 next (int i)
19 {
20 #include "body.inc"
21 return i;
22 }
When trying to insert a breakpoint on line 18, for instance:
(gdb) b small.c:18
Breakpoint 1 at 0x40049f: file body.inc, line 18.
^^
||
Here, the issue is that GDB reports the breakpoint to be in file
body.inc, which is true, but with the line number that corresponding
to the user-requested location, which is not correct.
Although the simple reproducer may look slightly artificial,
the above is simply one way to reproduce the same issue observed
when trying to insert a breakpoint on a function provided in
a .h files and then subsequently inlined in a C file.
What happens is the following:
1. We resolve the small.c:18 linespec into a symtab_and_line which
has "small.c" and 18 as the symtab and line number.
2. Next, we call skip_prologue_sal, which calculates the PC
past the prologue, and updates the symtab_and_line: PC,
but also symtab (now body.inc) and the new line (now 1).
3. However, right after that, we do:
/* Make sure the line matches the request, not what was
found. */
intermediate_results.sals[i].line = val.line;
We should either restore both symtab and line, or leave the actual
line to match the actual symtab. This patch chose the latter.
This introduces a few changes in a few tests, which required some
updates, but looking at those change, I believe them to be expected.
gdb/ChangeLog:
* linespec.c (create_sals_line_offset): Remove code that preserved
the symtab_and_line's line number.
gdb/testsuite/ChangeLog:
* gdb.base/break-include.c, gdb.base/break-include.inc,
gdb.base/break-include.exp: New files.
* gdb.base/ending-run.exp: Minor adaptations due to the breakpoint's
line number now being the actual line number where the breakpoint
was inserted.
* gdb.mi/mi-break.exp: Likewise.
* gdb.mi/mi-reverse.exp: Likewise.
* gdb.mi/mi-simplerun.exp: Ditto.
Tested on x86_64-linux.
WIP/fixup
---
gdb/linespec.c | 3 --
gdb/testsuite/gdb.base/break-include.c | 57 ++++++++++++++++++++++++++++++++
gdb/testsuite/gdb.base/break-include.exp | 34 +++++++++++++++++++
gdb/testsuite/gdb.base/break-include.inc | 18 ++++++++++
gdb/testsuite/gdb.base/ending-run.exp | 4 +--
gdb/testsuite/gdb.mi/mi-break.exp | 11 +++---
gdb/testsuite/gdb.mi/mi-reverse.exp | 2 +-
gdb/testsuite/gdb.mi/mi-simplerun.exp | 4 +--
8 files changed, 121 insertions(+), 12 deletions(-)
create mode 100644 gdb/testsuite/gdb.base/break-include.c
create mode 100644 gdb/testsuite/gdb.base/break-include.exp
create mode 100644 gdb/testsuite/gdb.base/break-include.inc
diff --git a/gdb/linespec.c b/gdb/linespec.c
index 8c36f2a..f81e4c1 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -2246,9 +2246,6 @@ create_sals_line_offset (struct linespec_state *self,
if (self->funfirstline)
skip_prologue_sal (&intermediate_results[i]);
- /* Make sure the line matches the request, not what was
- found. */
- intermediate_results[i].line = val.line;
add_sal_to_sals (self, &values, &intermediate_results[i],
sym ? SYMBOL_NATURAL_NAME (sym) : NULL, 0);
}
diff --git a/gdb/testsuite/gdb.base/break-include.c b/gdb/testsuite/gdb.base/break-include.c
new file mode 100644
index 0000000..3662bc9
--- /dev/null
+++ b/gdb/testsuite/gdb.base/break-include.c
@@ -0,0 +1,57 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2016-2017 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/>. */
+
+int next (int i);
+
+int
+main (void)
+{
+ int result = -1;
+
+ result = next (result);
+ return result;
+}
+
+/* The following function's implementation starts by including a file
+ (break-include.inc) which contains a copyright header followed by
+ a single C statement. When we place a breakpoint on the line where
+ the function name is declared, we expect GDB to skip the function's
+ prologue, and insert the breakpoint on the first line of "user" code
+ for that function, which we have set up to be that single statement
+ break-include.inc provides.
+
+ The purpose of this testcase is to verify that, when we insert
+ that breakpoint, GDB reports the location as being in that include
+ file, but also using the correct line number inside that include
+ file -- NOT the line number we originally used to insert the
+ breakpoint, nor the location where the file is included from.
+ In order to verify that GDB shows the right line number, we must
+ be careful that this first statement located in break-include.inc
+ and our function are not on the same line number. Otherwise,
+ we could potentially have a false PASS.
+
+ This is why we implement the following function as far away
+ from the start of this file as possible, as we know that
+ break-include.inc is a fairly short file (copyright header
+ and single statement only). */
+
+int
+next (int i) /* break here */
+{
+#include "break-include.inc"
+ return i;
+}
diff --git a/gdb/testsuite/gdb.base/break-include.exp b/gdb/testsuite/gdb.base/break-include.exp
new file mode 100644
index 0000000..a29a221
--- /dev/null
+++ b/gdb/testsuite/gdb.base/break-include.exp
@@ -0,0 +1,34 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2016-2017 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/>.
+
+standard_testfile
+
+if { [prepare_for_testing ${testfile}.exp $testfile] } {
+ return -1
+}
+
+set bp_line [gdb_get_line_number "break here" ${testfile}.c]
+set bp_line_actual [gdb_get_line_number "ANCHOR" ${testfile}.inc]
+
+gdb_test "break $testfile.c:$bp_line" \
+ ".*Breakpoint.*$testfile.inc, line $bp_line_actual\\."
+
+# Might as well verify that breaking on function "next" gives
+# the same result...
+
+gdb_test "break next" \
+ ".*Breakpoint.*$testfile.inc, line $bp_line_actual\\."
diff --git a/gdb/testsuite/gdb.base/break-include.inc b/gdb/testsuite/gdb.base/break-include.inc
new file mode 100644
index 0000000..4573672
--- /dev/null
+++ b/gdb/testsuite/gdb.base/break-include.inc
@@ -0,0 +1,18 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2016-2017 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+i = i + 1; /* ANCHOR */
diff --git a/gdb/testsuite/gdb.base/ending-run.exp b/gdb/testsuite/gdb.base/ending-run.exp
index 42cbf23..e2b1ccc 100644
--- a/gdb/testsuite/gdb.base/ending-run.exp
+++ b/gdb/testsuite/gdb.base/ending-run.exp
@@ -68,14 +68,14 @@ gdb_test_multiple "i b" "cleared bp at line before routine" {
gdb_test "b ending-run.c:1" ".*Breakpoint.*4.*"
gdb_test "b ending-run.c:$break1_line" ".*Note.*also.*Breakpoint.*5.*" "b ending-run.c:$break1_line, two"
gdb_test "cle ending-run.c:$break1_line" \
- ".*Deleted breakpoint 5.*" "Cleared 2 by line"
+ ".*Deleted breakpoints 4 5.*" "Cleared 2 by line"
gdb_test_multiple "info line ending-run.c:$break1_line" "" {
-re ".*address (0x\[0-9a-fA-F]*).*$gdb_prompt $" {
set line_nine $expect_out(1,string)
gdb_test "b ending-run.c:$break1_line" ".*Breakpoint 6.*ending-run.c, line $break1_line.*"
gdb_test "b *$line_nine" ".*Note.*also.*Breakpoint 7.*" "breakpoint 7 at *ending-run.c:$break1_line"
- gdb_test "cle" ".*Deleted breakpoints 4 6 7.*" "clear 2 by default"
+ gdb_test "cle" ".*Deleted breakpoints 6 7.*" "clear 2 by default"
}
-re ".*$gdb_prompt $" {
fail "need to fix test for new compile outcome"
diff --git a/gdb/testsuite/gdb.mi/mi-break.exp b/gdb/testsuite/gdb.mi/mi-break.exp
index 41a48a1..0005f7e 100644
--- a/gdb/testsuite/gdb.mi/mi-break.exp
+++ b/gdb/testsuite/gdb.mi/mi-break.exp
@@ -49,7 +49,9 @@ set fullname "fullname=\"${fullname_syntax}${srcfile}\""
proc test_tbreak_creation_and_listing {} {
global srcfile
global line_callee4_head
+ global line_callee4_body
global line_callee3_head
+ global line_callee3_body
global line_callee2_body
global line_main_body
@@ -75,7 +77,7 @@ proc test_tbreak_creation_and_listing {} {
lappend bps [mi_create_breakpoint "-t basics.c:$line_callee3_head" \
"insert temp breakpoint at basics.c:\$line_callee3_head" \
-number 3 -disp del -func callee3 -file ".*basics.c" \
- -line $line_callee3_head]
+ -line $line_callee3_body]
# Getting the quoting right is tricky.
# That is "\"<file>\":$line_callee4_head"
@@ -83,7 +85,7 @@ proc test_tbreak_creation_and_listing {} {
"-t \"\\\"${srcfile}\\\":$line_callee4_head\"" \
"insert temp breakpoint at \"<fullfilename>\":\$line_callee4_head" \
-number 4 -disp del -func callee4 -file ".*basics.c" \
- -line $line_callee4_head]
+ -line $line_callee4_body]
mi_gdb_test "666-break-list" \
"666\\\^done,[mi_make_breakpoint_table $bps]" \
@@ -319,6 +321,7 @@ proc test_breakpoint_commands {} {
proc test_explicit_breakpoints {} {
global srcfile
global line_callee3_head line_callee4_head
+ global line_callee3_body line_callee4_body
global line_callee2_body line_main_body
mi_delete_breakpoints
@@ -349,13 +352,13 @@ proc test_explicit_breakpoints {} {
lappend bps \
[mi_create_breakpoint "-t --source $srcfile --line $line_callee3_head" \
"insert temp explicit breakpoint at $srcfile:$line_callee3_head" \
- -func callee3 -file ".*$srcfile" -line $line_callee3_head]
+ -func callee3 -file ".*$srcfile" -line $line_callee3_body]
lappend bps \
[mi_create_breakpoint \
"-t --source \"$srcfile\" --line $line_callee4_head" \
"insert temp explicit breakpoint at \"$srcfile\":$line_callee4_head" \
- -func callee4 -file ".*$srcfile" -line $line_callee4_head]
+ -func callee4 -file ".*$srcfile" -line $line_callee4_body]
mi_gdb_test "-break-list" "\\^done,[mi_make_breakpoint_table $bps]" \
"list of explicit breakpoints"
diff --git a/gdb/testsuite/gdb.mi/mi-reverse.exp b/gdb/testsuite/gdb.mi/mi-reverse.exp
index 448a9a3..30b96f3 100644
--- a/gdb/testsuite/gdb.mi/mi-reverse.exp
+++ b/gdb/testsuite/gdb.mi/mi-reverse.exp
@@ -153,7 +153,7 @@ proc test_controlled_execution_reverse {} {
mi_create_breakpoint "-t basics.c:$line_callee3_head" \
"insert temp breakpoint at basics.c:$line_callee3_head" \
-number 3 -disp del -func callee3 -file ".*basics.c" \
- -line $line_callee3_head
+ -line $line_callee3_body
mi_execute_to "exec-continue --reverse" \
"breakpoint-hit" "callee3" \
diff --git a/gdb/testsuite/gdb.mi/mi-simplerun.exp b/gdb/testsuite/gdb.mi/mi-simplerun.exp
index db75f4d..e6b5a4f 100644
--- a/gdb/testsuite/gdb.mi/mi-simplerun.exp
+++ b/gdb/testsuite/gdb.mi/mi-simplerun.exp
@@ -78,13 +78,13 @@ proc test_breakpoints_creation_and_listing {} {
lappend bps [mi_create_breakpoint "basics.c:$line_callee3_head" \
"insert breakpoint at basics.c:\$line_callee3_head" \
-number 3 -func callee3 -file ".*basics.c" \
- -line $line_callee3_head]
+ -line $line_callee3_body]
lappend bps [mi_create_breakpoint \
"\"\\\"${srcfile}\\\":$line_callee4_head\"" \
"insert breakpoint at \"<fullfilename>\":\$line_callee4_head" \
-number 4 -func callee4 -file ".*basics.c" \
- -line $line_callee4_head]
+ -line $line_callee4_body]
mi_gdb_test "204-break-list" \
"204\\^done,[mi_make_breakpoint_table $bps]" \
--
2.1.4