Patchwork [RFC] Only compute realpath when basenames_may_differ is set

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Submitter Tom Tromey
Date May 30, 2019, 5:03 p.m.
Message ID <20190530170315.9938-1-tromey@adacore.com>
Download mbox | patch
Permalink /patch/32926/
State New
Headers show

Comments

Tom Tromey - May 30, 2019, 5:03 p.m.
A user noted that, when sources are symlinked, gdb annotations will
print the real path, rather than the name of the symlink.

It seems to me that it is better to print the name of the file that
was actually used in the build, unless there is some reason not to.

This patch implements this, with the caveat that it will not work when
basenames-may-differ is enabled.  The way this mode is currently
implemented, returning the symbolic (not real) path is not possible.

While I think it would be good to redo the source file name cache and
perhaps integrate it with class source_cache, I haven't done so here.

Regression tested on x86-64 Fedora 29.

gdb/ChangeLog
2019-05-30  Tom Tromey  <tromey@adacore.com>

	* source.c (find_and_open_source): Respect basenames_may_differ.

gdb/testsuite/ChangeLog
2019-05-30  Tom Tromey  <tromey@adacore.com>

	* gdb.base/annotate-symlink.exp: New file.
---
 gdb/ChangeLog                               |  4 ++
 gdb/source.c                                | 14 ++++--
 gdb/testsuite/ChangeLog                     |  4 ++
 gdb/testsuite/gdb.base/annotate-symlink.exp | 51 +++++++++++++++++++++
 4 files changed, 68 insertions(+), 5 deletions(-)
 create mode 100644 gdb/testsuite/gdb.base/annotate-symlink.exp
Tom Tromey - June 14, 2019, 2:30 p.m.
>>>>> "Tom" == Tom Tromey <tromey@adacore.com> writes:

Tom> A user noted that, when sources are symlinked, gdb annotations will
Tom> print the real path, rather than the name of the symlink.

Tom> It seems to me that it is better to print the name of the file that
Tom> was actually used in the build, unless there is some reason not to.

Tom> This patch implements this, with the caveat that it will not work when
Tom> basenames-may-differ is enabled.  The way this mode is currently
Tom> implemented, returning the symbolic (not real) path is not possible.

Tom> While I think it would be good to redo the source file name cache and
Tom> perhaps integrate it with class source_cache, I haven't done so here.

Tom> Regression tested on x86-64 Fedora 29.

Tom> gdb/ChangeLog
Tom> 2019-05-30  Tom Tromey  <tromey@adacore.com>

Tom> 	* source.c (find_and_open_source): Respect basenames_may_differ.

I'm checking this in now.

Tom
Tom de Vries - June 16, 2019, 10:34 p.m.
On 14-06-19 16:30, Tom Tromey wrote:
>>>>>> "Tom" == Tom Tromey <tromey@adacore.com> writes:
> 
> Tom> A user noted that, when sources are symlinked, gdb annotations will
> Tom> print the real path, rather than the name of the symlink.
> 
> Tom> It seems to me that it is better to print the name of the file that
> Tom> was actually used in the build, unless there is some reason not to.
> 
> Tom> This patch implements this, with the caveat that it will not work when
> Tom> basenames-may-differ is enabled.  The way this mode is currently
> Tom> implemented, returning the symbolic (not real) path is not possible.
> 
> Tom> While I think it would be good to redo the source file name cache and
> Tom> perhaps integrate it with class source_cache, I haven't done so here.
> 
> Tom> Regression tested on x86-64 Fedora 29.
> 
> Tom> gdb/ChangeLog
> Tom> 2019-05-30  Tom Tromey  <tromey@adacore.com>
> 
> Tom> 	* source.c (find_and_open_source): Respect basenames_may_differ.
> 
> I'm checking this in now.
> 

This caused PR24687 - "FAIL: gdb.base/fullname.exp: set breakpoint by
full path before/after loading symbols - built relative".

Thanks,
- Tom
Tom Tromey - June 17, 2019, 5:30 p.m.
Tom> This caused PR24687 - "FAIL: gdb.base/fullname.exp: set breakpoint by
Tom> full path before/after loading symbols - built relative".

Thanks for the report.  I replied in the bug -- I couldn't reproduce
this.

Tom

Patch

diff --git a/gdb/source.c b/gdb/source.c
index 9a30209880b..9e4b8e4fafb 100644
--- a/gdb/source.c
+++ b/gdb/source.c
@@ -987,7 +987,10 @@  find_and_open_source (const char *filename,
       result = gdb_open_cloexec (fullname->get (), OPEN_MODE, 0);
       if (result >= 0)
 	{
-	  *fullname = gdb_realpath (fullname->get ());
+	  if (basenames_may_differ)
+	    *fullname = gdb_realpath (fullname->get ());
+	  else
+	    *fullname = gdb_abspath (fullname->get ());
 	  return scoped_fd (result);
 	}
 
@@ -1036,15 +1039,16 @@  find_and_open_source (const char *filename,
 	filename = rewritten_filename.get ();
     }
 
-  result = openp (path, OPF_SEARCH_IN_PATH | OPF_RETURN_REALPATH, filename,
-		  OPEN_MODE, fullname);
+  openp_flags flags = OPF_SEARCH_IN_PATH;
+  if (basenames_may_differ)
+    flags |= OPF_RETURN_REALPATH;
+  result = openp (path, flags, filename, OPEN_MODE, fullname);
   if (result < 0)
     {
       /* Didn't work.  Try using just the basename.  */
       p = lbasename (filename);
       if (p != filename)
-	result = openp (path, OPF_SEARCH_IN_PATH | OPF_RETURN_REALPATH, p,
-			OPEN_MODE, fullname);
+	result = openp (path, flags, p, OPEN_MODE, fullname);
     }
 
   return scoped_fd (result);
diff --git a/gdb/testsuite/gdb.base/annotate-symlink.exp b/gdb/testsuite/gdb.base/annotate-symlink.exp
new file mode 100644
index 00000000000..6dba2fe823c
--- /dev/null
+++ b/gdb/testsuite/gdb.base/annotate-symlink.exp
@@ -0,0 +1,51 @@ 
+# Copyright (C) 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 <http://www.gnu.org/licenses/>.
+
+standard_testfile realname-expand.c realname-expand-real.c
+
+if [is_remote host] {
+    unsupported "compiling on a remote host does not support a filename with directory."
+    return 0
+}
+
+set srcdirabs [file join [pwd] $srcdir]
+set srcfilelink [standard_output_file realname-expand-link.c]
+
+remote_exec build "ln -sf ${srcdirabs}/${subdir}/${srcfile2} $srcfilelink"
+
+if { [file type $srcfilelink] != "link" } {
+    unsupported "target directory cannot have symbolic links"
+    return -1
+}
+
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile} ${srcfilelink}" "${binfile}" \
+		  executable {debug}] != "" } {
+    untested "failed to compile"
+    return -1
+}
+
+clean_restart ${testfile}
+
+if {![runto_main]} {
+    unsupported "failed to run to main"
+    return -1
+}
+
+gdb_breakpoint func message
+
+gdb_test_no_output "set annotate 1"
+
+gdb_test "continue" \
+    "Breakpoint .* func .*realname-expand-link.c:$decimal\r\n\032\032.*realname-expand-link.c:.*"