The provided patch adds a scope lookup with higher priority in the case
a file is provided for the evaluation.
Usual symbol lookup from GDB follows linker logic. This is what is
desired most of the time. In the usage case presented a full qualified
scope is provided, so the lookup has to follow this priority. Failing
in
finding the symbol at this scope usual path is followed.
As use and test case it is presented two shared objects having a global
variable with the same name but comming from different source files.
Without the patch evaluating those variables providing the file scope
returns the wrong value; It returns the value seen in the first loaded
shared object. Using the patch the value defined in the file scope is
the one returned. Without using this patch the result of the
evaluations
are:
print 'print-file-var-lib1.c'::this_version_id
$1 = 104
and
print 'print-file-var-lib2.c'::this_version_id
$2 = 104 # This value is wrong we have set 203 in the code
With the patch applied we get:
print 'print-file-var-lib1.c'::this_version_id
$1 = 104
and
print 'print-file-var-lib2.c'::this_version_id
$2 = 203 # Now value is correct
One of the already existing test cases in print-file-var.exp starts to
fail after aplying this patch. In fact the value that the linker
sees is different then the one debugger can read from the shared
object.
In this sense it looks like to me that the test has to be changed.
The fail is in the call:
print 'print-file-var-lib2.c'::this_version_id == v2
in this case v1 and v2 are the same and equal to the this_version_id
defined in print-file-var-lib1.c. Test is changed to assure that
when the scope operator is used the value seen in print-file-var-lib2.c
is the one GDB evaluates, i.e. 203.
* Reading again Simon's comments I have decided to take a quick look
on
the failing test. I have fixed it according to the logic of the
current
patch.
2017-10-18 Walfred Tedeschi <walfred.tedeschi@intel.com>
gdb/ChangeLog:
* symtab.c (lookup_global_symbol): Add new lookup to ensure
priority on given block.
gdb/testsuite/ChangeLog:
* gdb.base/print-file-var-dlopen-main.c: New file.
* gdb.base/print-file-var-dlopen.exp: New test based on
print-file-var.exp.
* gdb.base/print-file-var-dlopen-lib1.c: New file.
* gdb.base/print-file-var-dlopen-lib2.c: New file.
* gdb.base/print-file-var.exp: Modify expected result for
evaluating 'print-file-var-lib2.c'::this_version_id.
---
gdb/symtab.c | 4 +
.../gdb.base/print-file-var-dlopen-lib1.c | 25 ++++++
.../gdb.base/print-file-var-dlopen-lib2.c | 25 ++++++
.../gdb.base/print-file-var-dlopen-main.c | 61
+++++++++++++++
gdb/testsuite/gdb.base/print-file-var-dlopen.exp | 90
++++++++++++++++++++++
gdb/testsuite/gdb.base/print-file-var.exp | 4 +-
6 files changed, 208 insertions(+), 1 deletion(-)
create mode 100644 gdb/testsuite/gdb.base/print-file-var-dlopen-lib1.c
create mode 100644 gdb/testsuite/gdb.base/print-file-var-dlopen-lib2.c
create mode 100644 gdb/testsuite/gdb.base/print-file-var-dlopen-main.c
create mode 100644 gdb/testsuite/gdb.base/print-file-var-dlopen.exp
diff --git a/gdb/symtab.c b/gdb/symtab.c
index 16a6b2e..a2c307f 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -2589,6 +2589,10 @@ lookup_global_symbol (const char *name,
if (objfile != NULL)
result = solib_global_lookup (objfile, name, domain);
+ /* We still need to look on the global scope of current object file.
*/
+ if (result.symbol == NULL && objfile != NULL)
+ result = lookup_symbol_in_objfile (objfile, GLOBAL_BLOCK, name,
domain);
+
/* If that didn't work go a global search (of global blocks, heh).
*/
if (result.symbol == NULL)
{
diff --git a/gdb/testsuite/gdb.base/print-file-var-dlopen-lib1.c
b/gdb/testsuite/gdb.base/print-file-var-dlopen-lib1.c
new file mode 100644
index 0000000..09ec947
--- /dev/null
+++ b/gdb/testsuite/gdb.base/print-file-var-dlopen-lib1.c
@@ -0,0 +1,25 @@
+/* This testcase is part of GDB, the GNU debugger.
+ Copyright 2012-2017 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 this_version_id = 104;
+
+int
+get_version (void)
+{
+ static int test;
+ test = this_version_id;
+ return test;
+}
diff --git a/gdb/testsuite/gdb.base/print-file-var-dlopen-lib2.c
b/gdb/testsuite/gdb.base/print-file-var-dlopen-lib2.c
new file mode 100644
index 0000000..b097cd2
--- /dev/null
+++ b/gdb/testsuite/gdb.base/print-file-var-dlopen-lib2.c
@@ -0,0 +1,25 @@
+/* This testcase is part of GDB, the GNU debugger.
+ Copyright 2012-2017 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 this_version_id = 203;
+
+int
+get_version (void)
+{
+ static int test;
+ test = this_version_id;
+ return test;
+}
diff --git a/gdb/testsuite/gdb.base/print-file-var-dlopen-main.c
b/gdb/testsuite/gdb.base/print-file-var-dlopen-main.c
new file mode 100644
index 0000000..954a64e
--- /dev/null
+++ b/gdb/testsuite/gdb.base/print-file-var-dlopen-main.c
@@ -0,0 +1,61 @@
+/* This testcase is part of GDB, the GNU debugger.
+ Copyright 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/>. */
+
+#include <dlfcn.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int
+dummy (void)
+{
+ return 1;
+}
+
+int
+main (void)
+{
+ int (*get_version1) (void);
+ int (*get_version2) (void);
+ int v1, v2;
+
+ void *lib1 = dlopen ("print-file-var-dlopen-lib1.so", RTLD_LAZY);
+ void *lib2 = dlopen ("print-file-var-dlopen-lib2.so", RTLD_LAZY);
+
+ if (lib1 == NULL || lib2 == NULL)
+ return 1;
+
+ *(int **) (&get_version1) = dlsym (lib1, "get_version");
+ *(int **) (&get_version2) = dlsym (lib2, "get_version");
+
+ if (get_version1 != NULL
+ && get_version2 != NULL)
+ {
+ v1 = get_version1();
+ v2 = get_version2();
+ }
+
+
+ if (v1 != 104 || v2 != 203)
+ return 1;
+
+ dummy (); /* STOP */
+
+ dlclose (lib1);
+ dlclose (lib2);
+
+ return 0;
+}
+
diff --git a/gdb/testsuite/gdb.base/print-file-var-dlopen.exp
b/gdb/testsuite/gdb.base/print-file-var-dlopen.exp
new file mode 100644
index 0000000..9c3c0e6
--- /dev/null
+++ b/gdb/testsuite/gdb.base/print-file-var-dlopen.exp
@@ -0,0 +1,90 @@
+# Copyright 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/>. */
+