From: "Natarajan, Kavitha" <Kavitha.Natarajan@amd.com>
To: Tom Tromey <tom@tromey.com>,
"Natarajan, Kavitha via Gdb-patches" <gdb-patches@sourceware.org>
Cc: Bruno Larsen <blarsen@redhat.com>,
"George, Jini Susan" <JiniSusan.George@amd.com>,
"Parasuraman, Hariharan" <Hariharan.Parasuraman@amd.com>
Subject: RE: [PATCH] Debug support for global alias variable
Date: Mon, 18 Apr 2022 11:04:43 +0000 [thread overview]
Message-ID: <DM4PR12MB579651F1A1172BC69695CC93F7F39@DM4PR12MB5796.namprd12.prod.outlook.com> (raw)
In-Reply-To: <87ilra1gcx.fsf@tromey.com>
[-- Attachment #1: Type: text/plain, Size: 10049 bytes --]
[AMD Official Use Only]
Thank you Tom for reviewing my patch. I am sending the updated patch.
> > + if (((cu->per_cu->lang == language_c)
> > + || (cu->per_cu->lang == language_cplus))
>
> This expression is over-parenthesized.
> The inner parens can be removed.
>
> However, I don't understand why this would necessarily be specific to C or
> C++. The old read_namespace_alias wasn't, so doesn't this check possibly
> regress for some other language?
There doesn't seem to be any impact on other languages as the new symbol is
created only for TYPE_CODE_NAMESPACE in read_namespace_alias function.
However, it could regress with my change. So I have moved this check specific
to my change so that this change is specific to C/C++ global alias variables.
Thanks,
Kavitha
==============================================================
When clang emits the dwarf information of global alias variable
as DW_TAG_imported_declaration, gdb does not handle it. GDB reads
this tag as C++/fortran imported declaration (type alias, namespace
alias and fortran module). Added support to handle this tag as
alias variable.
This change fixes the failure in gdb.base/symbol-alias.exp testcase.
This testcase is also updated to test nested (recursive) alias.
---
gdb/dwarf2/read.c | 62 +++++++++++++++---------
gdb/testsuite/gdb.base/symbol-alias.exp | 63 ++++++++++++++++++++++++-
gdb/testsuite/gdb.base/symbol-alias2.c | 16 +++++++
3 files changed, 118 insertions(+), 23 deletions(-)
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 6dcd446e5f4..b0eed600312 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -957,6 +957,10 @@ static void build_type_psymtabs_reader (cutu_reader *reader,
static void dwarf2_build_psymtabs_hard (dwarf2_per_objfile *per_objfile);
+static void var_decode_location (struct attribute *attr,
+ struct symbol *sym,
+ struct dwarf2_cu *cu);
+
static unsigned int peek_abbrev_code (bfd *, const gdb_byte *);
static const gdb_byte *read_attribute (const struct die_reader_specs *,
@@ -1134,7 +1138,7 @@ static struct using_direct **using_directives (struct dwarf2_cu *cu);
static void read_import_statement (struct die_info *die, struct dwarf2_cu *);
-static int read_namespace_alias (struct die_info *die, struct dwarf2_cu *cu);
+static bool read_alias (struct die_info *die, struct dwarf2_cu *cu);
static struct type *read_module_type (struct die_info *die,
struct dwarf2_cu *cu);
@@ -8728,9 +8732,9 @@ process_die (struct die_info *die, struct dwarf2_cu *cu)
break;
case DW_TAG_imported_declaration:
cu->processing_has_namespace_info = true;
- if (read_namespace_alias (die, cu))
+ if (read_alias (die, cu))
break;
- /* The declaration is not a global namespace alias. */
+ /* The declaration is not a global namespace or variable alias. */
/* Fall through. */
case DW_TAG_imported_module:
cu->processing_has_namespace_info = true;
@@ -9198,18 +9202,19 @@ dwarf2_physname (const char *name, struct die_info *die, struct dwarf2_cu *cu)
return retval;
}
-/* Inspect DIE in CU for a namespace alias. If one exists, record
- a new symbol for it.
+/* Inspect DIE in CU for a namespace alias or a variable
+ with alias attribute. If one exists, record a new symbol
+ for it.
- Returns 1 if a namespace alias was recorded, 0 otherwise. */
+ Returns "true" if an alias was recorded, "false" otherwise. */
-static int
-read_namespace_alias (struct die_info *die, struct dwarf2_cu *cu)
+static bool
+read_alias (struct die_info *die, struct dwarf2_cu *cu)
{
struct attribute *attr;
- /* If the die does not have a name, this is not a namespace
- alias. */
+ /* If the die does not have a name, this is not a namespace alias
+ or variable alias. */
attr = dwarf2_attr (die, DW_AT_name, cu);
if (attr != NULL)
{
@@ -9235,26 +9240,41 @@ read_namespace_alias (struct die_info *die, struct dwarf2_cu *cu)
{
complaint (_("DIE at %s has too many recursively imported "
"declarations"), sect_offset_str (d->sect_off));
- return 0;
+ return false;
}
if (attr != NULL)
{
struct type *type;
- sect_offset sect_off = attr->get_ref_die_offset ();
-
- type = get_die_type_at_offset (sect_off, cu->per_cu, cu->per_objfile);
- if (type != NULL && type->code () == TYPE_CODE_NAMESPACE)
+ if (((cu->per_cu->lang == language_c)
+ || (cu->per_cu->lang == language_cplus))
+ && (d->tag == DW_TAG_variable))
{
- /* This declaration is a global namespace alias. Add
- a symbol for it whose type is the aliased namespace. */
- new_symbol (die, type, cu);
- return 1;
+ /* This declaration is a C/C++ global variable alias. Add
+ a symbol for it whose type is same as aliased variable. */
+ type = die_type (d, imported_cu);
+ struct symbol *sym = new_symbol (die, type, cu);
+ attr = dwarf2_attr (d, DW_AT_location, imported_cu);
+ sym->set_aclass_index (LOC_UNRESOLVED);
+ if (attr != nullptr)
+ var_decode_location (attr, sym, cu);
+ return true;
+ }
+ else
+ {
+ sect_offset sect_off = attr->get_ref_die_offset ();
+ type = get_die_type_at_offset (sect_off, cu->per_cu, cu->per_objfile);
+ if (type != NULL && type->code () == TYPE_CODE_NAMESPACE)
+ {
+ /* This declaration is a global namespace alias. Add
+ a symbol for it whose type is the aliased namespace. */
+ new_symbol (die, type, cu);
+ return true;
+ }
}
}
}
-
- return 0;
+ return false;
}
/* Return the using directives repository (global or local?) to use in the
diff --git a/gdb/testsuite/gdb.base/symbol-alias.exp b/gdb/testsuite/gdb.base/symbol-alias.exp
index 2b53cc31053..a9487b25f4d 100644
--- a/gdb/testsuite/gdb.base/symbol-alias.exp
+++ b/gdb/testsuite/gdb.base/symbol-alias.exp
@@ -15,6 +15,9 @@
# along with this program. If not, see <http://www.gnu.org/licenses/>.
standard_testfile symbol-alias.c symbol-alias2.c
+set using_clang [test_compiler_info clang-*]
+set old_clang [expr [test_compiler_info {clang-1[0-3]-*-*}] \
+ || [test_compiler_info {clang-[1-9]-*}]]
if { [prepare_for_testing "failed to prepare" ${testfile} [list $srcfile $srcfile2]] } {
return -1
@@ -31,6 +34,62 @@ foreach f {"func" "func_alias"} {
}
# Variables.
-foreach v {"g_var_s" "g_var_s_alias"} {
- gdb_test "p $v" "= {field1 = 1, field2 = 2}"
+gdb_test "p g_var_s" "= {field1 = 1, field2 = 2}"
+foreach v {"g_var_s_alias" "g_var_s_alias2"} {
+ gdb_test_multiple "p $v" "p $v" {
+ -re " = {field1 = 1, field2 = 2}.*$gdb_prompt $" {
+ pass "print alias of variable $v"
+ }
+ -re ".*has unknown type; cast it to its declared type.*$gdb_prompt $" {
+ if { $old_clang } {
+ xfail "print alias variable $v"
+ } else {
+ fail "print alias variable $v"
+ }
+ }
+ }
+}
+
+# Static Variable.
+gdb_test "p g_var" " = 1"
+gdb_test_multiple "p g_var_alias" "p g_var_alias" {
+ -re " = 1.*$gdb_prompt $" {
+ pass "print alias of static variable"
+ }
+ -re ".*has unknown type; cast it to its declared type.*$gdb_prompt $" {
+ if { $old_clang } {
+ xfail "print alias of static variable"
+ } else {
+ fail "print alias of static variable"
+ }
+ }
+}
+
+# Deferred Variable.
+gdb_test "p g_def_var" " = 2"
+gdb_test_multiple "p g_def_var_alias" "p g_def_var_alias" {
+ -re " = 2.*$gdb_prompt $" {
+ pass "print alias of deferred variable"
+ }
+ -re ".*has unknown type; cast it to its declared type.*$gdb_prompt $" {
+ if { $using_clang } {
+ xfail "print alias of deferred variable"
+ } else {
+ fail "print alias of deferred variable"
+ }
+ }
+}
+
+# Alias of deferred Variable alias.
+gdb_test_multiple "p g_def_var2_alias2" "p g_def_var2_alias2" {
+ -re " = 3.*$gdb_prompt $" {
+ pass "print alias of alias of deferred variable"
+ }
+ -re ".*has unknown type; cast it to its declared type.*$gdb_prompt $" {
+ if { $old_clang } {
+ xfail "print alias of alias of deferred variable"
+ } else {
+ fail "print alias of alias of deferred variable"
+ }
+ }
}
diff --git a/gdb/testsuite/gdb.base/symbol-alias2.c b/gdb/testsuite/gdb.base/symbol-alias2.c
index 34f4e121e25..41d4b6a53e5 100644
--- a/gdb/testsuite/gdb.base/symbol-alias2.c
+++ b/gdb/testsuite/gdb.base/symbol-alias2.c
@@ -23,6 +23,8 @@ struct S
struct S g_var_s = { 1, 2 };
+static int g_var = 1;
+
#ifdef __cplusplus
/* So that the alias attribute below work without having to figure out
this function's mangled name. */
@@ -38,3 +40,17 @@ func (void)
struct S *func_alias (void) __attribute__ ((alias ("func")));
extern struct S g_var_s_alias __attribute__ ((alias ("g_var_s")));
+
+extern struct S g_var_s_alias2 __attribute__ ((alias ("g_var_s_alias")));
+
+extern int g_var_alias __attribute__ ((alias ("g_var")));
+
+extern int g_def_var_alias __attribute__ ((alias ("g_def_var")));
+
+int g_def_var = 2;
+
+extern int g_def_var2_alias __attribute__ ((alias ("g_def_var2")));
+
+int g_def_var2 = 3;
+
+extern int g_def_var2_alias2 __attribute__ ((alias ("g_def_var2_alias")));
--
[-- Attachment #2: 0005-Debug-support-for-C-global-alias-variable-tom-tromey.patch --]
[-- Type: application/octet-stream, Size: 8595 bytes --]
When clang emits the dwarf information of global alias variable
as DW_TAG_imported_declaration, gdb does not handle it. GDB reads
this tag as C++/fortran imported declaration (type alias, namespace
alias and fortran module). Added support to handle this tag as
alias variable.
This change fixes the failure in gdb.base/symbol-alias.exp testcase.
This testcase is also updated to test nested (recursive) alias.
---
gdb/dwarf2/read.c | 62 +++++++++++++++---------
gdb/testsuite/gdb.base/symbol-alias.exp | 63 ++++++++++++++++++++++++-
gdb/testsuite/gdb.base/symbol-alias2.c | 16 +++++++
3 files changed, 118 insertions(+), 23 deletions(-)
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 6dcd446e5f4..b0eed600312 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -957,6 +957,10 @@ static void build_type_psymtabs_reader (cutu_reader *reader,
static void dwarf2_build_psymtabs_hard (dwarf2_per_objfile *per_objfile);
+static void var_decode_location (struct attribute *attr,
+ struct symbol *sym,
+ struct dwarf2_cu *cu);
+
static unsigned int peek_abbrev_code (bfd *, const gdb_byte *);
static const gdb_byte *read_attribute (const struct die_reader_specs *,
@@ -1134,7 +1138,7 @@ static struct using_direct **using_directives (struct dwarf2_cu *cu);
static void read_import_statement (struct die_info *die, struct dwarf2_cu *);
-static int read_namespace_alias (struct die_info *die, struct dwarf2_cu *cu);
+static bool read_alias (struct die_info *die, struct dwarf2_cu *cu);
static struct type *read_module_type (struct die_info *die,
struct dwarf2_cu *cu);
@@ -8728,9 +8732,9 @@ process_die (struct die_info *die, struct dwarf2_cu *cu)
break;
case DW_TAG_imported_declaration:
cu->processing_has_namespace_info = true;
- if (read_namespace_alias (die, cu))
+ if (read_alias (die, cu))
break;
- /* The declaration is not a global namespace alias. */
+ /* The declaration is not a global namespace or variable alias. */
/* Fall through. */
case DW_TAG_imported_module:
cu->processing_has_namespace_info = true;
@@ -9198,18 +9202,19 @@ dwarf2_physname (const char *name, struct die_info *die, struct dwarf2_cu *cu)
return retval;
}
-/* Inspect DIE in CU for a namespace alias. If one exists, record
- a new symbol for it.
+/* Inspect DIE in CU for a namespace alias or a variable
+ with alias attribute. If one exists, record a new symbol
+ for it.
- Returns 1 if a namespace alias was recorded, 0 otherwise. */
+ Returns "true" if an alias was recorded, "false" otherwise. */
-static int
-read_namespace_alias (struct die_info *die, struct dwarf2_cu *cu)
+static bool
+read_alias (struct die_info *die, struct dwarf2_cu *cu)
{
struct attribute *attr;
- /* If the die does not have a name, this is not a namespace
- alias. */
+ /* If the die does not have a name, this is not a namespace alias
+ or variable alias. */
attr = dwarf2_attr (die, DW_AT_name, cu);
if (attr != NULL)
{
@@ -9235,26 +9240,41 @@ read_namespace_alias (struct die_info *die, struct dwarf2_cu *cu)
{
complaint (_("DIE at %s has too many recursively imported "
"declarations"), sect_offset_str (d->sect_off));
- return 0;
+ return false;
}
if (attr != NULL)
{
struct type *type;
- sect_offset sect_off = attr->get_ref_die_offset ();
-
- type = get_die_type_at_offset (sect_off, cu->per_cu, cu->per_objfile);
- if (type != NULL && type->code () == TYPE_CODE_NAMESPACE)
+ if (((cu->per_cu->lang == language_c)
+ || (cu->per_cu->lang == language_cplus))
+ && (d->tag == DW_TAG_variable))
{
- /* This declaration is a global namespace alias. Add
- a symbol for it whose type is the aliased namespace. */
- new_symbol (die, type, cu);
- return 1;
+ /* This declaration is a C/C++ global variable alias. Add
+ a symbol for it whose type is same as aliased variable. */
+ type = die_type (d, imported_cu);
+ struct symbol *sym = new_symbol (die, type, cu);
+ attr = dwarf2_attr (d, DW_AT_location, imported_cu);
+ sym->set_aclass_index (LOC_UNRESOLVED);
+ if (attr != nullptr)
+ var_decode_location (attr, sym, cu);
+ return true;
+ }
+ else
+ {
+ sect_offset sect_off = attr->get_ref_die_offset ();
+ type = get_die_type_at_offset (sect_off, cu->per_cu, cu->per_objfile);
+ if (type != NULL && type->code () == TYPE_CODE_NAMESPACE)
+ {
+ /* This declaration is a global namespace alias. Add
+ a symbol for it whose type is the aliased namespace. */
+ new_symbol (die, type, cu);
+ return true;
+ }
}
}
}
-
- return 0;
+ return false;
}
/* Return the using directives repository (global or local?) to use in the
diff --git a/gdb/testsuite/gdb.base/symbol-alias.exp b/gdb/testsuite/gdb.base/symbol-alias.exp
index 2b53cc31053..a9487b25f4d 100644
--- a/gdb/testsuite/gdb.base/symbol-alias.exp
+++ b/gdb/testsuite/gdb.base/symbol-alias.exp
@@ -15,6 +15,9 @@
# along with this program. If not, see <http://www.gnu.org/licenses/>.
standard_testfile symbol-alias.c symbol-alias2.c
+set using_clang [test_compiler_info clang-*]
+set old_clang [expr [test_compiler_info {clang-1[0-3]-*-*}] \
+ || [test_compiler_info {clang-[1-9]-*}]]
if { [prepare_for_testing "failed to prepare" ${testfile} [list $srcfile $srcfile2]] } {
return -1
@@ -31,6 +34,62 @@ foreach f {"func" "func_alias"} {
}
# Variables.
-foreach v {"g_var_s" "g_var_s_alias"} {
- gdb_test "p $v" "= {field1 = 1, field2 = 2}"
+gdb_test "p g_var_s" "= {field1 = 1, field2 = 2}"
+foreach v {"g_var_s_alias" "g_var_s_alias2"} {
+ gdb_test_multiple "p $v" "p $v" {
+ -re " = {field1 = 1, field2 = 2}.*$gdb_prompt $" {
+ pass "print alias of variable $v"
+ }
+ -re ".*has unknown type; cast it to its declared type.*$gdb_prompt $" {
+ if { $old_clang } {
+ xfail "print alias variable $v"
+ } else {
+ fail "print alias variable $v"
+ }
+ }
+ }
+}
+
+# Static Variable.
+gdb_test "p g_var" " = 1"
+gdb_test_multiple "p g_var_alias" "p g_var_alias" {
+ -re " = 1.*$gdb_prompt $" {
+ pass "print alias of static variable"
+ }
+ -re ".*has unknown type; cast it to its declared type.*$gdb_prompt $" {
+ if { $old_clang } {
+ xfail "print alias of static variable"
+ } else {
+ fail "print alias of static variable"
+ }
+ }
+}
+
+# Deferred Variable.
+gdb_test "p g_def_var" " = 2"
+gdb_test_multiple "p g_def_var_alias" "p g_def_var_alias" {
+ -re " = 2.*$gdb_prompt $" {
+ pass "print alias of deferred variable"
+ }
+ -re ".*has unknown type; cast it to its declared type.*$gdb_prompt $" {
+ if { $using_clang } {
+ xfail "print alias of deferred variable"
+ } else {
+ fail "print alias of deferred variable"
+ }
+ }
+}
+
+# Alias of deferred Variable alias.
+gdb_test_multiple "p g_def_var2_alias2" "p g_def_var2_alias2" {
+ -re " = 3.*$gdb_prompt $" {
+ pass "print alias of alias of deferred variable"
+ }
+ -re ".*has unknown type; cast it to its declared type.*$gdb_prompt $" {
+ if { $old_clang } {
+ xfail "print alias of alias of deferred variable"
+ } else {
+ fail "print alias of alias of deferred variable"
+ }
+ }
}
diff --git a/gdb/testsuite/gdb.base/symbol-alias2.c b/gdb/testsuite/gdb.base/symbol-alias2.c
index 34f4e121e25..41d4b6a53e5 100644
--- a/gdb/testsuite/gdb.base/symbol-alias2.c
+++ b/gdb/testsuite/gdb.base/symbol-alias2.c
@@ -23,6 +23,8 @@ struct S
struct S g_var_s = { 1, 2 };
+static int g_var = 1;
+
#ifdef __cplusplus
/* So that the alias attribute below work without having to figure out
this function's mangled name. */
@@ -38,3 +40,17 @@ func (void)
struct S *func_alias (void) __attribute__ ((alias ("func")));
extern struct S g_var_s_alias __attribute__ ((alias ("g_var_s")));
+
+extern struct S g_var_s_alias2 __attribute__ ((alias ("g_var_s_alias")));
+
+extern int g_var_alias __attribute__ ((alias ("g_var")));
+
+extern int g_def_var_alias __attribute__ ((alias ("g_def_var")));
+
+int g_def_var = 2;
+
+extern int g_def_var2_alias __attribute__ ((alias ("g_def_var2")));
+
+int g_def_var2 = 3;
+
+extern int g_def_var2_alias2 __attribute__ ((alias ("g_def_var2_alias")));
--
2.25.1
next prev parent reply other threads:[~2022-04-18 11:04 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-04 13:44 Natarajan, Kavitha
2022-03-14 11:15 ` Natarajan, Kavitha
2022-03-24 6:36 ` Natarajan, Kavitha
2022-03-24 13:53 ` Bruno Larsen
2022-03-28 15:14 ` Natarajan, Kavitha
2022-03-29 14:02 ` Bruno Larsen
2022-03-30 11:30 ` Natarajan, Kavitha
2022-03-30 12:25 ` Natarajan, Kavitha
2022-04-05 6:26 ` Natarajan, Kavitha
2022-04-05 13:33 ` Bruno Larsen
2022-04-05 14:02 ` Natarajan, Kavitha
2022-04-12 8:38 ` Natarajan, Kavitha
2022-04-15 16:06 ` Tom Tromey
2022-04-18 11:04 ` Natarajan, Kavitha [this message]
2022-04-18 15:03 ` Tom Tromey
2022-04-19 12:45 ` Natarajan, Kavitha
2022-04-19 22:59 ` Tom Tromey
2022-04-20 6:00 ` Natarajan, Kavitha
2022-04-20 10:33 ` Pedro Alves
2022-04-20 12:17 ` Natarajan, Kavitha
2022-04-25 13:10 ` Natarajan, Kavitha
2022-05-05 9:53 ` Natarajan, Kavitha
2022-06-07 9:08 ` Natarajan, Kavitha
2022-06-08 16:29 ` Pedro Alves
2022-06-09 11:36 ` Pedro Alves
2022-06-13 11:11 ` Natarajan, Kavitha
2022-06-13 13:54 ` Pedro Alves
2022-06-13 17:28 ` Natarajan, Kavitha
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