[PATCH v3 0/1] gdb: Use a typedef's scoped type name to identify local typedefs

[PATCH v3 0/1] gdb: Use a typedef's scoped type name to identify local typedefs

[Christina Schimpe]

Hi all, 

here is an updated version of the patch. In addition to the feedback of Bruno
for V2, I corrected a typo in the commit message and applied some formatting
changes.

V2 of this patch can be found here:
https://sourceware.org/pipermail/gdb-patches/2021-November/183848.html

Changes since V2:
- Corrected a typo in the commit message (typefs -> typedefs).
- Formatting changes in gdb/testsuite/gdb.cp/ptype-flags.exp (line break)

Regards,
Christina


Christina Schimpe (1):
  gdb: Use a typedef's scoped type name to identify local typedefs

 gdb/testsuite/gdb.cp/ptype-flags.cc  | 23 ++++++++
 gdb/testsuite/gdb.cp/ptype-flags.exp | 88 ++++++++++++++++++++++------
 gdb/typeprint.c                      |  3 +-
 3 files changed, 95 insertions(+), 19 deletions(-)

-- 
2.25.1

Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de <http://www.intel.de>
Managing Directors: Christin Eisenschmid, Sharon Heck, Tiffany Doon Silva  
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928

[PATCH v3 1/1] gdb: Use a typedef's scoped type name to identify local typedefs

[Christina Schimpe]

GDB prints the wrong type for typedefs in case there is another typedef
available for the same raw type (gdb/16040).  The reason is that the
current hashmap based substitution mechanism always compares the target
type of a typedef and not its scoped name.

The original output of GDB for a program like

~~~~
namespace ns
{
  typedef double scoped_double;
}

typedef double global_double;

class TypedefHolder
{
public:
  double a;
  ns::scoped_double b;
  global_double c;

private:
  typedef double class_double;
  class_double d;

  double method1(ns::scoped_double) { return 24.0; }
  double method2(global_double) { return 24.0; }
};

int main()
{
  TypedefHolder th;
  return 0;
}
~~~~

is
~~~~

(gdb) b 27
Breakpoint 1 at 0x1131: file TypedefHolder.cc, line 27.
(gdb) r
Starting program: /tmp/typedefholder

Breakpoint 1, main () at TypedefHolder.cc:27
27	  return 0;
(gdb) ptype th
type = class TypedefHolder {
  public:
    class_double a;
    class_double b;
    class_double c;
  private:
    class_double d;

    class_double method1(class_double);
    class_double method2(class_double);

    typedef double class_double;
}
~~~~

Basically all attributes of a class which have the raw type "double" are
substituted by "class_double".

With the patch the output is the following

~~~~
type = class TypedefHolder {
  public:
    double a;
    ns::scoped_double b;
    global_double c;
  private:
    class_double d;

    double method1(ns::scoped_double);
    double method2(global_double);

    typedef double class_double;
}
~~~~
---
 gdb/testsuite/gdb.cp/ptype-flags.cc  | 23 ++++++++
 gdb/testsuite/gdb.cp/ptype-flags.exp | 88 ++++++++++++++++++++++------
 gdb/typeprint.c                      |  3 +-
 3 files changed, 95 insertions(+), 19 deletions(-)

diff --git a/gdb/testsuite/gdb.cp/ptype-flags.cc b/gdb/testsuite/gdb.cp/ptype-flags.cc
index fc92d3950c..564d272e57 100644
--- a/gdb/testsuite/gdb.cp/ptype-flags.cc
+++ b/gdb/testsuite/gdb.cp/ptype-flags.cc
@@ -38,7 +38,30 @@ public:
   double method(void) { return 23.0; }
 };
 
+namespace ns
+{
+  typedef double scoped_double;
+}
+
+typedef double global_double;
+
+class TypedefHolder
+{
+public:
+  double a;
+  ns::scoped_double b;
+  global_double c;
+
+private:
+  typedef double class_double;
+  class_double d;
+
+  double method1(ns::scoped_double) { return 24.0; }
+  double method2(global_double) { return 24.0; }
+};
+
 Holder<int> value;
+TypedefHolder value2;
 
 int main()
 {
diff --git a/gdb/testsuite/gdb.cp/ptype-flags.exp b/gdb/testsuite/gdb.cp/ptype-flags.exp
index c368415793..9734a70ee2 100644
--- a/gdb/testsuite/gdb.cp/ptype-flags.exp
+++ b/gdb/testsuite/gdb.cp/ptype-flags.exp
@@ -33,7 +33,9 @@ if ![runto_main] then {
 gdb_test_no_output "set language c++" ""
 gdb_test_no_output "set width 0" ""
 
-proc do_check {name {flags ""} {show_typedefs 1} {show_methods 1} {raw 0}} {
+proc do_check_holder {name {flags ""} {show_typedefs 1} {show_methods 1}
+		      {raw 0}} {
+
     set contents {
 	{ base "public Base<T>" }
 	{ field public "Simple<T> t;" }
@@ -62,24 +64,76 @@ proc do_check {name {flags ""} {show_typedefs 1} {show_methods 1} {raw 0}} {
 	"" {} $flags
 }
 
-do_check "basic test"
-do_check "no methods" "/m" 1 0
-do_check "no typedefs" "/t" 0 1
-do_check "no methods or typedefs" "/mt" 0 0
+proc do_check_typedef_holder {name {flags ""} {show_typedefs 1} {show_methods 1}
+			      {raw 0}} {
+
+    set contents {
+	{ field public "double a;" }
+	{ field public "ns::scoped_double b;" }
+	{ field public "global_double c;" }
+    }
+
+    if {$show_typedefs} {
+	lappend contents { typedef private "typedef double class_double;" }
+    }
+
+    if {$show_methods} {
+	lappend contents { method private "double method1(ns::scoped_double);" }
+	lappend contents { method private "double method2(global_double);" }
+    }
+
+    if {$raw} {
+	lappend contents { field private "TypedefHolder::class_double d;" }
+    } else {
+	lappend contents { field private "class_double d;" }
+    }
+
+    cp_test_ptype_class value2 $name "class" "TypedefHolder" $contents \
+	"" {} $flags
+}
 
-do_check "raw" "/r" 1 1 1
-do_check "raw no methods" "/rm" 1 0 1
-do_check "raw no typedefs" "/rt" 0 1 1
-do_check "raw no methods or typedefs" "/rmt" 0 0 1
+do_check_holder "basic test"
+do_check_holder "no methods" "/m" 1 0
+do_check_holder "no typedefs" "/t" 0 1
+do_check_holder "no methods or typedefs" "/mt" 0 0
+do_check_typedef_holder "typdefs class: basic test"
+do_check_typedef_holder "typdefs class: no methods" "/m" 1 0
+do_check_typedef_holder "typdefs class: no typedefs" "/t" 0 1 0
+do_check_typedef_holder "typdefs class:no methods or typedefs" "/mt" 0 0
+
+do_check_holder "raw" "/r" 1 1 1
+do_check_holder "raw no methods" "/rm" 1 0 1
+do_check_holder "raw no typedefs" "/rt" 0 1 1
+do_check_holder "raw no methods or typedefs" "/rmt" 0 0 1
+do_check_typedef_holder "typedef class: raw" "/r" 1 1 1
+do_check_typedef_holder "typedef class: raw no methods" "/rm" 1 0 1
+do_check_typedef_holder "typedef class: raw no typedefs" "/rt" 0 1 1
+do_check_typedef_holder "typedef class: raw no methods or typedefs" "/rmt" 0 0 1
 
 gdb_test_no_output "set print type methods off"
-do_check "basic test, default methods off" "" 1 0
-do_check "methods, default methods off" "/M" 1 1
-do_check "no typedefs, default methods off" "/t" 0 0
-do_check "methods, no typedefs, default methods off" "/Mt" 0 1
+do_check_holder "basic test, default methods off" "" 1 0
+do_check_holder "methods, default methods off" "/M" 1 1
+do_check_holder "no typedefs, default methods off" "/t" 0 0
+do_check_holder "methods, no typedefs, default methods off" "/Mt" 0 1
+do_check_typedef_holder \
+    "typedef class: basic test, default methods off" "" 1 0
+do_check_typedef_holder \
+    "typedef class: methods, default methods off" "/M" 1 1
+do_check_typedef_holder \
+    "typedef class: no typedefs, default methods off" "/t" 0 0
+do_check_typedef_holder \
+    "typedef class: methods, no typedefs, default methods off" "/Mt" 0 1
 
 gdb_test_no_output "set print type typedefs off"
-do_check "basic test, default methods+typedefs off" "" 0 0
-do_check "methods, default methods+typedefs off" "/M" 0 1
-do_check "typedefs, default methods+typedefs off" "/T" 1 0
-do_check "methods typedefs, default methods+typedefs off" "/MT" 1 1
+do_check_holder "basic test, default methods+typedefs off" "" 0 0
+do_check_holder "methods, default methods+typedefs off" "/M" 0 1
+do_check_holder "typedefs, default methods+typedefs off" "/T" 1 0
+do_check_holder "methods typedefs, default methods+typedefs off" "/MT" 1 1
+do_check_typedef_holder \
+    "typedef class: basic test, default methods+typedefs off" "" 0 0
+do_check_typedef_holder \
+    "typedef class: methods, default methods+typedefs off" "/M" 0 1
+do_check_typedef_holder \
+    "typedef class: typedefs, default methods+typedefs off" "/T" 1 0
+do_check_typedef_holder \
+    "typedef class: methods typedefs, default methods+typedefs off" "/MT" 1 1
diff --git a/gdb/typeprint.c b/gdb/typeprint.c
index 1312111b60..98f6af4104 100644
--- a/gdb/typeprint.c
+++ b/gdb/typeprint.c
@@ -201,9 +201,8 @@ static hashval_t
 hash_typedef_field (const void *p)
 {
   const struct decl_field *tf = (const struct decl_field *) p;
-  struct type *t = check_typedef (tf->type);
 
-  return htab_hash_string (TYPE_SAFE_NAME (t));
+  return htab_hash_string (TYPE_SAFE_NAME (tf->type));
 }
 
 /* An equality function for a typedef field.  */
-- 
2.25.1

Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de <http://www.intel.de>
Managing Directors: Christin Eisenschmid, Sharon Heck, Tiffany Doon Silva  
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928