[PATCH] [gdb/ada] Extend type equivalence test in ada_resolve_enum

[PATCH] [gdb/ada] Extend type equivalence test in ada_resolve_enum

[Tom de Vries]

When running test-case gdb.ada/local-enum.exp with target board debug-types, I
run into:
...
(gdb) print v1(three)^M
No name 'three' in enumeration type 'local__e1'^M
(gdb) FAIL: gdb.ada/local-enum.exp: print v1 element
...

The array V1 is of type A1 which is an array with index type E1, containing
"three" as enumerator:
...
  type E1 is (one, two, three);
  type A1 is array (E1) of Integer;
  V1 : A1 := (0, 1, 2);
...

There's also a type E2 that contains three as enumerator:
...
  type E2 is (three, four, five);
...

When doing "print v1(three)", it's the job of ada_resolve_enum to resolve
"three" to type E1 rather than type E2.

When using target board debug-types, the enums E1 and E2 are replicated in the
.debug_types section, and consequently in ada_resolve_enum the type
equivalence check using a pointer comparison fails:
...
  for (int i = 0; i < syms.size (); ++i)
    {
      /* We already know the name matches, so we're just looking for
	 an element of the correct enum type.  */
      if (ada_check_typedef (syms[i].symbol->type ()) == context_type)
 	return i;
    }
...

Fix this by also trying a structural comparison using
ada_identical_enum_types_p.

Tested on x86_64-linux.

PR ada/29335
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29335
---
 gdb/ada-lang.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index c0cc512bfa3..7b61cce9341 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -202,6 +202,7 @@ static struct type *ada_find_any_type (const char *name);
 static symbol_name_matcher_ftype *ada_get_symbol_name_matcher
   (const lookup_name_info &lookup_name);
 
+static int ada_identical_enum_types_p (struct type *type1, struct type *type2);
 \f
 
 /* The character set used for source files.  */
@@ -3799,11 +3800,24 @@ ada_resolve_enum (std::vector<struct block_symbol> &syms,
   gdb_assert (context_type->code () == TYPE_CODE_ENUM);
   context_type = ada_check_typedef (context_type);
 
+  /* We already know the name matches, so we're just looking for
+     an element of the correct enum type.  */
+  struct type *type1 = context_type;
   for (int i = 0; i < syms.size (); ++i)
     {
-      /* We already know the name matches, so we're just looking for
-	 an element of the correct enum type.  */
-      if (ada_check_typedef (syms[i].symbol->type ()) == context_type)
+      struct type *type2 = ada_check_typedef (syms[i].symbol->type ());
+      if (type1 == type2)
+	return i;
+    }
+
+  for (int i = 0; i < syms.size (); ++i)
+    {
+      struct type *type2 = ada_check_typedef (syms[i].symbol->type ());
+      if (type1->num_fields () != type2->num_fields ())
+	continue;
+      if (strcmp (type1->name (), type2->name ()) != 0)
+	continue;
+      if (ada_identical_enum_types_p (type1, type2))
 	return i;
     }
 

base-commit: 4d944db22c351296bad0b54d6a1857ad1fbde575
-- 
2.35.3

[PATCH] [gdb/symtab] Fix gdb-index writing for .debug_types

[Tom de Vries]

With test-case gdb.ada/same_enum.exp and target board dwarf4-gdb-index we run
into:
...
(gdb) print red^M
No definition of "red" in current context.^M
(gdb) FAIL: gdb.ada/same_enum.exp: print red
...

[ This is a regression since commit 844a72efbce ("Simplify gdb_index writing"),
so this is broken in gdb 12 and 13. ]

The easiest way to see what's going wrong is with readelf.  We have in section
.gdb_index:
...
[7194] pck__red:
        2 [static, variable]
        3 [static, variable]
...
which points to the CUs 2 and 3 in the CU list (shown using "2" and "3"), but
should be pointing to the TUs 2 and 3 in the TU list (shown using "T2" and
"T3").

Fix this by removing the counter / types_counter distinction in
write_gdbindex, such that we get the expected:
...
[7194] pck__red:
        T2 [static, variable]
        T3 [static, variable]
...

[ While reading write_gdbindex I noticed a few oddities related to dwz
handling, I've filed PR30829 about this. ]

Tested on x86_64-linux.

PR symtab/30827
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30827
---
 gdb/dwarf2/index-write.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/gdb/dwarf2/index-write.c b/gdb/dwarf2/index-write.c
index e178bb067a9..11f254e263a 100644
--- a/gdb/dwarf2/index-write.c
+++ b/gdb/dwarf2/index-write.c
@@ -1201,18 +1201,14 @@ write_gdbindex (dwarf2_per_bfd *per_bfd, cooked_index *table,
   data_buf types_cu_list;
 
   /* The CU list is already sorted, so we don't need to do additional
-     work here.  Also, the debug_types entries do not appear in
-     all_units, but only in their own hash table.  */
+     work here.  */
 
   int counter = 0;
-  int types_counter = 0;
   for (int i = 0; i < per_bfd->all_units.size (); ++i)
     {
       dwarf2_per_cu_data *per_cu = per_bfd->all_units[i].get ();
 
-      int &this_counter = per_cu->is_debug_types ? types_counter : counter;
-
-      const auto insertpair = cu_index_htab.emplace (per_cu, this_counter);
+      const auto insertpair = cu_index_htab.emplace (per_cu, counter);
       gdb_assert (insertpair.second);
 
       /* The all_units list contains CUs read from the objfile as well as
@@ -1234,7 +1230,7 @@ write_gdbindex (dwarf2_per_bfd *per_bfd, cooked_index *table,
       else
 	cu_list.append_uint (8, BFD_ENDIAN_LITTLE, per_cu->length ());
 
-      ++this_counter;
+      ++counter;
     }
 
   write_cooked_index (table, cu_index_htab, &symtab);
-- 
2.35.3

Re: [PATCH] [gdb/ada] Extend type equivalence test in ada_resolve_enum

[Tom Tromey]

>>>>> "Tom" == Tom de Vries via Gdb-patches <gdb-patches@sourceware.org> writes:

Tom> When using target board debug-types, the enums E1 and E2 are replicated in the
Tom> .debug_types section, and consequently in ada_resolve_enum the type
Tom> equivalence check using a pointer comparison fails:
Tom> ...
Tom>   for (int i = 0; i < syms.size (); ++i)
Tom>     {
Tom>       /* We already know the name matches, so we're just looking for
Tom> 	 an element of the correct enum type.  */
Tom>       if (ada_check_typedef (syms[i].symbol->type ()) == context_type)
Tom>  	return i;
Tom>     }
Tom> ...

Tom> Fix this by also trying a structural comparison using
Tom> ada_identical_enum_types_p.

Thank you.  I think this is ok.
Approved-By: Tom Tromey <tom@tromey.com>

Tom

Re: [PATCH] [gdb/symtab] Fix gdb-index writing for .debug_types

[Tom Tromey]

>>>>> "Tom" == Tom de Vries via Gdb-patches <gdb-patches@sourceware.org> writes:

Tom> Fix this by removing the counter / types_counter distinction in
Tom> write_gdbindex, such that we get the expected:
Tom> ...
Tom> [7194] pck__red:
Tom>         T2 [static, variable]
Tom>         T3 [static, variable]
Tom> ...

Tom> [ While reading write_gdbindex I noticed a few oddities related to dwz
Tom> handling, I've filed PR30829 about this. ]

Tom> Tested on x86_64-linux.

Ok.  Thank you.
Approved-By: Tom Tromey <tom@tromey.com>

Tom