gdb, types: Resolve pointer types dynamically

This commit allows pointers to be dynamic types (on the outmost
level).  Similar to references, a pointer is considered a dynamic type
if its target type is a dynamic type and it is on the outmost level.
Also this commit removes the redundant code inside function
"value_check_printable" for handling of DW_AT_associated type.

The pointer resolution follows the one of references.

This change generally makes the GDB output more verbose.  We are able to
print more details about a pointer's target like the dimension of an array.

In Fortran, if we have a pointer to a dynamic type

  type buffer
    real, dimension(:), pointer :: ptr
  end type buffer
  type(buffer), pointer :: buffer_ptr
  allocate (buffer_ptr)
  allocate (buffer_ptr%ptr (5))

which then gets allocated, we now resolve the dynamic type before
printing the pointer's type:

Before:

  (gdb) ptype buffer_ptr
  type = PTR TO -> ( Type buffer
    real(kind=4) :: alpha(:)
  End Type buffer )

After:

  (gdb) ptype buffer_ptr
  type = PTR TO -> ( Type buffer
    real(kind=4) :: alpha(5)
  End Type buffer )

Similarly in C++ we can dynamically resolve e.g. pointers to arrays:

  int len = 3;
  int arr[len];
  int (*ptr)[len];
  int ptr = &arr;

Once the pointer is assigned one gets:

Before:

  (gdb) p ptr
  $1 = (int (*)[variable length]) 0x123456
  (gdb) ptype ptr
  type = int (*)[variable length]

After:

  (gdb) p ptr
  $1 = (int (*)[3]) 0x123456
  (gdb) ptype ptr
  type = int (*)[3]

For more examples see the modified/added test cases.

Tested-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Approved-By: Tom Tromey <tom@tromey.com>

8 files changed, 177 insertions, 17 deletions

diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 2e55a29..ece161d 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -2043,8 +2043,9 @@ is_dynamic_type_internal (struct type *type, int top_level)
 {
   type = check_typedef (type);
 
-  /* We only want to recognize references at the outermost level.  */
-  if (top_level && type->code () == TYPE_CODE_REF)
+  /* We only want to recognize references and pointers at the outermost
+     level.  */
+  if (top_level && type->is_pointer_or_reference ())
     type = check_typedef (type->target_type ());
 
   /* Types that have a dynamic TYPE_DATA_LOCATION are considered
@@ -2780,6 +2781,8 @@ resolve_dynamic_type_internal (struct type *type,
       switch (type->code ())
 	{
 	case TYPE_CODE_REF:
+	case TYPE_CODE_PTR:
+	case TYPE_CODE_RVALUE_REF:
 	  {
 	    struct property_addr_info pinfo;
 
diff --git a/gdb/testsuite/gdb.cp/vla-cxx.cc b/gdb/testsuite/gdb.cp/vla-cxx.cc
index 6fc8885..7603b4b 100644
--- a/gdb/testsuite/gdb.cp/vla-cxx.cc
+++ b/gdb/testsuite/gdb.cp/vla-cxx.cc
@@ -40,6 +40,10 @@ int main(int argc, char **argv)
   typedef typeof (vla) &vlareftypedef;
   vlareftypedef vlaref2 (vla);
   container c;
+  typeof (vla) *ptr = nullptr;
+
+  // Before pointer assignment.
+  ptr = &vla;
 
   for (int i = 0; i < z; ++i)
     vla[i] = 5 + 2 * i;
diff --git a/gdb/testsuite/gdb.cp/vla-cxx.exp b/gdb/testsuite/gdb.cp/vla-cxx.exp
index 6e307ef..0033a96 100644
--- a/gdb/testsuite/gdb.cp/vla-cxx.exp
+++ b/gdb/testsuite/gdb.cp/vla-cxx.exp
@@ -23,6 +23,18 @@ if ![runto_main] {
     return -1
 }
 
+gdb_breakpoint [gdb_get_line_number "Before pointer assignment"]
+gdb_continue_to_breakpoint "Before pointer assignment"
+
+gdb_test "ptype ptr" "= int \\(\\*\\)\\\[3\\\]" \
+    "ptype ptr, before pointer assignment"
+
+gdb_test "print ptr" "= \\(int \\(\\*\\)\\\[3\\\]\\) 0x0" \
+    "print ptr, before pointer assignment"
+
+gdb_test "print *ptr" "Cannot access memory at address 0x0" \
+    "print *ptr, before pointer assignment"
+
 gdb_breakpoint [gdb_get_line_number "vlas_filled"]
 gdb_continue_to_breakpoint "vlas_filled"
 
@@ -33,3 +45,6 @@ gdb_test "print vlaref" " = \\(int \\(&\\)\\\[3\\\]\\) @$hex: \\{5, 7, 9\\}"
 # bug being tested, it's better not to depend on the exact spelling.
 gdb_test "print vlaref2" " = \\(.*\\) @$hex: \\{5, 7, 9\\}"
 gdb_test "print c" " = \\{e = \\{c = @$hex\\}\\}"
+gdb_test "ptype ptr" "int \\(\\*\\)\\\[3\\\]"
+gdb_test "print ptr" "\\(int \\(\\*\\)\\\[3\\\]\\) $hex"
+gdb_test "print *ptr" " = \\{5, 7, 9\\}"
diff --git a/gdb/testsuite/gdb.dwarf2/dynarr-ptr.exp b/gdb/testsuite/gdb.dwarf2/dynarr-ptr.exp
index 232f4e2..3b7fb72 100644
--- a/gdb/testsuite/gdb.dwarf2/dynarr-ptr.exp
+++ b/gdb/testsuite/gdb.dwarf2/dynarr-ptr.exp
@@ -154,7 +154,7 @@ gdb_test "print foo.three_ptr.all'length" \
     " = 3"
 
 gdb_test "ptype foo.three_ptr.all" \
-    " = array \\(<>\\) of integer"
+    " = array \\(1 \\.\\. 3\\) of integer"
 
 # foo.three_ptr
 
@@ -177,7 +177,7 @@ gdb_test "print foo.three_ptr'length" \
     " = 3"
 
 gdb_test "ptype foo.three_ptr" \
-    " = access array \\(<>\\) of integer"
+    " = access array \\(1 \\.\\. 3\\) of integer"
 
 # foo.three_ptr_tdef.all
 
@@ -203,7 +203,7 @@ gdb_test "print foo.three_ptr_tdef.all'length" \
     " = 3"
 
 gdb_test "ptype foo.three_ptr_tdef.all" \
-    " = array \\(<>\\) of integer"
+    " = array \\(1 \\.\\. 3\\) of integer"
 
 # foo.three_ptr_tdef
 
@@ -226,7 +226,7 @@ gdb_test "print foo.three_ptr_tdef'length" \
     " = 3"
 
 gdb_test "ptype foo.three_ptr_tdef" \
-    " = access array \\(<>\\) of integer"
+    " = access array \\(1 \\.\\. 3\\) of integer"
 
 # foo.five_ptr.all
 
@@ -258,7 +258,7 @@ gdb_test "print foo.five_ptr.all'length" \
     " = 5"
 
 gdb_test "ptype foo.five_ptr.all" \
-    " = array \\(<>\\) of integer"
+    " = array \\(2 \\.\\. 6\\) of integer"
 
 # foo.five_ptr
 
@@ -287,7 +287,7 @@ gdb_test "print foo.five_ptr'length" \
     " = 5"
 
 gdb_test "ptype foo.five_ptr" \
-    " = access array \\(<>\\) of integer"
+    " = access array \\(2 \\.\\. 6\\) of integer"
 
 # foo.five_ptr_tdef.all
 
@@ -319,7 +319,7 @@ gdb_test "print foo.five_ptr_tdef.all'length" \
     " = 5"
 
 gdb_test "ptype foo.five_ptr_tdef.all" \
-    " = array \\(<>\\) of integer"
+    " = array \\(2 \\.\\. 6\\) of integer"
 
 # foo.five_ptr_tdef
 
@@ -348,4 +348,4 @@ gdb_test "print foo.five_ptr_tdef'length" \
     " = 5"
 
 gdb_test "ptype foo.five_ptr_tdef" \
-    " = access array \\(<>\\) of integer"
+    " = access array \\(2 \\.\\. 6\\) of integer"
diff --git a/gdb/testsuite/gdb.fortran/pointer-to-pointer.exp b/gdb/testsuite/gdb.fortran/pointer-to-pointer.exp
index da1be8b..dfff519 100644
--- a/gdb/testsuite/gdb.fortran/pointer-to-pointer.exp
+++ b/gdb/testsuite/gdb.fortran/pointer-to-pointer.exp
@@ -41,7 +41,7 @@ gdb_test "print buffer" \
 gdb_test "ptype buffer" \
     [multi_line \
 	 "type = PTR TO -> \\( Type l_buffer" \
-	 "    $real4 :: alpha\\(:\\)" \
+	 "    $real4 :: alpha\\(5\\)" \
 	 "End Type l_buffer \\)" ]
 gdb_test "ptype buffer%alpha" "type = $real4 \\(5\\)"
 
diff --git a/gdb/testsuite/gdb.fortran/pointers.exp b/gdb/testsuite/gdb.fortran/pointers.exp
new file mode 100644
index 0000000..dafea39
--- /dev/null
+++ b/gdb/testsuite/gdb.fortran/pointers.exp
@@ -0,0 +1,115 @@
+# Copyright 2024 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 "pointers.f90"
+load_lib fortran.exp
+
+if {[prepare_for_testing ${testfile}.exp ${testfile} ${srcfile} \
+    {debug f90 quiet}]} {
+    return -1
+}
+
+if {![fortran_runto_main]} {
+    untested "could not run to main"
+    return -1
+}
+
+# Depending on the compiler being used, the type names can be printed
+# differently.
+set logical [fortran_logical4]
+set real [fortran_real4]
+set int [fortran_int4]
+set complex [fortran_complex4]
+
+gdb_breakpoint [gdb_get_line_number "Before pointer assignment"]
+gdb_continue_to_breakpoint "Before pointer assignment"
+gdb_test "print logp" "= \\(PTR TO -> \\( $logical \\)\\) 0x0" \
+    "print logp, not associated"
+gdb_test "print *logp" "Cannot access memory at address 0x0" \
+    "print *logp, not associated"
+gdb_test "print comp" "= \\(PTR TO -> \\( $complex \\)\\) 0x0" \
+    "print comp, not associated"
+gdb_test "print *comp" "Cannot access memory at address 0x0" \
+    "print *comp, not associated"
+gdb_test "print charp" "= \\(PTR TO -> \\( character\\*1 \\)\\) 0x0" \
+    "print charp, not associated"
+gdb_test "print *charp" "Cannot access memory at address 0x0" \
+    "print *charp, not associated"
+gdb_test "print charap" "= \\(PTR TO -> \\( character\\*3 \\)\\) 0x0" \
+    "print charap, not associated"
+gdb_test "print *charap" "Cannot access memory at address 0x0" \
+    "print *charap, not associated"
+gdb_test "print intp" "= \\(PTR TO -> \\( $int \\)\\) 0x0" \
+    "print intp, not associated"
+gdb_test "print *intp" "Cannot access memory at address 0x0" \
+    "print *intp, not associated"
+gdb_test "print intap" " = <not associated>" "print intap, not associated"
+gdb_test "print realp" "= \\(PTR TO -> \\( $real \\)\\) 0x0" \
+    "print realp, not associated"
+gdb_test "print *realp" "Cannot access memory at address 0x0" \
+    "print *realp, not associated"
+gdb_test "print \$my_var = intp" "= \\(PTR TO -> \\( $int \\)\\) 0x0"
+gdb_test "print cyclicp1" "= \\( i = -?\\d+, p = 0x0 \\)" \
+    "print cyclicp1, not associated"
+gdb_test "print cyclicp1%p" \
+    "= \\(PTR TO -> \\( Type typewithpointer \\)\\) 0x0" \
+    "print cyclicp1%p, not associated"
+
+gdb_breakpoint [gdb_get_line_number "Before value assignment"]
+gdb_continue_to_breakpoint "Before value assignment"
+gdb_test "print *(twop)%ivla2" "= <not allocated>"
+
+gdb_breakpoint [gdb_get_line_number "After value assignment"]
+gdb_continue_to_breakpoint "After value assignment"
+gdb_test "print logp" "= \\(PTR TO -> \\( $logical \\)\\) $hex\( <.*>\)?"
+gdb_test "print *logp" "= \\.TRUE\\."
+gdb_test "print comp" "= \\(PTR TO -> \\( $complex \\)\\) $hex\( <.*>\)?"
+gdb_test "print *comp" "= \\(1,2\\)"
+gdb_test "print charp" "= \\(PTR TO -> \\( character\\*1 \\)\\) $hex\( <.*>\)?"
+gdb_test "print *charp" "= 'a'"
+gdb_test "print charap" "= \\(PTR TO -> \\( character\\*3 \\)\\) $hex\( <.*>\)?"
+gdb_test "print *charap" "= 'abc'"
+gdb_test "print intp" "= \\(PTR TO -> \\( $int \\)\\) $hex\( <.*>\)?"
+gdb_test "print *intp" "= 10"
+gdb_test "print intap" "= \\(\\(1, 1, 3(, 1){7}\\) \\(1(, 1){9}\\)\\)" \
+    "print intap, associated"
+gdb_test "print intvlap" "= \\(2, 2, 2, 4(, 2){6}\\)" \
+    "print intvlap, associated"
+gdb_test "print realp" "= \\(PTR TO -> \\( $real \\)\\) $hex\( <.*>\)?"
+gdb_test "print *realp" "= 3\\.14000\\d+"
+gdb_test "print arrayOfPtr(2)%p" "= \\(PTR TO -> \\( Type two \\)\\) $hex\( <.*>\)?"
+gdb_test "print *(arrayOfPtr(2)%p)" \
+    "= \\( ivla1 = \\(11, 12, 13\\), ivla2 = \\(\\(211, 221\\) \\(212, 222\\)\\) \\)"
+gdb_test "print arrayOfPtr(3)%p" "= \\(PTR TO -> \\( Type two \\)\\) 0x0" \
+    "print arrayOfPtr(3)%p"
+
+gdb_test_multiple "print *(arrayOfPtr(3)%p)" \
+    "print *(arrayOfPtr(3)%p), associated" {
+    # gfortran
+    -re -wrap "Cannot access memory at address 0x0" {
+	pass $gdb_test_name
+    }
+    # ifx
+    -re -wrap "Location address is not set." {
+	pass $gdb_test_name
+    }
+}
+
+gdb_test "print cyclicp1" "= \\( i = 1, p = $hex\( <.*>\)? \\)"
+gdb_test "print cyclicp1%p" "= \\(PTR TO -> \\( Type typewithpointer \\)\\) $hex\( <.*>\)?"
+gdb_test "print *((integer*) &inta + 2)" "= 3" "print temporary pointer, array"
+gdb_test "print *((integer*) &intvla + 3)" "= 4" "print temporary pointer, allocated vla"
+gdb_test "print \$pc" "\\(PTR TO -> \\( void \\(\\) \\(\\) \\)\\) $hex <pointers\\+\\d+>" \
+    "Print program counter"
diff --git a/gdb/testsuite/gdb.fortran/pointers.f90 b/gdb/testsuite/gdb.fortran/pointers.f90
index cc4c3be..2b55c6a 100644
--- a/gdb/testsuite/gdb.fortran/pointers.f90
+++ b/gdb/testsuite/gdb.fortran/pointers.f90
@@ -20,14 +20,26 @@ program pointers
     integer, allocatable :: ivla2 (:, :)
   end type two
 
+  type :: typeWithPointer
+    integer i
+    type(typeWithPointer), pointer:: p
+  end type typeWithPointer
+
+  type :: twoPtr
+    type (two), pointer :: p
+  end type twoPtr
+
   logical, target :: logv
   complex, target :: comv
   character, target :: charv
   character (len=3), target :: chara
   integer, target :: intv
   integer, target, dimension (10,2) :: inta
+  integer, target, allocatable, dimension (:) :: intvla
   real, target :: realv
   type(two), target :: twov
+  type(twoPtr) :: arrayOfPtr (3)
+  type(typeWithPointer), target:: cyclicp1,cyclicp2
 
   logical, pointer :: logp
   complex, pointer :: comp
@@ -35,6 +47,7 @@ program pointers
   character (len=3), pointer :: charap
   integer, pointer :: intp
   integer, pointer, dimension (:,:) :: intap
+  integer, pointer, dimension (:) :: intvlap
   real, pointer :: realp
   type(two), pointer :: twop
 
@@ -44,8 +57,14 @@ program pointers
   nullify (charap)
   nullify (intp)
   nullify (intap)
+  nullify (intvlap)
   nullify (realp)
   nullify (twop)
+  nullify (arrayOfPtr(1)%p)
+  nullify (arrayOfPtr(2)%p)
+  nullify (arrayOfPtr(3)%p)
+  nullify (cyclicp1%p)
+  nullify (cyclicp2%p)
 
   logp => logv    ! Before pointer assignment
   comp => comv
@@ -53,8 +72,14 @@ program pointers
   charap => chara
   intp => intv
   intap => inta
+  intvlap => intvla
   realp => realv
   twop => twov
+  arrayOfPtr(2)%p => twov
+  cyclicp1%i = 1
+  cyclicp1%p => cyclicp2
+  cyclicp2%i = 2
+  cyclicp2%p => cyclicp1
 
   logv = associated(logp)     ! Before value assignment
   comv = cmplx(1,2)
@@ -63,6 +88,10 @@ program pointers
   intv = 10
   inta(:,:) = 1
   inta(3,1) = 3
+  allocate (intvla(10))
+  intvla(:) = 2
+  intvla(4) = 4
+  intvlap => intvla
   realv = 3.14
 
   allocate (twov%ivla1(3))
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 7a2065f..7b3ffc8 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -1156,12 +1156,6 @@ value_check_printable (struct value *val, struct ui_file *stream,
       return 0;
     }
 
-  if (type_not_associated (val->type ()))
-    {
-      val_print_not_associated (stream);
-      return 0;
-    }
-
   if (type_not_allocated (val->type ()))
     {
       val_print_not_allocated (stream);