[PATCH v2] guile: fix make-value with pointer type
George Barrett
bob@bob131.so
Sun Jun 6 19:56:40 GMT 2021
Calling the `make-value' procedure with an integer value and a pointer
type for the #:type argument triggers a failed assertion in
`get_unsigned_type_max', as that function doesn't consider pointers to
be an unsigned type. This commit fixes the issue by adding a separate
code path for pointers.
As previously suggested, range checking is done using a new helper
function in gdbtypes.
gdb/ChangeLog:
2021-06-07 George Barrett <bob@bob131.so>
* gdbtypes.h (get_pointer_type_max): Add declaration.
* gdbtypes.c (get_pointer_type_max): Add definition for new
helper function.
* guile/scm-math.c (vlscm_convert_typed_number): Add code path
for handling conversions to pointer types without failing an
assert.
gdb/testsuite/ChangeLog:
2021-06-07 George Barrett <bob@bob131.so>
* gdb.guile/scm-math.exp (test_value_numeric_ops): Add test
for creating pointers with make-value.
(test_make_pointer_value, test_pointer_numeric_range): Add
test procedures containing checks for integer-to-pointer
validation.
---
gdb/gdbtypes.c | 16 +++++++++++
gdb/gdbtypes.h | 2 ++
gdb/guile/scm-math.c | 18 +++++++++++--
gdb/testsuite/gdb.guile/scm-math.exp | 40 ++++++++++++++++++++++++++++
4 files changed, 74 insertions(+), 2 deletions(-)
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 84c4f34cf30..6e74cabc3b3 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -1931,6 +1931,22 @@ get_signed_type_minmax (struct type *type, LONGEST *min, LONGEST *max)
*max = ((ULONGEST) 1 << (n - 1)) - 1;
}
+/* Store in *MAX the largest value representable by pointer type
+ TYPE. */
+
+void
+get_pointer_type_max (struct type *type, CORE_ADDR *max)
+{
+ unsigned int n;
+
+ type = check_typedef (type);
+ gdb_assert (type->code () == TYPE_CODE_PTR);
+ gdb_assert (TYPE_LENGTH (type) <= sizeof (CORE_ADDR));
+
+ n = TYPE_LENGTH (type) * TARGET_CHAR_BIT;
+ *max = ((((CORE_ADDR) 1 << (n - 1)) - 1) << 1) | 1;
+}
+
/* Internal routine called by TYPE_VPTR_FIELDNO to return the value of
cplus_stuff.vptr_fieldno.
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index bb4d26eef1a..054a7096f0a 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -2499,6 +2499,8 @@ extern void get_unsigned_type_max (struct type *, ULONGEST *);
extern void get_signed_type_minmax (struct type *, LONGEST *, LONGEST *);
+extern void get_pointer_type_max (struct type *, CORE_ADDR *);
+
/* * Resolve all dynamic values of a type e.g. array bounds to static values.
ADDR specifies the location of the variable the type is bound to.
If TYPE has no dynamic properties return TYPE; otherwise a new type with
diff --git a/gdb/guile/scm-math.c b/gdb/guile/scm-math.c
index d9fd6718196..84de21cb440 100644
--- a/gdb/guile/scm-math.c
+++ b/gdb/guile/scm-math.c
@@ -524,8 +524,7 @@ vlscm_convert_typed_number (const char *func_name, int obj_arg_pos, SCM obj,
int type_arg_pos, SCM type_scm, struct type *type,
struct gdbarch *gdbarch, SCM *except_scmp)
{
- if (is_integral_type (type)
- || type->code () == TYPE_CODE_PTR)
+ if (is_integral_type (type))
{
if (type->is_unsigned ())
{
@@ -558,6 +557,21 @@ vlscm_convert_typed_number (const char *func_name, int obj_arg_pos, SCM obj,
return value_from_longest (type, gdbscm_scm_to_longest (obj));
}
}
+ else if (type->code () == TYPE_CODE_PTR)
+ {
+ CORE_ADDR max;
+
+ get_pointer_type_max (type, &max);
+ if (!scm_is_unsigned_integer (obj, 0, max))
+ {
+ *except_scmp
+ = gdbscm_make_out_of_range_error (func_name,
+ obj_arg_pos, obj,
+ _("value out of range for type"));
+ return NULL;
+ }
+ return value_from_pointer (type, gdbscm_scm_to_ulongest (obj));
+ }
else if (type->code () == TYPE_CODE_FLT)
return value_from_host_double (type, scm_to_double (obj));
else
diff --git a/gdb/testsuite/gdb.guile/scm-math.exp b/gdb/testsuite/gdb.guile/scm-math.exp
index ba975454ce5..ee428e5cc90 100644
--- a/gdb/testsuite/gdb.guile/scm-math.exp
+++ b/gdb/testsuite/gdb.guile/scm-math.exp
@@ -137,6 +137,15 @@ proc test_value_numeric_ops {} {
gdb_test "gu (print (value-sub b a))" \
"= 3" "subtract two pointer values"
+ # Test pointer creation.
+
+ gdb_test_no_output "gu (define void-pointer-type (type-pointer (arch-void-type (current-arch))))"
+ gdb_scm_test_silent_cmd "gu (define null-pointer (make-value 0 #:type void-pointer-type))" \
+ "test make-value with pointer type"
+ gdb_test "gu (print null-pointer)" "= 0x0"
+ gdb_test "gu (print (equal? (value-type null-pointer) void-pointer-type))" \
+ "= #t"
+
# Test some invalid operations.
gdb_test_multiple "gu (print (value-add i '()))" "catch error in guile type conversion" {
@@ -237,6 +246,36 @@ proc test_value_numeric_ranges {} {
}
}
+# Helper routine for test_pointer_numeric_range.
+
+proc test_make_pointer_value { size } {
+ set max [get_max_uint $size]
+ set max_hex [string repeat "f" [expr "$size / 4"]]
+
+ gdb_test "gu (print (make-value $max #:type void-pointer-type))" \
+ "= 0x$max_hex" "test make-value void* max"
+ gdb_test "gu (print (make-value 0 #:type void-pointer-type))" \
+ "= 0x0" "test make-value void* 0"
+
+ gdb_test "gu (print (make-value (+ $max 1) #:type void-pointer-type))" \
+ "ERROR.*Out of range.*" "test make-value void* max+1"
+ gdb_test "gu (print (make-value -1 #:type void-pointer-type))" \
+ "ERROR.*Out of range.*" "test make-value void* -1"
+}
+
+proc test_pointer_numeric_range {} {
+ # We can't assume anything about sizeof (void*) on the target.
+ # Keep it simple for now, this will cover everything important for
+ # the major targets.
+ set pointer_size [get_sizeof "void*" 0]
+ if { $pointer_size == 4 } {
+ test_make_pointer_value 32
+ }
+ if { $pointer_size == 8 } {
+ test_make_pointer_value 64
+ }
+}
+
proc test_value_boolean {} {
# Note: Boolean values print as 0,1 because they are printed in the
# current language (in this case C).
@@ -305,5 +344,6 @@ if ![gdb_guile_runto_main] {
test_value_numeric_ops
test_value_numeric_ranges
+test_pointer_numeric_range
test_value_boolean
test_value_compare
--
2.31.1
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