diff options
author | Joel Brobecker <brobecker@adacore.com> | 2014-12-08 10:37:00 -0500 |
---|---|---|
committer | Joel Brobecker <brobecker@adacore.com> | 2014-12-13 11:00:24 -0500 |
commit | c1b5a1a6e732a65350af930c499b23018f8663cc (patch) | |
tree | 3f1780b967531dc51b7067e7ed53cc0d1252de7e /gdb/ada-valprint.c | |
parent | 3c46a02f5083c4a9c07b563d44b8b6ded6d85bb1 (diff) |
Internal error trying to print uninitialized string.
Trying to print the value of a string whose size is not known at
compile-time before it gets assigned a value can lead to the following
internal error:
(gdb) p my_str
$1 =
/[...]/utils.c:1089: internal-error: virtual memory exhausted.
What happens is that my_str is described as a reference to an array
type whose bounds are dynamic. During the read of that variable's
value (in default_read_var_value), we end up resolving dynamic types
which, for reference types, makes us also resolve the target of that
reference type. This means we resolve our variable to a reference
to an array whose bounds are undefined, and unfortunately very far
appart.
So, when we pass that value to ada-valprint, and in particular to
da_val_print_ref, we eventually try to allocate too large of a buffer
corresponding to the (bogus) size of our array, hence the internal
error.
This patch fixes the problem by adding a size_check before trying
to print the dereferenced value. To perform this check, a function
that was previously specific to ada-lang.c (check_size) gets
exported, and renamed to something less prone to name collisions
(ada_ensure_varsize_limit).
gdb/ChangeLog:
* ada-lang.h (ada_ensure_varsize_limit): Declare.
* ada-lang.c (check_size): Remove advance declaration.
(ada_ensure_varsize_limit): Renames check_size.
Replace calls to check_size by calls to ada_ensure_varsize_limit
throughout.
* ada-valprint.c (ada_val_print_ref): Add call to
ada_ensure_varsize_limit. Add comment explaining why.
gdb/testsuite/ChangeLog:
* gdb.ada/str_uninit: New testcase.
Diffstat (limited to 'gdb/ada-valprint.c')
-rw-r--r-- | gdb/ada-valprint.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/gdb/ada-valprint.c b/gdb/ada-valprint.c index 6f68faebd3..1808cb6156 100644 --- a/gdb/ada-valprint.c +++ b/gdb/ada-valprint.c @@ -1055,6 +1055,12 @@ ada_val_print_ref (struct type *type, const gdb_byte *valaddr, if (ada_is_tagged_type (value_type (deref_val), 1)) deref_val = ada_tag_value_at_base_address (deref_val); + /* Make sure that the object does not have an unreasonable size + before trying to print it. This can happen for instance with + references to dynamic objects whose contents is uninitialized + (Eg: an array whose bounds are not set yet). */ + ada_ensure_varsize_limit (value_type (deref_val)); + val_print (value_type (deref_val), value_contents_for_printing (deref_val), value_embedded_offset (deref_val), |