From eca07816f8f4c9cb081123a8534a481b416d1add Mon Sep 17 00:00:00 2001 From: Joel Brobecker Date: Wed, 10 Jul 2013 00:34:38 +0000 Subject: [PATCH] ada-lang.c:coerce_unspec_val_to_type: Preserve laziness. ada-lang.c:coerce_unspec_val_to_type does: if (value_lazy (val) || TYPE_LENGTH (type) > TYPE_LENGTH (value_type (val))) result = allocate_value_lazy (type); else { result = allocate_value (type); memcpy (value_contents_raw (result), value_contents (val), TYPE_LENGTH (type)); } set_value_component_location (result, val); set_value_bitsize (result, value_bitsize (val)); set_value_bitpos (result, value_bitpos (val)); set_value_address (result, value_address (val)); set_value_optimized_out (result, value_optimized_out (val)); Notice that before value_optimized_out was made to auto-fetch lazy values, VAL would end up still lazy if it was lazy on entry. It's not really a problem here if VAL is lazy, and VAL->optimized_out is 0, because RESULT is also left lazy. IOW, this just wants to copy the VAL->optimized_out flag to RESULT->optimized_out, nothing else. As a side-effect of the change in value_optimized_out, the following testcase now regresses. Consider: type Small is range -64 .. 63; for Small'Size use 7; type Arr is array (1..10) of Small; pragma Pack (Arr); type Arr_Ptr is access Arr; An_Arr_Ptr : Arr_Ptr := new Arr'(10, 20, 30, 40, 50, 60, 62, 63, -23, 42); Trying to print one element of An_Arr_Ptr yields: (gdb) p an_arr_ptr(3) Cannot access memory at address 0x0 The patch adds the value_optimized_out_const function for that, allowing us to avoid trying to fetch a value at a dummy address. (I found this out by grepping for set_value_optimized_out and trying to convert the uses I found to instead allocate the value with allocate_optimized_out_value.) Tested on x86_64 Fedora 17. gdb/ 2013-07-09 Pedro Alves * ada-lang.c (coerce_unspec_val_to_type): Use value_optimized_out_const. * value.c (value_optimized_out_const): New function. * value.h (value_optimized_out_const): New declaration. --- gdb/ChangeLog | 8 ++++++++ gdb/ada-lang.c | 2 +- gdb/value.c | 6 ++++++ gdb/value.h | 8 +++++++- 4 files changed, 22 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index c4d38700371..b24b9884366 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,11 @@ +2013-07-09 Pedro Alves + + Checked in by Joel Brobecker . + * ada-lang.c (coerce_unspec_val_to_type): Use + value_optimized_out_const. + * value.c (value_optimized_out_const): New function. + * value.h (value_optimized_out_const): New declaration. + 2013-07-09 Doug Evans * defs.h (enum val_prettyformat): Renamed from val_prettyprint. diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c index 8240fee0e18..dc5f2b6e3bc 100644 --- a/gdb/ada-lang.c +++ b/gdb/ada-lang.c @@ -581,7 +581,7 @@ coerce_unspec_val_to_type (struct value *val, struct type *type) set_value_bitsize (result, value_bitsize (val)); set_value_bitpos (result, value_bitpos (val)); set_value_address (result, value_address (val)); - set_value_optimized_out (result, value_optimized_out (val)); + set_value_optimized_out (result, value_optimized_out_const (val)); return result; } } diff --git a/gdb/value.c b/gdb/value.c index ce4b13a17a2..04f325f9760 100644 --- a/gdb/value.c +++ b/gdb/value.c @@ -1062,6 +1062,12 @@ value_optimized_out (struct value *value) return value->optimized_out; } +int +value_optimized_out_const (const struct value *value) +{ + return value->optimized_out; +} + void set_value_optimized_out (struct value *value, int val) { diff --git a/gdb/value.h b/gdb/value.h index 44d2aa082b6..5e00c8999b0 100644 --- a/gdb/value.h +++ b/gdb/value.h @@ -319,10 +319,16 @@ extern int value_fetch_lazy (struct value *val); extern int value_contents_equal (struct value *val1, struct value *val2); /* If nonzero, this is the value of a variable which does not actually - exist in the program. */ + exist in the program, at least partially. If the value is lazy, + this may fetch it now. */ extern int value_optimized_out (struct value *value); extern void set_value_optimized_out (struct value *value, int val); +/* Like value_optimized_out, but don't fetch the value even if it is + lazy. Mainly useful for constructing other values using VALUE as + template. */ +extern int value_optimized_out_const (const struct value *value); + /* Like value_optimized_out, but return false if any bit in the object is valid. */ extern int value_entirely_optimized_out (const struct value *value); -- 2.30.2