From 26cb189f8b46dbe7b2d485525329a8919005ca8a Mon Sep 17 00:00:00 2001 From: Sanimir Agovic Date: Wed, 9 Oct 2013 15:28:22 +0100 Subject: [PATCH] vla: enable sizeof operator to work with variable length arrays In C99 the sizeof operator computes the size of a variable length array at runtime (6.5.3.4 The sizeof operator). This patch reflects the semantic change in the debugger. We now are able to get the size of a vla: 1| void foo (size_t n) { 2| int vla[n]; 3| } (gdb) p sizeof(vla) yields N * sizeof(int). * eval.c (evaluate_subexp_for_sizeof) : If the type passed to sizeof is dynamic evaluate the argument to compute the length. --- gdb/ChangeLog | 5 +++++ gdb/eval.c | 8 +++++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 5f94509..ebeb2ef 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,10 @@ 2014-04-11 Sanimir Agovic + * eval.c (evaluate_subexp_for_sizeof) : If the type + passed to sizeof is dynamic evaluate the argument to compute the length. + +2014-04-11 Sanimir Agovic + * dwarf2loc.c (dwarf2_locexpr_baton_eval): New function. (dwarf2_evaluate_property): New function. * dwarf2loc.h (dwarf2_evaluate_property): New function prototype. diff --git a/gdb/eval.c b/gdb/eval.c index 36615e1..26454f6 100644 --- a/gdb/eval.c +++ b/gdb/eval.c @@ -3040,8 +3040,14 @@ evaluate_subexp_for_sizeof (struct expression *exp, int *pos) return value_from_longest (size_type, (LONGEST) TYPE_LENGTH (type)); case OP_VAR_VALUE: - (*pos) += 4; type = check_typedef (SYMBOL_TYPE (exp->elts[pc + 2].symbol)); + if (is_dynamic_type (type)) + { + val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_NORMAL); + type = value_type (val); + } + else + (*pos) += 4; return value_from_longest (size_type, (LONGEST) TYPE_LENGTH (type)); -- 2.7.4