From bef16ab4e641636b4e85c3d863b4257ce0be4e6f Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Thu, 7 Feb 2019 13:26:40 +0000 Subject: tcg: Diagnose referenced labels that have not been emitted MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, a jump to a label that is not defined anywhere will be emitted not be relocated. This results in a jump to a random jump target. With tcg debugging, print a diagnostic to the -d op file and abort. This could help debug or detect errors like c2d9644e6d ("target/arm: Fix crash on conditional instruction in an IT block") Reported-by: Roman Kapl Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- tcg/tcg.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'tcg/tcg.c') diff --git a/tcg/tcg.c b/tcg/tcg.c index 20a5d8f315..9b2bf7f439 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -305,6 +305,9 @@ TCGLabel *gen_new_label(void) *l = (TCGLabel){ .id = s->nb_labels++ }; +#ifdef CONFIG_DEBUG_TCG + QSIMPLEQ_INSERT_TAIL(&s->labels, l, next); +#endif return l; } @@ -1092,6 +1095,9 @@ void tcg_func_start(TCGContext *s) QTAILQ_INIT(&s->ops); QTAILQ_INIT(&s->free_ops); +#ifdef CONFIG_DEBUG_TCG + QSIMPLEQ_INIT(&s->labels); +#endif } static inline TCGTemp *tcg_temp_alloc(TCGContext *s) @@ -3841,6 +3847,23 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) } #endif +#ifdef CONFIG_DEBUG_TCG + /* Ensure all labels referenced have been emitted. */ + { + TCGLabel *l; + bool error = false; + + QSIMPLEQ_FOREACH(l, &s->labels, next) { + if (unlikely(!l->present) && l->refs) { + qemu_log_mask(CPU_LOG_TB_OP, + "$L%d referenced but not present.\n", l->id); + error = true; + } + } + assert(!error); + } +#endif + #ifdef CONFIG_PROFILER atomic_set(&prof->opt_time, prof->opt_time - profile_getclock()); #endif -- cgit v1.2.3