From 27bfd83c336283d1f7a5345ee386c4cd7b80db61 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Sun, 6 Mar 2011 21:39:53 +0000 Subject: tcg: Add support for debugging leakage of temporaries Add support (if CONFIG_DEBUG_TCG is defined) for debugging leakage of temporary variables. Generally any temporaries created by a target while it is translating an instruction should be freed by the end of that instruction; otherwise carefully crafted guest code could cause TCG to run out of temporaries and assert. By calling tcg_check_temp_count() after each instruction we can check that we are not leaking temporaries in this way. Signed-off-by: Peter Maydell Signed-off-by: Aurelien Jarno --- tcg/tcg.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'tcg/tcg.h') diff --git a/tcg/tcg.h b/tcg/tcg.h index e1afde26b4..3fab8d6c27 100644 --- a/tcg/tcg.h +++ b/tcg/tcg.h @@ -323,6 +323,10 @@ struct TCGContext { int64_t restore_count; int64_t restore_time; #endif + +#ifdef CONFIG_DEBUG_TCG + int temps_in_use; +#endif }; extern TCGContext tcg_ctx; @@ -392,6 +396,19 @@ static inline TCGv_i64 tcg_temp_local_new_i64(void) void tcg_temp_free_i64(TCGv_i64 arg); char *tcg_get_arg_str_i64(TCGContext *s, char *buf, int buf_size, TCGv_i64 arg); +#if defined(CONFIG_DEBUG_TCG) +/* If you call tcg_clear_temp_count() at the start of a section of + * code which is not supposed to leak any TCG temporaries, then + * calling tcg_check_temp_count() at the end of the section will + * return 1 if the section did in fact leak a temporary. + */ +void tcg_clear_temp_count(void); +int tcg_check_temp_count(void); +#else +#define tcg_clear_temp_count() do { } while (0) +#define tcg_check_temp_count() 0 +#endif + void tcg_dump_info(FILE *f, fprintf_function cpu_fprintf); #define TCG_CT_ALIAS 0x80 -- cgit v1.2.3