[Qemu-devel] [PATCH] tcg: Add consistency checks for op definitions

[Stefan Weil]

When compiled with CONFIG_DEBUG_TCG, this code looks
for missing, duplicate and wrong entries in the
op definitions.

Errors will raise an assertion at program start
(all checks are done in the initial phase).

The current code contains such errors, at least for
i386 guest on i386 host.

Signed-off-by: Stefan Weil <address@hidden>
---
 tcg/tcg.c |   21 +++++++++++++++++++++
 tcg/tcg.h |    3 +++
 2 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 9949814..e6a1caf 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -981,9 +981,16 @@ void tcg_add_target_add_op_defs(const TCGTargetOpDef 
*tdefs)
         op = tdefs->op;
         assert(op >= 0 && op < NB_OPS);
         def = &tcg_op_defs[op];
+#if defined(CONFIG_DEBUG_TCG)
+        /* Duplicate entry in op definitions? */
+        assert(!def->used);
+        def->used = 1;
+#endif
         nb_args = def->nb_iargs + def->nb_oargs;
         for(i = 0; i < nb_args; i++) {
             ct_str = tdefs->args_ct_str[i];
+            /* Incomplete TCGTargetOpDef entry? */
+            assert(ct_str != NULL);
             tcg_regset_clear(def->args_ct[i].u.regs);
             def->args_ct[i].ct = 0;
             if (ct_str[0] >= '0' && ct_str[0] <= '9') {
@@ -1018,6 +1025,9 @@ void tcg_add_target_add_op_defs(const TCGTargetOpDef 
*tdefs)
             }
         }
 
+        /* TCGTargetOpDef entry with too much information? */
+        assert(i == TCG_MAX_OP_ARGS || tdefs->args_ct_str[i] == NULL);
+
         /* sort the constraints (XXX: this is just an heuristic) */
         sort_constraints(def, 0, def->nb_oargs);
         sort_constraints(def, def->nb_oargs, def->nb_iargs);
@@ -1035,6 +1045,17 @@ void tcg_add_target_add_op_defs(const TCGTargetOpDef 
*tdefs)
         tdefs++;
     }
 
+#if defined(CONFIG_DEBUG_TCG)
+    for (op = 0; op < ARRAY_SIZE(tcg_op_defs); op++) {
+        if (op < INDEX_op_call || op == INDEX_op_debug_insn_start) {
+            /* Wrong entry in op definitions? */
+            assert(!tcg_op_defs[op].used);
+        } else {
+            /* Missing entry in op definitions? */
+            assert(tcg_op_defs[op].used);
+        }
+    }
+#endif
 }
 
 #ifdef USE_LIVENESS_ANALYSIS
diff --git a/tcg/tcg.h b/tcg/tcg.h
index b218abe..aca9f27 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -404,6 +404,9 @@ typedef struct TCGOpDef {
     uint16_t copy_size;
     TCGArgConstraint *args_ct;
     int *sorted_args;
+#if defined(CONFIG_DEBUG_TCG)
+    int used;
+#endif
 } TCGOpDef;
         
 typedef struct TCGTargetOpDef {
-- 
1.6.6.1