tcg: Convert typecode_to_ffi from array to function

In the unlikely case of invalid typecode mask, the function
will abort instead of returning a NULL pointer.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221111074101.2069454-27-richard.henderson@linaro.org>
[PMD: Split from bigger patch]
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221122180804.938-2-philmd@linaro.org>

1 files changed, 20 insertions, 10 deletions

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 0ac270fc7f..992ce3b33d 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -555,14 +555,24 @@ static GHashTable *helper_table;
 #ifdef CONFIG_TCG_INTERPRETER
 static GHashTable *ffi_table;
 
-static ffi_type * const typecode_to_ffi[8] = {
-    [dh_typecode_void] = &ffi_type_void,
-    [dh_typecode_i32]  = &ffi_type_uint32,
-    [dh_typecode_s32]  = &ffi_type_sint32,
-    [dh_typecode_i64]  = &ffi_type_uint64,
-    [dh_typecode_s64]  = &ffi_type_sint64,
-    [dh_typecode_ptr]  = &ffi_type_pointer,
-};
+static ffi_type *typecode_to_ffi(int argmask)
+{
+    switch (argmask) {
+    case dh_typecode_void:
+        return &ffi_type_void;
+    case dh_typecode_i32:
+        return &ffi_type_uint32;
+    case dh_typecode_s32:
+        return &ffi_type_sint32;
+    case dh_typecode_i64:
+        return &ffi_type_uint64;
+    case dh_typecode_s64:
+        return &ffi_type_sint64;
+    case dh_typecode_ptr:
+        return &ffi_type_pointer;
+    }
+    g_assert_not_reached();
+}
 #endif
 
 typedef struct TCGCumulativeArgs {
@@ -779,14 +789,14 @@ static void tcg_context_init(unsigned max_cpus)
         nargs = DIV_ROUND_UP(nargs, 3);
 
         ca = g_malloc0(sizeof(*ca) + nargs * sizeof(ffi_type *));
-        ca->cif.rtype = typecode_to_ffi[typemask & 7];
+        ca->cif.rtype = typecode_to_ffi(typemask & 7);
         ca->cif.nargs = nargs;
 
         if (nargs != 0) {
             ca->cif.arg_types = ca->args;
             for (int j = 0; j < nargs; ++j) {
                 int typecode = extract32(typemask, (j + 1) * 3, 3);
-                ca->args[j] = typecode_to_ffi[typecode];
+                ca->args[j] = typecode_to_ffi(typecode);
             }
         }