tcg: Make DisasContextBase.tb const

There is nothing within the translators that ought to be
changing the TranslationBlock data, so make it const.

This does not actually use the read-only copy of the
data structure that exists within the rx region.

Reviewed-by: Joelle van Dyne <j@getutm.app>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

6 files changed, 8 insertions, 8 deletions

diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
index fb1e19c585..a49a794065 100644
--- a/accel/tcg/translator.c
+++ b/accel/tcg/translator.c
@@ -133,8 +133,8 @@ void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
     }
 
     /* The disas_log hook may use these values rather than recompute.  */
-    db->tb->size = db->pc_next - db->pc_first;
-    db->tb->icount = db->num_insns;
+    tb->size = db->pc_next - db->pc_first;
+    tb->icount = db->num_insns;
 
 #ifdef DEBUG_DISAS
     if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)
diff --git a/include/exec/gen-icount.h b/include/exec/gen-icount.h
index 822c43cfd3..aa4b44354a 100644
--- a/include/exec/gen-icount.h
+++ b/include/exec/gen-icount.h
@@ -32,7 +32,7 @@ static inline void gen_io_end(void)
     tcg_temp_free_i32(tmp);
 }
 
-static inline void gen_tb_start(TranslationBlock *tb)
+static inline void gen_tb_start(const TranslationBlock *tb)
 {
     TCGv_i32 count, imm;
 
@@ -71,7 +71,7 @@ static inline void gen_tb_start(TranslationBlock *tb)
     tcg_temp_free_i32(count);
 }
 
-static inline void gen_tb_end(TranslationBlock *tb, int num_insns)
+static inline void gen_tb_end(const TranslationBlock *tb, int num_insns)
 {
     if (tb_cflags(tb) & CF_USE_ICOUNT) {
         /* Update the num_insn immediate parameter now that we know
diff --git a/include/exec/translator.h b/include/exec/translator.h
index 638e1529c5..24232ead41 100644
--- a/include/exec/translator.h
+++ b/include/exec/translator.h
@@ -67,7 +67,7 @@ typedef enum DisasJumpType {
  * Architecture-agnostic disassembly context.
  */
 typedef struct DisasContextBase {
-    TranslationBlock *tb;
+    const TranslationBlock *tb;
     target_ulong pc_first;
     target_ulong pc_next;
     DisasJumpType is_jmp;
diff --git a/include/tcg/tcg-op.h b/include/tcg/tcg-op.h
index 5b3bdacc39..901b19f32a 100644
--- a/include/tcg/tcg-op.h
+++ b/include/tcg/tcg-op.h
@@ -805,7 +805,7 @@ static inline void tcg_gen_insn_start(target_ulong pc, target_ulong a1,
  * be NULL and @idx should be 0.  Otherwise, @tb should be valid and
  * @idx should be one of the TB_EXIT_ values.
  */
-void tcg_gen_exit_tb(TranslationBlock *tb, unsigned idx);
+void tcg_gen_exit_tb(const TranslationBlock *tb, unsigned idx);
 
 /**
  * tcg_gen_goto_tb() - output goto_tb TCG operation
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 2e3fdfdf6b..ef63edfc68 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -410,7 +410,7 @@ static inline bool use_goto_tb(DisasContext *s, int n, uint64_t dest)
 
 static inline void gen_goto_tb(DisasContext *s, int n, uint64_t dest)
 {
-    TranslationBlock *tb;
+    const TranslationBlock *tb;
 
     tb = s->base.tb;
     if (use_goto_tb(s, n, dest)) {
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index af7ce91ffa..19fa8e4691 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -2664,7 +2664,7 @@ void tcg_gen_extr32_i64(TCGv_i64 lo, TCGv_i64 hi, TCGv_i64 arg)
 
 /* QEMU specific operations.  */
 
-void tcg_gen_exit_tb(TranslationBlock *tb, unsigned idx)
+void tcg_gen_exit_tb(const TranslationBlock *tb, unsigned idx)
 {
     uintptr_t val = (uintptr_t)tb + idx;