tcg: Add in_code_gen_buffer

Create a function to determine if a pointer is within the buffer.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index bb1e97b13b..ef571b6f3e 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -680,6 +680,17 @@ extern __thread TCGContext *tcg_ctx;
 extern void *tcg_code_gen_epilogue;
 extern TCGv_env cpu_env;
 
+static inline bool in_code_gen_buffer(const void *p)
+{
+    const TCGContext *s = &tcg_init_ctx;
+    /*
+     * Much like it is valid to have a pointer to the byte past the
+     * end of an array (so long as you don't dereference it), allow
+     * a pointer to the byte past the end of the code gen buffer.
+     */
+    return (size_t)(p - s->code_gen_buffer) <= s->code_gen_buffer_size;
+}
+
 static inline size_t temp_idx(TCGTemp *ts)
 {
     ptrdiff_t n = ts - tcg_ctx->temps;