disas: add optional note support to cap_disas

Include support for outputting a note at the top of a chunk of
disassembly to capstone as well.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-Id: <20200513175134.19619-10-alex.bennee@linaro.org>

disas.c

@@ -260,7 +260,8 @@ static void cap_dump_insn_units(disassemble_info *info, cs_insn *insn,
     }
 }
 
-static void cap_dump_insn(disassemble_info *info, cs_insn *insn)
+static void cap_dump_insn(disassemble_info *info, cs_insn *insn,
+                          const char *note)
 {
     fprintf_function print = info->fprintf_func;
     int i, n, split;
@@ -281,7 +282,11 @@ static void cap_dump_insn(disassemble_info *info, cs_insn *insn)
     }
 
     /* Print the actual instruction.  */
-    print(info->stream, "  %-8s %s\n", insn->mnemonic, insn->op_str);
+    print(info->stream, "  %-8s %s", insn->mnemonic, insn->op_str);
+    if (note) {
+        print(info->stream, "\t\t%s", note);
+    }
+    print(info->stream, "\n");
 
     /* Dump any remaining part of the insn on subsequent lines.  */
     for (i = split; i < n; i += split) {
@@ -313,7 +318,7 @@ static bool cap_disas_target(disassemble_info *info, uint64_t pc, size_t size)
         size -= tsize;
 
         while (cs_disasm_iter(handle, &cbuf, &csize, &pc, insn)) {
-           cap_dump_insn(info, insn);
+            cap_dump_insn(info, insn, NULL);
         }
 
         /* If the target memory is not consumed, go back for more... */
@@ -342,7 +347,8 @@ static bool cap_disas_target(disassemble_info *info, uint64_t pc, size_t size)
 }
 
 /* Disassemble SIZE bytes at CODE for the host.  */
-static bool cap_disas_host(disassemble_info *info, void *code, size_t size)
+static bool cap_disas_host(disassemble_info *info, void *code, size_t size,
+                           const char *note)
 {
     csh handle;
     const uint8_t *cbuf;
@@ -358,7 +364,8 @@ static bool cap_disas_host(disassemble_info *info, void *code, size_t size)
     pc = (uintptr_t)code;
 
     while (cs_disasm_iter(handle, &cbuf, &size, &pc, insn)) {
-       cap_dump_insn(info, insn);
+        cap_dump_insn(info, insn, note);
+        note = NULL;
     }
     if (size != 0) {
         (*info->fprintf_func)(info->stream,
@@ -402,7 +409,7 @@ static bool cap_disas_monitor(disassemble_info *info, uint64_t pc, int count)
         csize += tsize;
 
         if (cs_disasm_iter(handle, &cbuf, &csize, &pc, insn)) {
-            cap_dump_insn(info, insn);
+            cap_dump_insn(info, insn, NULL);
             if (--count <= 0) {
                 break;
             }
@@ -416,7 +423,7 @@ static bool cap_disas_monitor(disassemble_info *info, uint64_t pc, int count)
 #endif /* !CONFIG_USER_ONLY */
 #else
 # define cap_disas_target(i, p, s)  false
-# define cap_disas_host(i, p, s)  false
+# define cap_disas_host(i, p, s, n)  false
 # define cap_disas_monitor(i, p, c)  false
 # define cap_disas_plugin(i, p, c) false
 #endif /* CONFIG_CAPSTONE */
@@ -664,7 +671,7 @@ void disas(FILE *out, void *code, unsigned long size, const char *note)
     print_insn = print_insn_hppa;
 #endif
 
-    if (s.info.cap_arch >= 0 && cap_disas_host(&s.info, code, size)) {
+    if (s.info.cap_arch >= 0 && cap_disas_host(&s.info, code, size, note)) {
         return;
     }