gdb: introduce displaced_debug_printf

Move all debug prints of the "displaced" category to use a new
displaced_debug_printf macro, like what was done for infrun and others
earlier.

The debug output for one displaced step one amd64 looks like:

    [displaced] displaced_step_prepare_throw: stepping process 3367044 now
    [displaced] displaced_step_prepare_throw: saved 0x555555555042: 1e fa 31 ed 49 89 d1 5e 48 89 e2 48 83 e4 f0 50
    [displaced] amd64_displaced_step_copy_insn: copy 0x555555555131->0x555555555042: b8 00 00 00 00 5d c3 0f 1f 84 00 00 00 00 00 f3
    [displaced] displaced_step_prepare_throw: displaced pc to 0x555555555042
    [displaced] resume_1: run 0x555555555042: b8 00 00 00
    [displaced] displaced_step_restore: restored process 3367044 0x555555555042
    [displaced] amd64_displaced_step_fixup: fixup (0x555555555131, 0x555555555042), insn = 0xb8 0x00 ...
    [displaced] amd64_displaced_step_fixup: relocated %rip from 0x555555555047 to 0x555555555136

On test case needed to be updated because it relied on the specific
formatting of the message.

gdb/ChangeLog:

	* infrun.h (displaced_debug_printf): New macro.  Replace
	displaced debug prints throughout to use it.
	(displaced_debug_printf_1): New declaration.
	(displaced_step_dump_bytes): Return string, remove ui_file
	parameter, update all callers.
	* infrun.c (displaced_debug_printf_1): New function.
	(displaced_step_dump_bytes): Return string, remove ui_file
	parameter

gdb/testsuite/ChangeLog:

	* gdb.arch/amd64-disp-step-avx.exp: Update displaced step debug
	expected output.

Change-Id: Ie78837f56431f6f98378790ba1e6051337bf6533

1 files changed, 15 insertions, 3 deletions

diff --git a/gdb/infrun.h b/gdb/infrun.h
index d0dca67a47..4fc1bf9458 100644
--- a/gdb/infrun.h
+++ b/gdb/infrun.h
@@ -47,6 +47,19 @@ void ATTRIBUTE_PRINTF (2, 3) infrun_debug_printf_1
 /* True if we are debugging displaced stepping.  */
 extern bool debug_displaced;
 
+/* Print a "displaced" debug statement.  Should be used through
+   displaced_debug_printf.  */
+void ATTRIBUTE_PRINTF (2, 3) displaced_debug_printf_1
+  (const char *func_name, const char *fmt, ...);
+
+#define displaced_debug_printf(fmt, ...) \
+  do \
+    { \
+      if (debug_displaced) \
+	displaced_debug_printf_1 (__func__, fmt, ##__VA_ARGS__); \
+    } \
+  while (0)
+
 /* Nonzero if we want to give control to the user when we're notified
    of shared library events by the dynamic linker.  */
 extern int stop_on_solib_events;
@@ -229,9 +242,8 @@ extern void update_signals_program_target (void);
    $_exitsignal.  */
 extern void clear_exit_convenience_vars (void);
 
-/* Dump LEN bytes at BUF in hex to FILE, followed by a newline.  */
-extern void displaced_step_dump_bytes (struct ui_file *file,
-				       const gdb_byte *buf, size_t len);
+/* Dump LEN bytes at BUF in hex to a string and return it.  */
+extern std::string displaced_step_dump_bytes (const gdb_byte *buf, size_t len);
 
 extern struct displaced_step_closure *get_displaced_step_closure_by_addr
     (CORE_ADDR addr);