[gdb] Print progress for debuginfod

Prints progress like:

Downloading 4.89 MB separate debug info for /usr/lib64/libgcrypt.so.20.
Downloading 1.10 MB separate debug info for /usr/lib64/liblzma.so.5.
Downloading 1.31 MB separate debug info for /usr/lib64/liblz4.so.1.
Downloading 0.96 MB separate debug info for /usr/lib64/libsmime3.so.
[###                                                                    ]

Tested on x86_64-linux.

ChangeLog:

2020-12-10  Martin Liska  <mliska@suse.cz>
	    Tom de Vries  <tdevries@suse.de>

	* gdb/debuginfod-support.c (struct user_data): Remove has_printed
	field.  Add meter field.
	(progressfn): Print progress using meter.

---
 gdb/debuginfod-support.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/gdb/debuginfod-support.c b/gdb/debuginfod-support.c
index 86630576e3..a17cb7c5a8 100644
--- a/gdb/debuginfod-support.c
+++ b/gdb/debuginfod-support.c
@@ -21,6 +21,8 @@
 #include "cli/cli-style.h"
 #include "gdbsupport/scoped_fd.h"
 #include "debuginfod-support.h"
+#include "gdbsupport/gdb_optional.h"
+#include <iomanip>
 
 #ifndef HAVE_LIBDEBUGINFOD
 scoped_fd
@@ -48,12 +50,12 @@ debuginfod_debuginfo_query (const unsigned char *build_id,
 struct user_data
 {
   user_data (const char *desc, const char *fname)
-    : desc (desc), fname (fname), has_printed (false)
+    : desc (desc), fname (fname)
   { }
 
   const char * const desc;
   const char * const fname;
-  bool has_printed;
+  gdb::optional<ui_out::progress_meter> meter;
 };
 
 /* Deleter for a debuginfod_client.  */
@@ -82,15 +84,21 @@ progressfn (debuginfod_client *c, long cur, long total)
       return 1;
     }
 
-  if (!data->has_printed && total != 0)
+  if (total == 0)
+    return 0;
+
+  if (!data->meter.has_value ())
     {
-      /* Print this message only once.  */
-      data->has_printed = true;
-      printf_filtered ("Downloading %s %ps...\n",
-		       data->desc,
-		       styled_string (file_name_style.style (), data->fname));
+      float size_in_mb = 1.0f * total / (1024 * 1024);
+      std::stringstream message;
+      message.precision (2);
+      message << "Downloading " << size_in_mb << " MB " << data->desc
+	      << " " << data->fname;
+      data->meter.emplace (current_uiout, message.str (), 1);
     }
 
+  current_uiout->progress ((double)cur / (double)total);
+
   return 0;
 }