gdb: Print percent 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.
  36%

ChangeLog:

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

	* gdb/debuginfod-support.c (struct user_data): Add
	last_percent_printed and first_line_printed field.
	(progressfn): Print progress.
	* utils.c (fputs_maybe_filtered): Handle '\r'.

---
 gdb/debuginfod-support.c | 36 ++++++++++++++++++++++++++++++------
 gdb/utils.c              |  6 ++++++
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/gdb/debuginfod-support.c b/gdb/debuginfod-support.c
index e21b2f40ca..3d74b2d9c8 100644
--- a/gdb/debuginfod-support.c
+++ b/gdb/debuginfod-support.c
@@ -46,12 +46,14 @@ 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), last_percent_printed (-1),
+      first_line_printed (false)
   { }
 
   const char * const desc;
   const char * const fname;
-  bool has_printed;
+  long last_percent_printed;
+  bool first_line_printed;
 };
 
 /* Deleter for a debuginfod_client.  */
@@ -80,14 +82,36 @@ progressfn (debuginfod_client *c, long cur, long total)
       return 1;
     }
 
-  if (!data->has_printed && total != 0)
+  if (total == 0)
+    return 0;
+
+  if (!data->first_line_printed)
     {
-      /* Print this message only once.  */
-      data->has_printed = true;
-      printf_filtered ("Downloading %s %ps...\n",
+      printf_filtered ("Downloading %.2f MB %s %ps.\n",
+		       1.0f * total / (1024 * 1024),
 		       data->desc,
 		       styled_string (file_name_style.style (), data->fname));
+      gdb_flush (gdb_stdout);
+      data->first_line_printed = true;
+    }
+
+  if (cur == total)
+    {
+      printf_filtered ("\r");
+      gdb_flush (gdb_stdout);
     }
+  else if (cur > 0)
+    {
+      /* Print this message only once.  */
+      long percent = 100 * cur / total;
+      if (percent != data->last_percent_printed)
+	{
+	  data->last_percent_printed = percent;
+	  printf_filtered ("\r%3ld%%", percent);
+	  gdb_flush (gdb_stdout);
+	}
+    }
+
 
   return 0;
 }
diff --git a/gdb/utils.c b/gdb/utils.c
index 3226656e2c..26c671a44c 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -1769,6 +1769,12 @@ fputs_maybe_filtered (const char *linebuffer, struct ui_file *stream,
 		 don't increment chars_printed here.  */
 	      lineptr += skip_bytes;
 	    }
+	  else if (*lineptr == '\r')
+	    {
+	      wrap_buffer.push_back ('\r');
+	      chars_printed = 0;
+	      lineptr++;
+	    }
 	  else
 	    {
 	      wrap_buffer.push_back (*lineptr);