Implement putstr and putstrn in ui_file

In my tour of the ui_file subsystem, I found that fputstr and fputstrn
can be simplified.  The _filtered forms are never used (and IMO
unlikely to ever be used) and so can be removed.  And, the interface
can be simplified by removing a callback function and moving the
implementation directly to ui_file.

A new self-test is included.  Previously, I think nothing was testing
this code.

Regression tested on x86-64 Fedora 34.

1 files changed, 21 insertions, 4 deletions

diff --git a/gdb/ui-file.h b/gdb/ui-file.h
index 89f249e..c097abf 100644
--- a/gdb/ui-file.h
+++ b/gdb/ui-file.h
@@ -34,12 +34,22 @@ public:
 
   void printf (const char *, ...) ATTRIBUTE_PRINTF (2, 3);
 
-  /* Print a string whose delimiter is QUOTER.  Note that these
-     routines should only be called for printing things which are
-     independent of the language of the program being debugged.  */
+  /* Print a NUL-terminated string whose delimiter is QUOTER.  Note
+     that these routines should only be called for printing things
+     which are independent of the language of the program being
+     debugged.
+
+     This will normally escape backslashes and instances of QUOTER.
+     If QUOTER is 0, it won't escape backslashes or any quoting
+     character.  As a side effect, if you pass the backslash character
+     as the QUOTER, this will escape backslashes as usual, but not any
+     other quoting character.  */
   void putstr (const char *str, int quoter);
 
-  void putstrn (const char *str, int n, int quoter);
+  /* Like putstr, but only print the first N characters of STR.  If
+     ASYNC_SAFE is true, then the output is done via the
+     write_async_safe method.  */
+  void putstrn (const char *str, int n, int quoter, bool async_safe = false);
 
   int putc (int c);
 
@@ -96,6 +106,13 @@ public:
        default.  */
     return false;
   }
+
+private:
+
+  /* Helper function for putstr and putstrn.  Print the character C on
+     this stream as part of the contents of a literal string whose
+     delimiter is QUOTER.  */
+  void printchar (int c, int quoter, bool async_safe);
 };
 
 typedef std::unique_ptr<ui_file> ui_file_up;