[PATCH 0/2] Fix two small Python flush problems

[PATCH 0/2] Fix two small Python flush problems

[Tom Tromey via Gdb-patches]

This short series fixes a couple of small problems with the 'flush'
function in Python.

First, I noticed that the documentation is missing a part of the
description.  Then, I noticed that the stdout/stderr 'flush' method
was incorrectly implemented.

Tom

[PATCH 1/2] Fix gdb.flush documentation

[Tom Tromey via Gdb-patches]

The gdb.flush documentation does not mention the 'stream' argument in
the function signature, only in the description.  This patch fixes the
oversight.
---
 gdb/doc/python.texi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index 9a823409854..7aa9e853d85 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -511,7 +511,7 @@ relevant stream.
 @end defun
 
 @findex gdb.flush
-@defun gdb.flush ()
+@defun gdb.flush (@r{[}, stream@r{]})
 Flush the buffer of a @value{GDBN} paginated stream so that the
 contents are displayed immediately.  @value{GDBN} will flush the
 contents of a stream automatically when it encounters a newline in the
-- 
2.34.1

[PATCH 2/2] Fix flush for sys.stderr

[Tom Tromey via Gdb-patches]

GDB overwrites Python's sys.stdout and sys.stderr, but does not
properly implement the 'flush' method -- it only ever will flush
stdout.  This patch fixes the bug.  I couldn't find a straightforward
way to write a test for this.
---
 gdb/python/lib/gdb/__init__.py      | 19 +++++++------------
 gdb/testsuite/gdb.python/python.exp |  4 ++--
 2 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/gdb/python/lib/gdb/__init__.py b/gdb/python/lib/gdb/__init__.py
index 5b10e3e2381..191915e4f3b 100644
--- a/gdb/python/lib/gdb/__init__.py
+++ b/gdb/python/lib/gdb/__init__.py
@@ -39,6 +39,9 @@ class _GdbFile(object):
     encoding = "UTF-8"
     errors = "strict"
 
+    def __init__(self, stream):
+        self.stream = stream
+
     def close(self):
         # Do nothing.
         return None
@@ -51,23 +54,15 @@ class _GdbFile(object):
             self.write(line)
 
     def flush(self):
-        flush()
-
+        flush(stream=self.stream)
 
-class _GdbOutputFile(_GdbFile):
     def write(self, s):
-        write(s, stream=STDOUT)
-
+        write(s, stream=self.stream)
 
-sys.stdout = _GdbOutputFile()
-
-
-class _GdbOutputErrorFile(_GdbFile):
-    def write(self, s):
-        write(s, stream=STDERR)
 
+sys.stdout = _GdbFile(STDOUT)
 
-sys.stderr = _GdbOutputErrorFile()
+sys.stderr = _GdbFile(STDERR)
 
 # Default prompt hook does nothing.
 prompt_hook = None
diff --git a/gdb/testsuite/gdb.python/python.exp b/gdb/testsuite/gdb.python/python.exp
index 8c0da6daa26..48ff07e91e5 100644
--- a/gdb/testsuite/gdb.python/python.exp
+++ b/gdb/testsuite/gdb.python/python.exp
@@ -297,8 +297,8 @@ with_test_prefix "test decode_line" {
 }
 
 # gdb.write
-gdb_test "python print (sys.stderr)" ".*gdb._GdbOutputErrorFile (instance|object) at.*" "test stderr location"
-gdb_test "python print (sys.stdout)" ".*gdb._GdbOutputFile (instance|object) at.*" "test stdout location"
+gdb_test "python print (sys.stderr)" ".*gdb._GdbFile (instance|object) at.*" "test stderr location"
+gdb_test "python print (sys.stdout)" ".*gdb._GdbFile (instance|object) at.*" "test stdout location"
 gdb_test "python gdb.write(\"Foo\\n\")" "Foo" "test default write"
 gdb_test "python gdb.write(\"Error stream\\n\", stream=gdb.STDERR)" "Error stream" "test stderr write"
 gdb_test "python gdb.write(\"Normal stream\\n\", stream=gdb.STDOUT)" "Normal stream" "test stdout write"
-- 
2.34.1

Re: [PATCH 1/2] Fix gdb.flush documentation

[Eli Zaretskii via Gdb-patches]

> Date: Mon, 15 Aug 2022 12:50:08 -0600
> From: Tom Tromey via Gdb-patches <gdb-patches@sourceware.org>
> Cc: Tom Tromey <tromey@adacore.com>
> 
> The gdb.flush documentation does not mention the 'stream' argument in
> the function signature, only in the description.  This patch fixes the
> oversight.

Thanks, this falls under the "obvious fix" category, I think.  It's
fine in any case.

Re: [PATCH 0/2] Fix two small Python flush problems

[Tom Tromey via Gdb-patches]

>>>>> "Tom" == Tom Tromey via Gdb-patches <gdb-patches@sourceware.org> writes:

Tom> This short series fixes a couple of small problems with the 'flush'
Tom> function in Python.

Tom> First, I noticed that the documentation is missing a part of the
Tom> description.  Then, I noticed that the stdout/stderr 'flush' method
Tom> was incorrectly implemented.

I'm checking these in now.

Tom