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[RFA] Fix "set" handling of Python parameters
- From: Tom Tromey <tom at tromey dot com>
- To: gdb-patches at sourceware dot org
- Cc: Tom Tromey <tom at tromey dot com>
- Date: Thu, 26 Apr 2018 16:51:40 -0600
- Subject: [RFA] Fix "set" handling of Python parameters
It's long bothered me that setting a Python parameter from the CLI
will print the "set" help text by default. I think usually "set"
commands should be silent. And, while you can modify this behavior a
bit by providing a "get_set_string" method, if this method returns an
empty string, a blank line will be printed.
This patch removes the "help" behavior and changes the get_set_string
behavior to avoid printing a blank line. The code has a comment about
preserving API behavior, but I don't think this is truly important;
and in any case the workaround -- implementing get_set_string -- is
trivial.
Regression tested on x86-64 Fedora 26.
gdb/ChangeLog
2018-04-26 Tom Tromey <tom@tromey.com>
* NEWS: Mention new "set" behavior.
* python/py-param.c (get_set_value): Don't print an empty string.
Don't call get_doc_string.
gdb/doc/ChangeLog
2018-04-26 Tom Tromey <tom@tromey.com>
* python.texi (Parameters In Python): Update get_set_string
documentation.
---
gdb/ChangeLog | 6 ++++++
gdb/NEWS | 6 ++++++
gdb/doc/ChangeLog | 5 +++++
gdb/doc/python.texi | 14 ++++++++------
gdb/python/py-param.c | 11 +++--------
gdb/testsuite/gdb.python/py-parameter.exp | 4 ++--
6 files changed, 30 insertions(+), 16 deletions(-)
diff --git a/gdb/NEWS b/gdb/NEWS
index 63fe30d175..c992048634 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -24,6 +24,12 @@ set|show record btrace cpu
Controls the processor to be used for enabling errata workarounds for
branch trace decode.
+* Python API
+
+ ** A gdb.Parameter will no longer print the "set" help text on an
+ ordinary "set"; instead by default a "set" will be silent unless
+ the get_set_string method returns a non-empty string.
+
* New targets
RiscV ELF riscv*-*-elf
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index ebd48fffe7..7bbfb09d04 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -3722,14 +3722,16 @@ parameter. It can be read and assigned to just as any other
attribute. @value{GDBN} does validation when assignments are made.
@end defvar
-There are two methods that should be implemented in any
-@code{Parameter} class. These are:
+There are two methods that may be implemented in any @code{Parameter}
+class. These are:
@defun Parameter.get_set_string (self)
-@value{GDBN} will call this method when a @var{parameter}'s value has
-been changed via the @code{set} API (for example, @kbd{set foo off}).
-The @code{value} attribute has already been populated with the new
-value and may be used in output. This method must return a string.
+If this method exists, @value{GDBN} will call it when a
+@var{parameter}'s value has been changed via the @code{set} API (for
+example, @kbd{set foo off}). The @code{value} attribute has already
+been populated with the new value and may be used in output. This
+method must return a string. If the returned string is not empty,
+@value{GDBN} will present it to the user.
@end defun
@defun Parameter.get_show_string (self, svalue)
diff --git a/gdb/python/py-param.c b/gdb/python/py-param.c
index 0f8d9b6b42..77311ad1bd 100644
--- a/gdb/python/py-param.c
+++ b/gdb/python/py-param.c
@@ -381,15 +381,10 @@ get_set_value (const char *args, int from_tty,
return;
}
}
- else
- {
- /* We have to preserve the existing < GDB 7.3 API. If a
- callback function does not exist, then attempt to read the
- set_doc attribute. */
- set_doc_string = get_doc_string (obj, set_doc_cst);
- }
- fprintf_filtered (gdb_stdout, "%s\n", set_doc_string.get ());
+ const char *str = set_doc_string.get ();
+ if (str != nullptr && str[0] != '\0')
+ fprintf_filtered (gdb_stdout, "%s\n", str);
}
/* A callback function that is registered against the respective
diff --git a/gdb/testsuite/gdb.python/py-parameter.exp b/gdb/testsuite/gdb.python/py-parameter.exp
index 3cd1198462..f52d737dbc 100644
--- a/gdb/testsuite/gdb.python/py-parameter.exp
+++ b/gdb/testsuite/gdb.python/py-parameter.exp
@@ -151,7 +151,7 @@ gdb_py_test_multiple "Simple gdb booleanparameter" \
"end"
gdb_test "show print test-nodoc-param" "This command is not documented.*" "show parameter on"
-gdb_test "set print test-nodoc-param off" "This command is not documented.*" "turn off parameter"
+gdb_test_no_output "set print test-nodoc-param off" "turn off parameter"
gdb_test "show print test-nodoc-param" "This command is not documented.*.*" "show parameter off"
gdb_test "python print (test_nodoc_param.value)" "False" "test parameter value"
gdb_test "help show print test-nodoc-param" "This command is not documented.*" "test show help"
@@ -173,7 +173,7 @@ gdb_py_test_multiple "Simple gdb booleanparameter" \
gdb_test "python print (test_param.value)" "True" "test parameter value"
gdb_test "show print test-param" "State of the Test Parameter on.*" "show parameter on"
-gdb_test "set print test-param off" "Set the state of the Test Parameter.*" "turn off parameter"
+gdb_test_no_output "set print test-param off" "turn off parameter"
gdb_test "show print test-param" "State of the Test Parameter off.*" "show parameter off"
gdb_test "python print (test_param.value)" "False" "test parameter value"
gdb_test "help show print test-param" "State of the Test Parameter.*" "test show help"
--
2.13.6