[binutils-gdb] gdb/python: reformat an error string

[Andrew Burgess]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=2708dbbd58fd5ccdbf07b6da812a45e228659268

commit 2708dbbd58fd5ccdbf07b6da812a45e228659268
Author: Andrew Burgess <andrew.burgess@embecosm.com>
Date:   Mon Jan 18 10:03:21 2021 +0000

    gdb/python: reformat an error string
    
    While working on another patch I noticed an oddly formatted error
    message in the Python code.
    
    When 'set python print-stack message' is in effect then consider this
    Python script:
    
      class TestCommand (gdb.Command):
          def __init__ (self):
              gdb.Command.__init__ (self, "test-cmd", gdb.COMMAND_DATA)
          def invoke(self, args, from_tty):
              raise RuntimeError ("bad")
      TestCommand ()
    
    And this GDB session:
    
      (gdb) source path/to/python/script.py
      (gdb) test-cmd
      Python Exception <class 'RuntimeError'> bad:
      Error occurred in Python: bad
    
    The line 'Python Exception <class 'RuntimeError'> bad:' doesn't look
    terrible in this situation, the colon at the end of the first line
    makes sense given the second line.
    
    However, there are places in GDB where there is no second line
    printed, for example consider this python script:
    
      def stop_listener (e):
          raise RuntimeError ("bad")
      gdb.events.stop.connect (stop_listener)
    
    Then this GDB session:
    
      (gdb) file helloworld.exe
      (gdb) start
      Temporary breakpoint 1 at 0x40112a: file hello.c, line 6.
      Starting program: helloworld.exe
    
      Temporary breakpoint 1, main () at hello.c:6
      6       printf ("Hello World\n");
      Python Exception <class 'RuntimeError'> bad:
      (gdb) si
      0x000000000040112f    6         printf ("Hello World\n");
      Python Exception <class 'RuntimeError'> bad:
    
    In this case there is no auxiliary information displayed after the
    warning, and the line ending in the colon looks weird to me.
    
    A quick survey of the code seems to indicate that it is not uncommon
    for there to be no auxiliary information line printed, its not just
    the one case I found above.
    
    I propose that the line that currently looks like this:
    
      Python Exception <class 'RuntimeError'> bad:
    
    Be reformatted like this:
    
      Python Exception <class 'RuntimeError'>: bad
    
    I think this looks fine then in either situation.  The first now looks
    like this:
    
      (gdb) test-cmd
      Python Exception <class 'RuntimeError'>: bad
      Error occurred in Python: bad
    
    And the second like this:
    
      (gdb) si
      0x000000000040112f    6         printf ("Hello World\n");
      Python Exception <class 'RuntimeError'>: bad
    
    There's just two tests that needed updating.  Errors are checked for
    in many more tests, but most of the time the pattern doesn't care
    about the colon.
    
    gdb/ChangeLog:
    
            * python/python.c (gdbpy_print_stack): Reformat an error message.
    
    gdb/testsuite/ChangeLog:
    
            * gdb.python/py-framefilter.exp: Update expected results.
            * gdb.python/python.exp: Update expected results.

Diff:
---
 gdb/ChangeLog                               | 4 ++++
 gdb/python/python.c                         | 2 +-
 gdb/testsuite/ChangeLog                     | 5 +++++
 gdb/testsuite/gdb.python/py-framefilter.exp | 2 +-
 gdb/testsuite/gdb.python/python.exp         | 2 +-
 5 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 634d272dbdf..a45c2c7499b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2021-02-08  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* python/python.c (gdbpy_print_stack): Reformat an error message.
+
 2021-02-08  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* tui/tui-interp.c (tui_command_line_handler): New function.
diff --git a/gdb/python/python.c b/gdb/python/python.c
index fd760f6a98b..009c0c4c6d7 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -1320,7 +1320,7 @@ gdbpy_print_stack (void)
 	      PyErr_Clear ();
 	    }
 	  else
-	    fprintf_filtered (gdb_stderr, "Python Exception %s %s: \n",
+	    fprintf_filtered (gdb_stderr, "Python Exception %s: %s\n",
 			      type.get (), msg.get ());
 	}
       catch (const gdb_exception &except)
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index ed496e4305e..8fb69c0bacf 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2021-02-08  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* gdb.python/py-framefilter.exp: Update expected results.
+	* gdb.python/python.exp: Update expected results.
+
 2021-02-08  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* gdb.tui/scroll.exp: Tighten expected results.  Remove comment
diff --git a/gdb/testsuite/gdb.python/py-framefilter.exp b/gdb/testsuite/gdb.python/py-framefilter.exp
index 346898950aa..a9c6ca642be 100644
--- a/gdb/testsuite/gdb.python/py-framefilter.exp
+++ b/gdb/testsuite/gdb.python/py-framefilter.exp
@@ -269,7 +269,7 @@ gdb_test_no_output  "enable frame-filter global Error" \
     "enable frame-filter global Error"
 set test "bt 1 with Error filter"
 gdb_test_multiple "bt 1" $test {
-    -re "Python Exception .*whoops:.*$gdb_prompt $" {
+    -re "Python Exception .*: whoops\r\n.*$gdb_prompt $" {
 	pass $test
     }
 }
diff --git a/gdb/testsuite/gdb.python/python.exp b/gdb/testsuite/gdb.python/python.exp
index 83e83b49f75..c7d879efe63 100644
--- a/gdb/testsuite/gdb.python/python.exp
+++ b/gdb/testsuite/gdb.python/python.exp
@@ -463,7 +463,7 @@ gdb_test_multiline "prompt substitution readline error_prompt" \
   "end" ""
 
 gdb_test_multiple "python gdb.prompt_hook = error_prompt" "set the hook error_prompt" {
-    -re "Python Exception (exceptions.RuntimeError|<(type 'exceptions.|class ')RuntimeError'>) Python exception called.*$gdb_prompt $" {
+    -re "Python Exception (exceptions.RuntimeError|<(type 'exceptions.|class ')RuntimeError'>): Python exception called\r\n$gdb_prompt $" {
 	pass $gdb_test_name
     }
 }