[binutils-gdb] Raise exception if ambiguous name is used in gdb.parameter

[binutils-gdb] Raise exception if ambiguous name is used in gdb.parameter

[Hannes Domani]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=276d9db22d768e6904937b8def1b05771588092b

commit 276d9db22d768e6904937b8def1b05771588092b
Author: Hannes Domani <ssbssa@yahoo.de>
Date:   Wed Feb 7 19:59:29 2024 +0100

    Raise exception if ambiguous name is used in gdb.parameter
    
    Currently gdb.parameter doesn't raise an exception if an
    ambiguous name is used, it instead returns the value of the
    last partly matching parameter:
    ```
    (gdb) show print sym
    Ambiguous show print command "sym": symbol, symbol-filename, symbol-loading.
    (gdb) show print symbol-loading
    Printing of symbol loading messages is "full".
    (gdb) py print(gdb.parameter("print sym"))
    full
    ```
    
    It's because lookup_cmd_composition_1 tries to detect
    ambigous names by checking the return value of find_cmd
    for CMD_LIST_AMBIGUOUS, which never happens, since only
    lookup_cmd_1 returns CMD_LIST_AMBIGUOUS.
    Instead the nfound argument contains the number of found
    matches.
    
    By using it instead, and by setting *CMD to the special value
    CMD_LIST_AMBIGUOUS in this case, gdbpy_parameter can now show
    the appropriate error message:
    ```
    (gdb) py print(gdb.parameter("print sym"))
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
    RuntimeError: Parameter `print sym' is ambiguous.
    Error while executing Python code.
    (gdb) py print(gdb.parameter("print symbol"))
    True
    (gdb) py print(gdb.parameter("print symbol-"))
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
    RuntimeError: Parameter `print symbol-' is ambiguous.
    Error while executing Python code.
    (gdb) py print(gdb.parameter("print symbol-load"))
    full
    ```
    
    Since the document command also uses lookup_cmd_composition, it needed
    to check for CMD_LIST_AMBIGUOUS as well, so it now also shows an
    "Ambiguous command" error message in this case.
    
    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=14639
    Approved-By: Tom Tromey <tom@tromey.com>

Diff:
---
 gdb/cli/cli-decode.c                      | 13 ++++++++++---
 gdb/cli/cli-script.c                      |  2 ++
 gdb/python/python.c                       |  5 ++++-
 gdb/testsuite/gdb.base/document.exp       | 10 ++++++++++
 gdb/testsuite/gdb.python/py-parameter.exp | 32 +++++++++++++++++++++++++++++++
 5 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index a69939e9035..bbabd40db07 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -2549,7 +2549,8 @@ deprecated_cmd_warning (const char *text, struct cmd_list_element *list)
    If TEXT is a subcommand (i.e. one that is preceded by a prefix
    command) set *PREFIX_CMD.
 
-   Set *CMD to point to the command TEXT indicates.
+   Set *CMD to point to the command TEXT indicates, or to
+   CMD_LIST_AMBIGUOUS if there are multiple possible matches.
 
    If any of *ALIAS, *PREFIX_CMD, or *CMD cannot be determined or do not
    exist, they are NULL when we return.
@@ -2589,7 +2590,12 @@ lookup_cmd_composition_1 (const char *text,
       *cmd = find_cmd (command.c_str (), len, cur_list, 1, &nfound);
 
       /* We only handle the case where a single command was found.  */
-      if (*cmd == CMD_LIST_AMBIGUOUS || *cmd == nullptr)
+      if (nfound > 1)
+	{
+	  *cmd = CMD_LIST_AMBIGUOUS;
+	  return 0;
+	}
+      else if (*cmd == nullptr)
 	return 0;
       else
 	{
@@ -2623,7 +2629,8 @@ lookup_cmd_composition_1 (const char *text,
    If TEXT is a subcommand (i.e. one that is preceded by a prefix
    command) set *PREFIX_CMD.
 
-   Set *CMD to point to the command TEXT indicates.
+   Set *CMD to point to the command TEXT indicates, or to
+   CMD_LIST_AMBIGUOUS if there are multiple possible matches.
 
    If any of *ALIAS, *PREFIX_CMD, or *CMD cannot be determined or do not
    exist, they are NULL when we return.
diff --git a/gdb/cli/cli-script.c b/gdb/cli/cli-script.c
index 439ba5004c7..f06724af325 100644
--- a/gdb/cli/cli-script.c
+++ b/gdb/cli/cli-script.c
@@ -1521,6 +1521,8 @@ do_document_command (const char *comname, int from_tty,
   lookup_cmd_composition (comfull, &alias, &prefix_cmd, &c);
   if (c == nullptr)
     error (_("Undefined command: \"%s\"."), comfull);
+  else if (c == CMD_LIST_AMBIGUOUS)
+    error (_("Ambiguous command: \"%s\"."), comfull);
 
   if (c->theclass != class_user
       && (alias == nullptr || alias->theclass != class_alias))
diff --git a/gdb/python/python.c b/gdb/python/python.c
index de3a94dfc9a..fc1de8b9441 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -559,7 +559,10 @@ gdbpy_parameter (PyObject *self, PyObject *args)
       GDB_PY_HANDLE_EXCEPTION (ex);
     }
 
-  if (!found)
+  if (cmd == CMD_LIST_AMBIGUOUS)
+    return PyErr_Format (PyExc_RuntimeError,
+			 _("Parameter `%s' is ambiguous."), arg);
+  else if (!found)
     return PyErr_Format (PyExc_RuntimeError,
 			 _("Could not find parameter `%s'."), arg);
 
diff --git a/gdb/testsuite/gdb.base/document.exp b/gdb/testsuite/gdb.base/document.exp
index b7cc92fb912..8a5e7d0d634 100644
--- a/gdb/testsuite/gdb.base/document.exp
+++ b/gdb/testsuite/gdb.base/document.exp
@@ -32,3 +32,13 @@ gdb_test "help do-document" "usage: do-document" "invoke help do-document"
 # Test that document of a non-existing command prints an error.  There
 # was a regression at one point causing this to crash.
 gdb_test "document nosuchcommand" "Undefined command: \"nosuchcommand\"\\."
+
+# Test that document of an ambiguous command prints an error.
+foreach_with_prefix cmd {1 2} {
+    gdb_test_multiple "define ambiguous_command_$cmd" "" {
+	-re "Type commands for definition of \"ambiguous_command_$cmd\".\r\nEnd with a line saying just \"end\".\r\n>$" {
+	    gdb_test "end" "" "define ambiguous_command_$cmd"
+	}
+    }
+}
+gdb_test "document ambiguous_command" "Ambiguous command: \"ambiguous_command\"."
diff --git a/gdb/testsuite/gdb.python/py-parameter.exp b/gdb/testsuite/gdb.python/py-parameter.exp
index 18c6837b1f1..94702f42816 100644
--- a/gdb/testsuite/gdb.python/py-parameter.exp
+++ b/gdb/testsuite/gdb.python/py-parameter.exp
@@ -588,6 +588,37 @@ proc_with_prefix test_language {} {
     gdb_test_no_output "set lang auto"
 }
 
+proc_with_prefix test_ambiguous_parameter {} {
+    gdb_test_multiline "create parameter" \
+	"python" "" \
+	"class TestAmbiguousParam (gdb.Parameter):" "" \
+	"   def __init__ (self, name, value):" "" \
+	"      super (TestAmbiguousParam, self).__init__ (name, gdb.COMMAND_DATA, gdb.PARAM_INTEGER)" "" \
+	"      self.value = value" "" \
+	"end"
+
+    # Create parameters.
+    gdb_test "python TestAmbiguousParam('test-ambiguous-value-1', 1)" ""
+    gdb_test "python TestAmbiguousParam('test-ambiguous-value-2-extra', 2)" ""
+    gdb_test "python TestAmbiguousParam('test-ambiguous', 3)" ""
+
+    # Test unambiguous matches.
+    gdb_test "python print(gdb.parameter('test-ambiguous-value-1'))" "1"
+    gdb_test "python print(gdb.parameter('test-ambiguous-value-2-extra'))" "2"
+    gdb_test "python print(gdb.parameter('test-ambiguous-value-2'))" "2"
+    gdb_test "python print(gdb.parameter('test-ambiguous'))" "3"
+
+    # Test ambiguous names.
+    gdb_test "python print(gdb.parameter('test-ambiguou'))" \
+	"Parameter .* is ambiguous.*Error while executing Python code."
+    gdb_test "python print(gdb.parameter('test-ambiguous-'))" \
+	"Parameter .* is ambiguous.*Error while executing Python code."
+    gdb_test "python print(gdb.parameter('test-ambiguous-v'))" \
+	"Parameter .* is ambiguous.*Error while executing Python code."
+    gdb_test "python print(gdb.parameter('test-ambiguous-value-1a'))" \
+	"Could not find parameter.*Error while executing Python code."
+}
+
 test_directories
 test_data_directory
 test_boolean_parameter
@@ -600,5 +631,6 @@ test_gdb_parameter
 test_integer_parameter
 test_throwing_parameter
 test_language
+test_ambiguous_parameter
 
 rename py_param_test_maybe_no_output ""