[RFA] Fix alias command not detecting non matching prefix & sometimes asserting.

Message ID 20190623154106.13224-1-philippe.waroquiers@skynet.be
State New
Headers show
Series
  • [RFA] Fix alias command not detecting non matching prefix & sometimes asserting.
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Commit Message

Philippe Waroquiers June 23, 2019, 3:41 p.m.
alias_command does not detect that the prefixes of the alias command and the
aliased command are not matching: it is comparing the alias prefix
with itself, instead of comparing it with the aliased command prefix.

This causes either the alias command to silently do nothing,
or to have GDB asserting:
    (gdb) alias assigne imprime limite-elements = set print elements
    ../../binutils-gdb/gdb/cli/cli-cmds.c:1552: internal-error: void alias_command(const char*, int): Assertion `c_command != NULL && c_command != (struct cmd_list_element *) -1' failed.
    A problem internal to GDB has been detected,

Fix the logic, and update gdb.base/alias.exp to test these cases.

gdb/ChangeLog
2019-06-23  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* cli/cli-cmds.c (alias_command): Compare the alias prefix
	with the command prefix.

gdb/testsuite/ChangeLog
2019-06-23  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* gdb.base/alias.exp: Test non matching/non existing prefixes.
---
 gdb/cli/cli-cmds.c               |  9 +++---
 gdb/testsuite/gdb.base/alias.exp | 50 ++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 4 deletions(-)

-- 
2.20.1

Comments

Tom Tromey June 25, 2019, 2:49 p.m. | #1
>>>>> "Philippe" == Philippe Waroquiers <philippe.waroquiers@skynet.be> writes:


Philippe> gdb/ChangeLog
Philippe> 2019-06-23  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

Philippe> 	* cli/cli-cmds.c (alias_command): Compare the alias prefix
Philippe> 	with the command prefix.

Philippe> gdb/testsuite/ChangeLog
Philippe> 2019-06-23  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

Philippe> 	* gdb.base/alias.exp: Test non matching/non existing prefixes.

Thank you for the patch.  This is ok.

Tom
Philippe Waroquiers June 25, 2019, 5:42 p.m. | #2
On Tue, 2019-06-25 at 08:49 -0600, Tom Tromey wrote:
> > > > > > "Philippe" == Philippe Waroquiers <philippe.waroquiers@skynet.be> writes:

> 

> Philippe> gdb/ChangeLog

> Philippe> 2019-06-23  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

> 

> Philippe> 	* cli/cli-cmds.c (alias_command): Compare the alias prefix

> Philippe> 	with the command prefix.

> 

> Philippe> gdb/testsuite/ChangeLog

> Philippe> 2019-06-23  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

> 

> Philippe> 	* gdb.base/alias.exp: Test non matching/non existing prefixes.

> 

> Thank you for the patch.  This is ok.

Thanks for the review, pushed (after updating the ChangeLogs ...)

Philippe

Patch

diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index 62f4d7f0c5..5124ab3f1b 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -1518,8 +1518,8 @@  alias_command (const char *args, int from_tty)
      Example: alias spe = set print elements
 
      Otherwise ALIAS and COMMAND must have the same number of words,
-     and every word except the last must match; and the last word of
-     ALIAS is made an alias of the last word of COMMAND.
+     and every word except the last must identify the same prefix command;
+     and the last word of ALIAS is made an alias of the last word of COMMAND.
      Example: alias set print elms = set pr elem
      Note that unambiguous abbreviations are allowed.  */
 
@@ -1538,10 +1538,11 @@  alias_command (const char *args, int from_tty)
 	error (_("Mismatched command length between ALIAS and COMMAND."));
 
       /* Create copies of ALIAS and COMMAND without the last word,
-	 and use that to verify the leading elements match.  */
+	 and use that to verify the leading elements give the same
+	 prefix command.  */
       std::string alias_prefix_string (argv_to_string (alias_argv,
 						       alias_argc - 1));
-      std::string command_prefix_string (argv_to_string (alias_argv,
+      std::string command_prefix_string (argv_to_string (command_argv.get (),
 							 command_argc - 1));
       alias_prefix = alias_prefix_string.c_str ();
       command_prefix = command_prefix_string.c_str ();
diff --git a/gdb/testsuite/gdb.base/alias.exp b/gdb/testsuite/gdb.base/alias.exp
index fe4eb44cd0..20722e5dea 100644
--- a/gdb/testsuite/gdb.base/alias.exp
+++ b/gdb/testsuite/gdb.base/alias.exp
@@ -66,3 +66,53 @@  gdb_test_no_output "alias set pr elms = set p elem"
 gdb_test_no_output "set pr elms 51"
 gdb_test "show print elements" "Limit .* is 51\[.\]" "verify set pr elms"
 gdb_test "help set print" "set print elms .*"
+
+# Verify alias command detects a non existing prefix.
+gdb_test "alias assigne imprime limite-elements = set print elements" \
+    "ALIAS and COMMAND prefixes do not match\." \
+    "assigne imprime prefix not defined"
+
+gdb_test "alias set imprime limite-elements = set print elements" \
+    "ALIAS and COMMAND prefixes do not match\." \
+    "set imprime prefix not defined"
+
+# Verify alias command detects a non matching prefix.
+gdb_test "alias set ada limite-elements = set print elements" \
+    "ALIAS and COMMAND prefixes do not match\." \
+    "mismatched prefix"
+
+# Verify alias command detects a non matching prefix due to length.
+gdb_test "alias set imprime-limite-elements = set print elements" \
+    "Mismatched command length between ALIAS and COMMAND\." \
+    "mismatched length"
+
+
+# Gradually define the prefixes and the limite-elements command.
+gdb_test_no_output "alias assigne = set" "alias assigne"
+gdb_test_no_output "alias assigne imprime = set print" "alias assigne imprime"
+gdb_test_no_output "alias assigne imprime limite-elements = set print elements" \
+    "alias assigne imprime limite-elements"
+
+# Define an alias using the command prefix with a command using an alias prefix.
+gdb_test_no_output "alias set print max-elements = assigne imprime elements" \
+    "alias set print max-elements using assigne imprime"
+
+
+# Tests the resulting prefixes and commands.
+gdb_test_no_output "assigne print elements 52"
+gdb_test "show print elements" "Limit .* is 52\[.\]" "verify 52"
+
+gdb_test_no_output "assigne imprime elements 53"
+gdb_test "show print elements" "Limit .* is 53\[.\]" "verify 53"
+
+gdb_test_no_output "assigne imprime limite-elements 54"
+gdb_test "show print elements" "Limit .* is 54\[.\]" "verify 54"
+
+gdb_test_no_output "set imprime elements 55"
+gdb_test "show print elements" "Limit .* is 55\[.\]" "verify 55"
+
+gdb_test_no_output "set print limite-elements 56"
+gdb_test "show print elements" "Limit .* is 56\[.\]" "verify 56"
+
+gdb_test_no_output "set print max-elements 57"
+gdb_test "show print elements" "Limit .* is 57\[.\]" "verify 57"