[gdb/testsuite] Make parse_args error out on remaining args

I noticed that introducing a typo here in gdb.mi/mi-breakpoint-changed.exp:
...
     set bp_re [mi_make_breakpoint \
-		   -number $bp_nr \
+		   -nunber $bp_nr \
 		   -type dprintf \
 		   -func marker \
 		   -script [string_to_regexp {["printf \"arg\" \""]}]]
...
didn't make the test fail.

Proc mi_make_breakpoint uses parse_args, but does not check the remaining args
as parse_args suggests:
...
proc parse_args { argset } {
    parse_list 2 args $argset "-" false

    # The remaining args should be checked to see that they match the
    # number of items expected to be passed into the procedure
}
...

We could add the missing check in mi_make_breakpoint, but I think the problem
is likely to occur again because the name parse_args does not suggest that
further action is required.

Fix this instead by:
- copying proc parse_args to new proc parse_some_args,
- adding new proc check_no_args_left, and
- calling check_no_args_left in parse_args.

Also be more strict in a few places where we do lassign for remaining args:
...
    lassign $args a b
...

There may be more arguments left in $args, so check that that's not the case
using check_no_args_left:
...
    set args [lassign $args a b]
    check_no_args_left
...

Fix a few test-cases that trigger on the stricter checking.

Tested on x86_64-linux.

Reviewed-By: Alexandra Petlanova Hajkova <ahajkova@redhat.com>

PR testsuite/32129
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32129

2 files changed, 28 insertions, 7 deletions

diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index c993f48fd34..7d8d4138f69 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -1559,7 +1559,7 @@ proc gdb_test { args } {
     global gdb_prompt
     upvar timeout timeout
 
-    parse_args {
+    parse_some_args {
 	{prompt ""}
 	{no-prompt-anchor}
 	{lbl}
@@ -1567,7 +1567,8 @@ proc gdb_test { args } {
 	{nonl}
     }
 
-    lassign $args command pattern message question response
+    set args [lassign $args command pattern message question response]
+    check_no_args_left
 
     # Can't have a question without a response.
     if { $question != "" && $response == "" || [llength $args] > 5 } {
@@ -1741,13 +1742,14 @@ if { [tcl_version_at_least 8 6 2] == 0 } {
 proc gdb_test_no_output { args } {
     global gdb_prompt
 
-    parse_args {
+    parse_some_args {
 	{prompt ""}
 	{no-prompt-anchor}
 	{nopass}
     }
 
-    lassign $args command message
+    set args [lassign $args command message]
+    check_no_args_left
 
     set prompt [fill_in_default_prompt $prompt [expr !${no-prompt-anchor}]]
 
@@ -1789,7 +1791,7 @@ proc gdb_test_no_output { args } {
 proc gdb_test_sequence { args } {
     global gdb_prompt
 
-    parse_args {{prompt ""}}
+    parse_some_args {{prompt ""}}
 
     if { $prompt == "" } {
 	set prompt "$gdb_prompt $"
@@ -9351,13 +9353,32 @@ proc parse_list { level listname argset prefix eval } {
 # Search the caller's args variable and set variables according to the list of
 # valid options described by ARGSET.
 
-proc parse_args { argset } {
+proc parse_some_args { argset } {
     parse_list 2 args $argset "-" false
 
     # The remaining args should be checked to see that they match the
     # number of items expected to be passed into the procedure...
 }
 
+# Check that the caller's args variable is empty.
+
+proc check_no_args_left {} {
+    # Require no remaining args.
+    upvar 1 args args
+    if { [llength $args] != 0 } {
+	error "Args left unparsed: $args"
+    }
+}
+
+# As parse_some_args, but check that no args remain after parsing.
+
+proc parse_args { argset } {
+    uplevel parse_some_args [list $argset]
+
+    # Require no remaining args.
+    uplevel check_no_args_left
+}
+
 # Process the caller's options variable and set variables according
 # to the list of valid options described by OPTIONSET.
 
diff --git a/gdb/testsuite/lib/mi-support.exp b/gdb/testsuite/lib/mi-support.exp
index a79b133fa4f..38321379721 100644
--- a/gdb/testsuite/lib/mi-support.exp
+++ b/gdb/testsuite/lib/mi-support.exp
@@ -2680,7 +2680,7 @@ proc mi_make_info_frame_regexp {args} {
 # build the regexp for matching against the -stack-info-frame output.
 
 proc mi_info_frame { test args } {
-    parse_args {{frame ""} {thread ""}}
+    parse_some_args {{frame ""} {thread ""}}
 
     set re [eval mi_make_info_frame_regexp $args]