Patchwork [gdb/testsuite] Introduce gdb_test_ext

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Submitter Andrew Burgess
Date Sept. 19, 2019, 4:18 p.m.
Message ID <20190919161846.GC4962@embecosm.com>
Download mbox | patch
Permalink /patch/34593/
State New
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Comments

Andrew Burgess - Sept. 19, 2019, 4:18 p.m.
* Tom de Vries <tdevries@suse.de> [2019-09-19 13:13:23 +0200]:

> Hi,
> 
> In commit 25e5c20918 "[gdb/testsuite] Allow some tests in gdb.base/store.exp
> to be unsupported" we replace a gdb_test:
> ...
>     gdb_test "print l" " = ${l}" \
>        "${prefix}; print old l, expecting ${l}"
> ...
> with a gdb_test_multiple:
> ...
>     set supported 1
>     set test "${prefix}; print old l, expecting ${l}"
>     gdb_test_multiple "print l" "$test"  {
>        -re " = <optimized out>\r\n$gdb_prompt $" {
>            unsupported $test
>            set supported 0
>        }
>        -re " = ${l}\r\n$gdb_prompt $" {
>            pass $test
>        }
>     }
> ...
> in order to handle the UNSUPPORTED case.
> 
> This has the drawback that we have to be explicit about the gdb_prompt, and
> move the gdb_test arguments around to fit the gdb_test_multiple format.
> 
> Introduce a new proc gdb_test_ext that behaves as gdb_test, but also allows
> extension, allowing us to rewrite the gdb_test_multiple above in a form
> resembling the original gdb_test:
> ...
>     set supported 1
>     gdb_test_ext "print l" " = ${l}" \
>        "${prefix}; print old l, expecting ${l}" \
>        -- [list "unsupported" " = <optimized out>" "set supported 0"]

I've also thought about this sort of problem in the past, and would
like to propose a similar, but slightly different solution.

My idea is more like a trimmed down gdb_test_multiple, so for your
example above you would write this:

    gdb_test_ext "print l" "${prefix}; print old l, expecting ${l}" {
	" = ${l}" {
	    pass $gdb_test_ext_name
	}
	" = <optimized out>" {
	    unsupported $gdb_test_ext_name
	    set supported 0
	}
    }

You don't put '-re' before each pattern, this is because they aren't
full patterns, gdb_test_ext will be extending them.

Unlike your solution the 'pass' case is not created automatically, you
need to write it yourself, so maybe that's a negative.  The advantages
I see of this approach is that there's not special handling for
different "types" of alternatives as in your original code, the action
block can contain anything 'unsupported', 'fail', etc.  Plus it's
formatted as a code body, which I like.

One other thing which I've wanted for _ages_ is to avoid having to set
the test name into a separate variable, which your solution offers
too.  The solution I offer is '$gdb_test_ext_name', this variable is
set auto-magically by the call to 'gdb_test_ext, and is available in
all of the action bodies for calls to pass/fail/unsupported/etc.

The patch below isn't complete yet - I've rewritten gdb_test_ext, and
updated store.exp, but this would need a commit message and ChangeLog
writing, I'm presenting this here for discussion on which solution
people prefer.

Thanks,
Andrew

---

Patch

diff --git a/gdb/testsuite/gdb.base/store.exp b/gdb/testsuite/gdb.base/store.exp
index 9c19ce15a7b..61d65127e8c 100644
--- a/gdb/testsuite/gdb.base/store.exp
+++ b/gdb/testsuite/gdb.base/store.exp
@@ -43,27 +43,25 @@  proc check_set { t l r new add } {
     set prefix "var ${t} l"
     gdb_test "tbreak wack_${t}"
 
-    set test "continue to wack_${t}"
-    gdb_test_multiple "continue" $test {
-	-re "register ${t} l = u, r = v;\r\n$gdb_prompt $" {
+    gdb_test_ext "continue" "continue to wack_${t}" {
+	"register ${t} l = u, r = v;" {
 	    # See GCC PR debug/53948.
 	    send_gdb "next\n"
 	    exp_continue
 	}
-	-re "l = add_${t} .l, r.;\r\n$gdb_prompt $" {
-	    pass $test
+	"l = add_${t} .l, r.;" {
+	    pass $gdb_test_ext_name
 	}
     }
 
     set supported 1
-    set test "${prefix}; print old l, expecting ${l}"
-    gdb_test_multiple "print l" "$test"  {
-	-re " = <optimized out>\r\n$gdb_prompt $" {
-	    unsupported $test
-	    set supported 0
+    gdb_test_ext "print l" "${prefix}; print old l, expecting ${l}" {
+	" = ${l}" {
+	    pass $gdb_test_ext_name
 	}
-	-re " = ${l}\r\n$gdb_prompt $" {
-	    pass $test
+	" = <optimized out>" {
+	    unsupported $gdb_test_ext_name
+	    set supported 0
 	}
     }
     if { $supported } {
@@ -102,14 +100,13 @@  proc up_set { t l r new } {
 	"${prefix}; up"
 
     set supported 1
-    set test "${prefix}; print old l, expecting ${l}"
-    gdb_test_multiple "print l" "$test"  {
-	-re " = <optimized out>\r\n$gdb_prompt $" {
-	    unsupported $test
-	    set supported 0
+    gdb_test_ext "print l" "${prefix}; print old l, expecting ${l}" {
+	" = ${l}" {
+	    pass $gdb_test_ext_name
 	}
-	-re " = ${l}\r\n$gdb_prompt $" {
-	    pass $test
+	" = <optimized out>" {
+	    unsupported $gdb_test_ext_name
+	    set supported 0
 	}
     }
     if { $supported } {
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index acbeb013768..976ac9d14e0 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -1103,6 +1103,78 @@  proc gdb_test { args } {
      }]
 }
 
+# As gdb_test, but with additional parameters, listed after a "--" separator.
+# Handled extra parameters:
+# - [list "unsupported" <pattern> [<code>]]
+# The idea is to prevent the need to rewrite gdb_test into gdb_test_multiple
+# if some modification is needed.
+
+
+
+# A cross between gdb_test_multiple and gdb_test.  The first
+# parameter, COMMAND, is the command to send to GDB, and the second
+# parameter, TESTNAME, is the name of the test.  The ARGS is a list of
+# items which should alternate between patterns and action bodies.
+# Unlike gdb_test_multiple each pattern will automatically have the
+# gdb_prompt pattern added to it.
+#
+# In addition, within the action bodies a new variable is available
+# for use, this is gdb_test_ext_name.  This variable will have the
+# value of TESTNAME.  This can be used like this:
+#
+# gdb_test_ext "some command" "a helpful test name" {
+#      "pattern1" {
+#          pass $gdb_test_ext_name
+#      }
+#      "pattern2" {
+#          fail $gdb_test_ext_name
+#      }
+# }
+proc gdb_test_ext { command testname args } {
+    global gdb_prompt
+    upvar timeout timeout
+
+    # Setup a default testname if the user was feeling lazy.
+    if { "$testname" == "" } {
+	set testname ${cmd}
+    }
+
+    # In order to support the gdb_test_ext_name variable we need to
+    # push the variable into the parent scope.  Before we blindly do
+    # that check the user hasn't already defined that variable.  If
+    # they haven't, go ahead and create it for them.
+    if { [uplevel { info exists gdb_test_ext_name }] } {
+	perror "variable gdb_test_ext_name unexpectedly exists"
+	return 1
+    }
+    uplevel " set gdb_test_ext_name \"$testname\" "
+
+    # Build up the user code.  We need to make use of some extra
+    # uplevel calls in here as gdb_test_multiple evaluates action
+    # bodies in the parent scope, so we add the extra uplevel to push
+    # things back to our parents scope.
+    set user_code {}
+    set args [lindex $args 0]
+    for { set index 0 } { [expr $index + 1] < [llength $args] } { incr index 2 } {
+	set pattern [uplevel [list subst [lindex $args ${index}]]]
+	set body [lindex $args [expr $index + 1]]
+
+	lappend user_code " -re "
+	lappend user_code "\"\\\[\\r\\n\\\]*(?:$pattern)\\\[\\r\\n\\\]+\$gdb_prompt $\""
+	lappend user_code " { uplevel { $body } } "
+    }
+    set user_code [join $user_code " "]
+
+    # Now we can actually run the test.
+    set result [gdb_test_multiple $command $testname $user_code]
+
+    # Don't drop litter!  Clean up the gdb_test_ext_name variable we
+    # created in the parent scope.
+    uplevel " unset gdb_test_ext_name "
+
+    return $result
+}
+
 # Return 1 if version MAJOR.MINOR is at least AT_LEAST_MAJOR.AT_LEAST_MINOR.
 proc version_at_least { major minor at_least_major at_least_minor} {
     if { $major > $at_least_major } {