[PATCH] PR testsuite/69181: ensure expected multiline outputs is cleared per-test (v2)

[David Malcolm <dmalcolm at redhat dot com>]

On Tue, 2016-01-12 at 23:21 -0700, Jeff Law wrote:
On 01/12/2016 12:34 PM, David Malcolm wrote:
> >> I looked at this code, and there are two near-identical blocks which
> >> reset all these variables. You are modifying only one of them, leaving
> >> the one inside the if { catch } thing unchanged - is this intentional?
> >
> > I'm not particularly strong at Tcl, but am I right in thinking that
> > given that we have this:
> >
> > 	if { [ catch { eval saved-dg-test $args } errmsg ] } {
> > 	    (A) set and unset various things
> > 	    error $errmsg $saved_info
> > 	}
> >         (B) set and unset the same various things as (A)
> >
> > that (B) will always be reached, and that the duplicates in (A) are
> > redundant? (unless they affect "error")
> Seems like it would, but, well it's TCL, so who in the hell knows.

I was wrong: "error" in Tcl is roughly equivalent to throwing an
exception.

Hence the above is actually akin to:

  try:
    eval saved-dg-test $args
  catch:
    do cleanup A
    re-raise current error
  do cleanup B

which is a workaround for the lack of a try-finally construct:

  try:
    eval saved-dg-test $args
  finally:
    do cleanup

So we do need error cleanup for both blocks (A) and (B).

> > I see that this pattern was introduced back in r67696 aka
> > 91a385a522a94154f9e0cd940c5937177737af02:
> Strangely, I can't find the patch in the archives nor any discussion for
> the patch.  It seems to have appeared from nowhere.   My search-fu must
> be weak tonight.  It may not have helped understand why this code is the
> way it is anyway.
>
> This duplication screams that it ought to be its own procedure if we're
> going to keep the apparently duplicated behaviour.

The following patch implements this, moving the existing cleanup into
a new "cleanup-after-saved-dg-test" proc, and calling it from both (A)
and (B).

I noticed in doing so that we were missing a:

  global additional_sources_used

and hence (if I understand Tcl correctly), the code was merely uselessly
setting a local with that name, rather than clearing the global.

Also, the cleanups weren't quite identical between (A) and (B); these
clauses:

	if [info exists set_target_env_var] {
	    unset set_target_env_var
	}
	if [info exists keep_saved_temps_suffixes] {
	    unset keep_saved_temps_suffixes
	}

were present in (B) but missing (A); also some of the ordering of
the cleanups varied between (A) and (B).

I assumed that these differences were unintentional, so the patch
consolidates things to make the cleanup identical between (A) and (B).

Successfully bootstrapped&regrtested on x86_64-pc-linux-gnu; as before,
adds 1 UNSUPPORTED (by design: gcc.dg/pr69181-1.c) and 1 PASS to gcc.sum.

OK for trunk?

Alternatively, would you prefer the simpler patch to add the cleanup
of multiline_expected_outputs to both (A) and (B), and leave the
consolidation idea for next stage 1?  (keeping the new test cases
and the renaming to lose the leading underscore).

gcc/testsuite/ChangeLog:
	PR testsuite/69181
	* gcc.dg/pr69181-1.c: New test file.
	* gcc.dg/pr69181-2.c: New test file.
	* lib/gcc-dg.exp (dg-test): Consolidate post-test cleanup of
	globals by moving it to...
	(cleanup-after-saved-dg-test): ...this new function.  Add
	"global additional_sources_used".  Add reset of global
	multiline_expected_outputs to the empty list.
	* lib/multiline.exp (_multiline_expected_outputs): Rename this
	global to...
	(multiline_expected_outputs): ...this, and updated comments to
	note that it is modified from gcc-dg.exp.
	(dg-end-multiline-output): Update for the above renaming.
	(handle-multiline-outputs): Likewise.  Remove the clearing
	of the expected outputs to the empty list.
---
 gcc/testsuite/gcc.dg/pr69181-1.c |  7 +++++++
 gcc/testsuite/gcc.dg/pr69181-2.c |  4 ++++
 gcc/testsuite/lib/gcc-dg.exp     | 36 ++++++++++++++++++------------------
 gcc/testsuite/lib/multiline.exp  | 22 +++++++++-------------
 4 files changed, 38 insertions(+), 31 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr69181-1.c
 create mode 100644 gcc/testsuite/gcc.dg/pr69181-2.c

diff --git a/gcc/testsuite/gcc.dg/pr69181-1.c b/gcc/testsuite/gcc.dg/pr69181-1.c
new file mode 100644
index 0000000..e851f0c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr69181-1.c
@@ -0,0 +1,7 @@
+/* { dg-do compile { target this_will_not_be_matched-*-* } } */
+
+/* { dg-begin-multiline-output "" }
+   This message should never be checked for.
+   In particular, it shouldn't be checked for in the *next*
+   test case.
+   { dg-end-multiline-output "" } */
diff --git a/gcc/testsuite/gcc.dg/pr69181-2.c b/gcc/testsuite/gcc.dg/pr69181-2.c
new file mode 100644
index 0000000..dca90dc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr69181-2.c
@@ -0,0 +1,4 @@
+/* Dummy test case, to verify that the dg-begin-multiline-output directive
+   from pr69181-1.c isn't erroneously expected to be handled in *this*
+   test case.  */
+int make_non_empty;
diff --git a/gcc/testsuite/lib/gcc-dg.exp b/gcc/testsuite/lib/gcc-dg.exp
index f9ec206..c003328 100644
--- a/gcc/testsuite/lib/gcc-dg.exp
+++ b/gcc/testsuite/lib/gcc-dg.exp
@@ -826,33 +826,21 @@ proc output-exists-not { args } {
 if { [info procs saved-dg-test] == [list] } {
     rename dg-test saved-dg-test
 
-    proc dg-test { args } {
+    # Helper function for cleanups that should happen after the call
+    # to the real dg-test, whether or not it returns normally, or
+    # fails with an error.
+    proc cleanup-after-saved-dg-test { } {
 	global additional_files
 	global additional_sources
+	global additional_sources_used
 	global additional_prunes
-	global errorInfo
 	global compiler_conditional_xfail_data
 	global shouldfail
 	global testname_with_flags
 	global set_target_env_var
 	global keep_saved_temps_suffixes
+	global multiline_expected_outputs
 
-	if { [ catch { eval saved-dg-test $args } errmsg ] } {
-	    set saved_info $errorInfo
-	    set additional_files ""
-	    set additional_sources ""
-	    set additional_sources_used ""
-	    set additional_prunes ""
-	    set shouldfail 0
-	    if [info exists compiler_conditional_xfail_data] {
-		unset compiler_conditional_xfail_data
-	    }
-	    if [info exists testname_with_flags] {
-		unset testname_with_flags
-	    }
-	    unset_timeout_vars
-	    error $errmsg $saved_info
-	}
 	set additional_files ""
 	set additional_sources ""
 	set additional_sources_used ""
@@ -871,6 +859,18 @@ if { [info procs saved-dg-test] == [list] } {
 	if [info exists testname_with_flags] {
 	    unset testname_with_flags
 	}
+	set multiline_expected_outputs []
+    }
+
+    proc dg-test { args } {
+	global errorInfo
+
+	if { [ catch { eval saved-dg-test $args } errmsg ] } {
+	    set saved_info $errorInfo
+	    cleanup-after-saved-dg-test
+	    error $errmsg $saved_info
+	}
+	cleanup-after-saved-dg-test
     }
 }
 
diff --git a/gcc/testsuite/lib/multiline.exp b/gcc/testsuite/lib/multiline.exp
index 6b2c1da..fd7affc 100644
--- a/gcc/testsuite/lib/multiline.exp
+++ b/gcc/testsuite/lib/multiline.exp
@@ -47,17 +47,18 @@
 # to have the testsuite verify the expected output.
 
 ############################################################################
-# Global variables.  Although global, these are intended to only be used from
-# within multiline.exp.
+# Global variables.
 ############################################################################
 
+# This is intended to only be used from within multiline.exp.
 # The line number of the last dg-begin-multiline-output directive.
 set _multiline_last_beginning_line -1
 
 # A list of
 #   first-line-number, last-line-number, lines
 # where each "lines" is a list of strings.
-set _multiline_expected_outputs []
+# This is cleared at the end of each test by gcc-dg.exp's wrapper for dg-test.
+set multiline_expected_outputs []
 
 ############################################################################
 # Exported functions.
@@ -94,9 +95,9 @@ proc dg-end-multiline-output { args } {
     verbose "lines: $lines" 3
     # Create an entry of the form:  first-line, last-line, lines
     set entry [list $_multiline_last_beginning_line $line $lines]
-    global _multiline_expected_outputs
-    lappend _multiline_expected_outputs $entry
-    verbose "within dg-end-multiline-output: _multiline_expected_outputs: $_multiline_expected_outputs" 3
+    global multiline_expected_outputs
+    lappend multiline_expected_outputs $entry
+    verbose "within dg-end-multiline-output: multiline_expected_outputs: $multiline_expected_outputs" 3
 
     set _multiline_last_beginning_line -1
 }
@@ -107,14 +108,12 @@ proc dg-end-multiline-output { args } {
 # those that weren't found.
 #
 # It returns a pruned version of its output.
-#
-# It also clears the list of expected multiline outputs.
 
 proc handle-multiline-outputs { text } {
-    global _multiline_expected_outputs
+    global multiline_expected_outputs
     global testname_with_flags
     set index 0
-    foreach entry $_multiline_expected_outputs {
+    foreach entry $multiline_expected_outputs {
 	verbose "  entry: $entry" 3
 	set start_line [lindex $entry 0]
 	set end_line   [lindex $entry 1]
@@ -140,9 +139,6 @@ proc handle-multiline-outputs { text } {
 	set index [expr $index + 1]
     }
 
-    # Clear the list of expected multiline outputs
-    set _multiline_expected_outputs []
-
     return $text
 }
 
-- 
1.8.5.3