Detect unused steps in isolation specs and do some cleanup

This is useful for developers to find out if an isolation spec is
over-engineered or if it needs more work by warning at the end of a
test run if a step is not used, generating a failure with extra diffs.

While on it, clean up all the specs which include steps not used in any
permutations to simplify them.

Author: Michael Paquier
Reviewed-by: Asim Praveen, Melanie Plageman
Discussion: https://postgr.es/m/20190819080820.GG18166@paquier.xyz

src/test/isolation/isolationtester.c

@@ -81,7 +81,7 @@ main(int argc, char **argv)
 				puts("isolationtester (PostgreSQL) " PG_VERSION);
 				exit(0);
 			default:
-				fprintf(stderr, "Usage: isolationtester [-n] [CONNINFO]\n");
+				fprintf(stderr, "Usage: isolationtester [CONNINFO]\n");
 				return EXIT_FAILURE;
 		}
 	}
@@ -235,10 +235,23 @@ static int *piles;
 static void
 run_testspec(TestSpec *testspec)
 {
+	int			i;
+
 	if (testspec->permutations)
 		run_named_permutations(testspec);
 	else
 		run_all_permutations(testspec);
+
+	/*
+	 * Verify that all steps have been used, complaining about anything
+	 * defined but not used.
+	 */
+	for (i = 0; i < testspec->nallsteps; i++)
+	{
+		if (!testspec->allsteps[i]->used)
+			fprintf(stderr, "unused step name: %s\n",
+					testspec->allsteps[i]->name);
+	}
 }
 
 /*
@@ -438,7 +451,11 @@ run_permutation(TestSpec *testspec, int nsteps, Step **steps)
 
 	printf("\nstarting permutation:");
 	for (i = 0; i < nsteps; i++)
+	{
+		/* Track the permutation as in-use */
+		steps[i]->used = true;
 		printf(" %s", steps[i]->name);
+	}
 	printf("\n");
 
 	/* Perform setup */

src/test/isolation/isolationtester.h

@@ -29,6 +29,7 @@ struct Session
 struct Step
 {
 	int			session;
+	bool		used;
 	char	   *name;
 	char	   *sql;
 	char	   *errormsg;

src/test/isolation/specparse.y

@@ -145,6 +145,7 @@ step:
 				$$ = pg_malloc(sizeof(Step));
 				$$->name = $2;
 				$$->sql = $3;
+				$$->used = false;
 				$$->errormsg = NULL;
 			}
 		;

src/test/isolation/specs/freeze-the-dead.spec

@@ -19,7 +19,6 @@ session "s1"
 step "s1_begin"		{ BEGIN; }
 step "s1_update"	{ UPDATE tab_freeze SET x = x + 1 WHERE id = 3; }
 step "s1_commit"	{ COMMIT; }
-step "s1_vacuum"	{ VACUUM FREEZE tab_freeze; }
 step "s1_selectone"	{
     BEGIN;
     SET LOCAL enable_seqscan = false;
@@ -28,7 +27,6 @@ step "s1_selectone"	{
     COMMIT;
 }
 step "s1_selectall"	{ SELECT * FROM tab_freeze ORDER BY name, id; }
-step "s1_reindex"	{ REINDEX TABLE tab_freeze; }
 
 session "s2"
 step "s2_begin"		{ BEGIN; }
@@ -40,7 +38,6 @@ session "s3"
 step "s3_begin"		{ BEGIN; }
 step "s3_key_share"	{ SELECT id FROM tab_freeze WHERE id = 3 FOR KEY SHARE; }
 step "s3_commit"	{ COMMIT; }
-step "s3_vacuum"	{ VACUUM FREEZE tab_freeze; }
 
 # This permutation verifies that a previous bug
 #     https://postgr.es/m/E5711E62-8FDF-4DCA-A888-C200BF6B5742@amazon.com

src/test/isolation/specs/insert-conflict-do-nothing.spec

@@ -33,7 +33,6 @@ setup
 step "donothing2" { INSERT INTO ints(key, val) VALUES(1, 'donothing2') ON CONFLICT DO NOTHING; }
 step "select2" { SELECT * FROM ints; }
 step "c2" { COMMIT; }
-step "a2" { ABORT; }
 
 # Regular case where one session block-waits on another to determine if it
 # should proceed with an insert or do nothing.

src/test/isolation/specs/insert-conflict-do-update-2.spec

@@ -32,7 +32,6 @@ setup
 step "insert2" { INSERT INTO upsert(key, payload) VALUES('FOOFOO', 'insert2') ON CONFLICT (lower(key)) DO UPDATE set key = EXCLUDED.key, payload = upsert.payload || ' updated by insert2'; }
 step "select2" { SELECT * FROM upsert; }
 step "c2" { COMMIT; }
-step "a2" { ABORT; }
 
 # One session (session 2) block-waits on another (session 1) to determine if it
 # should proceed with an insert or update.  The user can still usefully UPDATE

src/test/isolation/specs/insert-conflict-do-update.spec

@@ -30,7 +30,6 @@ setup
 step "insert2" { INSERT INTO upsert(key, val) VALUES(1, 'insert2') ON CONFLICT (key) DO UPDATE set val = upsert.val || ' updated by insert2'; }
 step "select2" { SELECT * FROM upsert; }
 step "c2" { COMMIT; }
-step "a2" { ABORT; }
 
 # One session (session 2) block-waits on another (session 1) to determine if it
 # should proceed with an insert or update.  Notably, this entails updating a

src/test/isolation/specs/sequence-ddl.spec

@@ -15,7 +15,6 @@ setup           { BEGIN; }
 step "s1alter"  { ALTER SEQUENCE seq1 MAXVALUE 10; }
 step "s1alter2" { ALTER SEQUENCE seq1 MAXVALUE 20; }
 step "s1restart" { ALTER SEQUENCE seq1 RESTART WITH 5; }
-step "s1setval" { SELECT setval('seq1', 5); }
 step "s1commit" { COMMIT; }
 
 session "s2"

src/test/isolation/specs/tuplelock-upgrade-no-deadlock.spec

@@ -19,7 +19,6 @@ teardown
 session "s0"
 step "s0_begin" { begin; }
 step "s0_keyshare" { select id from tlu_job where id = 1 for key share;}
-step "s0_share" { select id from tlu_job where id = 1 for share;}
 step "s0_rollback" { rollback; }
 
 session "s1"
@@ -28,7 +27,6 @@ step "s1_keyshare" { select id from tlu_job where id = 1 for key share;}
 step "s1_share" { select id from tlu_job where id = 1 for share; }
 step "s1_fornokeyupd" { select id from tlu_job where id = 1 for no key update; }
 step "s1_update" { update tlu_job set name = 'b' where id = 1;  }
-step "s1_delete" { delete from tlu_job where id = 1; }
 step "s1_savept_e" { savepoint s1_e; }
 step "s1_savept_f" { savepoint s1_f; }
 step "s1_rollback_e" { rollback to s1_e; }
@@ -44,7 +42,6 @@ step "s2_for_update" { select id from tlu_job where id = 1 for update; }
 step "s2_update" { update tlu_job set name = 'b' where id = 1; }
 step "s2_delete" { delete from tlu_job where id = 1; }
 step "s2_rollback" { rollback; }
-step "s2_commit" { commit; }
 
 session "s3"
 setup { begin; }