Optimize regular expression elimination (#2612)

3 files changed, 63 insertions, 0 deletions

diff --git a/test/regress/CMakeLists.txt b/test/regress/CMakeLists.txt
index a7b7532f1..bfcd640b9 100644
--- a/test/regress/CMakeLists.txt
+++ b/test/regress/CMakeLists.txt
@@ -1710,6 +1710,7 @@ set(regress_2_tests
   regress2/strings/cmu-disagree-0707-dd.smt2
   regress2/strings/cmu-prereg-fmf.smt2
   regress2/strings/cmu-repl-len-nterm.smt2
+  regress2/strings/non_termination_regular_expression6.smt2
   regress2/strings/norn-dis-0707-3.smt2
   regress2/strings/repl-repl.smt2
   regress2/sygus/MPwL_d1s3.sy
diff --git a/test/regress/Makefile.tests b/test/regress/Makefile.tests
index 523650926..fc080f0e0 100644
--- a/test/regress/Makefile.tests
+++ b/test/regress/Makefile.tests
@@ -1703,6 +1703,7 @@ REG2_TESTS = \
 	regress2/strings/cmu-disagree-0707-dd.smt2 \
 	regress2/strings/cmu-prereg-fmf.smt2 \
 	regress2/strings/cmu-repl-len-nterm.smt2 \
+	regress2/strings/non_termination_regular_expression6.smt2 \
 	regress2/strings/norn-dis-0707-3.smt2 \
 	regress2/strings/repl-repl.smt2 \
 	regress2/sygus/MPwL_d1s3.sy \
diff --git a/test/regress/regress2/strings/non_termination_regular_expression6.smt2 b/test/regress/regress2/strings/non_termination_regular_expression6.smt2
new file mode 100644
index 000000000..340cade1c
--- /dev/null
+++ b/test/regress/regress2/strings/non_termination_regular_expression6.smt2
@@ -0,0 +1,61 @@
+; COMMAND-LINE: --strings-exp --re-elim
+; EXPECT: unsat
+(set-logic ALL)
+(set-info :status unsat)
+(declare-const actionName String)
+(declare-const actionNamespace String)
+(declare-const resource_account String)
+(declare-const resource_partition String)
+(declare-const resource_prefix String)
+(declare-const resource_region String)
+(declare-const resource_resource String)
+(declare-const resource_service String)
+
+; Action: p0.0
+(declare-const p0.0.action Bool)
+(assert (= p0.0.action (and (= "sqs" actionNamespace) (= "sendmessage" actionName))))
+
+; Resource: p0.0
+(declare-const p0.0.resource Bool)
+(assert (= p0.0.resource (and (= resource_prefix "arn") (= resource_partition "aws") (= resource_service "sqs") (= resource_region "us-east-1") (= resource_account "111144448888") (str.in.re resource_resource (re.++ (str.to.re "ab") (re.* re.allchar) (str.to.re "b") (re.* re.allchar) (str.to.re "b") (re.* re.allchar) (str.to.re "b"))))))
+
+; Statement: p0.0
+(declare-const p0.0.statement.allows Bool)
+(assert (= p0.0.statement.allows (and p0.0.action p0.0.resource)))
+
+; Policy: 0
+(declare-const p0.denies Bool)
+(assert (not p0.denies))
+(declare-const p0.allows Bool)
+(assert (= p0.allows (and (not p0.denies) p0.0.statement.allows)))
+(declare-const p0.neutral Bool)
+(assert (= p0.neutral (and (not p0.allows) (not p0.denies))))
+
+; Action: p1.0
+(declare-const p1.0.action Bool)
+(assert (= p1.0.action (and (= "sqs" actionNamespace) (= "sendmessage" actionName))))
+
+; Resource: p1.0
+(declare-const p1.0.resource Bool)
+(assert (= p1.0.resource (and (= resource_prefix "arn") (= resource_partition "aws") (= resource_service "sqs") (= resource_region "us-east-1") (= resource_account "111144448888") (str.in.re resource_resource (re.++ (str.to.re "a") (re.* re.allchar) (str.to.re "b") (re.* re.allchar) (str.to.re "b") (re.* re.allchar) (str.to.re "b"))))))
+
+; Statement: p1.0
+(declare-const p1.0.statement.allows Bool)
+(assert (= p1.0.statement.allows (and p1.0.action p1.0.resource)))
+
+; Policy: 1
+(declare-const p1.denies Bool)
+(assert (not p1.denies))
+(declare-const p1.allows Bool)
+(assert (= p1.allows (and (not p1.denies) p1.0.statement.allows)))
+(declare-const p1.neutral Bool)
+(assert (= p1.neutral (and (not p1.allows) (not p1.denies))))
+
+; Resource service invariant
+(assert (not (str.contains resource_service ":")))
+(assert (= resource_prefix "arn"))
+
+; Goals
+(assert p0.allows)
+(assert (or p1.denies p1.neutral))
+(check-sat)