testsuite/gna: add a test for #1721

2 files changed, 29 insertions, 0 deletions

diff --git a/testsuite/gna/issue1721/testsuite.sh b/testsuite/gna/issue1721/testsuite.sh
index 70c249139..e4a6e56cc 100755
--- a/testsuite/gna/issue1721/testsuite.sh
+++ b/testsuite/gna/issue1721/testsuite.sh
@@ -7,6 +7,8 @@ export GHDL_STD_FLAGS=-fpsl
 analyze top1.vhdl
 elab_simulate top1
 
+analyze_failure top2.vhdl
+
 clean
 
 echo "Test successful"
diff --git a/testsuite/gna/issue1721/top2.vhdl b/testsuite/gna/issue1721/top2.vhdl
new file mode 100644
index 000000000..b213d96d5
--- /dev/null
+++ b/testsuite/gna/issue1721/top2.vhdl
@@ -0,0 +1,27 @@
+library ieee;
+use ieee.std_logic_1164.all;
+
+entity top2 is
+end entity;
+
+architecture a of top2 is
+    signal a,b,c,d : std_logic := '0';
+    signal clk_sys, clk1, clk2 : std_logic;
+begin
+  -- psl default clock is clk_sys;
+
+  -- Following throws bug occured with: "build_sere_fa: cannot handle N_IMP_SEQ"
+  -- This is strange because with "always" this is working.
+  -- According to PSL LRM 2003 FL_Property production for "always" is the
+  -- same as for "never":
+  --   FL_Property ::=
+  --        always FL_Property
+  --      | always Sequence
+  --
+  --   FL_Property ::=
+  --        never FL_Property
+  --      | never Sequence
+  -- Therefore I think if sequence implication works with one, it shall work
+  -- also with other.
+  -- psl my_seq : assert never {a} |=> {b; c};
+end a;