From abb777120a79efd29daf546807bd932c11e71dae Mon Sep 17 00:00:00 2001
From: Paul Bone <paul@bone.id.au>
Date: Sun, 26 Jan 2025 21:32:49 +1100
Subject: [PATCH] [compiler/parse] Accept programs that combine entrypoint and
 export

---
 src/parse.m                    | 13 ++++++++++---
 tests/modules/BUILD.plz        | 11 +++++++++++
 tests/modules/entrypoint_2.exp |  1 +
 tests/modules/entrypoint_2a.p  | 15 +++++++++++++++
 tests/modules/entrypoint_2b.p  | 14 ++++++++++++++
 tests/modules/entrypoint_3.exp |  1 +
 tests/modules/entrypoint_3a.p  | 16 ++++++++++++++++
 tests/modules/entrypoint_3b.p  | 14 ++++++++++++++
 8 files changed, 82 insertions(+), 3 deletions(-)
 create mode 100644 tests/modules/BUILD.plz
 create mode 100644 tests/modules/entrypoint_2.exp
 create mode 100644 tests/modules/entrypoint_2a.p
 create mode 100644 tests/modules/entrypoint_2b.p
 create mode 100644 tests/modules/entrypoint_3.exp
 create mode 100644 tests/modules/entrypoint_3a.p
 create mode 100644 tests/modules/entrypoint_3b.p

diff --git a/src/parse.m b/src/parse.m
index 9a3d3455..badf5096 100644
--- a/src/parse.m
+++ b/src/parse.m
@@ -1598,13 +1598,20 @@
     tokens::in, tokens::out) is det.
 
 maybe_parse_func_export(Sharing, IsEntrypoint, !Tokens) :-
+    parse_export(Sharing0, !Tokens),
     optional(match_token(entrypoint), ok(MaybeEntrypoint), !Tokens),
     ( MaybeEntrypoint = yes(_),
-        Sharing = s_private,
+        ( Sharing0 = s_private,
+            % the export keyword might have come after entrypoint, so check
+            % again.
+            parse_export(Sharing, !Tokens)
+        ; Sharing0 = s_public,
+            Sharing = s_public
+        ),
         IsEntrypoint = is_entrypoint
     ; MaybeEntrypoint = no,
-        parse_export(Sharing, !Tokens),
-        IsEntrypoint = not_entrypoint
+        IsEntrypoint = not_entrypoint,
+        Sharing = Sharing0
     ).
 
 :- pred parse_export_opaque(sharing_opaque::out,
diff --git a/tests/modules/BUILD.plz b/tests/modules/BUILD.plz
new file mode 100644
index 00000000..dba5b903
--- /dev/null
+++ b/tests/modules/BUILD.plz
@@ -0,0 +1,11 @@
+# This is free and unencumbered software released into the public domain.
+# See ../LICENSE.unlicense
+
+[entrypoint_2]
+type = program
+modules = [Entrypoint2a, Entrypoint2b]
+
+[entrypoint_3]
+type = program
+modules = [Entrypoint3a, Entrypoint3b]
+
diff --git a/tests/modules/entrypoint_2.exp b/tests/modules/entrypoint_2.exp
new file mode 100644
index 00000000..110c58e6
--- /dev/null
+++ b/tests/modules/entrypoint_2.exp
@@ -0,0 +1 @@
+Test 2
diff --git a/tests/modules/entrypoint_2a.p b/tests/modules/entrypoint_2a.p
new file mode 100644
index 00000000..d45a739b
--- /dev/null
+++ b/tests/modules/entrypoint_2a.p
@@ -0,0 +1,15 @@
+/*
+ * vim: ft=plasma
+ * This is free and unencumbered software released into the public domain.
+ * See ../LICENSE.unlicense
+ */
+
+module Entrypoint2a
+
+export entrypoint
+func test2a() uses IO -> Int {
+    print!("Test 2\n")
+
+    return 0
+}
+
diff --git a/tests/modules/entrypoint_2b.p b/tests/modules/entrypoint_2b.p
new file mode 100644
index 00000000..2dd66cb9
--- /dev/null
+++ b/tests/modules/entrypoint_2b.p
@@ -0,0 +1,14 @@
+/*
+ * vim: ft=plasma
+ * This is free and unencumbered software released into the public domain.
+ * See ../LICENSE.unlicense
+ */
+
+module Entrypoint2b
+
+import Entrypoint2a as T2a
+
+func test2b() uses IO -> Int {
+    return T2a.test2a!()
+}
+
diff --git a/tests/modules/entrypoint_3.exp b/tests/modules/entrypoint_3.exp
new file mode 100644
index 00000000..0256ffd2
--- /dev/null
+++ b/tests/modules/entrypoint_3.exp
@@ -0,0 +1 @@
+Test 3
diff --git a/tests/modules/entrypoint_3a.p b/tests/modules/entrypoint_3a.p
new file mode 100644
index 00000000..68df8118
--- /dev/null
+++ b/tests/modules/entrypoint_3a.p
@@ -0,0 +1,16 @@
+/*
+ * vim: ft=plasma
+ * This is free and unencumbered software released into the public domain.
+ * See ../LICENSE.unlicense
+ */
+
+module Entrypoint3a
+
+// entrypoint2 has the keywords in the opposite order.
+entrypoint export
+func test3a() uses IO -> Int {
+    print!("Test 3\n")
+
+    return 0
+}
+
diff --git a/tests/modules/entrypoint_3b.p b/tests/modules/entrypoint_3b.p
new file mode 100644
index 00000000..80368d73
--- /dev/null
+++ b/tests/modules/entrypoint_3b.p
@@ -0,0 +1,14 @@
+/*
+ * vim: ft=plasma
+ * This is free and unencumbered software released into the public domain.
+ * See ../LICENSE.unlicense
+ */
+
+module Entrypoint3b
+
+import Entrypoint3a as T3a
+
+func test3b() uses IO -> Int {
+    return T3a.test3a!()
+}
+