From 2299a2d4858dae1f60533b37bb7a776142b88870 Mon Sep 17 00:00:00 2001
From: Greg Hewgill <greg@hewgill.com>
Date: Fri, 31 Mar 2017 14:58:13 +1300
Subject: [PATCH] Fix internal compiler error with certain kinds of INOUT
 parameters (issue #146)

---
 src/analyzer.cpp             | 3 +++
 src/ast.h                    | 5 +++++
 t/errors/N3241.neon          | 6 ++++++
 t/parameter-inout-array.neon | 2 +-
 4 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 t/errors/N3241.neon

diff --git a/src/analyzer.cpp b/src/analyzer.cpp
index dc75a3cbf9..195fd01285 100644
--- a/src/analyzer.cpp
+++ b/src/analyzer.cpp
@@ -1561,6 +1561,9 @@ const ast::Expression *Analyzer::analyze(const pt::FunctionCallExpression *expr)
             if (not e->type->is_assignment_compatible(ftype->params[p]->type)) {
                 error2(3194, a->expr->token, "type mismatch", ftype->params[p]->declaration, "function argument here");
             }
+            if (ftype->params[p]->mode == ast::ParameterType::INOUT && not ref->can_generate_address()) {
+                error(3241, a->expr->token, "using this kind of expression with an INOUT parameter is currently not supported");
+            }
         }
         if (ftype->params[p]->mode == ast::ParameterType::OUT && a->mode.type != OUT) {
             error(3184, a->expr->token, "OUT keyword required");
diff --git a/src/ast.h b/src/ast.h
index 5cf075fe5b..ae7c499247 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -1629,6 +1629,7 @@ class ReferenceExpression: public Expression {
     ReferenceExpression(const Type *type, bool is_readonly): Expression(type, false, is_readonly) {}
 
     virtual void generate_expr(Emitter &emitter) const override { generate_load(emitter); }
+    virtual bool can_generate_address() const { return true; }
     virtual void generate_address_read(Emitter &) const = 0;
     virtual void generate_address_write(Emitter &) const = 0;
     virtual void generate_load(Emitter &) const;
@@ -1646,6 +1647,7 @@ class DummyExpression: public ReferenceExpression {
     virtual bool eval_boolean() const override { internal_error("DummyExpression"); }
     virtual Number eval_number() const override { internal_error("DummyExpression"); }
     virtual std::string eval_string() const override { internal_error("DummyExpression"); }
+    virtual bool can_generate_address() const { return false; }
     virtual void generate_address_read(Emitter &) const override { internal_error("DummyExpression"); }
     virtual void generate_address_write(Emitter &) const override { internal_error("DummyExpression"); }
     virtual void generate_load(Emitter &) const override { internal_error("DummyExpression"); }
@@ -1751,6 +1753,7 @@ class StringReferenceIndexExpression: public ReferenceExpression {
     virtual bool eval_boolean() const override { internal_error("StringReferenceIndexExpression"); }
     virtual Number eval_number() const override { internal_error("StringReferenceIndexExpression"); }
     virtual std::string eval_string() const override { internal_error("StringReferenceIndexExpression"); }
+    virtual bool can_generate_address() const { return false; }
     virtual void generate_address_read(Emitter &) const override { internal_error("StringReferenceIndexExpression"); }
     virtual void generate_address_write(Emitter &) const override { internal_error("StringReferenceIndexExpression"); }
     virtual void generate_load(Emitter &) const override;
@@ -1803,6 +1806,7 @@ class BytesReferenceIndexExpression: public ReferenceExpression {
     virtual bool eval_boolean() const override { internal_error("BytesReferenceIndexExpression"); }
     virtual Number eval_number() const override { internal_error("BytesReferenceIndexExpression"); }
     virtual std::string eval_string() const override { internal_error("BytesReferenceIndexExpression"); }
+    virtual bool can_generate_address() const { return false; }
     virtual void generate_address_read(Emitter &) const override { internal_error("BytesReferenceIndexExpression"); }
     virtual void generate_address_write(Emitter &) const override { internal_error("BytesReferenceIndexExpression"); }
     virtual void generate_load(Emitter &) const override;
@@ -1896,6 +1900,7 @@ class ArrayReferenceRangeExpression: public ReferenceExpression {
     virtual bool eval_boolean() const override { internal_error("ArrayReferenceRangeExpression"); }
     virtual Number eval_number() const override { internal_error("ArrayReferenceRangeExpression"); }
     virtual std::string eval_string() const override { internal_error("ArrayReferenceRangeExpression"); }
+    virtual bool can_generate_address() const { return false; }
     virtual void generate_address_read(Emitter &) const override { internal_error("StringReferenceRangeExpression"); }
     virtual void generate_address_write(Emitter &) const override { internal_error("StringReferenceRangeExpression"); }
     virtual void generate_load(Emitter &) const override;
diff --git a/t/errors/N3241.neon b/t/errors/N3241.neon
new file mode 100644
index 0000000000..a7fa2407e4
--- /dev/null
+++ b/t/errors/N3241.neon
@@ -0,0 +1,6 @@
+FUNCTION a_inout(INOUT p: Array<Number>)
+END FUNCTION
+
+VAR a: Array<Number> := []
+a_inout(INOUT a[0 TO 4])
+               %<
diff --git a/t/parameter-inout-array.neon b/t/parameter-inout-array.neon
index 9bac21912c..2d42cffc69 100644
--- a/t/parameter-inout-array.neon
+++ b/t/parameter-inout-array.neon
@@ -1,4 +1,4 @@
-% TODO
+% TODO https://github.com/ghewgill/neon-lang/issues/146
 FUNCTION a_inout(INOUT p: Array<Number>)
     p := [1, 2]
 END FUNCTION