Merge branch 'master' of https://github.com/redbrain/gccrs

7 files changed, 119 insertions, 37 deletions

diff --git a/gcc/rust/hir/rust-ast-lower-block.h b/gcc/rust/hir/rust-ast-lower-block.h
index 11f1ab8..f81a242 100644
--- a/gcc/rust/hir/rust-ast-lower-block.h
+++ b/gcc/rust/hir/rust-ast-lower-block.h
@@ -28,7 +28,7 @@ namespace HIR {
 class ASTLoweringBlock : public ASTLoweringBase
 {
 public:
-  static HIR::BlockExpr *translate (AST::BlockExpr *expr)
+  static HIR::BlockExpr *translate (AST::BlockExpr *expr, bool *terminated)
   {
     ASTLoweringBlock resolver;
     expr->accept_vis (resolver);
@@ -40,6 +40,7 @@ public:
 	  resolver.translated);
       }
 
+    *terminated = resolver.terminated;
     return resolver.translated;
   }
 
@@ -48,15 +49,18 @@ public:
   void visit (AST::BlockExpr &expr);
 
 private:
-  ASTLoweringBlock () : ASTLoweringBase (), translated (nullptr) {}
+  ASTLoweringBlock ()
+    : ASTLoweringBase (), translated (nullptr), terminated (false)
+  {}
 
   HIR::BlockExpr *translated;
+  bool terminated;
 };
 
 class ASTLoweringIfBlock : public ASTLoweringBase
 {
 public:
-  static HIR::IfExpr *translate (AST::IfExpr *expr)
+  static HIR::IfExpr *translate (AST::IfExpr *expr, bool *terminated)
   {
     ASTLoweringIfBlock resolver;
     expr->accept_vis (resolver);
@@ -67,7 +71,7 @@ public:
 	  resolver.translated->get_mappings ().get_hirid (),
 	  resolver.translated);
       }
-
+    *terminated = resolver.terminated;
     return resolver.translated;
   }
 
@@ -80,15 +84,19 @@ public:
   void visit (AST::IfExprConseqIf &expr);
 
 private:
-  ASTLoweringIfBlock () : ASTLoweringBase (), translated (nullptr) {}
+  ASTLoweringIfBlock ()
+    : ASTLoweringBase (), translated (nullptr), terminated (false)
+  {}
 
   HIR::IfExpr *translated;
+  bool terminated;
 };
 
 class ASTLoweringExprWithBlock : public ASTLoweringBase
 {
 public:
-  static HIR::ExprWithBlock *translate (AST::ExprWithBlock *expr)
+  static HIR::ExprWithBlock *translate (AST::ExprWithBlock *expr,
+					bool *terminated)
   {
     ASTLoweringExprWithBlock resolver;
     expr->accept_vis (resolver);
@@ -100,6 +108,7 @@ public:
 	  resolver.translated);
       }
 
+    *terminated = resolver.terminated;
     return resolver.translated;
   }
 
@@ -107,23 +116,31 @@ public:
 
   void visit (AST::IfExpr &expr)
   {
-    translated = ASTLoweringIfBlock::translate (&expr);
+    translated = ASTLoweringIfBlock::translate (&expr, &terminated);
   }
 
   void visit (AST::IfExprConseqElse &expr)
   {
-    translated = ASTLoweringIfBlock::translate (&expr);
+    translated = ASTLoweringIfBlock::translate (&expr, &terminated);
   }
 
   void visit (AST::IfExprConseqIf &expr)
   {
-    translated = ASTLoweringIfBlock::translate (&expr);
+    translated = ASTLoweringIfBlock::translate (&expr, &terminated);
+  }
+
+  void visit (AST::BlockExpr &expr)
+  {
+    translated = ASTLoweringBlock::translate (&expr, &terminated);
   }
 
 private:
-  ASTLoweringExprWithBlock () : ASTLoweringBase (), translated (nullptr) {}
+  ASTLoweringExprWithBlock ()
+    : ASTLoweringBase (), translated (nullptr), terminated (false)
+  {}
 
   HIR::ExprWithBlock *translated;
+  bool terminated;
 };
 
 } // namespace HIR
diff --git a/gcc/rust/hir/rust-ast-lower-expr.h b/gcc/rust/hir/rust-ast-lower-expr.h
index 87ba0dc..51bf108 100644
--- a/gcc/rust/hir/rust-ast-lower-expr.h
+++ b/gcc/rust/hir/rust-ast-lower-expr.h
@@ -107,7 +107,7 @@ private:
 class ASTLoweringExpr : public ASTLoweringBase
 {
 public:
-  static HIR::Expr *translate (AST::Expr *expr)
+  static HIR::Expr *translate (AST::Expr *expr, bool *terminated = nullptr)
   {
     ASTLoweringExpr resolver;
     expr->accept_vis (resolver);
@@ -121,6 +121,13 @@ public:
     resolver.mappings->insert_hir_expr (
       resolver.translated->get_mappings ().get_crate_num (),
       resolver.translated->get_mappings ().get_hirid (), resolver.translated);
+    resolver.mappings->insert_location (
+      resolver.translated->get_mappings ().get_crate_num (),
+      resolver.translated->get_mappings ().get_hirid (),
+      expr->get_locus_slow ());
+
+    if (terminated != nullptr)
+      *terminated = resolver.terminated;
 
     return resolver.translated;
   }
@@ -129,22 +136,22 @@ public:
 
   void visit (AST::IfExpr &expr)
   {
-    translated = ASTLoweringIfBlock::translate (&expr);
+    translated = ASTLoweringIfBlock::translate (&expr, &terminated);
   }
 
   void visit (AST::IfExprConseqElse &expr)
   {
-    translated = ASTLoweringIfBlock::translate (&expr);
+    translated = ASTLoweringIfBlock::translate (&expr, &terminated);
   }
 
   void visit (AST::IfExprConseqIf &expr)
   {
-    translated = ASTLoweringIfBlock::translate (&expr);
+    translated = ASTLoweringIfBlock::translate (&expr, &terminated);
   }
 
   void visit (AST::BlockExpr &expr)
   {
-    translated = ASTLoweringBlock::translate (&expr);
+    translated = ASTLoweringBlock::translate (&expr, &terminated);
   }
 
   void visit (AST::PathInExpression &expr)
@@ -154,6 +161,7 @@ public:
 
   void visit (AST::ReturnExpr &expr)
   {
+    terminated = true;
     HIR::Expr *return_expr
       = expr.has_returned_expr ()
 	  ? ASTLoweringExpr::translate (expr.get_returned_expr ().get ())
@@ -498,10 +506,13 @@ public:
   }
 
 private:
-  ASTLoweringExpr () : translated (nullptr), translated_array_elems (nullptr) {}
+  ASTLoweringExpr ()
+    : translated (nullptr), translated_array_elems (nullptr), terminated (false)
+  {}
 
   HIR::Expr *translated;
   HIR::ArrayElems *translated_array_elems;
+  bool terminated;
 };
 
 } // namespace HIR
diff --git a/gcc/rust/hir/rust-ast-lower-item.h b/gcc/rust/hir/rust-ast-lower-item.h
index 2a17880..4a5a3fe 100644
--- a/gcc/rust/hir/rust-ast-lower-item.h
+++ b/gcc/rust/hir/rust-ast-lower-item.h
@@ -185,9 +185,14 @@ public:
 	function_params.push_back (hir_param);
       }
 
+    bool terminated = false;
     std::unique_ptr<HIR::BlockExpr> function_body
       = std::unique_ptr<HIR::BlockExpr> (
-	ASTLoweringBlock::translate (function.get_definition ().get ()));
+	ASTLoweringBlock::translate (function.get_definition ().get (),
+				     &terminated));
+    if (!terminated && function.has_return_type ())
+      rust_error_at (function.get_definition ()->get_locus (),
+		     "missing return");
 
     auto crate_num = mappings->get_current_crate ();
     Analysis::NodeMapping mapping (crate_num, function.get_node_id (),
diff --git a/gcc/rust/hir/rust-ast-lower-stmt.h b/gcc/rust/hir/rust-ast-lower-stmt.h
index f4ecd8e..b672456 100644
--- a/gcc/rust/hir/rust-ast-lower-stmt.h
+++ b/gcc/rust/hir/rust-ast-lower-stmt.h
@@ -33,15 +33,12 @@ namespace HIR {
 class ASTLoweringStmt : public ASTLoweringBase
 {
 public:
-  static HIR::Stmt *translate (AST::Stmt *stmt)
+  static HIR::Stmt *translate (AST::Stmt *stmt, bool *terminated)
   {
     ASTLoweringStmt resolver;
     stmt->accept_vis (resolver);
-    if (resolver.translated == nullptr)
-      {
-	printf ("Failing translating: %s\n", stmt->as_string ().c_str ());
-	rust_assert (resolver.translated != nullptr);
-      }
+    rust_assert (resolver.translated != nullptr);
+    *terminated = resolver.terminated;
     return resolver.translated;
   }
 
@@ -50,7 +47,8 @@ public:
   void visit (AST::ExprStmtWithBlock &stmt)
   {
     HIR::ExprWithBlock *expr
-      = ASTLoweringExprWithBlock::translate (stmt.get_expr ().get ());
+      = ASTLoweringExprWithBlock::translate (stmt.get_expr ().get (),
+					     &terminated);
 
     auto crate_num = mappings->get_current_crate ();
     Analysis::NodeMapping mapping (crate_num, stmt.get_node_id (),
@@ -67,7 +65,8 @@ public:
 
   void visit (AST::ExprStmtWithoutBlock &stmt)
   {
-    HIR::Expr *expr = ASTLoweringExpr::translate (stmt.get_expr ().get ());
+    HIR::Expr *expr
+      = ASTLoweringExpr::translate (stmt.get_expr ().get (), &terminated);
 
     auto crate_num = mappings->get_current_crate ();
     Analysis::NodeMapping mapping (crate_num, stmt.get_node_id (),
@@ -110,9 +109,10 @@ public:
   }
 
 private:
-  ASTLoweringStmt () : translated (nullptr) {}
+  ASTLoweringStmt () : translated (nullptr), terminated (false) {}
 
   HIR::Stmt *translated;
+  bool terminated;
 };
 
 } // namespace HIR
diff --git a/gcc/rust/hir/rust-ast-lower.cc b/gcc/rust/hir/rust-ast-lower.cc
index 8dd8800..4f0d0d0 100644
--- a/gcc/rust/hir/rust-ast-lower.cc
+++ b/gcc/rust/hir/rust-ast-lower.cc
@@ -64,17 +64,44 @@ ASTLowering::go ()
 void
 ASTLoweringBlock::visit (AST::BlockExpr &expr)
 {
-  std::vector<std::unique_ptr<HIR::Stmt> > block_stmts;
-  std::unique_ptr<HIR::ExprWithoutBlock> block_expr;
   std::vector<HIR::Attribute> inner_attribs;
   std::vector<HIR::Attribute> outer_attribs;
 
+  std::vector<std::unique_ptr<HIR::Stmt> > block_stmts;
+  bool block_did_terminate = false;
   expr.iterate_stmts ([&] (AST::Stmt *s) mutable -> bool {
-    auto translated_stmt = ASTLoweringStmt::translate (s);
+    bool terminated = false;
+    auto translated_stmt = ASTLoweringStmt::translate (s, &terminated);
     block_stmts.push_back (std::unique_ptr<HIR::Stmt> (translated_stmt));
+    block_did_terminate = terminated;
+    return !block_did_terminate;
+  });
+
+  // if there was a return expression everything after that becomes
+  // unreachable code. This can be detected for any AST NodeIDs that have no
+  // associated HIR Mappings
+  expr.iterate_stmts ([&] (AST::Stmt *s) -> bool {
+    HirId ref;
+    if (!mappings->lookup_node_to_hir (mappings->get_current_crate (),
+				       s->get_node_id (), &ref))
+      rust_warning_at (s->get_locus_slow (), 0, "unreachable statement");
+
     return true;
   });
 
+  HIR::ExprWithoutBlock *tail_expr = nullptr;
+  if (expr.has_tail_expr () && !block_did_terminate)
+    {
+      tail_expr = (HIR::ExprWithoutBlock *) ASTLoweringExpr::translate (
+	expr.get_tail_expr ().get ());
+    }
+  else if (expr.has_tail_expr () && block_did_terminate)
+    {
+      // warning unreachable tail expressions
+      rust_warning_at (expr.get_tail_expr ()->get_locus_slow (), 0,
+		       "unreachable expression");
+    }
+
   auto crate_num = mappings->get_current_crate ();
   Analysis::NodeMapping mapping (crate_num, expr.get_node_id (),
 				 mappings->get_next_hir_id (crate_num),
@@ -82,17 +109,23 @@ ASTLoweringBlock::visit (AST::BlockExpr &expr)
 
   translated
     = new HIR::BlockExpr (mapping, std::move (block_stmts),
-			  std::move (block_expr), std::move (inner_attribs),
-			  std::move (outer_attribs), expr.get_locus ());
+			  std::unique_ptr<HIR::ExprWithoutBlock> (tail_expr),
+			  std::move (inner_attribs), std::move (outer_attribs),
+			  expr.get_locus ());
+
+  terminated = block_did_terminate || expr.has_tail_expr ();
 }
 
 void
 ASTLoweringIfBlock::visit (AST::IfExpr &expr)
 {
+  bool ignored_terminated = false;
   HIR::Expr *condition
-    = ASTLoweringExpr::translate (expr.get_condition_expr ().get ());
+    = ASTLoweringExpr::translate (expr.get_condition_expr ().get (),
+				  &ignored_terminated);
   HIR::BlockExpr *block
-    = ASTLoweringBlock::translate (expr.get_if_block ().get ());
+    = ASTLoweringBlock::translate (expr.get_if_block ().get (),
+				   &ignored_terminated);
 
   auto crate_num = mappings->get_current_crate ();
   Analysis::NodeMapping mapping (crate_num, expr.get_node_id (),
@@ -109,10 +142,18 @@ ASTLoweringIfBlock::visit (AST::IfExprConseqElse &expr)
 {
   HIR::Expr *condition
     = ASTLoweringExpr::translate (expr.get_condition_expr ().get ());
+
+  bool if_block_terminated = false;
+  bool else_block_termianted = false;
+
   HIR::BlockExpr *if_block
-    = ASTLoweringBlock::translate (expr.get_if_block ().get ());
+    = ASTLoweringBlock::translate (expr.get_if_block ().get (),
+				   &if_block_terminated);
   HIR::BlockExpr *else_block
-    = ASTLoweringBlock::translate (expr.get_else_block ().get ());
+    = ASTLoweringBlock::translate (expr.get_else_block ().get (),
+				   &else_block_termianted);
+
+  terminated = if_block_terminated && else_block_termianted;
 
   auto crate_num = mappings->get_current_crate ();
   Analysis::NodeMapping mapping (crate_num, expr.get_node_id (),
@@ -132,10 +173,14 @@ ASTLoweringIfBlock::visit (AST::IfExprConseqIf &expr)
 {
   HIR::Expr *condition
     = ASTLoweringExpr::translate (expr.get_condition_expr ().get ());
+
+  bool ignored_terminated = false;
   HIR::BlockExpr *block
-    = ASTLoweringBlock::translate (expr.get_if_block ().get ());
+    = ASTLoweringBlock::translate (expr.get_if_block ().get (),
+				   &ignored_terminated);
   HIR::IfExpr *conseq_if_expr
-    = ASTLoweringIfBlock::translate (expr.get_conseq_if_expr ().get ());
+    = ASTLoweringIfBlock::translate (expr.get_conseq_if_expr ().get (),
+				     &ignored_terminated);
 
   auto crate_num = mappings->get_current_crate ();
   Analysis::NodeMapping mapping (crate_num, expr.get_node_id (),
diff --git a/gcc/rust/hir/tree/rust-hir-expr.h b/gcc/rust/hir/tree/rust-hir-expr.h
index dc7ab5a..11be8b6 100644
--- a/gcc/rust/hir/tree/rust-hir-expr.h
+++ b/gcc/rust/hir/tree/rust-hir-expr.h
@@ -2594,6 +2594,8 @@ public:
       }
   }
 
+  bool is_final_stmt (Stmt *stmt) { return statements.back ().get () == stmt; }
+
   Location get_closing_locus ()
   {
     if (statements.size () == 0)
diff --git a/gcc/rust/hir/tree/rust-hir.h b/gcc/rust/hir/tree/rust-hir.h
index 7417a32..5d758ee 100644
--- a/gcc/rust/hir/tree/rust-hir.h
+++ b/gcc/rust/hir/tree/rust-hir.h
@@ -257,6 +257,8 @@ public:
     return Literal ("", CHAR, PrimitiveCoreType::CORETYPE_UNKNOWN);
   }
 
+  void set_lit_type (LitType lt) { type = lt; }
+
   // Returns whether literal is in an invalid state.
   bool is_error () const { return value_as_string == ""; }
 };