diff options
Diffstat (limited to 'gcc/rust/hir/rust-ast-lower.cc')
| -rw-r--r-- | gcc/rust/hir/rust-ast-lower.cc | 67 |
1 files changed, 56 insertions, 11 deletions
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 (), |