From: Philip Herron <philip.her...@embecosm.com> This is a simple walk_tree which acts on the monomorphized code. By walking the compiled translation unit of functions. --- gcc/rust/checks/lints/rust-lint-unused-var.cc | 98 +++++++++++++++++++ gcc/rust/checks/lints/rust-lint-unused-var.h | 36 +++++++ 2 files changed, 134 insertions(+) create mode 100644 gcc/rust/checks/lints/rust-lint-unused-var.cc create mode 100644 gcc/rust/checks/lints/rust-lint-unused-var.h
diff --git a/gcc/rust/checks/lints/rust-lint-unused-var.cc b/gcc/rust/checks/lints/rust-lint-unused-var.cc new file mode 100644 index 00000000000..d4317e53280 --- /dev/null +++ b/gcc/rust/checks/lints/rust-lint-unused-var.cc @@ -0,0 +1,98 @@ +// Copyright (C) 2021-2022 Free Software Foundation, Inc. + +// This file is part of GCC. + +// GCC is free software; you can redistribute it and/or modify it under +// the terms of the GNU General Public License as published by the Free +// Software Foundation; either version 3, or (at your option) any later +// version. + +// GCC is distributed in the hope that it will be useful, but WITHOUT ANY +// WARRANTY; without even the implied warranty of MERCHANTABILITY or +// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +// for more details. + +// You should have received a copy of the GNU General Public License +// along with GCC; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +#include "rust-lint-unused-var.h" +#include "print-tree.h" + +namespace Rust { +namespace Analysis { + +static void +check_decl (tree *t) +{ + rust_assert (TREE_CODE (*t) == VAR_DECL || TREE_CODE (*t) == PARM_DECL + || TREE_CODE (*t) == CONST_DECL); + + tree var_name = DECL_NAME (*t); + const char *var_name_ptr = IDENTIFIER_POINTER (var_name); + bool starts_with_under_score = strncmp (var_name_ptr, "_", 1) == 0; + + bool is_constant = TREE_CODE (*t) == CONST_DECL; + // if (!is_constant) + // { + // debug_tree (*t); + // rust_debug ("found var-decl: used %s artifical %s underscore %s name + // %s", + // TREE_USED (*t) ? "true" : "false", + // DECL_ARTIFICIAL (*t) ? "true" : "false", + // starts_with_under_score ? "true" : "false", var_name_ptr); + // } + + if (!TREE_USED (*t) && !DECL_ARTIFICIAL (*t) && !starts_with_under_score) + { + warning_at (DECL_SOURCE_LOCATION (*t), + is_constant ? OPT_Wunused_const_variable_ + : OPT_Wunused_variable, + "unused name %qE", *t); + } +} + +static tree +unused_var_walk_fn (tree *t, int *walk_subtrees, void *closure) +{ + switch (TREE_CODE (*t)) + { + case VAR_DECL: + case CONST_DECL: + check_decl (t); + break; + + default: + break; + } + return NULL_TREE; +} + +void +UnusedVariables::Lint (Compile::Context &ctx) +{ + for (auto &fndecl : ctx.get_func_decls ()) + { + for (tree p = DECL_ARGUMENTS (fndecl); p != NULL_TREE; p = DECL_CHAIN (p)) + { + check_decl (&p); + } + + walk_tree_without_duplicates (&DECL_SAVED_TREE (fndecl), + &unused_var_walk_fn, &ctx); + } + + for (auto &var : ctx.get_var_decls ()) + { + tree t = ctx.get_backend ()->var_expression (var, Location ()); + check_decl (&t); + } + + for (auto &const_decl : ctx.get_const_decls ()) + { + check_decl (&const_decl); + } +} + +} // namespace Analysis +} // namespace Rust diff --git a/gcc/rust/checks/lints/rust-lint-unused-var.h b/gcc/rust/checks/lints/rust-lint-unused-var.h new file mode 100644 index 00000000000..6fabfeff01b --- /dev/null +++ b/gcc/rust/checks/lints/rust-lint-unused-var.h @@ -0,0 +1,36 @@ +// Copyright (C) 2021-2022 Free Software Foundation, Inc. + +// This file is part of GCC. + +// GCC is free software; you can redistribute it and/or modify it under +// the terms of the GNU General Public License as published by the Free +// Software Foundation; either version 3, or (at your option) any later +// version. + +// GCC is distributed in the hope that it will be useful, but WITHOUT ANY +// WARRANTY; without even the implied warranty of MERCHANTABILITY or +// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +// for more details. + +// You should have received a copy of the GNU General Public License +// along with GCC; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +#ifndef RUST_LINT_UNUSED_VAR +#define RUST_LINT_UNUSED_VAR + +#include "rust-compile-context.h" + +namespace Rust { +namespace Analysis { + +class UnusedVariables +{ +public: + static void Lint (Compile::Context &ctx); +}; + +} // namespace Analysis +} // namespace Rust + +#endif // RUST_LINT_UNUSED_VAR -- 2.25.1
