From: Philip Herron <[email protected]>
Rust seems to allow duplicate HIR::Item 'main' functions but it needs
to be a root item to be the true main entry point. This means we can
use the canonical path to determine if this is a root one where
its CrateName::main or CrateName::Module::main.
Fixes Rust-GCC#3978
gcc/rust/ChangeLog:
* backend/rust-compile-base.cc: check the canonical path
gcc/testsuite/ChangeLog:
* rust/compile/issue-3978.rs: New test.
Signed-off-by: Philip Herron <[email protected]>
---
gcc/rust/backend/rust-compile-base.cc | 3 ++-
gcc/testsuite/rust/compile/issue-3978.rs | 8 ++++++++
2 files changed, 10 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/rust/compile/issue-3978.rs
diff --git a/gcc/rust/backend/rust-compile-base.cc
b/gcc/rust/backend/rust-compile-base.cc
index b2913ad3c38..8994520f16d 100644
--- a/gcc/rust/backend/rust-compile-base.cc
+++ b/gcc/rust/backend/rust-compile-base.cc
@@ -697,7 +697,8 @@ HIRCompileBase::compile_function (
= canonical_path.get () + fntype->subst_as_string ();
// we don't mangle the main fn since we haven't implemented the main shim
- bool is_main_fn = fn_name.compare ("main") == 0 && is_root_item;
+ bool is_main_fn = fn_name.compare ("main") == 0 && is_root_item
+ && canonical_path.size () <= 2;
if (is_main_fn)
{
rust_assert (!main_identifier_node);
diff --git a/gcc/testsuite/rust/compile/issue-3978.rs
b/gcc/testsuite/rust/compile/issue-3978.rs
new file mode 100644
index 00000000000..4f17d3d4d04
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-3978.rs
@@ -0,0 +1,8 @@
+type Dimension = usize;
+
+pub fn main() {}
+
+mod m2 {
+ fn main() {}
+ // { dg-warning "function is never used" "" { target *-*-* } .-1 }
+}
--
2.49.0
