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* [gcc/devel/rust/master] macros: Error out when repeating metavars which refer to repetitions
@ 2022-06-08 12:44 Thomas Schwinge
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From: Thomas Schwinge @ 2022-06-08 12:44 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:16da547c6de0957d4dd697c53260a6bb9a087163
commit 16da547c6de0957d4dd697c53260a6bb9a087163
Author: CohenArthur <arthur.cohen@epita.fr>
Date: Sat May 7 18:45:21 2022 +0200
macros: Error out when repeating metavars which refer to repetitions
In the case were a repeting metavar was used as a regular metavar ($var
instead of $($var)* for example), the compiler would crash on an
assertion that $var was only repeating once. We should instead error out
and point to the user that this is probably not what they intended to
do.
Diff:
---
gcc/rust/expand/rust-macro-substitute-ctx.cc | 15 +++++++++++++++
gcc/testsuite/rust/compile/macro-issue1224.rs | 9 +++++++++
2 files changed, 24 insertions(+)
diff --git a/gcc/rust/expand/rust-macro-substitute-ctx.cc b/gcc/rust/expand/rust-macro-substitute-ctx.cc
index a6933bb6aab..b7ab3abc0d9 100644
--- a/gcc/rust/expand/rust-macro-substitute-ctx.cc
+++ b/gcc/rust/expand/rust-macro-substitute-ctx.cc
@@ -16,6 +16,21 @@ SubstituteCtx::substitute_metavar (std::unique_ptr<AST::Token> &metavar)
}
else
{
+ // If we are expanding a metavar which has a lof of matches, we are
+ // currently expanding a repetition metavar - not a simple metavar. We
+ // need to error out and inform the user.
+ // Associated test case for an example: compile/macro-issue1224.rs
+ if (it->second.get_match_amount () != 1)
+ {
+ rust_error_at (metavar->get_locus (),
+ "metavariable is still repeating at this depth");
+ rust_inform (
+ metavar->get_locus (),
+ "you probably forgot the repetition operator: %<%s%s%s%>", "$(",
+ metavar->as_string ().c_str (), ")*");
+ return expanded;
+ }
+
// We only care about the vector when expanding repetitions.
// Just access the first element of the vector.
auto &frag = it->second.get_single_fragment ();
diff --git a/gcc/testsuite/rust/compile/macro-issue1224.rs b/gcc/testsuite/rust/compile/macro-issue1224.rs
new file mode 100644
index 00000000000..003bbcd5067
--- /dev/null
+++ b/gcc/testsuite/rust/compile/macro-issue1224.rs
@@ -0,0 +1,9 @@
+macro_rules! impl_uint {
+ ($($ty:ident),*) => {
+ impl $ty {} // { dg-error "metavariable is still repeating at this depth" }
+ // { dg-error "unrecognised token" "" { target *-*-* } .-1 } // Spurious
+ // { dg-error "could not parse type" "" { target *-*-* } .-2 } // Spurious
+ };
+}
+
+impl_uint!(u8, u16, u32, u64, u128);
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