From: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>
Date: Wed, 30 Jul 2025 11:11:52 +0000 (+0200)
Subject: gccrs: Fix infinite loop with missing comma
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=697025acf8bedcc59a2e34035ddb6f17a69b8c52;p=thirdparty%2Fgcc.git

gccrs: Fix infinite loop with missing comma

A missing comma between inline assembly templates did not throw an error
and looped indefinitely.

gcc/rust/ChangeLog:

	* expand/rust-macro-builtins-asm.cc (parse_format_strings): Emit an
	error when expecting a comma.

gcc/testsuite/ChangeLog:

	* rust/compile/issue-4006.rs: New test.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>
---

diff --git a/gcc/rust/expand/rust-macro-builtins-asm.cc b/gcc/rust/expand/rust-macro-builtins-asm.cc
index 9dc234cf850..61222dbeacb 100644
--- a/gcc/rust/expand/rust-macro-builtins-asm.cc
+++ b/gcc/rust/expand/rust-macro-builtins-asm.cc
@@ -937,7 +937,9 @@ parse_format_strings (InlineAsmContext inline_asm_ctx)
     {
       if (!parser.skip_token (COMMA))
 	{
-	  break;
+	  rust_error_at (parser.peek_current_token ()->get_locus (),
+			 "expected token %qs", ";");
+	  return tl::unexpected<InlineAsmParseError> (COMMITTED);
 	}
       // Ok after the comma is good, we better be parsing correctly
       // everything in here, which is formatted string in ABNF
diff --git a/gcc/testsuite/rust/compile/issue-4006.rs b/gcc/testsuite/rust/compile/issue-4006.rs
new file mode 100644
index 00000000000..328c7b65121
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-4006.rs
@@ -0,0 +1,13 @@
+#![feature(rustc_attrs)]
+
+#[rustc_builtin_macro]
+macro_rules! asm {
+    () => {};
+}
+
+pub fn main() {
+    asm!(
+        "xor eax, eax"
+        "xor eax, eax");
+    // { dg-error "expected token .;." "" { target *-*-* } .-1 }
+}