gccrs: Implement compilation support for TuplePatternItems::RANGED

Example GIMPLE output of the match statement for match-restpattern-tuple-1.rs:

...
RUSTTMP.2 = x;
_1 = RUSTTMP.2.__0;
_2 = _1 == 1;
_3 = RUSTTMP.2.__3;
_4 = _3 == 4;
_5 = _2 & _4;
if (_5 != 0) goto <D.109>; else goto <D.110>;
<D.109>:
{
    {

    }
    goto <D.104>;
}
<D.110>:
if (1 != 0) goto <D.111>; else goto <D.112>;
<D.111>:
{
    {

    }
    goto <D.104>;
}
<D.112>:
<D.104>:
...

gcc/rust/ChangeLog:

	* backend/rust-compile-pattern.cc (CompilePatternCheckExpr::visit(TuplePattern)):
		Implement check expression compilation for TuplePatternItems::RANGED.

Signed-off-by: Yap Zhi Heng <yapzhhg@gmail.com>

3 files changed, 43 insertions, 0 deletions

diff --git a/gcc/testsuite/rust/compile/match-restpattern-tuple-1.rs b/gcc/testsuite/rust/compile/match-restpattern-tuple-1.rs
new file mode 100644
index 0000000..5cce3c4
--- /dev/null
+++ b/gcc/testsuite/rust/compile/match-restpattern-tuple-1.rs
@@ -0,0 +1,8 @@
+fn main() {
+    let x = (1, 2, 3, 4);
+
+    match x {
+        (1, .., 4) => {},
+        _ => {}
+    }
+}
\ No newline at end of file
diff --git a/gcc/testsuite/rust/compile/match-restpattern-tuple-2.rs b/gcc/testsuite/rust/compile/match-restpattern-tuple-2.rs
new file mode 100644
index 0000000..40900a3
--- /dev/null
+++ b/gcc/testsuite/rust/compile/match-restpattern-tuple-2.rs
@@ -0,0 +1,8 @@
+fn main() {
+    let x = (1, 2, 3, 4);
+
+    match x {
+        (1, .., 2, 3, 4, 5) => {}, // { dg-error "expected a tuple with 4 elements, found one with 5 elements" }
+        _ => {}
+    }
+}
\ No newline at end of file
diff --git a/gcc/testsuite/rust/execute/torture/match-restpattern-tuple.rs b/gcc/testsuite/rust/execute/torture/match-restpattern-tuple.rs
new file mode 100644
index 0000000..2c1418c
--- /dev/null
+++ b/gcc/testsuite/rust/execute/torture/match-restpattern-tuple.rs
@@ -0,0 +1,27 @@
+// { dg-output "correct\r*" }
+extern "C" {
+    fn puts(s: *const i8);
+}
+
+fn main() -> i32 {
+    let x = (1, 2, 3, 4);
+    let mut ret = 1;
+
+    match x {
+        (1, .., 2, 4) => {
+            /* should not take this path */
+            unsafe { puts("wrong\0" as *const str as *const i8) }
+        },
+        (2, ..) => {
+            /* should not take this path */
+            unsafe { puts("wrong\0" as *const str as *const i8) }
+        },
+        (b, .., 4) => { 
+            ret -= b;
+            unsafe { puts("correct\0" as *const str as *const i8) }
+        },
+        _ => {}
+    }
+
+    ret
+}
\ No newline at end of file