[gcc/devel/rust/master] backend: Compile range patterns

[gcc/devel/rust/master] backend: Compile range patterns

[Thomas Schwinge]

https://gcc.gnu.org/g:b1eb3e036c6fb5acc28c714375e6309fb5aa9ec8

commit b1eb3e036c6fb5acc28c714375e6309fb5aa9ec8
Author: David Faust <david.faust@oracle.com>
Date:   Thu May 12 15:48:18 2022 -0700

    backend: Compile range patterns

Diff:
---
 gcc/rust/backend/rust-compile-pattern.cc           | 58 ++++++++++++++++++++++
 gcc/rust/backend/rust-compile-pattern.h            |  2 +-
 gcc/testsuite/rust/execute/torture/match_range1.rs | 34 +++++++++++++
 gcc/testsuite/rust/execute/torture/match_range2.rs | 40 +++++++++++++++
 4 files changed, 133 insertions(+), 1 deletion(-)

diff --git a/gcc/rust/backend/rust-compile-pattern.cc b/gcc/rust/backend/rust-compile-pattern.cc
index 9c1a35a5b91..aefa4eb08bb 100644
--- a/gcc/rust/backend/rust-compile-pattern.cc
+++ b/gcc/rust/backend/rust-compile-pattern.cc
@@ -105,6 +105,64 @@ CompilePatternCaseLabelExpr::visit (HIR::LiteralPattern &pattern)
   case_label_expr = build_case_label (lit, NULL_TREE, associated_case_label);
 }
 
+static tree
+compile_range_pattern_bound (HIR::RangePatternBound *bound,
+			     Analysis::NodeMapping mappings, Location locus,
+			     Context *ctx)
+{
+  tree result = NULL_TREE;
+  switch (bound->get_bound_type ())
+    {
+      case HIR::RangePatternBound::RangePatternBoundType::LITERAL: {
+	HIR::RangePatternBoundLiteral &ref
+	  = *static_cast<HIR::RangePatternBoundLiteral *> (bound);
+
+	HIR::LiteralExpr *litexpr
+	  = new HIR::LiteralExpr (mappings, ref.get_literal (), locus,
+				  std::vector<AST::Attribute> ());
+
+	result = CompileExpr::Compile (litexpr, ctx);
+      }
+      break;
+
+      case HIR::RangePatternBound::RangePatternBoundType::PATH: {
+	HIR::RangePatternBoundPath &ref
+	  = *static_cast<HIR::RangePatternBoundPath *> (bound);
+
+	result = ResolvePathRef::Compile (ref.get_path (), ctx);
+
+	// If the path resolves to a const expression, fold it.
+	result = ConstCtx::fold (result);
+      }
+      break;
+
+      case HIR::RangePatternBound::RangePatternBoundType::QUALPATH: {
+	HIR::RangePatternBoundQualPath &ref
+	  = *static_cast<HIR::RangePatternBoundQualPath *> (bound);
+
+	result = ResolvePathRef::Compile (ref.get_qualified_path (), ctx);
+
+	// If the path resolves to a const expression, fold it.
+	result = ConstCtx::fold (result);
+      }
+    }
+
+  return result;
+}
+
+void
+CompilePatternCaseLabelExpr::visit (HIR::RangePattern &pattern)
+{
+  tree upper = compile_range_pattern_bound (pattern.get_upper_bound ().get (),
+					    pattern.get_pattern_mappings (),
+					    pattern.get_locus (), ctx);
+  tree lower = compile_range_pattern_bound (pattern.get_lower_bound ().get (),
+					    pattern.get_pattern_mappings (),
+					    pattern.get_locus (), ctx);
+
+  case_label_expr = build_case_label (lower, upper, associated_case_label);
+}
+
 // setup the bindings
 
 void
diff --git a/gcc/rust/backend/rust-compile-pattern.h b/gcc/rust/backend/rust-compile-pattern.h
index 1b6e80fb88d..0eb5d61249b 100644
--- a/gcc/rust/backend/rust-compile-pattern.h
+++ b/gcc/rust/backend/rust-compile-pattern.h
@@ -37,13 +37,13 @@ public:
   void visit (HIR::StructPattern &pattern) override;
   void visit (HIR::TupleStructPattern &pattern) override;
   void visit (HIR::WildcardPattern &pattern) override;
+  void visit (HIR::RangePattern &pattern) override;
 
   // Empty visit for unused Pattern HIR nodes.
   void visit (HIR::GroupedPattern &) override {}
   void visit (HIR::IdentifierPattern &) override {}
   void visit (HIR::LiteralPattern &) override;
   void visit (HIR::QualifiedPathInExpression &) override {}
-  void visit (HIR::RangePattern &) override {}
   void visit (HIR::ReferencePattern &) override {}
   void visit (HIR::SlicePattern &) override {}
   void visit (HIR::TuplePattern &) override {}
diff --git a/gcc/testsuite/rust/execute/torture/match_range1.rs b/gcc/testsuite/rust/execute/torture/match_range1.rs
new file mode 100644
index 00000000000..8fe8f4c766f
--- /dev/null
+++ b/gcc/testsuite/rust/execute/torture/match_range1.rs
@@ -0,0 +1,34 @@
+// { dg-output "zero to END_RANGE\nzero to END_RANGE\nelse\n" }
+
+extern "C" {
+    fn printf(s: *const i8, ...);
+}
+
+const END_RANGE: i32 = 15;
+
+fn foo (x: i32) {
+    match x {
+        0..=END_RANGE => {
+            let a = "zero to END_RANGE\n\0";
+            let b = a as *const str;
+            let c = b as *const i8;
+            printf (c);
+        }
+
+        _ => {
+            let a = "else\n\0";
+            let b = a as *const str;
+            let c = b as *const i8;
+            printf (c);
+        }
+    }
+}
+
+fn main () -> i32 {
+
+    foo (11);
+    foo (15);
+    foo (21);
+
+    0
+}
diff --git a/gcc/testsuite/rust/execute/torture/match_range2.rs b/gcc/testsuite/rust/execute/torture/match_range2.rs
new file mode 100644
index 00000000000..82980c2f0c5
--- /dev/null
+++ b/gcc/testsuite/rust/execute/torture/match_range2.rs
@@ -0,0 +1,40 @@
+// { dg-output "lowercase\nuppercase\nother\n" }
+
+extern "C" {
+    fn printf(s: *const i8, ...);
+}
+
+const BIG_A: char = 'A';
+const BIG_Z: char = 'Z';
+
+fn bar (x: char) {
+    match x {
+
+        'a'..='z' => {
+            let a = "lowercase\n\0";
+            let b = a as *const str;
+            let c = b as *const i8;
+            printf (c);
+        }
+        BIG_A..=BIG_Z => {
+            let a = "uppercase\n\0";
+            let b = a as *const str;
+            let c = b as *const i8;
+            printf (c);
+        }
+        _ => {
+            let a = "other\n\0";
+            let b = a as *const str;
+            let c = b as *const i8;
+            printf (c);
+        }
+    }
+}
+
+fn main () -> i32 {
+    bar ('b');
+    bar ('X');
+    bar ('!');
+
+    0
+}