gccrs: Fix RangePattern negative literal bounds being treated as positive.

This commit removes the need for a tracking `has_minus` boolean in `RangePattern`
for both AST and HIR, and just parses the negatable literals as negative values.

gcc/rust/ChangeLog:

	* parse/rust-parse-impl.h:
		* parse_literal_or_range_pattern: Parse literal range bounds as negative values,
			instead of positive values with `has_minus` bool.
		* parse_range_pattern_bound: Ditto.
	* ast/rust-pattern.h (RangePatternBoundLiteral): Remove `has_minus` boolean.
	* hir/tree/rust-hir-pattern.h (RangePatternBoundLiteral): Ditto.
	* ast/rust-ast-collector.cc (visit(RestPattern)): Ditto.
	* ast/rust-pattern.cc (RangePatternBoundLiteral::as_string): Ditto.
	* hir/rust-ast-lower-base.cc (lower_range_pattern_bound): Ditto.
	* hir/rust-hir-dump.cc(visit(RangePatternBoundLiteral)): Ditto.
	* hir/tree/rust-hir.cc(RangePatternBoundLiteral::as_string): Ditto.

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

Author: Polygonalr

gcc/rust/ast/rust-ast-collector.cc

@@ -2509,10 +2509,6 @@ TokenCollector::visit (RestPattern &pattern)
 void
 TokenCollector::visit (RangePatternBoundLiteral &pattern)
 {
-  if (pattern.get_has_minus ())
-    {
-      push (Rust::Token::make (MINUS, pattern.get_locus ()));
-    }
   auto literal = pattern.get_literal ();
   visit (literal);
 }

gcc/rust/ast/rust-pattern.cc

@@ -76,9 +76,6 @@ RangePatternBoundLiteral::as_string () const
 {
   std::string str;
 
-  if (has_minus)
-    str += "-";
-
   str += literal.as_string ();
 
   return str;

gcc/rust/ast/rust-pattern.h

@@ -266,24 +266,18 @@ class RangePatternBoundLiteral : public RangePatternBound
   /* Can only be a char, byte, int, or float literal - same impl here as
    * previously */
 
-  // Minus prefixed to literal (if integer or floating-point)
-  bool has_minus;
-
   location_t locus;
 
 public:
   // Constructor
-  RangePatternBoundLiteral (Literal literal, location_t locus,
-			    bool has_minus = false)
-    : literal (literal), has_minus (has_minus), locus (locus)
+  RangePatternBoundLiteral (Literal literal, location_t locus)
+    : literal (literal), locus (locus)
   {}
 
   std::string as_string () const override;
 
   Literal get_literal () const { return literal; }
 
-  bool get_has_minus () const { return has_minus; }
-
   location_t get_locus () const { return locus; }
 
   void accept_vis (ASTVisitor &vis) override;

gcc/rust/hir/rust-ast-lower-base.cc

@@ -952,8 +952,7 @@ ASTLoweringBase::lower_range_pattern_bound (AST::RangePatternBound &bound)
 	HIR::Literal literal = lower_literal (ref.get_literal ());
 
 	hir_bound = std::unique_ptr<HIR::RangePatternBound> (
-	  new HIR::RangePatternBoundLiteral (literal, ref.get_locus (),
-					     ref.get_has_minus ()));
+	  new HIR::RangePatternBoundLiteral (literal, ref.get_locus ()));
       }
       break;
     case AST::RangePatternBound::RangePatternBoundType::PATH:

gcc/rust/hir/rust-hir-dump.cc

@@ -2217,7 +2217,6 @@ Dump::visit (RangePatternBoundLiteral &e)
 {
   begin ("RangePatternBoundLiteral");
   put_field ("literal", e.get_literal ().as_string ());
-  put_field ("has_minus", std::to_string (e.get_has_minus ()));
   end ("RangePatternBoundLiteral");
 }
 

gcc/rust/hir/tree/rust-hir-pattern.h

@@ -234,24 +234,19 @@ class RangePatternBoundLiteral : public RangePatternBound
   /* Can only be a char, byte, int, or float literal - same impl here as
    * previously */
 
-  // Minus prefixed to literal (if integer or floating-point)
-  bool has_minus;
-
   location_t locus;
 
 public:
   // Constructor
-  RangePatternBoundLiteral (Literal literal, location_t locus,
-			    bool has_minus = false)
-    : literal (literal), has_minus (has_minus), locus (locus)
+  RangePatternBoundLiteral (Literal literal, location_t locus)
+    : literal (literal), locus (locus)
   {}
 
   std::string as_string () const override;
 
   location_t get_locus () const { return locus; }
 
   Literal get_literal () const { return literal; }
-  bool get_has_minus () const { return has_minus; }
 
   void accept_vis (HIRFullVisitor &vis) override;
 

gcc/rust/hir/tree/rust-hir.cc

@@ -2375,11 +2375,6 @@ RangePatternBoundLiteral::as_string () const
 {
   std::string str;
 
-  if (has_minus)
-    {
-      str += "-";
-    }
-
   str += literal.as_string ();
 
   return str;

gcc/rust/parse/rust-parse-impl.h

@@ -10318,11 +10318,16 @@ Parser<ManagedTokenSource>::parse_literal_or_range_pattern ()
       AST::RangeKind kind = AST::tokenid_to_rangekind (next->get_id ());
       // range pattern
       lexer.skip_token ();
+      std::string range_lower_str;
+      if (has_minus)
+	range_lower_str = "-" + range_lower->get_str ();
+      else
+	range_lower_str = range_lower->get_str ();
       std::unique_ptr<AST::RangePatternBound> lower (
 	new AST::RangePatternBoundLiteral (
-	  AST::Literal (range_lower->get_str (), type,
+	  AST::Literal (range_lower_str, type,
 			PrimitiveCoreType::CORETYPE_UNKNOWN),
-	  range_lower->get_locus (), has_minus));
+	  range_lower->get_locus ()));
 
       std::unique_ptr<AST::RangePatternBound> upper
 	= parse_range_pattern_bound ();
@@ -10398,17 +10403,17 @@ Parser<ManagedTokenSource>::parse_range_pattern_bound ()
 	  lexer.skip_token (1);
 	  return std::unique_ptr<AST::RangePatternBoundLiteral> (
 	    new AST::RangePatternBoundLiteral (
-	      AST::Literal (range_lower->get_str (), AST::Literal::INT,
+	      AST::Literal ("-" + range_lower->get_str (), AST::Literal::INT,
 			    range_lower->get_type_hint ()),
-	      range_lower_locus, true));
+	      range_lower_locus));
 	case FLOAT_LITERAL:
 	  lexer.skip_token (1);
 	  rust_debug ("warning: used deprecated float range pattern bound");
 	  return std::unique_ptr<AST::RangePatternBoundLiteral> (
 	    new AST::RangePatternBoundLiteral (
-	      AST::Literal (range_lower->get_str (), AST::Literal::FLOAT,
+	      AST::Literal ("-" + range_lower->get_str (), AST::Literal::FLOAT,
 			    range_lower->get_type_hint ()),
-	      range_lower_locus, true));
+	      range_lower_locus));
 	default:
 	  add_error (Error (range_lower->get_locus (),
 			    "token type %qs cannot be parsed as range pattern "

gcc/testsuite/rust/compile/issue-4242.rs

@@ -0,0 +1,10 @@
+#![feature(exclusive_range_pattern)]
+
+fn main() {
+    let x = 1;
+
+    match x {
+        -55..0 => 2,
+        -99..-55 => 3,
+    };
+}

gcc/testsuite/rust/execute/torture/issue-4242.rs

@@ -0,0 +1,11 @@
+#![feature(exclusive_range_pattern)]
+
+fn main() -> i32 {
+    let x = -77;
+
+    match x {
+        -55..99 => 1,
+        -99..-55 => 0, // the correct case
+        _ => 1,
+    }
+}