gccrs: Add AltPattern HIR node

Example:
	match x {
	    0 | 1 => true,
	    _ => false
	}

gcc/rust/ChangeLog:

	* backend/rust-compile-fnparam.h:
	(CompileFnParam::visit): Add AltPattern visitor.
	* backend/rust-compile-pattern.h:
	(CompilePatternCaseLabelExpr::visit): Add AltPattern visitor.
	(CompilePatternBindings::visit): Add AltPattern visitor.
	(CompilePatternLet::visit): Add AltPattern visitor.
	* backend/rust-compile-resolve-path.h:
	(ResolvePathRef::visit): Add AltPattern visitor.
	* backend/rust-compile-var-decl.h:
	(CompileVarDecl::visit): Add AltPattern visitor.
	* checks/errors/rust-const-checker.cc
	(ConstChecker::visit): Add AltPattern visitor.
	* checks/errors/rust-const-checker.h:
	(ConstChecker::visit): Add AltPattern visitor.
	* checks/errors/rust-unsafe-checker.cc
	(UnsafeChecker::visit): Add AltPattern visitor.
	* checks/errors/rust-unsafe-checker.h:
	(UnsafeChecker::visit): Add AltPattern visitor.
	* hir/rust-hir-dump.cc
	(Dump::visit): Add AltPattern visitor.
	* hir/rust-hir-dump.h:
	(Dump::visit): Add AltPattern visitor.
	* hir/tree/rust-hir-full-decls.h
	(class AltPattern): Add forward declaration.
	* hir/tree/rust-hir-pattern.h
	(class AltPattern): New class.
	* hir/tree/rust-hir-visitor.h:
	(HIRFullVisitor::visit): Add AltPattern visitor.
	(HIRFullVisitorBase::visit): Add AltPattern visitor.
	(HIRPatternVisitor::visit): Add AltPattern visitor.
	* hir/tree/rust-hir.h:
	(Pattern::PatternType::ALT): New enumerator.
	* typecheck/rust-hir-type-check-pattern.cc
	(TypeCheckPattern::visit): Add AltPattern visitor.
	* typecheck/rust-hir-type-check-pattern.h:
	(TypeCheckPattern::visit): Add AltPattern visitor.

Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/gcc/rust/hir/tree/rust-hir-pattern.h b/gcc/rust/hir/tree/rust-hir-pattern.h
index 934a39a..5826c8b 100644
--- a/gcc/rust/hir/tree/rust-hir-pattern.h
+++ b/gcc/rust/hir/tree/rust-hir-pattern.h
@@ -1300,6 +1300,73 @@ protected:
   }
 };
 
+// HIR node for alternative patterns
+class AltPattern : public Pattern
+{
+  std::vector<std::unique_ptr<Pattern>> alts;
+  Location locus;
+  Analysis::NodeMapping mappings;
+
+public:
+public:
+  std::string as_string () const override;
+
+  AltPattern (Analysis::NodeMapping mappings,
+	      std::vector<std::unique_ptr<Pattern>> alts, Location locus)
+    : alts (std::move (alts)), locus (locus), mappings (mappings)
+  {}
+
+  // Copy constructor with vector clone
+  AltPattern (AltPattern const &other)
+    : locus (other.locus), mappings (other.mappings)
+  {
+    alts.reserve (other.alts.size ());
+    for (const auto &e : other.alts)
+      alts.push_back (e->clone_pattern ());
+  }
+
+  // Overloaded assignment operator to vector clone
+  AltPattern &operator= (AltPattern const &other)
+  {
+    locus = other.locus;
+    mappings = other.mappings;
+
+    alts.clear ();
+    alts.reserve (other.alts.size ());
+    for (const auto &e : other.alts)
+      alts.push_back (e->clone_pattern ());
+
+    return *this;
+  }
+
+  // move constructors
+  AltPattern (AltPattern &&other) = default;
+  AltPattern &operator= (AltPattern &&other) = default;
+
+  Location get_locus () const override { return locus; }
+
+  void accept_vis (HIRFullVisitor &vis) override;
+  void accept_vis (HIRPatternVisitor &vis) override;
+
+  Analysis::NodeMapping get_pattern_mappings () const override final
+  {
+    return mappings;
+  }
+
+  PatternType get_pattern_type () const override final
+  {
+    return PatternType::ALT;
+  }
+
+protected:
+  /* Use covariance to implement clone function as returning this object rather
+   * than base */
+  AltPattern *clone_pattern_impl () const override
+  {
+    return new AltPattern (*this);
+  }
+};
+
 // Moved definition to rust-path.h
 class PathPattern;