Added column!() macro

Addresses issue #979
1) Added the column!() macro using the LOCATION_COLUMN() from gcc_linemap
2) Added relevent test cases

Signed-off-by : M V V S Manoj Kumar <mvvsmanojkumar@gmail.com>

gcc/rust/expand/rust-macro-builtins.cc

@@ -49,4 +49,18 @@ MacroBuiltin::file (Location invoc_locus, AST::MacroInvocData &invoc)
 
   return AST::ASTFragment ({file_str});
 }
+AST::ASTFragment
+MacroBuiltin::column (Location invoc_locus, AST::MacroInvocData &invoc)
+{
+  auto current_column
+    = Session::get_instance ().linemap->location_to_column (invoc_locus);
+  // auto column_no
+  //   = AST::SingleASTNode (make_string (invoc_locus, current_column));
+
+  auto column_no = AST::SingleASTNode (std::unique_ptr<AST::Expr> (
+    new AST::LiteralExpr (std::to_string (current_column), AST::Literal::INT,
+			  PrimitiveCoreType::CORETYPE_U32, {}, invoc_locus)));
+
+  return AST::ASTFragment ({column_no});
+}
 } // namespace Rust

gcc/rust/expand/rust-macro-builtins.h

@@ -31,6 +31,9 @@ public:
 
   static AST::ASTFragment file (Location invoc_locus,
 				AST::MacroInvocData &invoc);
+
+  static AST::ASTFragment column (Location invoc_locus,
+				  AST::MacroInvocData &invoc);
 };
 } // namespace Rust
 

gcc/rust/rust-linemap.cc

@@ -42,6 +42,8 @@ public:
 
   int location_line (Location);
 
+  int location_column (Location);
+
 protected:
   Location get_predeclared_location ();
 
@@ -111,6 +113,13 @@ Gcc_linemap::location_line (Location loc)
   return LOCATION_LINE (loc.gcc_location ());
 }
 
+// Return the column number for a given location.
+int
+Gcc_linemap::location_column (Location loc)
+{
+  return LOCATION_COLUMN (loc.gcc_location ());
+}
+
 // Stop getting locations.
 
 void

gcc/rust/rust-linemap.h

@@ -72,6 +72,9 @@ public:
   // Return the line number for a given location.
   virtual int location_line (Location) = 0;
 
+  // Return the column number for a given location.
+  virtual int location_column (Location) = 0;
+
 protected:
   // Return a special Location used for predeclared identifiers.  This
   // Location should be different from that for any actual source
@@ -149,6 +152,12 @@ public:
     rust_assert (Linemap::instance_ != NULL);
     return Linemap::instance_->location_line (loc);
   }
+
+  static int location_to_column (Location loc)
+  {
+    rust_assert (Linemap::instance_ != NULL);
+    return Linemap::instance_->location_column (loc);
+  }
 };
 
 #endif // !defined(RUST_LINEMAP_H)

gcc/rust/util/rust-hir-map.cc

@@ -750,6 +750,7 @@ Mappings::insert_macro_def (AST::MacroRulesDefinition *macro)
     builtin_macros = {
       {"assert", MacroBuiltin::assert},
       {"file", MacroBuiltin::file},
+      {"column", MacroBuiltin::column},
     };
 
   auto builtin = builtin_macros.find (macro->get_rule_name ());

gcc/testsuite/rust/execute/torture/builtin_macros3.rs

@@ -0,0 +1,24 @@
+// { dg-output "14\n42\n" }
+macro_rules! column {
+    () => {{}};
+}
+
+extern "C" {
+    fn printf(fmt: *const i8, ...);
+}
+
+fn print(s: u32) {
+    printf("%u\n\0" as *const str as *const i8, s);
+}
+
+fn main() -> i32 {
+    let c0 = column!();
+
+    print(c0);
+
+    let c1 =                             column!();
+
+    print(c1);
+
+    0
+}