1 files changed, 173 insertions, 0 deletions
diff --git a/gcc/rust/expand/rust-macro-builtins.cc b/gcc/rust/expand/rust-macro-builtins.cc
index c33a2e8..14f60d2 100644
--- a/gcc/rust/expand/rust-macro-builtins.cc
+++ b/gcc/rust/expand/rust-macro-builtins.cc
@@ -20,6 +20,9 @@
 #include "rust-diagnostics.h"
 #include "rust-expr.h"
 #include "rust-session-manager.h"
+#include "rust-macro-invoc-lexer.h"
+#include "rust-lex.h"
+#include "rust-parse.h"
 
 namespace Rust {
 namespace {
@@ -30,6 +33,107 @@ make_string (Location locus, std::string value)
     new AST::LiteralExpr (value, AST::Literal::STRING,
 			  PrimitiveCoreType::CORETYPE_STR, {}, locus));
 }
+
+/* Parse a single string literal from the given delimited token tree,
+   and return the LiteralExpr for it. Allow for an optional trailing comma,
+   but otherwise enforce that these are the only tokens.  */
+
+std::unique_ptr<AST::LiteralExpr>
+parse_single_string_literal (AST::DelimTokenTree &invoc_token_tree,
+			     Location invoc_locus)
+{
+  MacroInvocLexer lex (invoc_token_tree.to_token_stream ());
+  Parser<MacroInvocLexer> parser (std::move (lex));
+
+  auto last_token_id = TokenId::RIGHT_CURLY;
+  switch (invoc_token_tree.get_delim_type ())
+    {
+    case AST::DelimType::PARENS:
+      last_token_id = TokenId::RIGHT_PAREN;
+      rust_assert (parser.skip_token (LEFT_PAREN));
+      break;
+
+    case AST::DelimType::CURLY:
+      rust_assert (parser.skip_token (LEFT_CURLY));
+      break;
+
+    case AST::DelimType::SQUARE:
+      last_token_id = TokenId::RIGHT_SQUARE;
+      rust_assert (parser.skip_token (LEFT_SQUARE));
+      break;
+    }
+
+  std::unique_ptr<AST::LiteralExpr> lit_expr = nullptr;
+
+  if (parser.peek_current_token ()->get_id () == STRING_LITERAL)
+    {
+      lit_expr = parser.parse_literal_expr ();
+      parser.maybe_skip_token (COMMA);
+      if (parser.peek_current_token ()->get_id () != last_token_id)
+	{
+	  lit_expr = nullptr;
+	  rust_error_at (invoc_locus, "macro takes 1 argument");
+	}
+    }
+  else if (parser.peek_current_token ()->get_id () == last_token_id)
+    rust_error_at (invoc_locus, "macro takes 1 argument");
+  else
+    rust_error_at (invoc_locus, "argument must be a string literal");
+
+  parser.skip_token (last_token_id);
+
+  return lit_expr;
+}
+
+/* Treat PATH as a path relative to the source file currently being
+   compiled, and return the absolute path for it.  */
+
+std::string
+source_relative_path (std::string path, Location locus)
+{
+  std::string compile_fname
+    = Session::get_instance ().linemap->location_file (locus);
+
+  auto dir_separator_pos = compile_fname.rfind (file_separator);
+
+  /* If there is no file_separator in the path, use current dir ('.').  */
+  std::string dirname;
+  if (dir_separator_pos == std::string::npos)
+    dirname = std::string (".") + file_separator;
+  else
+    dirname = compile_fname.substr (0, dir_separator_pos) + file_separator;
+
+  return dirname + path;
+}
+
+/* Read the full contents of the file FILENAME and return them in a vector.
+   FIXME: platform specific.  */
+
+std::vector<uint8_t>
+load_file_bytes (const char *filename)
+{
+  RAIIFile file_wrap (filename);
+  if (file_wrap.get_raw () == nullptr)
+    {
+      rust_error_at (Location (), "cannot open filename %s: %m", filename);
+      return std::vector<uint8_t> ();
+    }
+
+  FILE *f = file_wrap.get_raw ();
+  fseek (f, 0L, SEEK_END);
+  long fsize = ftell (f);
+  fseek (f, 0L, SEEK_SET);
+
+  std::vector<uint8_t> buf (fsize);
+
+  if (fread (&buf[0], fsize, 1, f) != 1)
+    {
+      rust_error_at (Location (), "error reading file %s: %m", filename);
+      return std::vector<uint8_t> ();
+    }
+
+  return buf;
+}
 } // namespace
 
 AST::ASTFragment
@@ -63,4 +167,73 @@ MacroBuiltin::column (Location invoc_locus, AST::MacroInvocData &invoc)
 
   return AST::ASTFragment ({column_no});
 }
+
+/* Expand builtin macro include_bytes!("filename"), which includes the contents
+   of the given file as reference to a byte array. Yields an expression of type
+   &'static [u8; N].  */
+
+AST::ASTFragment
+MacroBuiltin::include_bytes (Location invoc_locus, AST::MacroInvocData &invoc)
+{
+  /* Get target filename from the macro invocation, which is treated as a path
+     relative to the include!-ing file (currently being compiled).  */
+  auto lit_expr
+    = parse_single_string_literal (invoc.get_delim_tok_tree (), invoc_locus);
+  if (lit_expr == nullptr)
+    return AST::ASTFragment::create_error ();
+
+  std::string target_filename
+    = source_relative_path (lit_expr->as_string (), invoc_locus);
+
+  std::vector<uint8_t> bytes = load_file_bytes (target_filename.c_str ());
+
+  /* Is there a more efficient way to do this?  */
+  std::vector<std::unique_ptr<AST::Expr>> elts;
+  for (uint8_t b : bytes)
+    {
+      elts.emplace_back (
+	new AST::LiteralExpr (std::string (1, (char) b), AST::Literal::BYTE,
+			      PrimitiveCoreType::CORETYPE_U8,
+			      {} /* outer_attrs */, invoc_locus));
+    }
+
+  auto elems = std::unique_ptr<AST::ArrayElems> (
+    new AST::ArrayElemsValues (std::move (elts), invoc_locus));
+
+  auto array = std::unique_ptr<AST::Expr> (
+    new AST::ArrayExpr (std::move (elems), {}, {}, invoc_locus));
+
+  auto borrow = std::unique_ptr<AST::Expr> (
+    new AST::BorrowExpr (std::move (array), false, false, {}, invoc_locus));
+
+  auto node = AST::SingleASTNode (std::move (borrow));
+  return AST::ASTFragment ({node});
+}
+
+/* Expand builtin macro include_str!("filename"), which includes the contents
+   of the given file as a string. The file must be UTF-8 encoded. Yields an
+   expression of type &'static str.  */
+
+AST::ASTFragment
+MacroBuiltin::include_str (Location invoc_locus, AST::MacroInvocData &invoc)
+{
+  /* Get target filename from the macro invocation, which is treated as a path
+     relative to the include!-ing file (currently being compiled).  */
+  auto lit_expr
+    = parse_single_string_literal (invoc.get_delim_tok_tree (), invoc_locus);
+  if (lit_expr == nullptr)
+    return AST::ASTFragment::create_error ();
+
+  std::string target_filename
+    = source_relative_path (lit_expr->as_string (), invoc_locus);
+
+  std::vector<uint8_t> bytes = load_file_bytes (target_filename.c_str ());
+
+  /* FIXME: Enforce that the file contents are valid UTF-8.  */
+  std::string str ((const char *) &bytes[0], bytes.size ());
+
+  auto node = AST::SingleASTNode (make_string (invoc_locus, str));
+  return AST::ASTFragment ({node});
+}
+
 } // namespace Rust