1 files changed, 100 insertions, 0 deletions
diff --git a/third_party/nix/src/libexpr/parser.hh b/third_party/nix/src/libexpr/parser.hh
new file mode 100644
index 000000000000..70b5450b5aa8
--- /dev/null
+++ b/third_party/nix/src/libexpr/parser.hh
@@ -0,0 +1,100 @@
+// Parser utilities for use in parser.y
+#pragma once
+
+// TODO(tazjin): Audit these includes, they were in parser.y
+#include <optional>
+#include <variant>
+
+#include <glog/logging.h>
+
+#include "libexpr/eval.hh"
+#include "libexpr/nixexpr.hh"
+#include "libutil/util.hh"
+
+#define YY_DECL                                                               \
+  int yylex(YYSTYPE* yylval_param, YYLTYPE* yylloc_param, yyscan_t yyscanner, \
+            nix::ParseData* data)
+
+#define CUR_POS makeCurPos(*yylocp, data)
+
+namespace nix {
+
+struct ParseData {
+  EvalState& state;
+  SymbolTable& symbols;
+  Expr* result;
+  Path basePath;
+  std::optional<Symbol> path;
+  std::string error;
+  Symbol sLetBody;
+
+  ParseData(EvalState& state)
+      : state(state),
+        symbols(state.symbols),
+        sLetBody(symbols.Create("<let-body>")){};
+};
+
+// Clang fails to identify these functions as used, probably because
+// of some interaction between the lexer/parser codegen and something
+// else.
+//
+// To avoid warnings for that we disable -Wunused-function in this block.
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-function"
+
+// TODO(tazjin): move dupAttr to anonymous namespace
+static void dupAttr(const AttrPath& attrPath, const Pos& pos,
+                    const Pos& prevPos) {
+  throw ParseError(format("attribute '%1%' at %2% already defined at %3%") %
+                   showAttrPath(attrPath) % pos % prevPos);
+}
+
+static void dupAttr(Symbol attr, const Pos& pos, const Pos& prevPos) {
+  throw ParseError(format("attribute '%1%' at %2% already defined at %3%") %
+                   attr % pos % prevPos);
+}
+
+void addAttr(ExprAttrs* attrs, AttrPath& attrPath, Expr* e, const Pos& pos);
+
+void addFormal(const Pos& pos, Formals* formals, const Formal& formal);
+
+Expr* stripIndentation(const Pos& pos, SymbolTable& symbols, VectorExprs& es);
+
+Path resolveExprPath(Path path);
+
+// implementations originally from lexer.l
+
+static Expr* unescapeStr(SymbolTable& symbols, const char* s, size_t length) {
+  std::string t;
+  t.reserve(length);
+  char c;
+  while ((c = *s++)) {
+    if (c == '\\') {
+      assert(*s);
+      c = *s++;
+      if (c == 'n') {
+        t += '\n';
+      } else if (c == 'r') {
+        t += '\r';
+      } else if (c == 't') {
+        t += '\t';
+      } else {
+        t += c;
+      }
+    } else if (c == '\r') {
+      /* Normalise CR and CR/LF into LF. */
+      t += '\n';
+      if (*s == '\n') {
+        s++;
+      } /* cr/lf */
+    } else {
+      t += c;
+    }
+  }
+  return new ExprString(symbols.Create(t));
+}
+
+#pragma clang diagnostic pop  // re-enable -Wunused-function
+
+}  // namespace nix