8 files changed, 57 insertions, 56 deletions
diff --git a/src/libexpr/Makefile.am b/src/libexpr/Makefile.am
deleted file mode 100644
index 7edbe77157d8..000000000000
--- a/src/libexpr/Makefile.am
+++ /dev/null
@@ -1,40 +0,0 @@
-pkglib_LTLIBRARIES = libexpr.la
-
-libexpr_la_SOURCES = \
- nixexpr.cc eval.cc primops.cc lexer-tab.cc parser-tab.cc \
- get-drvs.cc attr-path.cc value-to-xml.cc value-to-json.cc \
- common-opts.cc names.cc
-
-pkginclude_HEADERS = \
- nixexpr.hh eval.hh eval-inline.hh lexer-tab.hh parser-tab.hh \
- get-drvs.hh attr-path.hh value-to-xml.hh value-to-json.hh \
- common-opts.hh names.hh symbol-table.hh value.hh
-
-libexpr_la_LIBADD = ../libutil/libutil.la ../libstore/libstore.la \
- ../boost/format/libformat.la @BDW_GC_LIBS@
-
-BUILT_SOURCES = \
- parser-tab.hh lexer-tab.hh parser-tab.cc lexer-tab.cc
-
-EXTRA_DIST = lexer.l parser.y
-
-AM_CXXFLAGS = \
- -I$(srcdir)/.. \
- -I$(srcdir)/../libutil -I$(srcdir)/../libstore
-
-
-# Parser generation.
-
-parser-tab.cc parser-tab.hh: parser.y
-	$(bison) -v -o parser-tab.cc $(srcdir)/parser.y -d
-
-lexer-tab.cc lexer-tab.hh: lexer.l
-	$(flex) --outfile lexer-tab.cc --header-file=lexer-tab.hh $(srcdir)/lexer.l 
-
-
-# SDF stuff (not built by default).
-nix.tbl: nix.sdf
-	sdf2table -m Nix -s -i nix.sdf -o nix.tbl
-
-test.ast: test.nix nix.tbl
-	sglri -p nix.tbl -i test.nix -o test.ast
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 3d8ee9934016..2087c7c43ffb 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -129,7 +129,15 @@ string showType(const Value & v)
 }
 
 
-Symbol getName(const AttrName & name, EvalState & state, Env & env) {
+/* Called when the Boehm GC runs out of memory. */
+static void * oomHandler(size_t requested)
+{
+    /* Convert this to a proper C++ exception. */
+    throw std::bad_alloc();
+}
+
+
+static Symbol getName(const AttrName & name, EvalState & state, Env & env) {
     if (name.symbol.set()) {
         return name.symbol;
     } else {
@@ -168,8 +176,16 @@ EvalState::EvalState()
     countCalls = getEnv("NIX_COUNT_CALLS", "0") != "0";
 
 #if HAVE_BOEHMGC
-    static bool gcInitialised = true;
-    if (gcInitialised) {
+    static bool gcInitialised = false;
+    if (!gcInitialised) {
+
+        /* Initialise the Boehm garbage collector.  This isn't
+           necessary on most platforms, but for portability we do it
+           anyway. */
+        GC_INIT();
+
+        GC_oom_fn = oomHandler;
+
         /* Set the initial heap size to something fairly big (25% of
            physical RAM, up to a maximum of 384 MiB) so that in most
            cases we don't need to garbage collect at all.  (Collection
@@ -193,6 +209,7 @@ EvalState::EvalState()
             debug(format("setting initial heap size to %1% bytes") % size);
             GC_expand_hp(size);
         }
+
         gcInitialised = true;
     }
 #endif
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 45ab423c18a1..5ae5a1e3cf24 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -82,8 +82,6 @@ void copyContext(const Value & v, PathSet & context);
    paths. */
 typedef std::map<Path, Path> SrcToStore;
 
-struct EvalState;
-
 
 std::ostream & operator << (std::ostream & str, const Value & v);
 
@@ -216,9 +214,9 @@ private:
 
     inline Value * lookupVar(Env * env, const ExprVar & var, bool noEval);
 
-    friend class ExprVar;
-    friend class ExprAttrs;
-    friend class ExprLet;
+    friend struct ExprVar;
+    friend struct ExprAttrs;
+    friend struct ExprLet;
 
     Expr * parse(const char * text, const Path & path,
         const Path & basePath, StaticEnv & staticEnv);
@@ -278,9 +276,9 @@ private:
     typedef std::map<Pos, unsigned int> AttrSelects;
     AttrSelects attrSelects;
 
-    friend class ExprOpUpdate;
-    friend class ExprOpConcatLists;
-    friend class ExprSelect;
+    friend struct ExprOpUpdate;
+    friend struct ExprOpConcatLists;
+    friend struct ExprSelect;
     friend void prim_getAttr(EvalState & state, Value * * args, Value & v);
 };
 
diff --git a/src/libexpr/local.mk b/src/libexpr/local.mk
new file mode 100644
index 000000000000..431f84b0999e
--- /dev/null
+++ b/src/libexpr/local.mk
@@ -0,0 +1,24 @@
+libraries += libexpr
+
+libexpr_NAME = libnixexpr
+
+libexpr_DIR := $(d)
+
+libexpr_SOURCES := $(wildcard $(d)/*.cc) $(d)/lexer-tab.cc $(d)/parser-tab.cc
+
+libexpr_LIBS = libutil libstore libformat
+
+# The dependency on libgc must be propagated (i.e. meaning that
+# programs/libraries that use libexpr must explicitly pass -lgc),
+# because inline functions in libexpr's header files call libgc.
+libexpr_LDFLAGS_PROPAGATED = $(BDW_GC_LIBS)
+
+$(d)/parser-tab.cc $(d)/parser-tab.hh: $(d)/parser.y
+	$(trace-gen) bison -v -o $(libexpr_DIR)/parser-tab.cc $< -d
+
+$(d)/lexer-tab.cc $(d)/lexer-tab.hh: $(d)/lexer.l
+	$(trace-gen) flex --outfile $(libexpr_DIR)/lexer-tab.cc --header-file=$(libexpr_DIR)/lexer-tab.hh $<
+
+clean-files += $(d)/parser-tab.cc $(d)/parser-tab.hh $(d)/lexer-tab.cc $(d)/lexer-tab.hh
+
+dist-files += $(d)/parser-tab.cc $(d)/parser-tab.hh $(d)/lexer-tab.cc $(d)/lexer-tab.hh
diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index bc6993477c48..7586fffb83d4 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -48,7 +48,7 @@ std::ostream & operator << (std::ostream & str, const Pos & pos);
 
 struct Env;
 struct Value;
-struct EvalState;
+class EvalState;
 struct StaticEnv;
 struct Expr;
 
@@ -71,6 +71,7 @@ string showAttrPath(const AttrPath & attrPath);
 
 struct Expr
 {
+    virtual ~Expr() { };
     virtual void show(std::ostream & str);
     virtual void bindVars(const StaticEnv & env);
     virtual void eval(EvalState & state, Env & env, Value & v);
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index 55a42fcaba9f..8a084fea0697 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -252,7 +252,7 @@ void yyerror(YYLTYPE * loc, yyscan_t scanner, ParseData * data, const char * err
   nix::Formals * formals;
   nix::Formal * formal;
   nix::NixInt n;
-  char * id; // !!! -> Symbol
+  const char * id; // !!! -> Symbol
   char * path;
   char * uri;
   std::vector<nix::AttrName> * attrNames;
@@ -414,7 +414,7 @@ expr_simple
 string_parts
   : STR
   | string_parts_interpolated { $$ = new ExprConcatStrings(true, $1); }
-  | { $$ = new ExprString(data->symbols.create("")) }
+  | { $$ = new ExprString(data->symbols.create("")); }
   ;
 
 string_parts_interpolated
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 4f836e279425..ca316f08af13 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -1322,6 +1322,7 @@ void EvalState::createBaseEnv()
     /* Add a wrapper around the derivation primop that computes the
        `drvPath' and `outPath' attributes lazily. */
     string path = findFile("nix/derivation.nix");
+    assert(!path.empty());
     sDerivationNix = symbols.create(path);
     evalFile(path, v);
     addConstant("derivation", v);
diff --git a/src/libexpr/value.hh b/src/libexpr/value.hh
index 982582793419..2feb2f9492ca 100644
--- a/src/libexpr/value.hh
+++ b/src/libexpr/value.hh
@@ -22,13 +22,13 @@ typedef enum {
 } ValueType;
 
 
-struct Bindings;
+class Bindings;
 struct Env;
 struct Expr;
 struct ExprLambda;
 struct PrimOp;
 struct PrimOp;
-struct Symbol;
+class Symbol;
 
 
 typedef long NixInt;