Add C++ API.

Fixes #71

Author: davidzchen

BUILD

@@ -17,31 +17,25 @@ genrule(
 # TODO(dzc): Remove the includes = ["."] lines from all cc_* targets once
 # bazelbuild/bazel#445 is fixed.
 cc_library(
-    name = "jsonnet-common",
+    name = "libjsonnet",
     srcs = [
         "core/desugaring.cpp",
+        "core/libjsonnet.cpp",
         "core/lexer.cpp",
         "core/parser.cpp",
         "core/static_analysis.cpp",
         "core/vm.cpp",
-        "stdlib/std.jsonnet.h",
-    ],
-    hdrs = [
-        "core/desugaring.h",
-        "core/lexer.h",
-        "core/parser.h",
-        "core/static_analysis.h",
-        "core/static_error.h",
-        "core/vm.h",
     ],
+    hdrs = ["core/libjsonnet.h"],
     includes = ["."],
+    linkopts = ["-lm"],
 )
 
 cc_library(
-    name = "libjsonnet",
-    srcs = ["core/libjsonnet.cpp"],
-    hdrs = ["core/libjsonnet.h"],
-    deps = [":jsonnet-common"],
+    name = "jsonnet-cpp",
+    srcs = ["cpp/jsonnet.cc"],
+    hdrs = ["cpp/jsonnet.h"],
+    deps = [":libjsonnet"],
     includes = ["."],
 )
 
@@ -81,3 +75,25 @@ sh_test(
         ":object_jsonnet",
     ],
 )
+
+cc_binary(
+    name = "libjsonnet_cpp_test_snippet",
+    srcs = ["cpp/libjsonnet_cpp_test_snippet.cc"],
+    deps = [":jsonnet-cpp"],
+)
+
+cc_binary(
+    name = "libjsonnet_cpp_test_file",
+    srcs = ["cpp/libjsonnet_cpp_test_file.cc"],
+    deps = [":jsonnet-cpp"],
+)
+
+sh_test(
+    name = "libjsonnet_cpp_test",
+    srcs = ["cpp/libjsonnet_cpp_test.sh"],
+    data = [
+        ":libjsonnet_cpp_test_snippet",
+        ":libjsonnet_cpp_test_file",
+        ":object_jsonnet",
+    ],
+)

Makefile

@@ -48,16 +48,25 @@ LIB_SRC = \
 	core/parser.cpp \
 	core/static_analysis.cpp \
 	core/vm.cpp
+
 LIB_OBJ = $(LIB_SRC:.cpp=.o)
 
+LIB_CPP_SRC = \
+	$(LIB_SRC) \
+	cpp/jsonnet.cc
+
+LIB_CPP_OBJ = $(LIB_CPP_SRC:.cpp=.o)
+
 ALL = \
 	jsonnet \
 	libjsonnet.so \
+	libjsonnet-cpp.so \
 	libjsonnet_test_snippet \
 	libjsonnet_test_file \
 	libjsonnet.js \
 	doc/libjsonnet.js \
 	$(LIB_OBJ)
+
 ALL_HEADERS = \
 	core/ast.h \
 	core/desugaring.h \
@@ -68,6 +77,7 @@ ALL_HEADERS = \
 	core/static_analysis.h \
 	core/static_error.h \
 	core/vm.h \
+	cpp/jsonnet.h \
 	stdlib/std.jsonnet.h
 
 default: jsonnet
@@ -105,6 +115,9 @@ jsonnet: cmd/jsonnet.cpp $(LIB_OBJ)
 libjsonnet.so: $(LIB_OBJ)
 	$(CXX) $(LDFLAGS) $(LIB_OBJ) $(SHARED_LDFLAGS) -o $@
 
+libjsonnet-cpp.so: $(LIB_CPP_OBJ)
+	$(CXX) $(LDFLAGS) $(LIB_CPP_OBJ) $(SHARED_LDFLAGS) -o $@
+
 # Javascript build of C binding
 JS_EXPORTED_FUNCTIONS = 'EXPORTED_FUNCTIONS=["_jsonnet_make", "_jsonnet_evaluate_snippet", "_jsonnet_realloc", "_jsonnet_destroy"]'
 

cpp/jsonnet.cc

@@ -0,0 +1,132 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "cpp/jsonnet.h"
+
+namespace jsonnet {
+
+Jsonnet::Jsonnet() {}
+Jsonnet::~Jsonnet() {
+  if (vm_ != nullptr) {
+    ::jsonnet_destroy(vm_);
+  }
+}
+
+bool Jsonnet::Init() {
+  vm_ = static_cast<struct JsonnetVm*>(::jsonnet_make());
+  return vm_ != nullptr;
+}
+
+void Jsonnet::SetMaxStack(uint32_t depth) {
+  ::jsonnet_max_stack(vm_, static_cast<unsigned>(depth));
+}
+
+void Jsonnet::SetGcMinObjects(uint32_t objects) {
+  ::jsonnet_gc_min_objects(vm_, static_cast<unsigned>(objects));
+}
+
+void Jsonnet::SetGcGrowthTrigger(double growth) {
+  ::jsonnet_gc_growth_trigger(vm_, growth);
+}
+
+void Jsonnet::SetStringOutput(bool string_output) {
+  ::jsonnet_string_output(vm_, string_output);
+}
+
+void Jsonnet::SetDebugAst(bool debug_ast) {
+  ::jsonnet_debug_ast(vm_, static_cast<int>(debug_ast));
+}
+
+void Jsonnet::SetMaxTrace(uint32_t lines) {
+  ::jsonnet_max_trace(vm_, static_cast<unsigned>(lines));
+}
+
+void Jsonnet::BindExtVar(const std::string& key, const std::string& value) {
+  ::jsonnet_ext_var(vm_, key.c_str(), value.c_str());
+}
+
+void Jsonnet::BindExtCodeVar(const std::string& key,
+                             const std::string& value) {
+  ::jsonnet_ext_code(vm_, key.c_str(), value.c_str());
+}
+
+bool Jsonnet::EvaluateFile(const std::string& filename, std::string* output) {
+  if (output == nullptr) {
+    return false;
+  }
+  int error = 0;
+  const char* jsonnet_output =
+      ::jsonnet_evaluate_file(vm_, filename.c_str(), &error);
+  output->assign(jsonnet_output);
+  return error == 0;
+}
+
+bool Jsonnet::EvaluateSnippet(const std::string& filename,
+                              const std::string& snippet,
+                              std::string* output) {
+  if (output == nullptr) {
+    return false;
+  }
+  int error = 0;
+  const char* jsonnet_output = ::jsonnet_evaluate_snippet(
+      vm_, filename.c_str(), snippet.c_str(), &error);
+  output->assign(jsonnet_output);
+  return error == 0;
+}
+
+namespace {
+void ParseMultiOutput(const char* jsonnet_output,
+                      std::map<std::string, std::string>* outputs) {
+  for (const char* c = jsonnet_output; *c != '\0'; ) {
+    const char *filename = c;
+    const char *c2 = c;
+    while (*c2 != '\0') ++c2;
+    ++c2;
+    const char *json = c2;
+    while (*c2 != '\0') ++c2;
+    ++c2;
+    c = c2;
+    outputs->insert(std::make_pair(filename, json));
+  }
+}
+}  // namespace
+
+bool Jsonnet::EvaluateFileMulti(
+    const std::string& filename,
+    std::map<std::string, std::string>* outputs) {
+  if (outputs == nullptr) {
+    return false;
+  }
+  int error = 0;
+  const char* jsonnet_output =
+      ::jsonnet_evaluate_file_multi(vm_, filename.c_str(), &error);
+  ParseMultiOutput(jsonnet_output, outputs);
+  return error == 0;
+}
+
+bool Jsonnet::EvaluateSnippetMulti(
+    const std::string& filename,
+    const std::string& snippet,
+    std::map<std::string, std::string>* outputs) {
+  if (outputs == nullptr) {
+    return false;
+  }
+  int error = 0;
+  const char* jsonnet_output = ::jsonnet_evaluate_snippet_multi(
+      vm_, filename.c_str(), snippet.c_str(), &error);
+  ParseMultiOutput(jsonnet_output, outputs);
+  return error == 0;
+}
+
+}  // namespace jsonnet