YAML: Add an optional 'flow' field to the mapping trait to allow flow mapping output.

This patch adds an optional 'flow' field to the MappingTrait
class so that yaml IO will be able to output flow mappings.

Reviewers: Justin Bogner

Differential Revision: http://reviews.llvm.org/D9450

llvm-svn: 236456

1 files changed, 85 insertions, 0 deletions

diff --git a/llvm/unittests/Support/YAMLIOTest.cpp b/llvm/unittests/Support/YAMLIOTest.cpp
index b14ac62b071..0a7060cde02 100644
--- a/llvm/unittests/Support/YAMLIOTest.cpp
+++ b/llvm/unittests/Support/YAMLIOTest.cpp
@@ -1367,6 +1367,91 @@ TEST(YAMLIO, TestValidatingInput) {
   EXPECT_TRUE(!!yin.error());
 }
 
+//===----------------------------------------------------------------------===//
+//  Test flow mapping
+//===----------------------------------------------------------------------===//
+
+struct FlowFooBar {
+  int foo;
+  int bar;
+
+  FlowFooBar() : foo(0), bar(0) {}
+  FlowFooBar(int foo, int bar) : foo(foo), bar(bar) {}
+};
+
+typedef std::vector<FlowFooBar> FlowFooBarSequence;
+
+LLVM_YAML_IS_SEQUENCE_VECTOR(FlowFooBar)
+
+struct FlowFooBarDoc {
+  FlowFooBar attribute;
+  FlowFooBarSequence seq;
+};
+
+namespace llvm {
+namespace yaml {
+  template <>
+  struct MappingTraits<FlowFooBar> {
+    static void mapping(IO &io, FlowFooBar &fb) {
+      io.mapRequired("foo", fb.foo);
+      io.mapRequired("bar", fb.bar);
+    }
+
+    static const bool flow = true;
+  };
+
+  template <>
+  struct MappingTraits<FlowFooBarDoc> {
+    static void mapping(IO &io, FlowFooBarDoc &fb) {
+      io.mapRequired("attribute", fb.attribute);
+      io.mapRequired("seq", fb.seq);
+    }
+  };
+}
+}
+
+//
+// Test writing then reading back custom mappings
+//
+TEST(YAMLIO, TestReadWriteMyFlowMapping) {
+  std::string intermediate;
+  {
+    FlowFooBarDoc doc;
+    doc.attribute = FlowFooBar(42, 907);
+    doc.seq.push_back(FlowFooBar(1, 2));
+    doc.seq.push_back(FlowFooBar(0, 0));
+    doc.seq.push_back(FlowFooBar(-1, 1024));
+
+    llvm::raw_string_ostream ostr(intermediate);
+    Output yout(ostr);
+    yout << doc;
+
+    // Verify that mappings were written in flow style
+    ostr.flush();
+    llvm::StringRef flowOut(intermediate);
+    EXPECT_NE(llvm::StringRef::npos, flowOut.find("{ foo: 42, bar: 907 }"));
+    EXPECT_NE(llvm::StringRef::npos, flowOut.find("- { foo: 1, bar: 2 }"));
+    EXPECT_NE(llvm::StringRef::npos, flowOut.find("- { foo: 0, bar: 0 }"));
+    EXPECT_NE(llvm::StringRef::npos, flowOut.find("- { foo: -1, bar: 1024 }"));
+  }
+
+  {
+    Input yin(intermediate);
+    FlowFooBarDoc doc2;
+    yin >> doc2;
+
+    EXPECT_FALSE(yin.error());
+    EXPECT_EQ(doc2.attribute.foo, 42);
+    EXPECT_EQ(doc2.attribute.bar, 907);
+    EXPECT_EQ(doc2.seq.size(), 3UL);
+    EXPECT_EQ(doc2.seq[0].foo, 1);
+    EXPECT_EQ(doc2.seq[0].bar, 2);
+    EXPECT_EQ(doc2.seq[1].foo, 0);
+    EXPECT_EQ(doc2.seq[1].bar, 0);
+    EXPECT_EQ(doc2.seq[2].foo, -1);
+    EXPECT_EQ(doc2.seq[2].bar, 1024);
+  }
+}
 
 //===----------------------------------------------------------------------===//
 //  Test error handling