Tighten up the yamilizer so it stops eliding empty sequences if the embedded empty sequence is the first key/value in a map which is itself in a sequence.

Patch with help from Nick Kledzik.

llvm-svn: 188508
This commit is contained in:
Aaron Ballman 2013-08-15 23:17:53 +00:00
parent 1de76773bc
commit 0e63e53da1
3 changed files with 84 additions and 2 deletions

View File

@ -323,6 +323,7 @@ public:
virtual bool preflightElement(unsigned, void *&) = 0;
virtual void postflightElement(void*) = 0;
virtual void endSequence() = 0;
virtual bool canElideEmptySequence() = 0;
virtual unsigned beginFlowSequence() = 0;
virtual bool preflightFlowElement(unsigned, void *&) = 0;
@ -388,7 +389,7 @@ public:
typename llvm::enable_if_c<has_SequenceTraits<T>::value,void>::type
mapOptional(const char* Key, T& Val) {
// omit key/value instead of outputting empty sequence
if ( this->outputting() && !(Val.begin() != Val.end()) )
if ( this->canElideEmptySequence() && !(Val.begin() != Val.end()) )
return;
this->processKey(Key, Val, false);
}
@ -715,6 +716,7 @@ private:
virtual void endBitSetScalar();
virtual void scalarString(StringRef &);
virtual void setError(const Twine &message);
virtual bool canElideEmptySequence();
class HNode {
public:
@ -837,7 +839,7 @@ public:
virtual void endBitSetScalar();
virtual void scalarString(StringRef &);
virtual void setError(const Twine &message);
virtual bool canElideEmptySequence();
public:
// These are only used by operator<<. They could be private
// if that templated operator could be made a friend.

View File

@ -334,6 +334,10 @@ void Input::setError(const Twine &Message) {
this->setError(CurrentNode, Message);
}
bool Input::canElideEmptySequence() {
return false;
}
Input::MapHNode::~MapHNode() {
for (MapHNode::NameToNode::iterator i = Mapping.begin(), End = Mapping.end();
i != End; ++i) {
@ -532,6 +536,19 @@ void Output::scalarString(StringRef &S) {
void Output::setError(const Twine &message) {
}
bool Output::canElideEmptySequence() {
// Normally, with an optional key/value where the value is an empty sequence,
// the whole key/value can be not written. But, that produces wrong yaml
// if the key/value is the only thing in the map and the map is used in
// a sequence. This detects if the this sequence is the first key/value
// in map that itself is embedded in a sequnce.
if (StateStack.size() < 2)
return true;
if (StateStack.back() != inMapFirstKey)
return true;
return (StateStack[StateStack.size()-2] != inSeq);
}
void Output::output(StringRef s) {
Column += s.size();
Out << s;

View File

@ -1297,3 +1297,66 @@ TEST(YAMLIO, TestReadBuiltInTypesHex64Error) {
EXPECT_TRUE(yin.error());
}
struct OptionalTest {
std::vector<int> Numbers;
};
struct OptionalTestSeq {
std::vector<OptionalTest> Tests;
};
LLVM_YAML_IS_SEQUENCE_VECTOR(OptionalTest);
namespace llvm {
namespace yaml {
template <>
struct MappingTraits<OptionalTest> {
static void mapping(IO& IO, OptionalTest &OT) {
IO.mapOptional("Numbers", OT.Numbers);
}
};
template <>
struct MappingTraits<OptionalTestSeq> {
static void mapping(IO &IO, OptionalTestSeq &OTS) {
IO.mapOptional("Tests", OTS.Tests);
}
};
}
}
TEST(YAMLIO, SequenceElideTest) {
// Test that writing out a purely optional structure with its fields set to
// default followed by other data is properly read back in.
OptionalTestSeq Seq;
OptionalTest One, Two, Three, Four;
int N[] = {1, 2, 3};
Three.Numbers.assign(N, N + 3);
Seq.Tests.push_back(One);
Seq.Tests.push_back(Two);
Seq.Tests.push_back(Three);
Seq.Tests.push_back(Four);
std::string intermediate;
{
llvm::raw_string_ostream ostr(intermediate);
Output yout(ostr);
yout << Seq;
}
Input yin(intermediate);
OptionalTestSeq Seq2;
yin >> Seq2;
EXPECT_FALSE(yin.error());
EXPECT_EQ(4UL, Seq2.Tests.size());
EXPECT_TRUE(Seq2.Tests[0].Numbers.empty());
EXPECT_TRUE(Seq2.Tests[1].Numbers.empty());
EXPECT_EQ(1, Seq2.Tests[2].Numbers[0]);
EXPECT_EQ(2, Seq2.Tests[2].Numbers[1]);
EXPECT_EQ(3, Seq2.Tests[2].Numbers[2]);
EXPECT_TRUE(Seq2.Tests[3].Numbers.empty());
}