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Remove the code from conversion service that allows implicit mut->ptr…
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… conversions
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@lucteo
lucteo committed Nov 28, 2019
1 parent 5bd8772 commit b914d05
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Showing 2 changed files with 20 additions and 99 deletions.
115 changes: 18 additions & 97 deletions src/SparrowFrontend/Services/Convert/ConvertServiceImpl.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -357,22 +357,23 @@ ElemConvType checkElementaryCast(int srcKind, int destKind) {
return conversions[src][dest];
}

const char* kindToStr(int kind) {
if (kind == typeKindData)
return "data";
if (kind == typeKindPtr)
return "ptr";
if (kind == typeKindConst)
return "const";
if (kind == typeKindMutable)
return "mut";
if (kind == typeKindTemp)
return "tmp";
if (kind == 0)
return "none";
ASSERT(false);
return "???";
}
// Used for debugging:
// const char* kindToStr(int kind) {
// if (kind == typeKindData)
// return "data";
// if (kind == typeKindPtr)
// return "ptr";
// if (kind == typeKindConst)
// return "const";
// if (kind == typeKindMutable)
// return "mut";
// if (kind == typeKindTemp)
// return "tmp";
// if (kind == 0)
// return "none";
// ASSERT(false);
// return "???";
// }

//! A stack of node kinds, from which we can pop the base kinds.
struct KindStack {
Expand Down Expand Up @@ -420,14 +421,6 @@ int setPlainIfKindMissing(int kind) { return kind == 0 ? typeKindData : kind; }
bool ConvertServiceImpl::checkWrapperTypes(
ConversionResult& res, TypeWithStorage src, TypeWithStorage dest, bool canAddRef) {

bool doDebug = src.description() == StringRef("FooType/ct") &&
dest.description() == StringRef("#Concept1/ct");
doDebug = doDebug || (src.description() == StringRef("Float32") &&
dest.description() == StringRef("Float32 ptr"));
doDebug = false;
if (doDebug)
cerr << "\n" << src.description() << " -> " << dest.description() << "\n";

// Analyze the two types: figure our their base type and all the wrappers
static KindStack srcKinds;
static KindStack destKinds;
Expand All @@ -450,56 +443,7 @@ bool ConvertServiceImpl::checkWrapperTypes(
if (srcBase != destBase)
return false;

// First, treat the special case of adding a pointer
// Allowed conversions:
// - T <cat1> -> T <cat0>? ptr <cat2>?, if T <cat1> -> T <cat2>
// in any other case, adding ptrs is forbidden
if (srcPtrs == 0 && destPtrs == 1 && canAddRef) {
auto cat1 = srcKinds[0];
ASSERT(srcKinds[1] == 0);
auto k = destKinds[0];
auto cat2 = k == typeKindPtr ? destKinds[1] : destKinds[2];

if (doDebug)
cerr << " try to add ptr: " << srcBase << " " << kindToStr(cat1) << " -> " << srcBase
<< " cat? ptr " << kindToStr(cat2) << "\n";

auto conv = checkElementaryCast(setPlainIfKindMissing(cat1), setPlainIfKindMissing(cat2));
if (conv == none)
return false;
switch (conv) {
case direct:
// T <cat> -> T ptr <cat>
src = addRef(src);
res.addConversion(convImplicit, ConvAction(ActionType::addRef, src));
return true;
case catCast:
// T <cat1> -> T ptr <cat2>
src = addRef(src); // => T ptr <cat1>
res.addConversion(convImplicit, ConvAction(ActionType::addRef, src));
// now, T ptr <cat1> -> T ptr <cat2>
res.addConversion(convImplicit, ConvAction(ActionType::bitcast, dest));
return true;
case addCat:
case ptr2Cat:
// T -> T ptr <cat>
// Disallow adding two pointers
return false;
case removeCat:
case cat2Ptr:
// T <cat> -> T ptr
// bitcast category into pointer
res.addConversion(convImplicit, ConvAction(ActionType::bitcast, dest));
return true;
case addPtr:
case removePtr:
default:
ASSERT(false);
return false;
}
}
// Cannot add ptrs in any other ptr cardinality
// TODO: what about T ptr mut -> T ptr ptr ?
// Cannot add ptrs
if (srcPtrs < destPtrs)
return false;

Expand All @@ -508,8 +452,6 @@ bool ConvertServiceImpl::checkWrapperTypes(
// We check categories at every iteration
// Note: between pointers we may have at most one cat type, but nothing else.
int numIterations = std::min(srcPtrs, destPtrs);
if (doDebug)
cerr << " numIterations: " << numIterations << "\n";
bool needsCast = false;
for (int i = 0; i < numIterations; i++) {
// Get the two groups of kinds that we need to compare
Expand All @@ -524,11 +466,6 @@ bool ConvertServiceImpl::checkWrapperTypes(
if (destCat == 0)
destCat = typeKindData;

if (doDebug) {
cerr << " src ptr:" << srcPtr << " cat:" << srcCat << "; dest ptr:" << destPtr
<< " cat:" << destCat << "\n";
}

// Check elementary casts between possible category types
auto conv = checkElementaryCast(srcCat, destCat);
if (conv == none)
Expand All @@ -547,9 +484,6 @@ bool ConvertServiceImpl::checkWrapperTypes(
int destKind = setPlainIfKindMissing(destKinds[0]);
int srcKind = setPlainIfKindMissing(srcKinds[0]);
auto conv = checkElementaryCast(srcKind, destKind);
if (doDebug)
cerr << " " << kindToStr(srcKind) << " -> " << kindToStr(destKind) << " => " << conv
<< "\n";
if (conv == none)
return false;

Expand Down Expand Up @@ -602,8 +536,6 @@ bool ConvertServiceImpl::checkWrapperTypes(

// Do we just need to add a category?
if (shouldAddCat) {
if (doDebug)
cerr << " adding cat => addRef (direct)\n";
ASSERT(srcKinds.empty());
res.addConversion(convDirect, ConvAction(ActionType::addRef, dest));
return true;
Expand All @@ -619,26 +551,17 @@ bool ConvertServiceImpl::checkWrapperTypes(
if (kind == typeKindPtr)
remainingPtrs++;
}
if (doDebug) {
cerr << " num remaining ptrs: " << remainingPtrs << "\n";
cerr << " needsDeref: " << needsDeref << "\n";
cerr << " needsCast: " << needsCast << "\n";
}
for (int i = 0; i < remainingPtrs; i++) {
src = removeRef(src);
res.addConversion(convImplicit, ConvAction(ActionType::dereference, src));
}
// TODO: remove this
if (Feather::isCategoryType(src) && src.numReferences() > dest.numReferences()) {
if (doDebug)
cerr << " try extra deref by removing cat (" << src << " -> " << dest << ")\n";
src = removeCategoryIfPresent(src);
res.addConversion(convDirect, ConvAction(ActionType::dereference, src));
// TODO (now): Should we make this convImplicit?
}
if (src != dest) {
if (doDebug)
cerr << " bitcast: " << src << " -> " << dest << "\n";
if (needsCast)
res.addConversion(needsImplicit ? convImplicit : convDirect,
ConvAction(ActionType::bitcast, dest));
Expand All @@ -648,8 +571,6 @@ bool ConvertServiceImpl::checkWrapperTypes(
REP_INTERNAL(NOLOC, "Invalid conversion between %1% and %2%") % src % dest;
}

if (doDebug)
cerr << " res: " << res << "\n";
return true;
}

Expand Down
4 changes: 2 additions & 2 deletions unittests/SparrowFrontend/TestConvert.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -321,9 +321,9 @@ TEST_CASE_METHOD(ConvertFixture, "Conversion rules") {
auto t2 = PtrType::get(t1); // @@i8
auto t0mut = MutableType::get(t0); // i8 mut
auto t1mut = MutableType::get(t1); // @i8 mut
CHECK(getConvType(t0, t1) == convImplicit);
CHECK(getConvType(t0, t1) == convNone);
CHECK(getConvType(t0mut, t0) == convDirect);
CHECK(getConvType(t0mut, t1) == convImplicit);
CHECK(getConvType(t0mut, t1) == convNone);
CHECK(getConvType(t1mut, t1) == convDirect);
CHECK(getConvType(t1mut, t2) == convNone);
CHECK(getConvType(t1, t0mut) == convImplicit);
Expand Down

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