Merge pull request #1142 from dcci/formatterdecimal

packages/Python/lldbsuite/test/lang/swift/foundation_value_types/decimal/Makefile

@@ -0,0 +1,4 @@
+LEVEL = ../../../../make
+SWIFT_SOURCES := main.swift
+SWIFT_OBJC_INTEROP := 1
+include $(LEVEL)/Makefile.rules

packages/Python/lldbsuite/test/lang/swift/foundation_value_types/decimal/TestSwiftFoundationTypeDecimal.py

@@ -0,0 +1,5 @@
+import lldbsuite.test.lldbinline as lldbinline
+from lldbsuite.test.decorators import *
+
+lldbinline.MakeInlineTest(__file__, globals(),
+                          decorators=[swiftTest,skipUnlessDarwin])

packages/Python/lldbsuite/test/lang/swift/foundation_value_types/decimal/main.swift

@@ -0,0 +1,18 @@
+import Foundation
+
+func main() {
+  let x = Decimal(42.5)
+  let y = Decimal(422.5)
+  let z = Decimal(-23.6)
+  let patatino = Decimal(12345567888.1234)
+  return //%self.expect("frame var -d run -- x", substrs=['42.5'])
+         //%self.expect("expr -d run -- x", substrs=['42.5'])
+         //%self.expect("frame var -d run -- y", substrs=['422.5'])
+         //%self.expect("expr -d run -- y", substrs=['422.5'])
+         //%self.expect("frame var -d run -- z", substrs=['-23.6'])
+         //%self.expect("expr -d run -- z", substrs=['-23.6'])
+         //%self.expect("frame var -d run -- patatino", substrs=['12345567888.123'])
+         //%self.expect("expr -d run -- patatino", substrs=['12345567888.123'])
+}
+
+main()

source/Plugins/Language/Swift/FoundationValueTypes.cpp

@@ -471,6 +471,85 @@ bool lldb_private::formatters::swift::Data_SummaryProvider(
   return true;
 }
 
+bool lldb_private::formatters::swift::Decimal_SummaryProvider(
+    ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
+
+  // The layout of the type is:
+  // public struct Decimal {
+  //   fileprivate var __exponent : Int8
+  //   fileprivate var __lengthAndFlags: UInt8
+  //   fileprivate var __reserved: UInt16
+  //   public var _mantissa: (UInt16, UInt16, UInt16, UInt16, UInt16, UInt16,
+  //   UInt16, UInt16)
+  // We do have to harcode the offset of the variables because they're
+  // fileprivate, but we can access `_mantissa` by name.
+
+  ProcessSP process(valobj.GetProcessSP());
+  if (!process)
+    return false;
+
+  Status error;
+  DataExtractor data_extractor;
+  if (!valobj.GetData(data_extractor, error))
+    return false;
+
+  offset_t offset_ptr = 0;
+  int8_t exponent = data_extractor.GetU8(&offset_ptr);
+  uint8_t length_and_flags = data_extractor.GetU8(&offset_ptr);
+  uint8_t length = length_and_flags & 0xf;
+  bool isNegative = length_and_flags & 0x10;
+
+  static ConstString g_mantissa("_mantissa");
+  ValueObjectSP mantissa_sp = valobj.GetChildAtNamePath(g_mantissa);
+  if (!mantissa_sp)
+    return false;
+
+  // Easy case. length == 0 is either `NaN` or `0`.
+  if (length == 0) {
+    if (isNegative)
+      stream.Printf("NaN");
+    else
+      stream.Printf("0");
+    return true;
+  }
+
+  // Mantissa is represented as a tuple of 8 UInt16.
+  const uint8_t num_children = 8;
+  if (mantissa_sp->GetNumChildren() != num_children)
+    return false;
+
+  std::vector<double> mantissa_elements;
+  for (int i = 0; i < 8; ++i) {
+    ValueObjectSP child_sp = mantissa_sp->GetChildAtIndex(i, true);
+    if (!child_sp)
+      return false;
+    static ConstString g_value("_value");
+    ValueObjectSP value_sp = child_sp->GetChildAtNamePath(g_value);
+    if (!value_sp)
+      return false;
+    auto val = value_sp->GetValueAsUnsigned(0) & 0xffff;
+    mantissa_elements.push_back(static_cast<double>(val));
+  }
+
+  // Compute the value using mantissa and exponent
+  double d = 0.0;
+  for (int i = std::min(length, num_children); i > 0; i--) {
+    d = (d * 65536) + mantissa_elements[i - 1];
+  }
+
+  if (exponent < 0)
+    for (int i = exponent; i < 0; ++i)
+      d /= 10.0;
+  else
+    for (int i = 0; i < exponent; ++i)
+      d *= 10.0;
+
+  if (isNegative)
+    d = -d;
+
+  stream.Printf("%lf\n", d);
+  return true;
+}
 class URLComponentsSyntheticChildrenFrontEnd
     : public SyntheticChildrenFrontEnd {
 public:

source/Plugins/Language/Swift/FoundationValueTypes.h

@@ -46,6 +46,9 @@ bool UUID_SummaryProvider(ValueObject &valobj, Stream &stream,
 bool Data_SummaryProvider(ValueObject &valobj, Stream &stream,
                           const TypeSummaryOptions &options);
 
+bool Decimal_SummaryProvider(ValueObject &valobj, Stream &stream,
+                             const TypeSummaryOptions &options);
+
 SyntheticChildrenFrontEnd *
 URLComponentsSyntheticFrontEndCreator(CXXSyntheticChildren *,
                                       lldb::ValueObjectSP);

source/Plugins/Language/Swift/SwiftLanguage.cpp

@@ -626,6 +626,12 @@ LoadFoundationValueTypesFormatters(lldb::TypeCategoryImplSP swift_category_sp) {
       "Data summary provider", ConstString("Foundation.Data"),
       TypeSummaryImpl::Flags(summary_flags).SetDontShowChildren(true));
 
+  lldb_private::formatters::AddCXXSummary(
+      swift_category_sp,
+      lldb_private::formatters::swift::Decimal_SummaryProvider,
+      "Decimal summary provider", ConstString("Foundation.Decimal"),
+      TypeSummaryImpl::Flags(summary_flags).SetDontShowChildren(true));
+
   lldb_private::formatters::AddCXXSynthetic(
       swift_category_sp,
       lldb_private::formatters::swift::URLComponentsSyntheticFrontEndCreator,