From 6385dbb95e5f6d4918535ac251e6b30eebb71490 Mon Sep 17 00:00:00 2001 From: Frederic Riss Date: Wed, 4 Mar 2015 22:07:41 +0000 Subject: [PATCH] DWARFFormValue: Add getAsSignedConstant method. The implementation accepts explicitely signed forms (DW_FORM_sdata), but also unsigned forms as long as they fit in an int64_t. llvm-svn: 231299 --- include/llvm/DebugInfo/DWARF/DWARFFormValue.h | 1 + lib/DebugInfo/DWARF/DWARFFormValue.cpp | 19 +++++ .../DebugInfo/DWARF/DWARFFormValueTest.cpp | 74 +++++++++++++++++++ 3 files changed, 94 insertions(+) diff --git a/include/llvm/DebugInfo/DWARF/DWARFFormValue.h b/include/llvm/DebugInfo/DWARF/DWARFFormValue.h index 5bb6d1b9ddb..f12c491af5c 100644 --- a/include/llvm/DebugInfo/DWARF/DWARFFormValue.h +++ b/include/llvm/DebugInfo/DWARF/DWARFFormValue.h @@ -74,6 +74,7 @@ public: /// DWARFFormValue has form class is suitable for representing Foo. Optional getAsReference(const DWARFUnit *U) const; Optional getAsUnsignedConstant() const; + Optional getAsSignedConstant() const; Optional getAsCString(const DWARFUnit *U) const; Optional getAsAddress(const DWARFUnit *U) const; Optional getAsSectionOffset() const; diff --git a/lib/DebugInfo/DWARF/DWARFFormValue.cpp b/lib/DebugInfo/DWARF/DWARFFormValue.cpp index 45bd1973a76..6946f833424 100644 --- a/lib/DebugInfo/DWARF/DWARFFormValue.cpp +++ b/lib/DebugInfo/DWARF/DWARFFormValue.cpp @@ -18,6 +18,7 @@ #include "llvm/Support/Format.h" #include "llvm/Support/raw_ostream.h" #include +#include using namespace llvm; using namespace dwarf; using namespace syntax; @@ -557,6 +558,24 @@ Optional DWARFFormValue::getAsUnsignedConstant() const { return Value.uval; } +Optional DWARFFormValue::getAsSignedConstant() const { + if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || + (Form == DW_FORM_udata && uint64_t(LLONG_MAX) < Value.uval)) + return None; + switch (Form) { + case DW_FORM_data4: + return int32_t(Value.uval); + case DW_FORM_data2: + return int16_t(Value.uval); + case DW_FORM_data1: + return int8_t(Value.uval); + case DW_FORM_sdata: + case DW_FORM_data8: + default: + return Value.sval; + } +} + Optional> DWARFFormValue::getAsBlock() const { if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc)) return None; diff --git a/unittests/DebugInfo/DWARF/DWARFFormValueTest.cpp b/unittests/DebugInfo/DWARF/DWARFFormValueTest.cpp index 4521132de5e..be78f116ce4 100644 --- a/unittests/DebugInfo/DWARF/DWARFFormValueTest.cpp +++ b/unittests/DebugInfo/DWARF/DWARFFormValueTest.cpp @@ -8,7 +8,10 @@ //===----------------------------------------------------------------------===// #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" +#include "llvm/ADT/SmallString.h" #include "llvm/Support/Dwarf.h" +#include "llvm/Support/LEB128.h" +#include "llvm/Support/Host.h" #include "gtest/gtest.h" using namespace llvm; using namespace dwarf; @@ -46,4 +49,75 @@ TEST(DWARFFormValue, FormClass) { EXPECT_TRUE(isFormClass(DW_FORM_ref_sig8, DWARFFormValue::FC_Reference)); } +template +DWARFFormValue createDataXFormValue(uint16_t Form, RawTypeT Value) { + char Raw[sizeof(RawTypeT)]; + memcpy(Raw, &Value, sizeof(RawTypeT)); + uint32_t Offset = 0; + DWARFFormValue Result(Form); + DataExtractor Data(StringRef(Raw, sizeof(RawTypeT)), + sys::IsLittleEndianHost, sizeof(void*)); + Result.extractValue(Data, &Offset, nullptr); + return Result; +} + +DWARFFormValue createULEBFormValue(uint64_t Value) { + SmallString<10> RawData; + raw_svector_ostream OS(RawData); + encodeULEB128(Value, OS); + uint32_t Offset = 0; + DWARFFormValue Result(DW_FORM_udata); + DataExtractor Data(OS.str(), sys::IsLittleEndianHost, sizeof(void*)); + Result.extractValue(Data, &Offset, nullptr); + return Result; +} + +DWARFFormValue createSLEBFormValue(int64_t Value) { + SmallString<10> RawData; + raw_svector_ostream OS(RawData); + encodeSLEB128(Value, OS); + uint32_t Offset = 0; + DWARFFormValue Result(DW_FORM_sdata); + DataExtractor Data(OS.str(), sys::IsLittleEndianHost, sizeof(void*)); + Result.extractValue(Data, &Offset, nullptr); + return Result; +} + +TEST(DWARFFormValue, SignedConstantForms) { + // Check that we correctly sign extend fixed size forms. + auto Sign1 = createDataXFormValue(DW_FORM_data1, -123); + auto Sign2 = createDataXFormValue(DW_FORM_data2, -12345); + auto Sign4 = createDataXFormValue(DW_FORM_data4, -123456789); + auto Sign8 = createDataXFormValue(DW_FORM_data8, -1); + EXPECT_EQ(Sign1.getAsSignedConstant().getValue(), -123); + EXPECT_EQ(Sign2.getAsSignedConstant().getValue(), -12345); + EXPECT_EQ(Sign4.getAsSignedConstant().getValue(), -123456789); + EXPECT_EQ(Sign8.getAsSignedConstant().getValue(), -1); + + // Check that we can handle big positive values, but that we return + // an error just over the limit. + auto UMax = createULEBFormValue(LLONG_MAX); + auto TooBig = createULEBFormValue(LLONG_MAX + 1); + EXPECT_EQ(UMax.getAsSignedConstant().getValue(), LLONG_MAX); + EXPECT_EQ(TooBig.getAsSignedConstant().hasValue(), false); + + // Sanity check some other forms. + auto Data1 = createDataXFormValue(DW_FORM_data1, 120); + auto Data2 = createDataXFormValue(DW_FORM_data2, 32000); + auto Data4 = createDataXFormValue(DW_FORM_data4, 2000000000); + auto Data8 = createDataXFormValue(DW_FORM_data8, 0x1234567812345678LL); + auto LEBMin = createSLEBFormValue(LLONG_MIN); + auto LEBMax = createSLEBFormValue(LLONG_MAX); + auto LEB1 = createSLEBFormValue(-42); + auto LEB2 = createSLEBFormValue(42); + EXPECT_EQ(Data1.getAsSignedConstant().getValue(), 120); + EXPECT_EQ(Data2.getAsSignedConstant().getValue(), 32000); + EXPECT_EQ(Data4.getAsSignedConstant().getValue(), 2000000000); + EXPECT_EQ(Data8.getAsSignedConstant().getValue(), 0x1234567812345678LL); + EXPECT_EQ(LEBMin.getAsSignedConstant().getValue(), LLONG_MIN); + EXPECT_EQ(LEBMax.getAsSignedConstant().getValue(), LLONG_MAX); + EXPECT_EQ(LEB1.getAsSignedConstant().getValue(), -42); + EXPECT_EQ(LEB2.getAsSignedConstant().getValue(), 42); +} + } // end anonymous namespace