From 4d9039c8dc2d1f0be1b5ee486d5a83b1614b038a Mon Sep 17 00:00:00 2001 From: Jim Ingham Date: Wed, 31 Mar 2021 16:59:52 -0700 Subject: [PATCH] Add support for fetching signed values from tagged pointers. The ObjC runtime offers both signed & unsigned tagged pointer value accessors to tagged pointer providers, but lldb's tagged pointer code only implemented the unsigned one. This patch adds an emulation of the signed one. The motivation for doing this is that NSNumbers use the signed accessor (they are always signed) and we need to follow that in our summary provider or we will get incorrect values for negative NSNumbers. The data-formatter-objc test file had NSNumber examples (along with lots of other goodies) but the NSNumber values weren't tested. So I also added checks for those values to the test. I also did a quick audit of the other types in that main.m file, and it looks like pretty much all the other values are either intermediates or are tested. Differential Revision: https://reviews.llvm.org/D99694 --- lldb/source/Plugins/Language/ObjC/Cocoa.cpp | 12 +++++++--- .../AppleObjCRuntime/AppleObjCClassDescriptorV2.h | 28 ++++++++++++++++++++-- .../ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.h | 6 +++++ .../ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp | 27 ++++++++++++--------- .../LanguageRuntime/ObjC/ObjCLanguageRuntime.h | 10 ++++++++ .../data-formatter-objc/TestDataFormatterObjCCF.py | 26 +++++++++++++++++++- 6 files changed, 92 insertions(+), 17 deletions(-) diff --git a/lldb/source/Plugins/Language/ObjC/Cocoa.cpp b/lldb/source/Plugins/Language/ObjC/Cocoa.cpp index d871d34..fe64740 100644 --- a/lldb/source/Plugins/Language/ObjC/Cocoa.cpp +++ b/lldb/source/Plugins/Language/ObjC/Cocoa.cpp @@ -351,7 +351,7 @@ static void NSNumber_FormatInt(ValueObject &valobj, Stream &stream, int value, } static void NSNumber_FormatLong(ValueObject &valobj, Stream &stream, - uint64_t value, lldb::LanguageType lang) { + int64_t value, lldb::LanguageType lang) { static ConstString g_TypeHint("NSNumber:long"); std::string prefix, suffix; @@ -456,9 +456,15 @@ bool lldb_private::formatters::NSNumberSummaryProvider( return NSDecimalNumberSummaryProvider(valobj, stream, options); if (class_name == "NSNumber" || class_name == "__NSCFNumber") { - uint64_t value = 0; + int64_t value = 0; uint64_t i_bits = 0; - if (descriptor->GetTaggedPointerInfo(&i_bits, &value)) { + if (descriptor->GetTaggedPointerInfoSigned(&i_bits, &value)) { + // Check for "preserved" numbers. We still don't support them yet. + if (i_bits & 0x8) { + lldbassert(!static_cast("We should handle preserved numbers!")); + return false; + } + switch (i_bits) { case 0: NSNumber_FormatChar(valobj, stream, (char)value, options.GetLanguage()); diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCClassDescriptorV2.h b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCClassDescriptorV2.h index 9ef21c6..1bea314 100644 --- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCClassDescriptorV2.h +++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCClassDescriptorV2.h @@ -41,6 +41,12 @@ public: return false; } + bool GetTaggedPointerInfoSigned(uint64_t *info_bits = nullptr, + int64_t *value_bits = nullptr, + uint64_t *payload = nullptr) override { + return false; + } + uint64_t GetInstanceSize() override; ObjCLanguageRuntime::ObjCISA GetISA() override { return m_objc_class_ptr; } @@ -253,7 +259,7 @@ public: ClassDescriptorV2Tagged( ObjCLanguageRuntime::ClassDescriptorSP actual_class_sp, - uint64_t payload) { + uint64_t u_payload, int64_t s_payload) { if (!actual_class_sp) { m_valid = false; return; @@ -264,9 +270,10 @@ public: return; } m_valid = true; - m_payload = payload; + m_payload = u_payload; m_info_bits = (m_payload & 0x0FULL); m_value_bits = (m_payload & ~0x0FULL) >> 4; + m_value_bits_signed = (s_payload & ~0x0FLL) >> 4; } ~ClassDescriptorV2Tagged() override = default; @@ -308,6 +315,18 @@ public: return true; } + bool GetTaggedPointerInfoSigned(uint64_t *info_bits = nullptr, + int64_t *value_bits = nullptr, + uint64_t *payload = nullptr) override { + if (info_bits) + *info_bits = GetInfoBits(); + if (value_bits) + *value_bits = GetValueBitsSigned(); + if (payload) + *payload = GetPayload(); + return true; + } + uint64_t GetInstanceSize() override { return (IsValid() ? m_pointer_size : 0); } @@ -319,6 +338,10 @@ public: // these calls are not part of any formal tagged pointers specification virtual uint64_t GetValueBits() { return (IsValid() ? m_value_bits : 0); } + virtual int64_t GetValueBitsSigned() { + return (IsValid() ? m_value_bits_signed : 0); + } + virtual uint64_t GetInfoBits() { return (IsValid() ? m_info_bits : 0); } virtual uint64_t GetPayload() { return (IsValid() ? m_payload : 0); } @@ -329,6 +352,7 @@ private: bool m_valid; uint64_t m_info_bits; uint64_t m_value_bits; + int64_t m_value_bits_signed; uint64_t m_payload; }; diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.h b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.h index 4eb7d97..0164f83 100644 --- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.h +++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.h @@ -64,6 +64,12 @@ public: return false; } + bool GetTaggedPointerInfoSigned(uint64_t *info_bits = nullptr, + int64_t *value_bits = nullptr, + uint64_t *payload = nullptr) override { + return false; + } + uint64_t GetInstanceSize() override { return m_instance_size; } ObjCISA GetISA() override { return m_isa; } diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp index 523b8e9..6b65ace 100644 --- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp +++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp @@ -2457,7 +2457,6 @@ ObjCLanguageRuntime::ClassDescriptorSP AppleObjCRuntimeV2::TaggedPointerVendorRuntimeAssisted::GetClassDescriptor( lldb::addr_t ptr) { ClassDescriptorSP actual_class_descriptor_sp; - uint64_t data_payload; uint64_t unobfuscated = (ptr) ^ m_runtime.GetTaggedPointerObfuscator(); if (!IsPossibleTaggedPointer(unobfuscated)) @@ -2485,12 +2484,15 @@ AppleObjCRuntimeV2::TaggedPointerVendorRuntimeAssisted::GetClassDescriptor( m_cache[slot] = actual_class_descriptor_sp; } - data_payload = + uint64_t data_payload = (((uint64_t)unobfuscated << m_objc_debug_taggedpointer_payload_lshift) >> m_objc_debug_taggedpointer_payload_rshift); - - return ClassDescriptorSP( - new ClassDescriptorV2Tagged(actual_class_descriptor_sp, data_payload)); + int64_t data_payload_signed = + ((int64_t)((int64_t)unobfuscated + << m_objc_debug_taggedpointer_payload_lshift) >> + m_objc_debug_taggedpointer_payload_rshift); + return ClassDescriptorSP(new ClassDescriptorV2Tagged( + actual_class_descriptor_sp, data_payload, data_payload_signed)); } AppleObjCRuntimeV2::TaggedPointerVendorExtended::TaggedPointerVendorExtended( @@ -2542,7 +2544,6 @@ ObjCLanguageRuntime::ClassDescriptorSP AppleObjCRuntimeV2::TaggedPointerVendorExtended::GetClassDescriptor( lldb::addr_t ptr) { ClassDescriptorSP actual_class_descriptor_sp; - uint64_t data_payload; uint64_t unobfuscated = (ptr) ^ m_runtime.GetTaggedPointerObfuscator(); if (!IsPossibleTaggedPointer(unobfuscated)) @@ -2573,12 +2574,16 @@ AppleObjCRuntimeV2::TaggedPointerVendorExtended::GetClassDescriptor( m_ext_cache[slot] = actual_class_descriptor_sp; } - data_payload = (((uint64_t)unobfuscated - << m_objc_debug_taggedpointer_ext_payload_lshift) >> - m_objc_debug_taggedpointer_ext_payload_rshift); + uint64_t data_payload = (((uint64_t)unobfuscated + << m_objc_debug_taggedpointer_ext_payload_lshift) >> + m_objc_debug_taggedpointer_ext_payload_rshift); + int64_t data_payload_signed = + ((int64_t)((int64_t)unobfuscated + << m_objc_debug_taggedpointer_ext_payload_lshift) >> + m_objc_debug_taggedpointer_ext_payload_rshift); - return ClassDescriptorSP( - new ClassDescriptorV2Tagged(actual_class_descriptor_sp, data_payload)); + return ClassDescriptorSP(new ClassDescriptorV2Tagged( + actual_class_descriptor_sp, data_payload, data_payload_signed)); } AppleObjCRuntimeV2::NonPointerISACache::NonPointerISACache( diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h b/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h index 683eff7..9fc8586 100644 --- a/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h +++ b/lldb/source/Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h @@ -87,10 +87,20 @@ public: virtual bool IsValid() = 0; + /// There are two routines in the ObjC runtime that tagged pointer clients + /// can call to get the value from their tagged pointer, one that retrieves + /// it as an unsigned value and one a signed value. These two + /// GetTaggedPointerInfo methods mirror those two ObjC runtime calls. + /// @{ virtual bool GetTaggedPointerInfo(uint64_t *info_bits = nullptr, uint64_t *value_bits = nullptr, uint64_t *payload = nullptr) = 0; + virtual bool GetTaggedPointerInfoSigned(uint64_t *info_bits = nullptr, + int64_t *value_bits = nullptr, + uint64_t *payload = nullptr) = 0; + /// @} + virtual uint64_t GetInstanceSize() = 0; // use to implement version-specific additional constraints on pointers diff --git a/lldb/test/API/functionalities/data-formatter/data-formatter-objc/TestDataFormatterObjCCF.py b/lldb/test/API/functionalities/data-formatter/data-formatter-objc/TestDataFormatterObjCCF.py index 63f4b71..63ba598 100644 --- a/lldb/test/API/functionalities/data-formatter/data-formatter-objc/TestDataFormatterObjCCF.py +++ b/lldb/test/API/functionalities/data-formatter/data-formatter-objc/TestDataFormatterObjCCF.py @@ -45,7 +45,6 @@ class ObjCDataFormatterCF(ObjCDataFormatterTestCase): '(Point) point = (v=7, h=12)', '(Point *) point_ptr = (v=7, h=12)', '(SEL) foo_selector = "foo_selector_impl"' ] - self.expect("frame variable", substrs=expect_strings) if self.getArchitecture() in ['i386', 'x86_64']: @@ -56,3 +55,28 @@ class ObjCDataFormatterCF(ObjCDataFormatterTestCase): '(HIRect) hi_rect = origin=(x = 3, y = 5) size=(width = 4, height = 6)', ] self.expect("frame variable", substrs=extra_string) + + # The original tests left out testing the NSNumber values, so do that here. + # This set is all pointers, with summaries, so we only check the summary. + var_list_pointer = [ + ['NSNumber *', 'num1', '(int)5'], + ['NSNumber *', 'num2', '(float)3.140000'], + ['NSNumber *', 'num3', '(double)3.14'], + ['NSNumber *', 'num4', '(int128_t)18446744073709551614'], + ['NSNumber *', 'num5', '(char)65'], + ['NSNumber *', 'num6', '(long)255'], + ['NSNumber *', 'num7', '(long)2000000'], + ['NSNumber *', 'num8_Y', 'YES'], + ['NSNumber *', 'num8_N', 'NO'], + ['NSNumber *', 'num9', '(short)-31616'], + ['NSNumber *', 'num_at1', '(int)12'], + ['NSNumber *', 'num_at2', '(int)-12'], + ['NSNumber *', 'num_at3', '(double)12.5'], + ['NSNumber *', 'num_at4', '(double)-12.5'], + ['NSDecimalNumber *', 'decimal_number', '123456 x 10^-10'], + ['NSDecimalNumber *', 'decimal_number_neg', '-123456 x 10^10'] + ] + for type, var_path, summary in var_list_pointer: + self.expect_var_path(var_path, summary, None, type) + + -- 2.7.4