X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FAsmPrinter%2FDIEHash.cpp;h=02010654a6f469cacd47a1d3b406e14a48a97ac6;hb=da921ff605b31a92014857dc0f7c37edca5b8913;hp=40db1b2eb0c8e8e2176405eaa13105b08c734f5f;hpb=c3e9457f6d66d1cc16fc37e39ed5fe13f835875c;p=oota-llvm.git diff --git a/lib/CodeGen/AsmPrinter/DIEHash.cpp b/lib/CodeGen/AsmPrinter/DIEHash.cpp index 40db1b2eb0c..02010654a6f 100644 --- a/lib/CodeGen/AsmPrinter/DIEHash.cpp +++ b/lib/CodeGen/AsmPrinter/DIEHash.cpp @@ -11,13 +11,13 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "dwarfdebug" - -#include "DIE.h" +#include "ByteStreamer.h" #include "DIEHash.h" -#include "DwarfCompileUnit.h" +#include "DwarfDebug.h" #include "llvm/ADT/ArrayRef.h" #include "llvm/ADT/StringRef.h" +#include "llvm/CodeGen/AsmPrinter.h" +#include "llvm/CodeGen/DIE.h" #include "llvm/Support/Debug.h" #include "llvm/Support/Dwarf.h" #include "llvm/Support/Endian.h" @@ -26,22 +26,17 @@ using namespace llvm; +#define DEBUG_TYPE "dwarfdebug" + /// \brief Grabs the string in whichever attribute is passed in and returns /// a reference to it. -static StringRef getDIEStringAttr(DIE *Die, uint16_t Attr) { - const SmallVectorImpl &Values = Die->getValues(); - const DIEAbbrev &Abbrevs = Die->getAbbrev(); - +static StringRef getDIEStringAttr(const DIE &Die, uint16_t Attr) { // Iterate through all the attributes until we find the one we're // looking for, if we can't find it return an empty string. - for (size_t i = 0; i < Values.size(); ++i) { - if (Abbrevs.getData()[i].getAttribute() == Attr) { - DIEValue *V = Values[i]; - assert(isa(V) && "String requested. Not a string."); - DIEString *S = cast(V); - return S->getString(); - } - } + for (const auto &V : Die.values()) + if (V.getAttribute() == Attr) + return V.getDIEString().getString(); + return StringRef(""); } @@ -68,31 +63,48 @@ void DIEHash::addULEB128(uint64_t Value) { } while (Value != 0); } +void DIEHash::addSLEB128(int64_t Value) { + DEBUG(dbgs() << "Adding ULEB128 " << Value << " to hash.\n"); + bool More; + do { + uint8_t Byte = Value & 0x7f; + Value >>= 7; + More = !((((Value == 0) && ((Byte & 0x40) == 0)) || + ((Value == -1) && ((Byte & 0x40) != 0)))); + if (More) + Byte |= 0x80; // Mark this byte to show that more bytes will follow. + Hash.update(Byte); + } while (More); +} + /// \brief Including \p Parent adds the context of Parent to the hash.. -void DIEHash::addParentContext(DIE *Parent) { +void DIEHash::addParentContext(const DIE &Parent) { DEBUG(dbgs() << "Adding parent context to hash...\n"); // [7.27.2] For each surrounding type or namespace beginning with the // outermost such construct... - SmallVector Parents; - while (Parent->getTag() != dwarf::DW_TAG_compile_unit) { - Parents.push_back(Parent); - Parent = Parent->getParent(); + SmallVector Parents; + const DIE *Cur = &Parent; + while (Cur->getParent()) { + Parents.push_back(Cur); + Cur = Cur->getParent(); } + assert(Cur->getTag() == dwarf::DW_TAG_compile_unit || + Cur->getTag() == dwarf::DW_TAG_type_unit); // Reverse iterate over our list to go from the outermost construct to the // innermost. - for (SmallVectorImpl::reverse_iterator I = Parents.rbegin(), - E = Parents.rend(); + for (SmallVectorImpl::reverse_iterator I = Parents.rbegin(), + E = Parents.rend(); I != E; ++I) { - DIE *Die = *I; + const DIE &Die = **I; // ... Append the letter "C" to the sequence... addULEB128('C'); // ... Followed by the DWARF tag of the construct... - addULEB128(Die->getTag()); + addULEB128(Die.getTag()); // ... Then the name, taken from the DW_AT_name attribute. StringRef Name = getDIEStringAttr(Die, dwarf::DW_AT_name); @@ -103,140 +115,391 @@ void DIEHash::addParentContext(DIE *Parent) { } // Collect all of the attributes for a particular DIE in single structure. -void DIEHash::collectAttributes(DIE *Die, DIEAttrs &Attrs) { - const SmallVectorImpl &Values = Die->getValues(); - const DIEAbbrev &Abbrevs = Die->getAbbrev(); - +void DIEHash::collectAttributes(const DIE &Die, DIEAttrs &Attrs) { #define COLLECT_ATTR(NAME) \ - Attrs.NAME.Val = Values[i]; \ - Attrs.NAME.Desc = &Abbrevs.getData()[i]; + case dwarf::NAME: \ + Attrs.NAME = V; \ + break - for (size_t i = 0, e = Values.size(); i != e; ++i) { + for (const auto &V : Die.values()) { DEBUG(dbgs() << "Attribute: " - << dwarf::AttributeString(Abbrevs.getData()[i].getAttribute()) + << dwarf::AttributeString(V.getAttribute()) << " added.\n"); - switch (Abbrevs.getData()[i].getAttribute()) { - case dwarf::DW_AT_name: + switch (V.getAttribute()) { COLLECT_ATTR(DW_AT_name); - break; - case dwarf::DW_AT_language: - COLLECT_ATTR(DW_AT_language); - break; + COLLECT_ATTR(DW_AT_accessibility); + COLLECT_ATTR(DW_AT_address_class); + COLLECT_ATTR(DW_AT_allocated); + COLLECT_ATTR(DW_AT_artificial); + COLLECT_ATTR(DW_AT_associated); + COLLECT_ATTR(DW_AT_binary_scale); + COLLECT_ATTR(DW_AT_bit_offset); + COLLECT_ATTR(DW_AT_bit_size); + COLLECT_ATTR(DW_AT_bit_stride); + COLLECT_ATTR(DW_AT_byte_size); + COLLECT_ATTR(DW_AT_byte_stride); + COLLECT_ATTR(DW_AT_const_expr); + COLLECT_ATTR(DW_AT_const_value); + COLLECT_ATTR(DW_AT_containing_type); + COLLECT_ATTR(DW_AT_count); + COLLECT_ATTR(DW_AT_data_bit_offset); + COLLECT_ATTR(DW_AT_data_location); + COLLECT_ATTR(DW_AT_data_member_location); + COLLECT_ATTR(DW_AT_decimal_scale); + COLLECT_ATTR(DW_AT_decimal_sign); + COLLECT_ATTR(DW_AT_default_value); + COLLECT_ATTR(DW_AT_digit_count); + COLLECT_ATTR(DW_AT_discr); + COLLECT_ATTR(DW_AT_discr_list); + COLLECT_ATTR(DW_AT_discr_value); + COLLECT_ATTR(DW_AT_encoding); + COLLECT_ATTR(DW_AT_enum_class); + COLLECT_ATTR(DW_AT_endianity); + COLLECT_ATTR(DW_AT_explicit); + COLLECT_ATTR(DW_AT_is_optional); + COLLECT_ATTR(DW_AT_location); + COLLECT_ATTR(DW_AT_lower_bound); + COLLECT_ATTR(DW_AT_mutable); + COLLECT_ATTR(DW_AT_ordering); + COLLECT_ATTR(DW_AT_picture_string); + COLLECT_ATTR(DW_AT_prototyped); + COLLECT_ATTR(DW_AT_small); + COLLECT_ATTR(DW_AT_segment); + COLLECT_ATTR(DW_AT_string_length); + COLLECT_ATTR(DW_AT_threads_scaled); + COLLECT_ATTR(DW_AT_upper_bound); + COLLECT_ATTR(DW_AT_use_location); + COLLECT_ATTR(DW_AT_use_UTF8); + COLLECT_ATTR(DW_AT_variable_parameter); + COLLECT_ATTR(DW_AT_virtuality); + COLLECT_ATTR(DW_AT_visibility); + COLLECT_ATTR(DW_AT_vtable_elem_location); + COLLECT_ATTR(DW_AT_type); default: break; } } } -// Hash an individual attribute \param Attr based on the type of attribute and -// the form. -void DIEHash::hashAttribute(AttrEntry Attr) { - const DIEValue *Value = Attr.Val; - const DIEAbbrevData *Desc = Attr.Desc; +void DIEHash::hashShallowTypeReference(dwarf::Attribute Attribute, + const DIE &Entry, StringRef Name) { + // append the letter 'N' + addULEB128('N'); + + // the DWARF attribute code (DW_AT_type or DW_AT_friend), + addULEB128(Attribute); + + // the context of the tag, + if (const DIE *Parent = Entry.getParent()) + addParentContext(*Parent); + + // the letter 'E', + addULEB128('E'); + + // and the name of the type. + addString(Name); + + // Currently DW_TAG_friends are not used by Clang, but if they do become so, + // here's the relevant spec text to implement: + // + // For DW_TAG_friend, if the referenced entry is the DW_TAG_subprogram, + // the context is omitted and the name to be used is the ABI-specific name + // of the subprogram (e.g., the mangled linker name). +} + +void DIEHash::hashRepeatedTypeReference(dwarf::Attribute Attribute, + unsigned DieNumber) { + // a) If T is in the list of [previously hashed types], use the letter + // 'R' as the marker + addULEB128('R'); + + addULEB128(Attribute); + + // and use the unsigned LEB128 encoding of [the index of T in the + // list] as the attribute value; + addULEB128(DieNumber); +} + +void DIEHash::hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag, + const DIE &Entry) { + assert(Tag != dwarf::DW_TAG_friend && "No current LLVM clients emit friend " + "tags. Add support here when there's " + "a use case"); + // Step 5 + // If the tag in Step 3 is one of [the below tags] + if ((Tag == dwarf::DW_TAG_pointer_type || + Tag == dwarf::DW_TAG_reference_type || + Tag == dwarf::DW_TAG_rvalue_reference_type || + Tag == dwarf::DW_TAG_ptr_to_member_type) && + // and the referenced type (via the [below attributes]) + // FIXME: This seems overly restrictive, and causes hash mismatches + // there's a decl/def difference in the containing type of a + // ptr_to_member_type, but it's what DWARF says, for some reason. + Attribute == dwarf::DW_AT_type) { + // ... has a DW_AT_name attribute, + StringRef Name = getDIEStringAttr(Entry, dwarf::DW_AT_name); + if (!Name.empty()) { + hashShallowTypeReference(Attribute, Entry, Name); + return; + } + } + + unsigned &DieNumber = Numbering[&Entry]; + if (DieNumber) { + hashRepeatedTypeReference(Attribute, DieNumber); + return; + } - // TODO: Add support for types. + // otherwise, b) use the letter 'T' as the marker, ... + addULEB128('T'); - // Add the letter A to the hash. - addULEB128('A'); + addULEB128(Attribute); - // Then the attribute code and form. - addULEB128(Desc->getAttribute()); - addULEB128(Desc->getForm()); + // ... process the type T recursively by performing Steps 2 through 7, and + // use the result as the attribute value. + DieNumber = Numbering.size(); + computeHash(Entry); +} - // TODO: Add support for additional forms. - switch (Desc->getForm()) { - // TODO: We'll want to add DW_FORM_string here if we start emitting them again. - case dwarf::DW_FORM_strp: - addString(cast(Value)->getString()); +// Hash all of the values in a block like set of values. This assumes that +// all of the data is going to be added as integers. +void DIEHash::hashBlockData(const DIE::const_value_range &Values) { + for (const auto &V : Values) + Hash.update((uint64_t)V.getDIEInteger().getValue()); +} + +// Hash the contents of a loclistptr class. +void DIEHash::hashLocList(const DIELocList &LocList) { + HashingByteStreamer Streamer(*this); + DwarfDebug &DD = *AP->getDwarfDebug(); + const DebugLocStream &Locs = DD.getDebugLocs(); + for (const auto &Entry : Locs.getEntries(Locs.getList(LocList.getValue()))) + DD.emitDebugLocEntry(Streamer, Entry); +} + +// Hash an individual attribute \param Attr based on the type of attribute and +// the form. +void DIEHash::hashAttribute(DIEValue Value, dwarf::Tag Tag) { + dwarf::Attribute Attribute = Value.getAttribute(); + + // Other attribute values use the letter 'A' as the marker, and the value + // consists of the form code (encoded as an unsigned LEB128 value) followed by + // the encoding of the value according to the form code. To ensure + // reproducibility of the signature, the set of forms used in the signature + // computation is limited to the following: DW_FORM_sdata, DW_FORM_flag, + // DW_FORM_string, and DW_FORM_block. + + switch (Value.getType()) { + case DIEValue::isNone: + llvm_unreachable("Expected valid DIEValue"); + + // 7.27 Step 3 + // ... An attribute that refers to another type entry T is processed as + // follows: + case DIEValue::isEntry: + hashDIEEntry(Attribute, Tag, Value.getDIEEntry().getEntry()); + break; + case DIEValue::isInteger: { + addULEB128('A'); + addULEB128(Attribute); + switch (Value.getForm()) { + case dwarf::DW_FORM_data1: + case dwarf::DW_FORM_data2: + case dwarf::DW_FORM_data4: + case dwarf::DW_FORM_data8: + case dwarf::DW_FORM_udata: + case dwarf::DW_FORM_sdata: + addULEB128(dwarf::DW_FORM_sdata); + addSLEB128((int64_t)Value.getDIEInteger().getValue()); + break; + // DW_FORM_flag_present is just flag with a value of one. We still give it a + // value so just use the value. + case dwarf::DW_FORM_flag_present: + case dwarf::DW_FORM_flag: + addULEB128(dwarf::DW_FORM_flag); + addULEB128((int64_t)Value.getDIEInteger().getValue()); + break; + default: + llvm_unreachable("Unknown integer form!"); + } break; - case dwarf::DW_FORM_data1: - case dwarf::DW_FORM_data2: - case dwarf::DW_FORM_data4: - case dwarf::DW_FORM_data8: - case dwarf::DW_FORM_udata: - addULEB128(cast(Value)->getValue()); + } + case DIEValue::isString: + addULEB128('A'); + addULEB128(Attribute); + addULEB128(dwarf::DW_FORM_string); + addString(Value.getDIEString().getString()); break; + case DIEValue::isBlock: + case DIEValue::isLoc: + case DIEValue::isLocList: + addULEB128('A'); + addULEB128(Attribute); + addULEB128(dwarf::DW_FORM_block); + if (Value.getType() == DIEValue::isBlock) { + addULEB128(Value.getDIEBlock().ComputeSize(AP)); + hashBlockData(Value.getDIEBlock().values()); + } else if (Value.getType() == DIEValue::isLoc) { + addULEB128(Value.getDIELoc().ComputeSize(AP)); + hashBlockData(Value.getDIELoc().values()); + } else { + // We could add the block length, but that would take + // a bit of work and not add a lot of uniqueness + // to the hash in some way we could test. + hashLocList(Value.getDIELocList()); + } + break; + // FIXME: It's uncertain whether or not we should handle this at the moment. + case DIEValue::isExpr: + case DIEValue::isLabel: + case DIEValue::isDelta: + case DIEValue::isTypeSignature: + llvm_unreachable("Add support for additional value types."); } } // Go through the attributes from \param Attrs in the order specified in 7.27.4 // and hash them. -void DIEHash::hashAttributes(const DIEAttrs &Attrs) { +void DIEHash::hashAttributes(const DIEAttrs &Attrs, dwarf::Tag Tag) { #define ADD_ATTR(ATTR) \ { \ - if (ATTR.Val != 0) \ - hashAttribute(ATTR); \ + if (ATTR) \ + hashAttribute(ATTR, Tag); \ } - // FIXME: Add the rest. ADD_ATTR(Attrs.DW_AT_name); - ADD_ATTR(Attrs.DW_AT_language); + ADD_ATTR(Attrs.DW_AT_accessibility); + ADD_ATTR(Attrs.DW_AT_address_class); + ADD_ATTR(Attrs.DW_AT_allocated); + ADD_ATTR(Attrs.DW_AT_artificial); + ADD_ATTR(Attrs.DW_AT_associated); + ADD_ATTR(Attrs.DW_AT_binary_scale); + ADD_ATTR(Attrs.DW_AT_bit_offset); + ADD_ATTR(Attrs.DW_AT_bit_size); + ADD_ATTR(Attrs.DW_AT_bit_stride); + ADD_ATTR(Attrs.DW_AT_byte_size); + ADD_ATTR(Attrs.DW_AT_byte_stride); + ADD_ATTR(Attrs.DW_AT_const_expr); + ADD_ATTR(Attrs.DW_AT_const_value); + ADD_ATTR(Attrs.DW_AT_containing_type); + ADD_ATTR(Attrs.DW_AT_count); + ADD_ATTR(Attrs.DW_AT_data_bit_offset); + ADD_ATTR(Attrs.DW_AT_data_location); + ADD_ATTR(Attrs.DW_AT_data_member_location); + ADD_ATTR(Attrs.DW_AT_decimal_scale); + ADD_ATTR(Attrs.DW_AT_decimal_sign); + ADD_ATTR(Attrs.DW_AT_default_value); + ADD_ATTR(Attrs.DW_AT_digit_count); + ADD_ATTR(Attrs.DW_AT_discr); + ADD_ATTR(Attrs.DW_AT_discr_list); + ADD_ATTR(Attrs.DW_AT_discr_value); + ADD_ATTR(Attrs.DW_AT_encoding); + ADD_ATTR(Attrs.DW_AT_enum_class); + ADD_ATTR(Attrs.DW_AT_endianity); + ADD_ATTR(Attrs.DW_AT_explicit); + ADD_ATTR(Attrs.DW_AT_is_optional); + ADD_ATTR(Attrs.DW_AT_location); + ADD_ATTR(Attrs.DW_AT_lower_bound); + ADD_ATTR(Attrs.DW_AT_mutable); + ADD_ATTR(Attrs.DW_AT_ordering); + ADD_ATTR(Attrs.DW_AT_picture_string); + ADD_ATTR(Attrs.DW_AT_prototyped); + ADD_ATTR(Attrs.DW_AT_small); + ADD_ATTR(Attrs.DW_AT_segment); + ADD_ATTR(Attrs.DW_AT_string_length); + ADD_ATTR(Attrs.DW_AT_threads_scaled); + ADD_ATTR(Attrs.DW_AT_upper_bound); + ADD_ATTR(Attrs.DW_AT_use_location); + ADD_ATTR(Attrs.DW_AT_use_UTF8); + ADD_ATTR(Attrs.DW_AT_variable_parameter); + ADD_ATTR(Attrs.DW_AT_virtuality); + ADD_ATTR(Attrs.DW_AT_visibility); + ADD_ATTR(Attrs.DW_AT_vtable_elem_location); + ADD_ATTR(Attrs.DW_AT_type); + + // FIXME: Add the extended attributes. } // Add all of the attributes for \param Die to the hash. -void DIEHash::addAttributes(DIE *Die) { - DIEAttrs Attrs; - memset(&Attrs, 0, sizeof(Attrs)); +void DIEHash::addAttributes(const DIE &Die) { + DIEAttrs Attrs = {}; collectAttributes(Die, Attrs); - hashAttributes(Attrs); + hashAttributes(Attrs, Die.getTag()); +} + +void DIEHash::hashNestedType(const DIE &Die, StringRef Name) { + // 7.27 Step 7 + // ... append the letter 'S', + addULEB128('S'); + + // the tag of C, + addULEB128(Die.getTag()); + + // and the name. + addString(Name); } // Compute the hash of a DIE. This is based on the type signature computation // given in section 7.27 of the DWARF4 standard. It is the md5 hash of a // flattened description of the DIE. -void DIEHash::computeHash(DIE *Die) { - +void DIEHash::computeHash(const DIE &Die) { // Append the letter 'D', followed by the DWARF tag of the DIE. addULEB128('D'); - addULEB128(Die->getTag()); + addULEB128(Die.getTag()); // Add each of the attributes of the DIE. addAttributes(Die); // Then hash each of the children of the DIE. - for (std::vector::const_iterator I = Die->getChildren().begin(), - E = Die->getChildren().end(); - I != E; ++I) - computeHash(*I); + for (auto &C : Die.children()) { + // 7.27 Step 7 + // If C is a nested type entry or a member function entry, ... + if (isType(C.getTag()) || C.getTag() == dwarf::DW_TAG_subprogram) { + StringRef Name = getDIEStringAttr(C, dwarf::DW_AT_name); + // ... and has a DW_AT_name attribute + if (!Name.empty()) { + hashNestedType(C, Name); + continue; + } + } + computeHash(C); + } + + // Following the last (or if there are no children), append a zero byte. + Hash.update(makeArrayRef((uint8_t)'\0')); } /// This is based on the type signature computation given in section 7.27 of the -/// DWARF4 standard. It is the md5 hash of a flattened description of the DIE -/// with the exception that we are hashing only the context and the name of the -/// type. -uint64_t DIEHash::computeDIEODRSignature(DIE *Die) { - - // Add the contexts to the hash. We won't be computing the ODR hash for - // function local types so it's safe to use the generic context hashing - // algorithm here. - // FIXME: If we figure out how to account for linkage in some way we could - // actually do this with a slight modification to the parent hash algorithm. - DIE *Parent = Die->getParent(); - if (Parent) - addParentContext(Parent); - - // Add the current DIE information. - - // Add the DWARF tag of the DIE. - addULEB128(Die->getTag()); +/// DWARF4 standard. It is an md5 hash of the flattened description of the DIE +/// with the inclusion of the full CU and all top level CU entities. +// TODO: Initialize the type chain at 0 instead of 1 for CU signatures. +uint64_t DIEHash::computeCUSignature(const DIE &Die) { + Numbering.clear(); + Numbering[&Die] = 1; - // Add the name of the type to the hash. - addString(getDIEStringAttr(Die, dwarf::DW_AT_name)); + // Hash the DIE. + computeHash(Die); - // Now get the result. + // Now return the result. MD5::MD5Result Result; Hash.final(Result); // ... take the least significant 8 bytes and return those. Our MD5 // implementation always returns its results in little endian, swap bytes // appropriately. - return *reinterpret_cast(Result + 8); + return support::endian::read64le(Result + 8); } /// This is based on the type signature computation given in section 7.27 of the /// DWARF4 standard. It is an md5 hash of the flattened description of the DIE -/// with the inclusion of the full CU and all top level CU entities. -uint64_t DIEHash::computeCUSignature(DIE *Die) { +/// with the inclusion of additional forms not specifically called out in the +/// standard. +uint64_t DIEHash::computeTypeSignature(const DIE &Die) { + Numbering.clear(); + Numbering[&Die] = 1; + + if (const DIE *Parent = Die.getParent()) + addParentContext(*Parent); // Hash the DIE. computeHash(Die); @@ -248,5 +511,5 @@ uint64_t DIEHash::computeCUSignature(DIE *Die) { // ... take the least significant 8 bytes and return those. Our MD5 // implementation always returns its results in little endian, swap bytes // appropriately. - return *reinterpret_cast(Result + 8); + return support::endian::read64le(Result + 8); }