#define DEBUG_TYPE "dwarfdebug"
-#include "DIE.h"
#include "DIEHash.h"
-#include "DwarfCompileUnit.h"
+
+#include "DIE.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Debug.h"
/// \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<DIEValue *> &Values = Die->getValues();
- const DIEAbbrev &Abbrevs = Die->getAbbrev();
+static StringRef getDIEStringAttr(const DIE &Die, uint16_t Attr) {
+ const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
+ const DIEAbbrev &Abbrevs = Die.getAbbrev();
// Iterate through all the attributes until we find the one we're
// looking for, if we can't find it return an empty string.
}
/// \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<DIE *, 1> Parents;
- while (Parent->getTag() != dwarf::DW_TAG_compile_unit) {
- Parents.push_back(Parent);
- Parent = Parent->getParent();
+ SmallVector<const DIE *, 1> 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<DIE *>::reverse_iterator I = Parents.rbegin(),
- E = Parents.rend();
+ for (SmallVectorImpl<const DIE *>::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);
}
// Collect all of the attributes for a particular DIE in single structure.
-void DIEHash::collectAttributes(DIE *Die, DIEAttrs &Attrs) {
- const SmallVectorImpl<DIEValue *> &Values = Die->getValues();
- const DIEAbbrev &Abbrevs = Die->getAbbrev();
+void DIEHash::collectAttributes(const DIE &Die, DIEAttrs &Attrs) {
+ const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
+ const DIEAbbrev &Abbrevs = Die.getAbbrev();
#define COLLECT_ATTR(NAME) \
case dwarf::NAME: \
}
}
+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;
+ }
+
+ // otherwise, b) use the letter 'T' as a the marker, ...
+ addULEB128('T');
+
+ addULEB128(Attribute);
+
+ // ... process the type T recursively by performing Steps 2 through 7, and
+ // use the result as the attribute value.
+ DieNumber = Numbering.size();
+ computeHash(Entry);
+}
+
// Hash an individual attribute \param Attr based on the type of attribute and
// the form.
-void DIEHash::hashAttribute(AttrEntry Attr) {
+void DIEHash::hashAttribute(AttrEntry Attr, dwarf::Tag Tag) {
const DIEValue *Value = Attr.Val;
const DIEAbbrevData *Desc = Attr.Desc;
+ dwarf::Attribute Attribute = Desc->getAttribute();
- // 7.27s3
+ // 7.27 Step 3
// ... An attribute that refers to another type entry T is processed as
// follows:
- // a) If T is in the list of [previously hashed types], use the letter 'R' as
- // the marker and use the unsigned LEB128 encoding of [the index of T in the
- // list] as the attribute value; otherwise,
-
- // [TODO: implement clause (a)]
-
if (const DIEEntry *EntryAttr = dyn_cast<DIEEntry>(Value)) {
- DIE *Entry = EntryAttr->getEntry();
-
- // b) use the letter 'T' as a the marker, ...
- addULEB128('T');
-
- addULEB128(Desc->getAttribute());
-
- // ... process the type T recursively by performing Steps 2 through 7, and
- // use the result as the attribute value.
- computeHash(Entry);
+ hashDIEEntry(Attribute, Tag, *EntryAttr->getEntry());
return;
}
// Other attribute values use the letter 'A' as the marker, ...
addULEB128('A');
- addULEB128(Desc->getAttribute());
+ addULEB128(Attribute);
// ... 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
case dwarf::DW_FORM_string:
llvm_unreachable(
"Add support for DW_FORM_string if we ever start emitting them again");
+ case dwarf::DW_FORM_GNU_str_index:
case dwarf::DW_FORM_strp:
addULEB128(dwarf::DW_FORM_string);
addString(cast<DIEString>(Value)->getString());
addULEB128(dwarf::DW_FORM_sdata);
addSLEB128((int64_t)cast<DIEInteger>(Value)->getValue());
break;
- // TODO: Add support for additional forms.
+ default:
+ llvm_unreachable("Add support for additional forms");
}
}
// 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); \
+ hashAttribute(ATTR, Tag); \
}
ADD_ATTR(Attrs.DW_AT_name);
}
// Add all of the attributes for \param Die to the hash.
-void DIEHash::addAttributes(DIE *Die) {
+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<DIE *>::const_iterator I = Die->getChildren().begin(),
- E = Die->getChildren().end();
- I != E; ++I)
- computeHash(*I);
+ for (std::vector<DIE *>::const_iterator I = Die.getChildren().begin(),
+ E = Die.getChildren().end();
+ I != E; ++I) {
+ // 7.27 Step 7
+ // If C is a nested type entry or a member function entry, ...
+ if (isType((*I)->getTag()) || (*I)->getTag() == dwarf::DW_TAG_subprogram) {
+ StringRef Name = getDIEStringAttr(**I, dwarf::DW_AT_name);
+ // ... and has a DW_AT_name attribute
+ if (!Name.empty()) {
+ hashNestedType(**I, Name);
+ continue;
+ }
+ }
+ computeHash(**I);
+ }
// Following the last (or if there are no children), append a zero byte.
Hash.update(makeArrayRef((uint8_t)'\0'));
/// 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) {
+uint64_t DIEHash::computeDIEODRSignature(const 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);
+ if (const DIE *Parent = Die.getParent())
+ addParentContext(*Parent);
// Add the current DIE information.
// Add the DWARF tag of the DIE.
- addULEB128(Die->getTag());
+ addULEB128(Die.getTag());
// Add the name of the type to the hash.
addString(getDIEStringAttr(Die, dwarf::DW_AT_name));
/// 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(DIE *Die) {
+uint64_t DIEHash::computeCUSignature(const DIE &Die) {
+ Numbering.clear();
+ Numbering[&Die] = 1;
// Hash the DIE.
computeHash(Die);
/// DWARF4 standard. It is an md5 hash of the flattened description of the DIE
/// with the inclusion of additional forms not specifically called out in the
/// standard.
-uint64_t DIEHash::computeTypeSignature(DIE *Die) {
+uint64_t DIEHash::computeTypeSignature(const DIE &Die) {
+ Numbering.clear();
+ Numbering[&Die] = 1;
- if (DIE *Parent = Die->getParent())
- addParentContext(Parent);
+ if (const DIE *Parent = Die.getParent())
+ addParentContext(*Parent);
// Hash the DIE.
computeHash(Die);