[llvm] r188243 - Add the start of DIE hashing for DWARF4 type units and split dwarf
David Blaikie
dblaikie at gmail.com
Wed Aug 14 15:26:04 PDT 2013
Passed by reference (& passed another of these by const ref, rather
than value, below - since I assume this will grow to be clearly more
than you want to pass by value?) rather than pointer in r188422.
On Tue, Aug 13, 2013 at 1:01 AM, Eric Christopher <echristo at gmail.com> wrote:
> I did. Thanks.
>
> On Aug 13, 2013 12:59 AM, "Evgeniy Stepanov" <eugeni.stepanov at gmail.com>
> wrote:
>>
>> I've tried to fix this in r188254. Please verify.
>>
>> On Tue, Aug 13, 2013 at 11:34 AM, Evgeniy Stepanov
>> <eugeni.stepanov at gmail.com> wrote:
>> > On Tue, Aug 13, 2013 at 5:21 AM, Eric Christopher <echristo at gmail.com>
>> > wrote:
>> >> Author: echristo
>> >> Date: Mon Aug 12 20:21:55 2013
>> >> New Revision: 188243
>> >>
>> >> URL: http://llvm.org/viewvc/llvm-project?rev=188243&view=rev
>> >> Log:
>> >> Add the start of DIE hashing for DWARF4 type units and split dwarf
>> >> CUs.
>> >>
>> >> Currently only hashes the name of CUs and the names of any children,
>> >> but it's an obvious first step to show the framework. The testcase
>> >> should continue to be correct, however, as it's an empty TU.
>> >>
>> >> Added:
>> >> llvm/trunk/test/DebugInfo/X86/fission-hash.ll
>> >> Modified:
>> >> llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.cpp
>> >> llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.h
>> >> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>> >>
>> >> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.cpp?rev=188243&r1=188242&r2=188243&view=diff
>> >>
>> >> ==============================================================================
>> >> --- llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.cpp (original)
>> >> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.cpp Mon Aug 12 20:21:55
>> >> 2013
>> >> @@ -102,6 +102,92 @@ void DIEHash::addParentContext(DIE *Pare
>> >> }
>> >> }
>> >>
>> >> +// Collect all of the attributes for a particular DIE in single
>> >> structure.
>> >> +void DIEHash::collectAttributes(DIE *Die, DIEAttrs Attrs) {
>> >
>> > I wonder if you meant to pass Attrs by reference?
>> > Otherwise this function does not seem to be doing anything useful.
>> >
>> >> + const SmallVectorImpl<DIEValue *> &Values = Die->getValues();
>> >> + const DIEAbbrev &Abbrevs = Die->getAbbrev();
>> >> +
>> >> +#define COLLECT_ATTR(NAME)
>> >> \
>> >> + Attrs.NAME.Val = Values[i];
>> >> \
>> >> + Attrs.NAME.Desc = &Abbrevs.getData()[i];
>> >> +
>> >> + for (size_t i = 0, e = Values.size(); i != e; ++i) {
>> >> + DEBUG(dbgs() << "Attribute: "
>> >> + <<
>> >> dwarf::AttributeString(Abbrevs.getData()[i].getAttribute())
>> >> + << " added.\n");
>> >> + switch (Abbrevs.getData()[i].getAttribute()) {
>> >> + case dwarf::DW_AT_name:
>> >> + COLLECT_ATTR(DW_AT_name);
>> >> + break;
>> >> + 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;
>> >> +
>> >> + // TODO: Add support for types.
>> >> +
>> >> + // Add the letter A to the hash.
>> >> + addULEB128('A');
>> >> +
>> >> + // Then the attribute code and form.
>> >> + addULEB128(Desc->getAttribute());
>> >> + addULEB128(Desc->getForm());
>> >> +
>> >> + // TODO: Add support for additional forms.
>> >> + switch (Desc->getForm()) {
>> >> + case dwarf::DW_FORM_strp:
>> >> + addString(cast<DIEString>(Value)->getString());
>> >> + break;
>> >> + }
>> >> +}
>> >> +
>> >> +// Go through the attributes from \param Attrs in the order specified
>> >> in 7.27.4
>> >> +// and hash them.
>> >> +void DIEHash::hashAttributes(DIEAttrs Attrs) {
>> >> +#define ADD_ATTR(ATTR)
>> >> \
>> >> + {
>> >> \
>> >> + if (ATTR.Val != 0)
>> >> \
>> >> + hashAttribute(ATTR);
>> >> \
>> >> + }
>> >> +
>> >> + // FIXME: Add the rest.
>> >> + ADD_ATTR(Attrs.DW_AT_name);
>> >> +}
>> >> +
>> >> +// Add all of the attributes for \param Die to the hash.
>> >> +void DIEHash::addAttributes(DIE *Die) {
>> >> + DIEAttrs Attrs;
>> >> + memset(&Attrs, 0, sizeof(Attrs));
>> >> + collectAttributes(Die, Attrs);
>> >> + hashAttributes(Attrs);
>> >> +}
>> >> +
>> >> +// 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) {
>> >> +
>> >> + // Append the letter 'D', followed by the DWARF tag of the DIE.
>> >> + addULEB128('D');
>> >> + 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);
>> >> +}
>> >> +
>> >> /// 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
>> >> @@ -129,6 +215,24 @@ uint64_t DIEHash::computeDIEODRSignature
>> >> 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<support::ulittle64_t *>(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) {
>> >> +
>> >> + // Hash the DIE.
>> >> + computeHash(Die);
>> >> +
>> >> + // 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.
>> >>
>> >> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.h
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.h?rev=188243&r1=188242&r2=188243&view=diff
>> >>
>> >> ==============================================================================
>> >> --- llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.h (original)
>> >> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DIEHash.h Mon Aug 12 20:21:55
>> >> 2013
>> >> @@ -20,15 +20,35 @@ class CompileUnit;
>> >> /// \brief An object containing the capability of hashing and adding
>> >> hash
>> >> /// attributes onto a DIE.
>> >> class DIEHash {
>> >> + // The entry for a particular attribute.
>> >> + struct AttrEntry {
>> >> + const DIEValue *Val;
>> >> + const DIEAbbrevData *Desc;
>> >> + };
>> >> +
>> >> + // Collection of all attributes used in hashing a particular DIE.
>> >> + struct DIEAttrs {
>> >> + AttrEntry DW_AT_name;
>> >> + };
>> >> +
>> >> public:
>> >> /// \brief Computes the ODR signature
>> >> uint64_t computeDIEODRSignature(DIE *Die);
>> >>
>> >> + /// \brief Computes the CU signature
>> >> + uint64_t computeCUSignature(DIE *Die);
>> >> +
>> >> // Helper routines to process parts of a DIE.
>> >> - private:
>> >> +private:
>> >> /// \brief Adds the parent context of \param Die to the hash.
>> >> void addParentContext(DIE *Die);
>> >> -
>> >> +
>> >> + /// \brief Adds the attributes of \param Die to the hash.
>> >> + void addAttributes(DIE *Die);
>> >> +
>> >> + /// \brief Computes the full DWARF4 7.27 hash of the DIE.
>> >> + void computeHash(DIE *Die);
>> >> +
>> >> // Routines that add DIEValues to the hash.
>> >> private:
>> >> /// \brief Encodes and adds \param Value to the hash as a ULEB128.
>> >> @@ -36,7 +56,17 @@ private:
>> >>
>> >> /// \brief Adds \param Str to the hash and includes a NULL byte.
>> >> void addString(StringRef Str);
>> >> -
>> >> +
>> >> + /// \brief Collects the attributes of DIE \param Die into the \param
>> >> Attrs
>> >> + /// structure.
>> >> + void collectAttributes(DIE *Die, DIEAttrs Attrs);
>> >> +
>> >> + /// \brief Hashes the attributes in \param Attrs in order.
>> >> + void hashAttributes(DIEAttrs Attrs);
>> >> +
>> >> + /// \brief Hashes an individual attribute.
>> >> + void hashAttribute(AttrEntry Attr);
>> >> +
>> >> private:
>> >> MD5 Hash;
>> >> };
>> >>
>> >> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=188243&r1=188242&r2=188243&view=diff
>> >>
>> >> ==============================================================================
>> >> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
>> >> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Mon Aug 12
>> >> 20:21:55 2013
>> >> @@ -67,6 +67,11 @@ GenerateODRHash("generate-odr-hash", cl:
>> >> cl::desc("Add an ODR hash to external type DIEs."),
>> >> cl::init(false));
>> >>
>> >> +static cl::opt<bool>
>> >> +GenerateCUHash("generate-cu-hash", cl::Hidden,
>> >> + cl::desc("Add the CU hash as the dwo_id."),
>> >> + cl::init(false));
>> >> +
>> >> namespace {
>> >> enum DefaultOnOff {
>> >> Default,
>> >> @@ -1024,14 +1029,19 @@ void DwarfDebug::finalizeModuleInfo() {
>> >> // If we're splitting the dwarf out now that we've got the entire
>> >> // CU then construct a skeleton CU based upon it.
>> >> if (useSplitDwarf()) {
>> >> + uint64_t ID = 0;
>> >> + if (GenerateCUHash) {
>> >> + DIEHash CUHash;
>> >> + ID = CUHash.computeCUSignature(TheCU->getCUDie());
>> >> + }
>> >> // This should be a unique identifier when we want to build .dwp
>> >> files.
>> >> TheCU->addUInt(TheCU->getCUDie(), dwarf::DW_AT_GNU_dwo_id,
>> >> - dwarf::DW_FORM_data8, 0);
>> >> + dwarf::DW_FORM_data8, ID);
>> >> // Now construct the skeleton CU associated.
>> >> CompileUnit *SkCU = constructSkeletonCU(CUI->first);
>> >> // This should be a unique identifier when we want to build .dwp
>> >> files.
>> >> SkCU->addUInt(SkCU->getCUDie(), dwarf::DW_AT_GNU_dwo_id,
>> >> - dwarf::DW_FORM_data8, 0);
>> >> + dwarf::DW_FORM_data8, ID);
>> >> }
>> >> }
>> >>
>> >>
>> >> Added: llvm/trunk/test/DebugInfo/X86/fission-hash.ll
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/fission-hash.ll?rev=188243&view=auto
>> >>
>> >> ==============================================================================
>> >> --- llvm/trunk/test/DebugInfo/X86/fission-hash.ll (added)
>> >> +++ llvm/trunk/test/DebugInfo/X86/fission-hash.ll Mon Aug 12 20:21:55
>> >> 2013
>> >> @@ -0,0 +1,15 @@
>> >> +; RUN: llc -split-dwarf=Enable -generate-cu-hash -O0 %s
>> >> -mtriple=x86_64-unknown-linux-gnu -filetype=obj -o %t
>> >> +; RUN: llvm-dwarfdump -debug-dump=all %t | FileCheck %s
>> >> +
>> >> +; The source is an empty file.
>> >> +
>> >> +; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x356a7d50a77f5177)
>> >> +; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x356a7d50a77f5177)
>> >> +
>> >> +!llvm.dbg.cu = !{!0}
>> >> +!llvm.module.flags = !{!3}
>> >> +
>> >> +!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"clang
>> >> version 3.4 (trunk 188230) (llvm/trunk 188234)", i1 false, metadata !"", i32
>> >> 0, metadata !2, metadata !2, metadata !2, metadata !2, metadata !2, metadata
>> >> !"foo.dwo"} ; [ DW_TAG_compile_unit ]
>> >> [/usr/local/google/home/echristo/tmp/foo.c] [DW_LANG_C99]
>> >> +!1 = metadata !{metadata !"foo.c", metadata
>> >> !"/usr/local/google/home/echristo/tmp"}
>> >> +!2 = metadata !{i32 0}
>> >> +!3 = metadata !{i32 2, metadata !"Dwarf Version", i32 3}
>> >>
>> >>
>> >> _______________________________________________
>> >> llvm-commits mailing list
>> >> llvm-commits at cs.uiuc.edu
>> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>
>
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