[llvm] r198398 - Revert "Debug Info: Type Units: Simplify type hashing using IR-provided unique names."
David Blaikie
dblaikie at gmail.com
Thu Jan 2 20:49:04 PST 2014
Author: dblaikie
Date: Thu Jan 2 22:49:04 2014
New Revision: 198398
URL: http://llvm.org/viewvc/llvm-project?rev=198398&view=rev
Log:
Revert "Debug Info: Type Units: Simplify type hashing using IR-provided unique names."
Reverting due to bot failure I won't have time to investigate until
tomorrow.
This reverts commit r198397.
Modified:
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
llvm/trunk/test/DebugInfo/X86/c-type-units.ll
llvm/trunk/test/DebugInfo/X86/generate-odr-hash.ll
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=198398&r1=198397&r2=198398&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Thu Jan 2 22:49:04 2014
@@ -58,6 +58,11 @@ static cl::opt<bool> UnknownLocations(
cl::desc("Make an absence of debug location information explicit."),
cl::init(false));
+static cl::opt<bool>
+GenerateODRHash("generate-odr-hash", cl::Hidden,
+ 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));
@@ -1014,6 +1019,41 @@ void DwarfDebug::collectDeadVariables()
}
}
+// Type Signature [7.27] and ODR Hash code.
+
+/// \brief Grabs the string in whichever attribute is passed in and returns
+/// a reference to it. Returns "" if the attribute doesn't exist.
+static StringRef getDIEStringAttr(DIE *Die, unsigned Attr) {
+ DIEValue *V = Die->findAttribute(Attr);
+
+ if (DIEString *S = dyn_cast_or_null<DIEString>(V))
+ return S->getString();
+
+ return StringRef("");
+}
+
+/// Return true if the current DIE is contained within an anonymous namespace.
+static bool isContainedInAnonNamespace(DIE *Die) {
+ DIE *Parent = Die->getParent();
+
+ while (Parent) {
+ if (Parent->getTag() == dwarf::DW_TAG_namespace &&
+ getDIEStringAttr(Parent, dwarf::DW_AT_name) == "")
+ return true;
+ Parent = Parent->getParent();
+ }
+
+ return false;
+}
+
+/// Test if the current CU language is C++ and that we have
+/// a named type that is not contained in an anonymous namespace.
+static bool shouldAddODRHash(DwarfTypeUnit *CU, DIE *Die) {
+ return CU->getLanguage() == dwarf::DW_LANG_C_plus_plus &&
+ getDIEStringAttr(Die, dwarf::DW_AT_name) != "" &&
+ !isContainedInAnonNamespace(Die);
+}
+
void DwarfDebug::finalizeModuleInfo() {
// Collect info for variables that were optimized out.
collectDeadVariables();
@@ -3001,8 +3041,8 @@ void DwarfDebug::emitDebugStrDWO() {
OffSec, StrSym);
}
-void DwarfDebug::addDwarfTypeUnitType(uint16_t Language, StringRef Identifier,
- DIE *RefDie, DICompositeType CTy) {
+void DwarfDebug::addDwarfTypeUnitType(uint16_t Language, DIE *RefDie,
+ DICompositeType CTy) {
const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
if (!TU) {
DIE *UnitDie = new DIE(dwarf::DW_TAG_type_unit);
@@ -3017,14 +3057,16 @@ void DwarfDebug::addDwarfTypeUnitType(ui
DIE *Die = NewTU->createTypeDIE(CTy);
- MD5 Hash;
- Hash.update(Identifier);
- // ... take the least significant 8 bytes and return those. Our MD5
- // implementation always returns its results in little endian, swap bytes
- // appropriately.
- MD5::MD5Result Result;
- Hash.final(Result);
- uint64_t Signature = *reinterpret_cast<uint64_t *>(Result + 8);
+ if (GenerateODRHash && shouldAddODRHash(NewTU, Die))
+ NewTU->addUInt(UnitDie, dwarf::DW_AT_GNU_odr_signature,
+ dwarf::DW_FORM_data8,
+ DIEHash().computeDIEODRSignature(*Die));
+ // FIXME: This won't handle circularly referential structures, as the DIE
+ // may have references to other DIEs still under construction and missing
+ // their signature. Hashing should walk through the signatures to their
+ // referenced type, or possibly walk the precomputed hashes of related types
+ // at the end.
+ uint64_t Signature = DIEHash().computeTypeSignature(*Die);
NewTU->setTypeSignature(Signature);
NewTU->setType(Die);
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h?rev=198398&r1=198397&r2=198398&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h Thu Jan 2 22:49:04 2014
@@ -695,8 +695,7 @@ public:
/// \brief Add a DIE to the set of types that we're going to pull into
/// type units.
- void addDwarfTypeUnitType(uint16_t Language, StringRef Identifier, DIE *Die,
- DICompositeType CTy);
+ void addDwarfTypeUnitType(uint16_t Language, DIE *Die, DICompositeType CTy);
/// \brief Add a label so that arange data can be generated for it.
void addArangeLabel(SymbolCU SCU) { ArangeLabels.push_back(SCU); }
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp?rev=198398&r1=198397&r2=198398&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp Thu Jan 2 22:49:04 2014
@@ -928,6 +928,41 @@ DIE *DwarfUnit::createTypeDIE(DIComposit
return TyDIE;
}
+/// Return true if the type is appropriately scoped to be contained inside
+/// its own type unit.
+static bool isDwarfTypeUnitScoped(DIType Ty, const DwarfDebug *DD) {
+ DIScope Parent = DD->resolve(Ty.getContext());
+ while (Parent) {
+ // Don't generate a hash for anything scoped inside a function.
+ if (Parent.isSubprogram())
+ return false;
+ Parent = DD->resolve(Parent.getContext());
+ }
+ return true;
+}
+
+/// Return true if the type should be split out into a type unit.
+static bool shouldCreateDwarfTypeUnit(DICompositeType CTy,
+ const DwarfDebug *DD) {
+ if (!GenerateDwarfTypeUnits)
+ return false;
+
+ uint16_t Tag = CTy.getTag();
+
+ switch (Tag) {
+ case dwarf::DW_TAG_structure_type:
+ case dwarf::DW_TAG_union_type:
+ case dwarf::DW_TAG_enumeration_type:
+ case dwarf::DW_TAG_class_type:
+ // If this is a class, structure, union, or enumeration type
+ // that is a definition (not a declaration), and not scoped
+ // inside a function then separate this out as a type unit.
+ return !CTy.isForwardDecl() && isDwarfTypeUnitScoped(CTy, DD);
+ default:
+ return false;
+ }
+}
+
/// getOrCreateTypeDIE - Find existing DIE or create new DIE for the
/// given DIType.
DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
@@ -954,13 +989,11 @@ DIE *DwarfUnit::getOrCreateTypeDIE(const
constructTypeDIE(*TyDIE, DIBasicType(Ty));
else if (Ty.isCompositeType()) {
DICompositeType CTy(Ty);
- if (GenerateDwarfTypeUnits && !Ty.isForwardDecl())
- if (MDString *TypeId = CTy.getIdentifier()) {
- DD->addDwarfTypeUnitType(getLanguage(), TypeId->getString(), TyDIE,
- CTy);
- // Skip updating the accellerator tables since this is not the full type
- return TyDIE;
- }
+ if (shouldCreateDwarfTypeUnit(CTy, DD)) {
+ DD->addDwarfTypeUnitType(getLanguage(), TyDIE, CTy);
+ // Skip updating the accellerator tables since this is not the full type
+ return TyDIE;
+ }
constructTypeDIE(*TyDIE, CTy);
} else {
assert(Ty.isDerivedType() && "Unknown kind of DIType");
Modified: llvm/trunk/test/DebugInfo/X86/c-type-units.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/c-type-units.ll?rev=198398&r1=198397&r2=198398&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/c-type-units.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/c-type-units.ll Thu Jan 2 22:49:04 2014
@@ -5,9 +5,8 @@
; struct foo {
; } f;
-; no known LLVM frontends produce appropriate unique identifiers for C types,
-; so we don't produce type units for them
-; CHECK-NOT: DW_TAG_type_unit
+; CHECK: DW_TAG_type_unit
+; CHECK-NEXT: DW_AT_language [DW_FORM_data2] (0x000c)
%struct.foo = type {}
Modified: llvm/trunk/test/DebugInfo/X86/generate-odr-hash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/generate-odr-hash.ll?rev=198398&r1=198397&r2=198398&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/generate-odr-hash.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/generate-odr-hash.ll Thu Jan 2 22:49:04 2014
@@ -1,6 +1,6 @@
; REQUIRES: object-emission
-; RUN: llc %s -o %t -filetype=obj -O0 -generate-type-units -mtriple=x86_64-unknown-linux-gnu
+; RUN: llc %s -o %t -filetype=obj -O0 -generate-type-units -generate-odr-hash -mtriple=x86_64-unknown-linux-gnu
; RUN: llvm-dwarfdump %t | FileCheck %s
; Generated from:
@@ -46,31 +46,18 @@
; CHECK-LABEL: .debug_info contents:
; CHECK: Compile Unit: length = [[CU_SIZE:[0-9a-f]+]]
-; CHECK: DW_TAG_structure_type
-; CHECK-NEXT: DW_AT_signature
-; CHECK: DW_TAG_class_type
-; CHECK-NEXT: DW_AT_signature
-
-; Ensure the CU-local type 'walrus' is not placed in a type unit.
-; CHECK: DW_TAG_structure_type
-; CHECK-NEXT: debug_str{{.*}}"walrus"
-; CHECK-NEXT: DW_AT_byte_size
-; CHECK-NEXT: DW_AT_decl_file
-; CHECK-NEXT: DW_AT_decl_line
-
; CHECK-LABEL: .debug_types contents:
; Check that we generate a hash for bar and the value.
-; CHECK-NOT: type_signature
-; CHECK-LABEL: type_signature = 0x1d02f3be30cc5688
+; CHECK-LABEL: type_signature = 0x6a7ee3d400662e88
+; CHECK: DW_AT_GNU_odr_signature [DW_FORM_data8] (0x200520c0d5b90eff)
; CHECK: DW_TAG_structure_type
; CHECK-NEXT: debug_str{{.*}}"bar"
; Check that we generate a hash for fluffy and the value.
-; CHECK-NOT: type_signature
-; CHECK-LABEL: type_signature = 0xb04af47397402e77
-; CHECK-NOT: DW_AT_GNU_odr_signature [DW_FORM_data8] (0x9a0124d5a0c21c52)
+; CHECK-LABEL: type_signature = 0x139b2e1ea94afec7
+; CHECK: DW_AT_GNU_odr_signature [DW_FORM_data8] (0x9a0124d5a0c21c52)
; CHECK: DW_TAG_namespace
; CHECK-NEXT: debug_str{{.*}}"echidna"
; CHECK: DW_TAG_namespace
@@ -80,22 +67,34 @@
; CHECK: DW_TAG_class_type
; CHECK-NEXT: debug_str{{.*}}"fluffy"
+; namespace and won't violate any ODR-ness.
+; CHECK-LABEL: type_signature = 0xc0d031d6449dbca7
+; CHECK: DW_TAG_type_unit
+; CHECK-NOT: NULL
+; We emit no hash for walrus since the type is contained in an anonymous
+; CHECK-NOT: DW_AT_GNU_odr_signature
+; CHECK: DW_TAG_structure_type
+; CHECK-NEXT: debug_str{{.*}}"walrus"
+; CHECK-NEXT: DW_AT_byte_size
+; CHECK-NEXT: DW_AT_decl_file
+; CHECK-NEXT: DW_AT_decl_line
+; CHECK: DW_TAG_subprogram
+
; Check that we generate a hash for wombat and the value, but not for the
; anonymous type contained within.
-; CHECK-NOT: type_signature
-; CHECK-LABEL: type_signature = 0xfd756cee88f8a118
-; CHECK-NOT: DW_AT_GNU_odr_signature [DW_FORM_data8] (0x685bcc220141e9d7)
+; CHECK-LABEL: type_signature = 0x73776f130648b986
+; CHECK: DW_AT_GNU_odr_signature [DW_FORM_data8] (0x685bcc220141e9d7)
; CHECK: DW_TAG_structure_type
; CHECK-NEXT: debug_str{{.*}}"wombat"
-; CHECK-NOT: type_signature
-; CHECK-LABEL: type_signature = 0xe94f6d3843e62d6b
+; CHECK-LABEL: type_signature = 0xbf6fc40e82583d7c
; CHECK: DW_TAG_type_unit
; CHECK-NOT: NULL
+; Check that we generate no ODR hash for the anonymous type nested inside 'wombat'
; CHECK-NOT: DW_AT_GNU_odr_signature
; CHECK: DW_TAG_structure_type
; The signature for the outer 'wombat' type
-; CHECK: DW_AT_signature [DW_FORM_ref_sig8] (0xfd756cee88f8a118)
+; CHECK: DW_AT_signature [DW_FORM_ref_sig8] (0x73776f130648b986)
; CHECK: DW_TAG_structure_type
; CHECK-NOT: DW_AT_name
; CHECK-NOT: DW_AT_GNU_odr_signature
@@ -108,16 +107,18 @@
; Don't emit pubtype entries for type DIEs in the compile unit that just indirect to a type unit.
; CHECK-NEXT: unit_size = [[CU_SIZE]]
; CHECK-NEXT: Offset Name
-; CHECK-NEXT: "walrus"
; Type unit for 'bar'
-; CHECK-NEXT: unit_size = 0x00000023
+; CHECK-NEXT: unit_size = 0x0000002b
; CHECK-NEXT: Offset Name
; CHECK-NEXT: "bar"
-; CHECK-NEXT: unit_size = 0x0000005d
+; CHECK-NEXT: unit_size = 0x00000065
; CHECK-NEXT: Offset Name
; CHECK-NEXT: "int"
; CHECK-NEXT: "echidna::capybara::mongoose::fluffy"
-; CHECK-NEXT: unit_size = 0x0000003a
+; CHECK-NEXT: unit_size = 0x0000003b
+; CHECK-NEXT: Offset Name
+; CHECK-NEXT: "walrus"
+; CHECK-NEXT: unit_size = 0x00000042
; CHECK-NEXT: Offset Name
; CHECK-NEXT: "wombat"
; CHECK-NEXT: unit_size = 0x0000004b
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