[IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
llvm-svn: 290153
diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index eb24ac6..862a02c 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -980,41 +980,55 @@
if (Record.size() < 11 || Record.size() > 12)
return error("Invalid record");
- IsDistinct = Record[0];
+ IsDistinct = Record[0] & 1;
+ unsigned Version = Record[0] >> 1;
- // Upgrade old metadata, which stored a global variable reference or a
- // ConstantInt here.
- Metadata *Expr = getMDOrNull(Record[9]);
- uint32_t AlignInBits = 0;
- if (Record.size() > 11) {
- if (Record[11] > (uint64_t)std::numeric_limits<uint32_t>::max())
- return error("Alignment value is too large");
- AlignInBits = Record[11];
- }
- GlobalVariable *Attach = nullptr;
- if (auto *CMD = dyn_cast_or_null<ConstantAsMetadata>(Expr)) {
- if (auto *GV = dyn_cast<GlobalVariable>(CMD->getValue())) {
- Attach = GV;
- Expr = nullptr;
- } else if (auto *CI = dyn_cast<ConstantInt>(CMD->getValue())) {
- Expr = DIExpression::get(Context,
- {dwarf::DW_OP_constu, CI->getZExtValue(),
- dwarf::DW_OP_stack_value});
- } else {
- Expr = nullptr;
+ if (Version == 1) {
+ MetadataList.assignValue(
+ GET_OR_DISTINCT(DIGlobalVariable,
+ (Context, getMDOrNull(Record[1]),
+ getMDString(Record[2]), getMDString(Record[3]),
+ getMDOrNull(Record[4]), Record[5],
+ getDITypeRefOrNull(Record[6]), Record[7],
+ Record[8], getMDOrNull(Record[10]), Record[11])),
+ NextMetadataNo++);
+ } else if (Version == 0) {
+ // Upgrade old metadata, which stored a global variable reference or a
+ // ConstantInt here.
+ Metadata *Expr = getMDOrNull(Record[9]);
+ uint32_t AlignInBits = 0;
+ if (Record.size() > 11) {
+ if (Record[11] > (uint64_t)std::numeric_limits<uint32_t>::max())
+ return error("Alignment value is too large");
+ AlignInBits = Record[11];
}
- }
+ GlobalVariable *Attach = nullptr;
+ if (auto *CMD = dyn_cast_or_null<ConstantAsMetadata>(Expr)) {
+ if (auto *GV = dyn_cast<GlobalVariable>(CMD->getValue())) {
+ Attach = GV;
+ Expr = nullptr;
+ } else if (auto *CI = dyn_cast<ConstantInt>(CMD->getValue())) {
+ Expr = DIExpression::get(Context,
+ {dwarf::DW_OP_constu, CI->getZExtValue(),
+ dwarf::DW_OP_stack_value});
+ } else {
+ Expr = nullptr;
+ }
+ }
+ DIGlobalVariable *DGV = GET_OR_DISTINCT(
+ DIGlobalVariable,
+ (Context, getMDOrNull(Record[1]), getMDString(Record[2]),
+ getMDString(Record[3]), getMDOrNull(Record[4]), Record[5],
+ getDITypeRefOrNull(Record[6]), Record[7], Record[8],
+ getMDOrNull(Record[10]), AlignInBits));
- DIGlobalVariable *DGV = GET_OR_DISTINCT(
- DIGlobalVariable,
- (Context, getMDOrNull(Record[1]), getMDString(Record[2]),
- getMDString(Record[3]), getMDOrNull(Record[4]), Record[5],
- getDITypeRefOrNull(Record[6]), Record[7], Record[8], Expr,
- getMDOrNull(Record[10]), AlignInBits));
- MetadataList.assignValue(DGV, NextMetadataNo++);
-
- if (Attach)
- Attach->addDebugInfo(DGV);
+ auto *DGVE =
+ DIGlobalVariableExpression::getDistinct(Context, DGV, Expr);
+ MetadataList.assignValue(DGVE, NextMetadataNo++);
+ if (Attach)
+ Attach->addDebugInfo(DGVE);
+ } else
+ return error("Invalid record");
break;
}
@@ -1064,6 +1078,17 @@
NextMetadataNo++);
break;
}
+ case bitc::METADATA_GLOBAL_VAR_EXPR: {
+ if (Record.size() != 3)
+ return error("Invalid record");
+
+ IsDistinct = Record[0];
+ MetadataList.assignValue(GET_OR_DISTINCT(DIGlobalVariableExpression,
+ (Context, getMDOrNull(Record[1]),
+ getMDOrNull(Record[2]))),
+ NextMetadataNo++);
+ break;
+ }
case bitc::METADATA_OBJC_PROPERTY: {
if (Record.size() != 8)
return error("Invalid record");
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index cff2fd0..8f23e31 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -210,6 +210,9 @@
SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
void writeDIExpression(const DIExpression *N,
SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
+ void writeDIGlobalVariableExpression(const DIGlobalVariableExpression *N,
+ SmallVectorImpl<uint64_t> &Record,
+ unsigned Abbrev);
void writeDIObjCProperty(const DIObjCProperty *N,
SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
void writeDIImportedEntity(const DIImportedEntity *N,
@@ -1674,7 +1677,8 @@
void ModuleBitcodeWriter::writeDIGlobalVariable(
const DIGlobalVariable *N, SmallVectorImpl<uint64_t> &Record,
unsigned Abbrev) {
- Record.push_back(N->isDistinct());
+ const uint64_t Version = 1 << 1;
+ Record.push_back((uint64_t)N->isDistinct() | Version);
Record.push_back(VE.getMetadataOrNullID(N->getScope()));
Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
@@ -1683,7 +1687,7 @@
Record.push_back(VE.getMetadataOrNullID(N->getType()));
Record.push_back(N->isLocalToUnit());
Record.push_back(N->isDefinition());
- Record.push_back(VE.getMetadataOrNullID(N->getRawExpr()));
+ Record.push_back(/* expr */ 0);
Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
Record.push_back(N->getAlignInBits());
@@ -1735,6 +1739,17 @@
Record.clear();
}
+void ModuleBitcodeWriter::writeDIGlobalVariableExpression(
+ const DIGlobalVariableExpression *N, SmallVectorImpl<uint64_t> &Record,
+ unsigned Abbrev) {
+ Record.push_back(N->isDistinct());
+ Record.push_back(VE.getMetadataOrNullID(N->getVariable()));
+ Record.push_back(VE.getMetadataOrNullID(N->getExpression()));
+
+ Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR_EXPR, Record, Abbrev);
+ Record.clear();
+}
+
void ModuleBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
SmallVectorImpl<uint64_t> &Record,
unsigned Abbrev) {