[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/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) {