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[DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.

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In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is

!DILabel(scope: !1, name: "foo", file: !2, line: 3)

We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is

llvm.dbg.label(metadata !1)

It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.

We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.

Differential Revision: https://reviews.llvm.org/D45024

Patch by Hsiangkai Wang.

llvm-svn: 331841
This commit is contained in:
Shiva Chen
2018-05-09 02:40:45 +00:00
parent 49914cc807
commit 2c864551df
753 changed files with 1698 additions and 1293 deletions
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17
llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
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@@ -335,6 +335,8 @@ private:
unsigned Abbrev);
void writeDILocalVariable(const DILocalVariable *N,
SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
void writeDILabel(const DILabel *N,
SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
void writeDIExpression(const DIExpression *N,
SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
void writeDIGlobalVariableExpression(const DIGlobalVariableExpression *N,
@@ -1628,7 +1630,7 @@ void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
Record.push_back(N->getThisAdjustment());
Record.push_back(VE.getMetadataOrNullID(N->getThrownTypes().get()));
@@ -1785,6 +1787,19 @@ void ModuleBitcodeWriter::writeDILocalVariable(
Record.clear();
}
void ModuleBitcodeWriter::writeDILabel(
const DILabel *N, SmallVectorImpl<uint64_t> &Record,
unsigned Abbrev) {
Record.push_back((uint64_t)N->isDistinct());
Record.push_back(VE.getMetadataOrNullID(N->getScope()));
Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
Record.push_back(VE.getMetadataOrNullID(N->getFile()));
Record.push_back(N->getLine());
Stream.EmitRecord(bitc::METADATA_LABEL, Record, Abbrev);
Record.clear();
}
void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
SmallVectorImpl<uint64_t> &Record,
unsigned Abbrev) {