Refactor data-in-code annotations.

Use a dedicated MachO load command to annotate data-in-code regions.
This is the same format the linker produces for final executable images,
allowing consistency of representation and use of introspection tools
for both object and executable files.

Data-in-code regions are annotated via ".data_region"/".end_data_region"
directive pairs, with an optional region type.

data_region_directive := ".data_region" { region_type }
region_type := "jt8" | "jt16" | "jt32" | "jta32"
end_data_region_directive := ".end_data_region"

The previous handling of ARM-style "$d.*" labels was broken and has
been removed. Specifically, it didn't handle ARM vs. Thumb mode when
marking the end of the section.

rdar://11459456

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157062 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach
2012-05-18 19:12:01 +00:00
parent 18e2f6e94c
commit 3e96531186
28 changed files with 411 additions and 215 deletions

View File

@@ -1,4 +1,3 @@
//===- lib/MC/MCMachOStreamer.cpp - Mach-O Object Output ------------===//
//
// The LLVM Compiler Infrastructure
//
@@ -33,6 +32,8 @@ class MCMachOStreamer : public MCObjectStreamer {
private:
virtual void EmitInstToData(const MCInst &Inst);
void EmitDataRegion(DataRegionData::KindTy Kind);
void EmitDataRegionEnd();
public:
MCMachOStreamer(MCContext &Context, MCAsmBackend &MAB,
raw_ostream &OS, MCCodeEmitter *Emitter)
@@ -46,6 +47,7 @@ public:
virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
MCSymbol *EHSymbol);
virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
virtual void EmitDataRegion(MCDataRegionType Kind);
virtual void EmitThumbFunc(MCSymbol *Func);
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
@@ -138,6 +140,26 @@ void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeMask);
}
void MCMachOStreamer::EmitDataRegion(DataRegionData::KindTy Kind) {
// Create a temporary label to mark the start of the data region.
MCSymbol *Start = getContext().CreateTempSymbol();
EmitLabel(Start);
// Record the region for the object writer to use.
DataRegionData Data = { Kind, Start, NULL };
std::vector<DataRegionData> &Regions = getAssembler().getDataRegions();
Regions.push_back(Data);
}
void MCMachOStreamer::EmitDataRegionEnd() {
std::vector<DataRegionData> &Regions = getAssembler().getDataRegions();
assert(Regions.size() && "Mismatched .end_data_region!");
DataRegionData &Data = Regions.back();
assert(Data.End == NULL && "Mismatched .end_data_region!");
// Create a temporary label to mark the end of the data region.
Data.End = getContext().CreateTempSymbol();
EmitLabel(Data.End);
}
void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
// Let the target do whatever target specific stuff it needs to do.
getAssembler().getBackend().handleAssemblerFlag(Flag);
@@ -153,6 +175,26 @@ void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
}
}
void MCMachOStreamer::EmitDataRegion(MCDataRegionType Kind) {
switch (Kind) {
case MCDR_DataRegion:
EmitDataRegion(DataRegionData::Data);
return;
case MCDR_DataRegionJT8:
EmitDataRegion(DataRegionData::JumpTable8);
return;
case MCDR_DataRegionJT16:
EmitDataRegion(DataRegionData::JumpTable16);
return;
case MCDR_DataRegionJT32:
EmitDataRegion(DataRegionData::JumpTable32);
return;
case MCDR_DataRegionEnd:
EmitDataRegionEnd();
return;
}
}
void MCMachOStreamer::EmitThumbFunc(MCSymbol *Symbol) {
// Remember that the function is a thumb function. Fixup and relocation
// values will need adjusted.