Track the compact unwind encoding for when we are unable to generate compact unwind information.
Compact unwind has an encoding for when we're not able to generate compact
unwind and must generate an EH frame instead. Track that, but still emit that CU
encoding.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179220 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/MC/MCObjectFileInfo.h b/include/llvm/MC/MCObjectFileInfo.h
index c8d7484..a5853b6 100644
--- a/include/llvm/MC/MCObjectFileInfo.h
+++ b/include/llvm/MC/MCObjectFileInfo.h
@@ -46,10 +46,15 @@
unsigned FDEEncoding;
unsigned FDECFIEncoding;
unsigned TTypeEncoding;
- // Section flags for eh_frame
+
+ /// Section flags for eh_frame
unsigned EHSectionType;
unsigned EHSectionFlags;
+ /// CompactUnwindDwarfEHFrameOnly - Compact unwind encoding indicating that we
+ /// should emit only an EH frame.
+ unsigned CompactUnwindDwarfEHFrameOnly;
+
/// TextSection - Section directive for standard text.
///
const MCSection *TextSection;
@@ -201,6 +206,10 @@
}
unsigned getTTypeEncoding() const { return TTypeEncoding; }
+ unsigned getCompactUnwindDwarfEHFrameOnly() const {
+ return CompactUnwindDwarfEHFrameOnly;
+ }
+
const MCSection *getTextSection() const { return TextSection; }
const MCSection *getDataSection() const { return DataSection; }
const MCSection *getBSSSection() const { return BSSSection; }
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index 0f8f074..9e00361 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -1168,10 +1168,10 @@
// .quad except_tab1
uint32_t Encoding = Frame.CompactUnwindEncoding;
- if (!Encoding) return false;
+ bool DwarfEHFrameOnly = (Encoding == MOFI->getCompactUnwindDwarfEHFrameOnly());
// The encoding needs to know we have an LSDA.
- if (Frame.Lsda)
+ if (!DwarfEHFrameOnly && Frame.Lsda)
Encoding |= 0x40000000;
Streamer.SwitchSection(MOFI->getCompactUnwindSection());
@@ -1194,11 +1194,10 @@
Twine::utohexstr(Encoding));
Streamer.EmitIntValue(Encoding, Size);
-
// Personality Function
Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_absptr);
if (VerboseAsm) Streamer.AddComment("Personality Function");
- if (Frame.Personality)
+ if (!DwarfEHFrameOnly && Frame.Personality)
Streamer.EmitSymbolValue(Frame.Personality, Size);
else
Streamer.EmitIntValue(0, Size); // No personality fn
@@ -1206,7 +1205,7 @@
// LSDA
Size = getSizeForEncoding(Streamer, Frame.LsdaEncoding);
if (VerboseAsm) Streamer.AddComment("LSDA");
- if (Frame.Lsda)
+ if (!DwarfEHFrameOnly && Frame.Lsda)
Streamer.EmitSymbolValue(Frame.Lsda, Size);
else
Streamer.EmitIntValue(0, Size); // No LSDA
diff --git a/lib/MC/MCObjectFileInfo.cpp b/lib/MC/MCObjectFileInfo.cpp
index d19e79a..79ebad1 100644
--- a/lib/MC/MCObjectFileInfo.cpp
+++ b/lib/MC/MCObjectFileInfo.cpp
@@ -145,12 +145,16 @@
LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
SectionKind::getReadOnlyWithRel());
- if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
+ if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) {
CompactUnwindSection =
Ctx->getMachOSection("__LD", "__compact_unwind",
MCSectionMachO::S_ATTR_DEBUG,
SectionKind::getReadOnly());
+ if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
+ CompactUnwindDwarfEHFrameOnly = 0x04000000;
+ }
+
// Debug Information.
DwarfAccelNamesSection =
Ctx->getMachOSection("__DWARF", "__apple_names",
@@ -629,6 +633,8 @@
PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
TTypeEncoding = dwarf::DW_EH_PE_absptr;
+ CompactUnwindDwarfEHFrameOnly = 0;
+
EHFrameSection = 0; // Created on demand.
CompactUnwindSection = 0; // Used only by selected targets.
DwarfAccelNamesSection = 0; // Used only by selected targets.