[xray] Add XRay support for Mach-O in CodeGen
Currently, XRay only supports emitting the XRay table (xray_instr_map) on ELF binaries. Let's add Mach-O support.
Differential Revision: https://reviews.llvm.org/D26983
llvm-svn: 287734
diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index 2d49ccc..b2d96a3 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -39,6 +39,7 @@
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCSymbolELF.h"
#include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCSectionMachO.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
@@ -155,10 +156,12 @@
// code duplication as it is now for x86_64, ARM32 and AArch64.
if (Sleds.empty())
return;
+
+ auto PrevSection = OutStreamer->getCurrentSectionOnly();
+ auto Fn = MF->getFunction();
+ MCSection *Section;
+
if (STI->isTargetELF()) {
- auto PrevSection = OutStreamer->getCurrentSectionOnly();
- auto Fn = MF->getFunction();
- MCSection *Section;
if (Fn->hasComdat())
Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
@@ -166,31 +169,37 @@
else
Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC);
-
- // Before we switch over, we force a reference to a label inside the
- // xray_instr_map section. Since EmitXRayTable() is always called just
- // before the function's end, we assume that this is happening after the
- // last return instruction.
- //
- // We then align the reference to 16 byte boundaries, which we determined
- // experimentally to be beneficial to avoid causing decoder stalls.
- MCSymbol *Tmp = OutContext.createTempSymbol("xray_synthetic_", true);
- OutStreamer->EmitCodeAlignment(16);
- OutStreamer->EmitSymbolValue(Tmp, 8, false);
- OutStreamer->SwitchSection(Section);
- OutStreamer->EmitLabel(Tmp);
- for (const auto &Sled : Sleds) {
- OutStreamer->EmitSymbolValue(Sled.Sled, 8);
- OutStreamer->EmitSymbolValue(CurrentFnSym, 8);
- auto Kind = static_cast<uint8_t>(Sled.Kind);
- OutStreamer->EmitBytes(
- StringRef(reinterpret_cast<const char *>(&Kind), 1));
- OutStreamer->EmitBytes(
- StringRef(reinterpret_cast<const char *>(&Sled.AlwaysInstrument), 1));
- OutStreamer->EmitZeros(14);
- }
- OutStreamer->SwitchSection(PrevSection);
+ } else if (STI->isTargetMachO()) {
+ Section = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
+ SectionKind::getReadOnlyWithRel());
+ } else {
+ llvm_unreachable("Unsupported target");
}
+
+ // Before we switch over, we force a reference to a label inside the
+ // xray_instr_map section. Since EmitXRayTable() is always called just
+ // before the function's end, we assume that this is happening after the
+ // last return instruction.
+ //
+ // We then align the reference to 16 byte boundaries, which we determined
+ // experimentally to be beneficial to avoid causing decoder stalls.
+ MCSymbol *Tmp = OutContext.createTempSymbol("xray_synthetic_", true);
+ OutStreamer->EmitCodeAlignment(16);
+ OutStreamer->EmitSymbolValue(Tmp, 8, false);
+ OutStreamer->SwitchSection(Section);
+ OutStreamer->EmitLabel(Tmp);
+ for (const auto &Sled : Sleds) {
+ OutStreamer->EmitSymbolValue(Sled.Sled, 8);
+ OutStreamer->EmitSymbolValue(CurrentFnSym, 8);
+ auto Kind = static_cast<uint8_t>(Sled.Kind);
+ OutStreamer->EmitBytes(
+ StringRef(reinterpret_cast<const char *>(&Kind), 1));
+ OutStreamer->EmitBytes(
+ StringRef(reinterpret_cast<const char *>(&Sled.AlwaysInstrument), 1));
+ OutStreamer->EmitZeros(14);
+ }
+ OutStreamer->SwitchSection(PrevSection);
+
Sleds.clear();
}