[XRay] Make the xray_instr_map section specification more correct
Summary:
We also add a test to show what currently happens when we create a
section per function and emit an xray_instr_map. This illustrates the
relationship (or lack thereof) between the per-function section and the
xray_instr_map section.
We also change the code generation slightly so that we don't always
create group sections, but rather only do so if a function where the
table is associated with is in a group.
Also in this change:
- Remove the "merge" flag on the xray_instr_map section.
- Test that we're generating the right table for comdat and non-comdat functions.
Reviewers: echristo, majnemer
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23104
llvm-svn: 277580
diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp
index 906e342..18f9b3e 100644
--- a/llvm/lib/Target/X86/X86MCInstLower.cpp
+++ b/llvm/lib/Target/X86/X86MCInstLower.cpp
@@ -1096,11 +1096,18 @@
if (Sleds.empty())
return;
if (Subtarget->isTargetELF()) {
- auto *Section = OutContext.getELFSection(
- "xray_instr_map", ELF::SHT_PROGBITS,
- ELF::SHF_ALLOC | ELF::SHF_GROUP | ELF::SHF_MERGE, 0,
- CurrentFnSym->getName());
auto PrevSection = OutStreamer->getCurrentSectionOnly();
+ auto Fn = MF->getFunction();
+ MCSection *Section = nullptr;
+ if (Fn->hasComdat()) {
+ Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
+ ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
+ Fn->getComdat()->getName());
+ OutStreamer->SwitchSection(Section);
+ } else {
+ Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
+ ELF::SHF_ALLOC);
+ }
OutStreamer->SwitchSection(Section);
for (const auto &Sled : Sleds) {
OutStreamer->EmitSymbolValue(Sled.Sled, 8);