[PATCH] D97336: [InstrProfiling] Use nobits for __llvm_prf_cnts with binutils >=2.28

[Petr Hosek via Phabricator via llvm-commits]

phosek created this revision.
phosek added reviewers: davidxl, MaskRay, mcgrathr.
Herald added a subscriber: hiraditya.
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Herald added a subscriber: llvm-commits.

binutils <2.28 have a bug which causes __start_/__stop_ symbols have
incorrect address for nobits section which causes counters to come up
as empty in raw profiles.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D97336

Files:
  llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp


Index: llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
===================================================================
--- llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -425,7 +425,8 @@
                                                            MMI, Streamer);
 }
 
-static SectionKind getELFKindForNamedSection(StringRef Name, SectionKind K) {
+static SectionKind getELFKindForNamedSection(MCContext &Ctx, StringRef Name,
+                                             SectionKind K) {
   // N.B.: The defaults used in here are not the same ones used in MC.
   // We follow gcc, MC follows gas. For example, given ".section .eh_frame",
   // both gas and MC will produce a section with no flags. Given
@@ -441,7 +442,8 @@
     return SectionKind::getMetadata();
 
   if (Name == getInstrProfSectionName(IPSK_cnts, Triple::ELF,
-                                      /*AddSegmentInfo=*/false))
+                                      /*AddSegmentInfo=*/false) &&
+      Ctx.getAsmInfo()->binutilsIsAtLeast(2, 28))
     return SectionKind::getBSS();
 
   if (Name.empty() || Name[0] != '.') return K;
@@ -674,7 +676,7 @@
   }
 
   // Infer section flags from the section name if we can.
-  Kind = getELFKindForNamedSection(SectionName, Kind);
+  Kind = getELFKindForNamedSection(getContext(), SectionName, Kind);
 
   StringRef Group = "";
   bool IsComdat = false;


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