[Remarks] Emit a section containing remark diagnostics metadata

A section containing metadata on remark diagnostics will be emitted if
the flag (-mllvm) -remarks-section is present.

For now, the metadata is:

* a magic number for remarks: "REMARKS\0"
* the version number: a little-endian uint64_t
* the absolute file path to the serialized remark diagnostics: a
  null-terminated string.

Differential Revision: https://reviews.llvm.org/D59571

llvm-svn: 357043

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCObjectFileInfo.cpp b/llvm/lib/MC/MCObjectFileInfo.cpp
index 1c845f64050..0faa236c153 100644
--- a/llvm/lib/MC/MCObjectFileInfo.cpp
+++ b/llvm/lib/MC/MCObjectFileInfo.cpp
@@ -290,6 +290,9 @@ void MCObjectFileInfo::initMachOMCObjectFileInfo(const Triple &T) {
   FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
                                          0, SectionKind::getMetadata());
 
+  RemarksSection = Ctx->getMachOSection(
+      "__LLVM", "__remarks", MachO::S_ATTR_DEBUG, SectionKind::getMetadata());
+
   TLSExtraDataSection = TLSTLVSection;
 }
 
@@ -475,6 +478,9 @@ void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) {
       Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
 
   StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0);
+
+  RemarksSection =
+      Ctx->getELFSection(".remarks", ELF::SHT_PROGBITS, ELF::SHF_EXCLUDE);
 }
 
 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) {