From cceae7feda8e33194d1a6c5963bd4114bb8d2b36 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Tue, 31 May 2016 23:01:54 +0000
Subject: Add support for metadata attachments for global variables.

This patch adds an IR, assembly and bitcode representation for metadata
attachments for globals. Future patches will port existing features to use
these new attachments.

Differential Revision: http://reviews.llvm.org/D20074

llvm-svn: 271348
---
 llvm/lib/Bitcode/Reader/BitcodeReader.cpp | 39 ++++++++++++++++++++++++-------
 1 file changed, 30 insertions(+), 9 deletions(-)

(limited to 'llvm/lib/Bitcode/Reader/BitcodeReader.cpp')

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 2cd1297d902..55c0d064938 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -443,6 +443,9 @@ private:
                                        unsigned &NextMetadataNo);
   std::error_code parseMetadataKinds();
   std::error_code parseMetadataKindRecord(SmallVectorImpl<uint64_t> &Record);
+  std::error_code
+  parseGlobalObjectAttachment(GlobalObject &GO,
+                              ArrayRef<uint64_t> Record);
   std::error_code parseMetadataAttachment(Function &F);
   ErrorOr<std::string> parseModuleTriple();
   std::error_code parseUseLists();
@@ -3820,6 +3823,16 @@ std::error_code BitcodeReader::parseModule(uint64_t ResumeBit,
       }
       break;
     }
+    case bitc::MODULE_CODE_GLOBALVAR_ATTACHMENT: {
+      if (Record.size() % 2 == 0)
+        return error("Invalid record");
+      unsigned ValueID = Record[0];
+      if (ValueID >= ValueList.size())
+        return error("Invalid record");
+      if (auto *GV = dyn_cast<GlobalVariable>(ValueList[ValueID]))
+        parseGlobalObjectAttachment(*GV, ArrayRef<uint64_t>(Record).slice(1));
+      break;
+    }
     // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
     //             alignment, section, visibility, gc, unnamed_addr,
     //             prologuedata, dllstorageclass, comdat, prefixdata]
@@ -4144,6 +4157,21 @@ ErrorOr<std::string> BitcodeReader::parseIdentificationBlock() {
   }
 }
 
+std::error_code BitcodeReader::parseGlobalObjectAttachment(
+    GlobalObject &GO, ArrayRef<uint64_t> Record) {
+  assert(Record.size() % 2 == 0);
+  for (unsigned I = 0, E = Record.size(); I != E; I += 2) {
+    auto K = MDKindMap.find(Record[I]);
+    if (K == MDKindMap.end())
+      return error("Invalid ID");
+    MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[I + 1]);
+    if (!MD)
+      return error("Invalid metadata attachment");
+    GO.setMetadata(K->second, MD);
+  }
+  return std::error_code();
+}
+
 /// Parse metadata attachments.
 std::error_code BitcodeReader::parseMetadataAttachment(Function &F) {
   if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
@@ -4175,15 +4203,8 @@ std::error_code BitcodeReader::parseMetadataAttachment(Function &F) {
         return error("Invalid record");
       if (RecordLength % 2 == 0) {
         // A function attachment.
-        for (unsigned I = 0; I != RecordLength; I += 2) {
-          auto K = MDKindMap.find(Record[I]);
-          if (K == MDKindMap.end())
-            return error("Invalid ID");
-          MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[I + 1]);
-          if (!MD)
-            return error("Invalid metadata attachment");
-          F.setMetadata(K->second, MD);
-        }
+        if (std::error_code EC = parseGlobalObjectAttachment(F, Record))
+          return EC;
         continue;
       }
 
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