Add code for emitting the attribute groups.

This is some initial code for emitting the attribute groups into the bitcode.

NOTE: This format *may* change! Do not rely upon the attribute groups' bitcode
not changing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174845 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Bitcode/LLVMBitCodes.h

@@ -29,13 +29,12 @@ namespace bitc {
 
     // Module sub-block id's.
     PARAMATTR_BLOCK_ID,
-
-    UNUSED_ID1,
+    PARAMATTR_GROUP_BLOCK_ID,
 
     CONSTANTS_BLOCK_ID,
     FUNCTION_BLOCK_ID,
 
-    UNUSED_ID2,
+    UNUSED_ID1,
 
     VALUE_SYMTAB_BLOCK_ID,
     METADATA_BLOCK_ID,
@@ -69,7 +68,7 @@ namespace bitc {
     // ALIAS: [alias type, aliasee val#, linkage, visibility]
     MODULE_CODE_ALIAS       = 9,
 
-    /// MODULE_CODE_PURGEVALS: [numvals]
+    // MODULE_CODE_PURGEVALS: [numvals]
     MODULE_CODE_PURGEVALS   = 10,
 
     MODULE_CODE_GCNAME      = 11   // GCNAME: [strchr x N]
@@ -78,10 +77,11 @@ namespace bitc {
   /// PARAMATTR blocks have code for defining a parameter attribute set.
   enum AttributeCodes {
     // FIXME: Remove `PARAMATTR_CODE_ENTRY_OLD' in 4.0
-    PARAMATTR_CODE_ENTRY_OLD = 1, // ENTRY: [paramidx0, attr0,
-                                  //         paramidx1, attr1...]
-    PARAMATTR_CODE_ENTRY = 2      // ENTRY: [paramidx0, attrgrp0,
-                                  //         paramidx1, attrgrp1...]
+    PARAMATTR_CODE_ENTRY_OLD  = 1, // ENTRY: [paramidx0, attr0,
+                                   //         paramidx1, attr1...]
+    PARAMATTR_CODE_ENTRY      = 2, // ENTRY: [paramidx0, attrgrp0,
+                                   //         paramidx1, attrgrp1, ...]
+    PARAMATTR_GRP_CODE_ENTRY  = 3  // ENTRY: [id, attr0, att1, ...]
   };
 
   /// TYPE blocks have codes for each type primitive they use.

lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -185,13 +185,63 @@ static uint64_t encodeLLVMAttributesForBitcode(AttributeSet Attrs,
   return EncodedAttrs;
 }
 
+static void WriteAttributeGroupTable(const ValueEnumerator &VE,
+                                     BitstreamWriter &Stream) {
+  const std::vector<AttributeSet> &Attrs = VE.getAttributeSets();
+  if (Attrs.empty()) return;
+
+  Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
+
+  SmallVector<uint64_t, 64> Record;
+  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
+    AttributeSet AS = Attrs[i];
+    for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
+      AttributeSet A = AS.getSlotAttributes(i);
+
+      Record.push_back(VE.getAttributeSetID(A));
+      Record.push_back(AS.getSlotIndex(i));
+
+      for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
+           I != E; ++I) {
+        Attribute Attr = *I;
+        if (Attr.isEnumAttribute()) {
+          Record.push_back(0);
+          Record.push_back(Attr.getKindAsEnum());
+        } else if (Attr.isAlignAttribute()) {
+          Record.push_back(1);
+          Record.push_back(Attr.getKindAsEnum());
+          Record.push_back(Attr.getValueAsInt());
+        } else {
+          StringRef Kind = Attr.getKindAsString();
+          StringRef Val = Attr.getValueAsString();
+
+          Record.push_back(Val.empty() ? 3 : 4);
+          Record.append(Kind.begin(), Kind.end());
+          Record.push_back(0);
+          if (!Val.empty()) {
+            Record.append(Val.begin(), Val.end());
+            Record.push_back(0);
+          }
+        }
+      }
+
+      Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
+      Record.clear();
+    }
+  }
+
+  Stream.ExitBlock();
+}
+
 static void WriteAttributeTable(const ValueEnumerator &VE,
                                 BitstreamWriter &Stream) {
   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
   if (Attrs.empty()) return;
 
   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 
+  // FIXME: Remove this! It no longer works with the current attributes classes.
+
   SmallVector<uint64_t, 64> Record;
   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
     const AttributeSet &A = Attrs[i];
@@ -1854,6 +1904,9 @@ static void WriteModule(const Module *M, BitstreamWriter &Stream) {
   // Emit blockinfo, which defines the standard abbreviations etc.
   WriteBlockInfo(VE, Stream);
 
+  // Emit information about attribute groups.
+  WriteAttributeGroupTable(VE, Stream);
+
   // Emit information about parameter attributes.
   WriteAttributeTable(VE, Stream);