Bump feature value to a 16byte value.

Author: rlavaee

llvm/include/llvm/Object/ELFTypes.h

@@ -841,7 +841,7 @@ struct BBAddrMap {
     bool hasPGOAnalysisBBData() const { return BBFreq || BrProb; }
 
     // Encodes to minimum bit width representation.
-    uint8_t encode() const {
+    uint16_t encode() const {
       return (static_cast<uint8_t>(FuncEntryCount) << 0) |
              (static_cast<uint8_t>(BBFreq) << 1) |
              (static_cast<uint8_t>(BrProb) << 2) |
@@ -854,7 +854,7 @@ struct BBAddrMap {
 
     // Decodes from minimum bit width representation and validates no
     // unnecessary bits are used.
-    static Expected<Features> decode(uint8_t Val) {
+    static Expected<Features> decode(uint16_t Val) {
       Features Feat{
           static_cast<bool>(Val & (1 << 0)), static_cast<bool>(Val & (1 << 1)),
           static_cast<bool>(Val & (1 << 2)), static_cast<bool>(Val & (1 << 3)),

llvm/include/llvm/ObjectYAML/ELFYAML.h

@@ -166,7 +166,7 @@ struct BBAddrMapEntry {
     std::optional<llvm::yaml::Hex64> Hash;
   };
   uint8_t Version;
-  llvm::yaml::Hex8 Feature;
+  llvm::yaml::Hex16 Feature;
 
   struct BBRangeEntry {
     llvm::yaml::Hex64 BaseAddress;

llvm/lib/Object/ELF.cpp

@@ -831,7 +831,7 @@ decodeBBAddrMapImpl(const ELFFile<ELFT> &EF,
   };
 
   uint8_t Version = 0;
-  uint8_t Feature = 0;
+  uint16_t Feature = 0;
   BBAddrMap::Features FeatEnable{};
   while (!ULEBSizeErr && !MetadataDecodeErr && Cur &&
          Cur.tell() < Content.size()) {
@@ -841,7 +841,7 @@ decodeBBAddrMapImpl(const ELFFile<ELFT> &EF,
     if (Version < 2 || Version > 5)
       return createError("unsupported SHT_LLVM_BB_ADDR_MAP version: " +
                          Twine(static_cast<int>(Version)));
-    Feature = Data.getU8(Cur); // Feature byte
+    Feature = Version < 5 ? Data.getU8(Cur) : Data.getU16(Cur);
     if (!Cur)
       break;
     auto FeatEnableOrErr = BBAddrMap::Features::decode(Feature);
@@ -860,7 +860,7 @@ decodeBBAddrMapImpl(const ELFFile<ELFT> &EF,
                          " feature = " + Twine(static_cast<int>(Feature)));
     if (FeatEnable.PostLinkCfg && Version < 5)
       return createError("version should be >= 5 for SHT_LLVM_BB_ADDR_MAP when "
-                         "basic block hash feature is enabled: version = " +
+                         "post link cfg feature is enabled: version = " +
                          Twine(static_cast<int>(Version)) +
                          " feature = " + Twine(static_cast<int>(Feature)));
     uint32_t NumBlocksInBBRange = 0;

llvm/lib/ObjectYAML/ELFEmitter.cpp

@@ -1470,8 +1470,14 @@ void ELFState<ELFT>::writeSectionContent(
                              << static_cast<int>(E.Version)
                              << "; encoding using the most recent version";
       CBA.write(E.Version);
-      CBA.write(E.Feature);
-      SHeader.sh_size += 2;
+      SHeader.sh_size += 1;
+      if (E.Version < 5) {
+        CBA.write(static_cast<uint8_t>(E.Feature));
+        SHeader.sh_size += 1;
+      } else {
+        CBA.write<uint16_t>(E.Feature, ELFT::Endianness);
+        SHeader.sh_size += 2;
+      }
     }
     auto FeatureOrErr = llvm::object::BBAddrMap::Features::decode(E.Feature);
     bool MultiBBRangeFeatureEnabled = false;

llvm/lib/ObjectYAML/ELFYAML.cpp

@@ -1886,7 +1886,7 @@ void MappingTraits<ELFYAML::BBAddrMapEntry>::mapping(
     IO &IO, ELFYAML::BBAddrMapEntry &E) {
   assert(IO.getContext() && "The IO context is not initialized");
   IO.mapRequired("Version", E.Version);
-  IO.mapOptional("Feature", E.Feature, Hex8(0));
+  IO.mapOptional("Feature", E.Feature, Hex16(0));
   IO.mapOptional("NumBBRanges", E.NumBBRanges);
   IO.mapOptional("BBRanges", E.BBRanges);
 }

llvm/test/tools/llvm-readobj/ELF/bb-addr-map-pgo-analysis-map.test

@@ -15,7 +15,7 @@
 
 ## Check that a malformed section can be handled.
 # RUN: yaml2obj %s -DBITS=32 -DSIZE=24 -o %t2.o
-# RUN: llvm-readobj %t2.o --bb-addr-map 2>&1 | FileCheck --match-full-lines %s -DOFFSET=0x00000014 -DFILE=%t2.o --check-prefix=TRUNCATED
+# RUN: llvm-readobj %t2.o --bb-addr-map 2>&1 | FileCheck --match-full-lines %s -DOFFSET=0x00000015 -DFILE=%t2.o --check-prefix=TRUNCATED
 
 ## Check that missing features can be handled.
 # RUN: yaml2obj %s -DBITS=32 -DFEATURE=0x2 -o %t3.o

llvm/test/tools/yaml2obj/ELF/bb-addr-map-pgo-analysis-map.yaml

@@ -27,7 +27,7 @@ Sections:
 ## Test the following cases:
 
 ## 1) We can produce an .llvm_bb_addr_map section from a description with
-##    Entries and PGO Analysis data.
+##    Entries and PGO Analysis and Post Link data.
   - Name: '.llvm_bb_addr_map (1)'
     Type: SHT_LLVM_BB_ADDR_MAP
     Entries:
@@ -68,8 +68,8 @@ Sections:
                Metadata:      0x00000003
 
 ## Check that yaml2obj generates a warning when we use unsupported feature.
-# RUN: not yaml2obj --docnum=2  %s 2>&1 | FileCheck %s --check-prefix=INVALID-FEATURE
-# INVALID-FEATURE: error: out of range hex8 number
+# RUN: yaml2obj --docnum=2  %s 2>&1 | FileCheck %s --check-prefix=INVALID-FEATURE
+# INVALID-FEATURE: warning: invalid encoding for BBAddrMap::Features: 0x100
 
 --- !ELF
 FileHeader:

llvm/tools/obj2yaml/elf2yaml.cpp

@@ -895,7 +895,7 @@ ELFDumper<ELFT>::dumpBBAddrMapSection(const Elf_Shdr *Shdr) {
   std::vector<ELFYAML::PGOAnalysisMapEntry> PGOAnalyses;
   DataExtractor::Cursor Cur(0);
   uint8_t Version = 0;
-  uint8_t Feature = 0;
+  uint16_t Feature = 0;
   uint64_t Address = 0;
   while (Cur && Cur.tell() < Content.size()) {
     if (Shdr->sh_type == ELF::SHT_LLVM_BB_ADDR_MAP) {
@@ -905,7 +905,7 @@ ELFDumper<ELFT>::dumpBBAddrMapSection(const Elf_Shdr *Shdr) {
             errc::invalid_argument,
             "invalid SHT_LLVM_BB_ADDR_MAP section version: " +
                 Twine(static_cast<int>(Version)));
-      Feature = Data.getU8(Cur);
+      Feature = Version < 5 ? Data.getU8(Cur) : Data.getU16(Cur);
     }
     uint64_t NumBBRanges = 1;
     uint64_t NumBlocks = 0;

llvm/unittests/Object/ELFObjectFileTest.cpp

@@ -1474,7 +1474,7 @@ TEST(ELFObjectFileTest, ReadPGOAnalysisMap) {
     DoCheckFails(
         TruncatedYamlString, /*TextSectionIndex=*/std::nullopt,
         "unable to read SHT_LLVM_BB_ADDR_MAP section with index 6: "
-        "unexpected end of data at offset 0xa while reading [0x3, 0xb)");
+        "unexpected end of data at offset 0xa while reading [0x4, 0xc)");
     // Check that we can read the other section's bb-address-maps which are
     // valid.
     DoCheckSucceeds(TruncatedYamlString, /*TextSectionIndex=*/2,

llvm/unittests/Object/ELFTypesTest.cpp

@@ -116,7 +116,7 @@ TEST(ELFTypesTest, BBAddrMapFeaturesEncodingTest) {
        {false, false, false, false, false, false, true, false},
        {false, false, false, false, false, false, false, true},
        {false, false, false, false, false, false, true, true}}};
-  const std::array<uint8_t, 14> Encoded = {
+  const std::array<uint16_t, 14> Encoded = {
       {0b0000, 0b0001, 0b0010, 0b0100, 0b1000, 0b0011, 0b0110, 0b1110, 0b1111,
        0b1'0000, 0b10'0000, 0b100'0000, 0b1000'0000, 0b1100'0000}};
   for (const auto &[Feat, EncodedVal] : llvm::zip(Decoded, Encoded))
@@ -128,3 +128,14 @@ TEST(ELFTypesTest, BBAddrMapFeaturesEncodingTest) {
     EXPECT_EQ(*FeatEnableOrError, Feat);
   }
 }
+
+TEST(ELFTypesTest, BBAddrMapFeaturesInvalidEncodingTest) {
+  const std::array<std::string, 2> Errors = {
+      "invalid encoding for BBAddrMap::Features: 0x100",
+      "invalid encoding for BBAddrMap::Features: 0x1000"};
+  const std::array<uint16_t, 2> Values = {{0b1'0000'0000, 0b1'0000'0000'0000}};
+  for (const auto &[Val, Error] : llvm::zip(Values, Errors)) {
+    EXPECT_THAT_ERROR(BBAddrMap::Features::decode(Val).takeError(),
+                      FailedWithMessage(Error));
+  }
+}