[llvm] Implements PGOBBAddrMap in Object and ObjectYAML with tests [1/5] (PR #71750)

[Micah Weston via llvm-commits]

================
@@ -744,6 +745,386 @@ TEST(ELFObjectFileTest, ReadBBAddrMap) {
                   Section1BBAddrMaps);
 }
 
+// Tests for error paths of the ELFFile::decodeBBAddrMap with PGOBBAddrMap API.
+TEST(ELFObjectFileTest, InvalidDecodePGOBBAddrMap) {
+  if (IsHostWindows())
+    GTEST_SKIP();
+  StringRef CommonYamlString(R"(
+--- !ELF
+FileHeader:
+  Class: ELFCLASS64
+  Data:  ELFDATA2LSB
+  Type:  ET_EXEC
+Sections:
+  - Type: SHT_LLVM_BB_ADDR_MAP
+    Name: .llvm_bb_addr_map
+    Entries:
+      - Address: 0x11111
+)");
+
+  auto DoCheck = [&](StringRef YamlString, const char *ErrMsg) {
+    SmallString<0> Storage;
+    Expected<ELFObjectFile<ELF64LE>> ElfOrErr =
+        toBinary<ELF64LE>(Storage, YamlString);
+    ASSERT_THAT_EXPECTED(ElfOrErr, Succeeded());
+    const ELFFile<ELF64LE> &Elf = ElfOrErr->getELFFile();
+
+    Expected<const typename ELF64LE::Shdr *> BBAddrMapSecOrErr =
+        Elf.getSection(1);
+    ASSERT_THAT_EXPECTED(BBAddrMapSecOrErr, Succeeded());
+
+    std::vector<PGOAnalysisMap> PGOAnalyses;
+    EXPECT_THAT_ERROR(
+        Elf.decodeBBAddrMap(**BBAddrMapSecOrErr, nullptr, &PGOAnalyses)
+            .takeError(),
+        FailedWithMessage(ErrMsg));
+  };
+
+  // Check that we can detect unsupported versions that is too low
+  SmallString<128> UnsupportedLowVersionYamlString(CommonYamlString);
+  UnsupportedLowVersionYamlString += R"(
+        Version: 1
+        Feature: 0x4
+        BBEntries:
+          - AddressOffset: 0x0
+            Size:          0x1
+            Metadata:      0x2
+)";
+
+  DoCheck(UnsupportedLowVersionYamlString,
+          "version should be >= 2 for SHT_LLVM_BB_ADDR_MAP when PGO features "
+          "are enabled: version = 1 feature = 4");
+
+  SmallString<128> CommonVersionedYamlString(CommonYamlString);
+  CommonVersionedYamlString += R"(
+        Version: 2
+        BBEntries:
+          - ID:            1
+            AddressOffset: 0x0
+            Size:          0x1
+            Metadata:      0x2
+)";
+
+  // Check that we fail when function entry count is enabled but not provided.
+  SmallString<128> MissingFuncEntryCount(CommonYamlString);
+  MissingFuncEntryCount += R"(
+        Version: 2
+        Feature: 0x01
+)";
+
+  DoCheck(MissingFuncEntryCount,
+          "unable to decode LEB128 at offset 0x0000000b: malformed uleb128, "
+          "extends past end");
+
+  // Check that we fail when basic block frequency is enabled but not provided.
+  SmallString<128> MissingBBFreq(CommonYamlString);
+  MissingBBFreq += R"(
+        Version: 2
+        Feature: 0x02
+        BBEntries:
+          - ID:            1
+            AddressOffset: 0x0
+            Size:          0x1
+            Metadata:      0x2
+)";
+
+  DoCheck(MissingBBFreq, "unable to decode LEB128 at offset 0x0000000f: "
+                         "malformed uleb128, extends past end");
+
+  // Check that we fail when branch probability is enabled but not provided.
+  SmallString<128> MissingBrProb(CommonYamlString);
+  MissingBrProb += R"(
+        Version: 2
+        Feature: 0x02
----------------
red1bluelost wrote:

Good catch.

https://github.com/llvm/llvm-project/pull/71750