[dwarfdump] Verify line table prologue

This patch adds prologue verification, which is already present in
Apple's dwarfdump. It checks for invalid directory indices and warns
about duplicate file paths.

Differential revision: https://reviews.llvm.org/D37511

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312782 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 1a443ce)

Author: JDevlieghere

lib/DebugInfo/DWARF/DWARFVerifier.cpp

@@ -417,10 +417,50 @@ void DWARFVerifier::verifyDebugLineRows() {
     // .debug_info verifier or in verifyDebugLineStmtOffsets().
     if (!LineTable)
       continue;
+
+    // Verify prologue.
     uint32_t MaxFileIndex = LineTable->Prologue.FileNames.size();
+    uint32_t MaxDirIndex = LineTable->Prologue.IncludeDirectories.size();
+    uint32_t FileIndex = 1;
+    StringMap<uint16_t> FullPathMap;
+    for (const auto &FileName : LineTable->Prologue.FileNames) {
+      // Verify directory index.
+      if (FileName.DirIdx > MaxDirIndex) {
+        ++NumDebugLineErrors;
+        OS << "error: .debug_line["
+           << format("0x%08" PRIx64,
+                     *toSectionOffset(Die.find(DW_AT_stmt_list)))
+           << "].prologue.file_names[" << FileIndex
+           << "].dir_idx contains an invalid index: " << FileName.DirIdx
+           << "\n";
+      }
+
+      // Check file paths for duplicates.
+      std::string FullPath;
+      const bool HasFullPath = LineTable->getFileNameByIndex(
+          FileIndex, CU->getCompilationDir(),
+          DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, FullPath);
+      assert(HasFullPath && "Invalid index?");
+      (void)HasFullPath;
+      auto It = FullPathMap.find(FullPath);
+      if (It == FullPathMap.end())
+        FullPathMap[FullPath] = FileIndex;
+      else if (It->second != FileIndex) {
+        OS << "warning: .debug_line["
+           << format("0x%08" PRIx64,
+                     *toSectionOffset(Die.find(DW_AT_stmt_list)))
+           << "].prologue.file_names[" << FileIndex
+           << "] is a duplicate of file_names[" << It->second << "]\n";
+      }
+
+      FileIndex++;
+    }
+
+    // Verify rows.
     uint64_t PrevAddress = 0;
     uint32_t RowIndex = 0;
     for (const auto &Row : LineTable->Rows) {
+      // Verify row address.
       if (Row.Address < PrevAddress) {
         ++NumDebugLineErrors;
         OS << "error: .debug_line["
@@ -436,6 +476,7 @@ void DWARFVerifier::verifyDebugLineRows() {
         OS << '\n';
       }
 
+      // Verify file index.
       if (Row.File > MaxFileIndex) {
         ++NumDebugLineErrors;
         OS << "error: .debug_line["

unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp

@@ -1658,6 +1658,13 @@ TEST(DWARFDebugInfo, TestImplicitConstAbbrevs) {
   EXPECT_EQ(DIEs.find(Val2)->second, AbbrevPtrVal2);
 }
 
+void VerifyWarning(DWARFContext &DwarfContext, StringRef Error) {
+  SmallString<1024> Str;
+  raw_svector_ostream Strm(Str);
+  EXPECT_TRUE(DwarfContext.verify(Strm, DIDT_All));
+  EXPECT_TRUE(Str.str().contains(Error));
+}
+
 void VerifyError(DWARFContext &DwarfContext, StringRef Error) {
   SmallString<1024> Str;
   raw_svector_ostream Strm(Str);
@@ -2062,6 +2069,156 @@ TEST(DWARFDebugInfo, TestDwarfVerifyInvalidLineFileIndex) {
                              "file index 5 (valid values are [1,1]):");
 }
 
+TEST(DWARFDebugInfo, TestDwarfVerifyInvalidLineTablePorlogueDirIndex) {
+  // Create a single compile unit whose line table has a prologue with an
+  // invalid dir index.
+  StringRef yamldata = R"(
+    debug_str:
+      - ''
+      - /tmp/main.c
+    debug_abbrev:
+      - Code:            0x00000001
+        Tag:             DW_TAG_compile_unit
+        Children:        DW_CHILDREN_no
+        Attributes:
+          - Attribute:       DW_AT_name
+            Form:            DW_FORM_strp
+          - Attribute:       DW_AT_stmt_list
+            Form:            DW_FORM_sec_offset
+    debug_info:
+      - Length:
+          TotalLength:     16
+        Version:         4
+        AbbrOffset:      0
+        AddrSize:        8
+        Entries:
+          - AbbrCode:        0x00000001
+            Values:
+              - Value:           0x0000000000000001
+              - Value:           0x0000000000000000
+    debug_line:
+      - Length:
+          TotalLength:     61
+        Version:         2
+        PrologueLength:  34
+        MinInstLength:   1
+        DefaultIsStmt:   1
+        LineBase:        251
+        LineRange:       14
+        OpcodeBase:      13
+        StandardOpcodeLengths: [ 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1 ]
+        IncludeDirs:
+          - /tmp
+        Files:
+          - Name:            main.c
+            DirIdx:          2
+            ModTime:         0
+            Length:          0
+        Opcodes:
+          - Opcode:          DW_LNS_extended_op
+            ExtLen:          9
+            SubOpcode:       DW_LNE_set_address
+            Data:            4096
+          - Opcode:          DW_LNS_advance_line
+            SData:           9
+            Data:            4096
+          - Opcode:          DW_LNS_copy
+            Data:            4096
+          - Opcode:          DW_LNS_advance_pc
+            Data:            16
+          - Opcode:          DW_LNS_set_file
+            Data:            1
+          - Opcode:          DW_LNS_extended_op
+            ExtLen:          1
+            SubOpcode:       DW_LNE_end_sequence
+            Data:            1
+  )";
+  auto ErrOrSections = DWARFYAML::EmitDebugSections(yamldata);
+  ASSERT_TRUE((bool)ErrOrSections);
+  std::unique_ptr<DWARFContext> DwarfContext =
+      DWARFContext::create(*ErrOrSections, 8);
+  VerifyError(*DwarfContext,
+              "error: .debug_line[0x00000000].prologue."
+              "file_names[1].dir_idx contains an invalid index: 2");
+}
+
+TEST(DWARFDebugInfo, TestDwarfVerifyDuplicateFileWarning) {
+  // Create a single compile unit whose line table has a prologue with an
+  // invalid dir index.
+  StringRef yamldata = R"(
+    debug_str:
+      - ''
+      - /tmp/main.c
+    debug_abbrev:
+      - Code:            0x00000001
+        Tag:             DW_TAG_compile_unit
+        Children:        DW_CHILDREN_no
+        Attributes:
+          - Attribute:       DW_AT_name
+            Form:            DW_FORM_strp
+          - Attribute:       DW_AT_stmt_list
+            Form:            DW_FORM_sec_offset
+    debug_info:
+      - Length:
+          TotalLength:     16
+        Version:         4
+        AbbrOffset:      0
+        AddrSize:        8
+        Entries:
+          - AbbrCode:        0x00000001
+            Values:
+              - Value:           0x0000000000000001
+              - Value:           0x0000000000000000
+    debug_line:
+      - Length:
+          TotalLength:     71
+        Version:         2
+        PrologueLength:  44
+        MinInstLength:   1
+        DefaultIsStmt:   1
+        LineBase:        251
+        LineRange:       14
+        OpcodeBase:      13
+        StandardOpcodeLengths: [ 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1 ]
+        IncludeDirs:
+          - /tmp
+        Files:
+          - Name:            main.c
+            DirIdx:          1
+            ModTime:         0
+            Length:          0
+          - Name:            main.c
+            DirIdx:          1
+            ModTime:         0
+            Length:          0
+        Opcodes:
+          - Opcode:          DW_LNS_extended_op
+            ExtLen:          9
+            SubOpcode:       DW_LNE_set_address
+            Data:            4096
+          - Opcode:          DW_LNS_advance_line
+            SData:           9
+            Data:            4096
+          - Opcode:          DW_LNS_copy
+            Data:            4096
+          - Opcode:          DW_LNS_advance_pc
+            Data:            16
+          - Opcode:          DW_LNS_set_file
+            Data:            1
+          - Opcode:          DW_LNS_extended_op
+            ExtLen:          1
+            SubOpcode:       DW_LNE_end_sequence
+            Data:            2
+  )";
+  auto ErrOrSections = DWARFYAML::EmitDebugSections(yamldata);
+  ASSERT_TRUE((bool)ErrOrSections);
+  std::unique_ptr<DWARFContext> DwarfContext =
+      DWARFContext::create(*ErrOrSections, 8);
+  VerifyWarning(*DwarfContext,
+                "warning: .debug_line[0x00000000].prologue.file_names[2] is "
+                "a duplicate of file_names[1]");
+}
+
 TEST(DWARFDebugInfo, TestDwarfVerifyCUDontShareLineTable) {
   // Create a two compile units where both compile units share the same
   // DW_AT_stmt_list value and verify we report the error correctly.