[llvm-pdbutil] Create DBI section headers in yaml2pdb (#166566)

Nerixyz · web-flow · commit d99c840d1629 · 2025-11-15T16:29:23.000+01:00
The section headers present in the DBI stream got lost when using `pdb2yaml` and `yaml2pdb`. They are a list of COFF section headers. The `llvm::object::coff_section` didn't have a YAML mapping, so I added one in llvm-pdbutil. The mapping for COFF sections in ObjectYAML includes the section data itself, so we can't use it here. Creation of the section map and headers in yaml2pdb is done like in LLD: https://github.com/llvm/llvm-project/blob/438a18c1e105ca04e624239644195e48b28b5099/lld/COFF/PDB.cpp#L1695-L1703
diff --git a/llvm/test/tools/llvm-pdbutil/dbi-section-headers.test b/llvm/test/tools/llvm-pdbutil/dbi-section-headers.test
@@ -0,0 +1,131 @@
+# RUN: llvm-pdbutil yaml2pdb %s --pdb=%t.pdb
+# RUN: llvm-pdbutil dump --section-headers --section-map %t.pdb | FileCheck --check-prefix=CHECK-YAML2PDB %s
+
+# RUN: llvm-pdbutil pdb2yaml --section-headers %t.pdb > %t.yaml
+# RUN: FileCheck --input-file=%t.yaml --check-prefix=CHECK-PDB2YAML %s
+
+# CHECK-YAML2PDB:                      Section Headers
+# CHECK-YAML2PDB:  SECTION HEADER #1
+# CHECK-YAML2PDB:     .text name
+# CHECK-YAML2PDB:        47 virtual size
+# CHECK-YAML2PDB:      1000 virtual address
+# CHECK-YAML2PDB:       200 size of raw data
+# CHECK-YAML2PDB:       400 file pointer to raw data
+# CHECK-YAML2PDB:         0 file pointer to relocation table
+# CHECK-YAML2PDB:         0 file pointer to line numbers
+# CHECK-YAML2PDB:         0 number of relocations
+# CHECK-YAML2PDB:         0 number of line numbers
+# CHECK-YAML2PDB:  60000020 flags
+# CHECK-YAML2PDB:           IMAGE_SCN_CNT_CODE
+# CHECK-YAML2PDB:           IMAGE_SCN_MEM_EXECUTE
+# CHECK-YAML2PDB:           IMAGE_SCN_MEM_READ
+
+# CHECK-YAML2PDB:  SECTION HEADER #2
+# CHECK-YAML2PDB:    .rdata name
+# CHECK-YAML2PDB:        64 virtual size
+# CHECK-YAML2PDB:      2000 virtual address
+# CHECK-YAML2PDB:       200 size of raw data
+# CHECK-YAML2PDB:       600 file pointer to raw data
+# CHECK-YAML2PDB:         0 file pointer to relocation table
+# CHECK-YAML2PDB:         0 file pointer to line numbers
+# CHECK-YAML2PDB:         0 number of relocations
+# CHECK-YAML2PDB:         0 number of line numbers
+# CHECK-YAML2PDB:  40000040 flags
+# CHECK-YAML2PDB:           IMAGE_SCN_CNT_INITIALIZED_DATA
+# CHECK-YAML2PDB:           IMAGE_SCN_MEM_READ
+
+# CHECK-YAML2PDB:  SECTION HEADER #3
+# CHECK-YAML2PDB:    .pdata name
+# CHECK-YAML2PDB:        18 virtual size
+# CHECK-YAML2PDB:      3000 virtual address
+# CHECK-YAML2PDB:       200 size of raw data
+# CHECK-YAML2PDB:       800 file pointer to raw data
+# CHECK-YAML2PDB:         0 file pointer to relocation table
+# CHECK-YAML2PDB:         0 file pointer to line numbers
+# CHECK-YAML2PDB:         0 number of relocations
+# CHECK-YAML2PDB:         0 number of line numbers
+# CHECK-YAML2PDB:  40000040 flags
+# CHECK-YAML2PDB:           IMAGE_SCN_CNT_INITIALIZED_DATA
+# CHECK-YAML2PDB:           IMAGE_SCN_MEM_READ
+
+# CHECK-YAML2PDB:                        Section Map
+# CHECK-YAML2PDB:  Section 0000 | ovl = 0, group = 0, frame = 1, name = 65535
+# CHECK-YAML2PDB:                 class = 65535, offset = 0, size = 71
+# CHECK-YAML2PDB:                 flags = read | execute | 32 bit addr | selector
+# CHECK-YAML2PDB:  Section 0001 | ovl = 0, group = 0, frame = 2, name = 65535
+# CHECK-YAML2PDB:                 class = 65535, offset = 0, size = 100
+# CHECK-YAML2PDB:                 flags = read | 32 bit addr | selector
+# CHECK-YAML2PDB:  Section 0002 | ovl = 0, group = 0, frame = 3, name = 65535
+# CHECK-YAML2PDB:                 class = 65535, offset = 0, size = 24
+# CHECK-YAML2PDB:                 flags = read | 32 bit addr | selector
+# CHECK-YAML2PDB:  Section 0003 | ovl = 0, group = 0, frame = 4, name = 65535
+# CHECK-YAML2PDB:                 class = 65535, offset = 0, size = 4294967295
+# CHECK-YAML2PDB:                 flags = 32 bit addr | absolute addr
+
+# CHECK-PDB2YAML:DbiStream:
+# CHECK-PDB2YAML:  SectionHeaders:
+# CHECK-PDB2YAML:    - Name:            .text
+# CHECK-PDB2YAML:      VirtualSize:     71
+# CHECK-PDB2YAML:      VirtualAddress:  4096
+# CHECK-PDB2YAML:      SizeOfRawData:   512
+# CHECK-PDB2YAML:      PointerToRawData: 1024
+# CHECK-PDB2YAML:      PointerToRelocations: 0
+# CHECK-PDB2YAML:      PointerToLinenumbers: 0
+# CHECK-PDB2YAML:      NumberOfRelocations: 0
+# CHECK-PDB2YAML:      NumberOfLinenumbers: 0
+# CHECK-PDB2YAML:      Characteristics: 1610612768
+# CHECK-PDB2YAML:    - Name:            .rdata
+# CHECK-PDB2YAML:      VirtualSize:     100
+# CHECK-PDB2YAML:      VirtualAddress:  8192
+# CHECK-PDB2YAML:      SizeOfRawData:   512
+# CHECK-PDB2YAML:      PointerToRawData: 1536
+# CHECK-PDB2YAML:      PointerToRelocations: 0
+# CHECK-PDB2YAML:      PointerToLinenumbers: 0
+# CHECK-PDB2YAML:      NumberOfRelocations: 0
+# CHECK-PDB2YAML:      NumberOfLinenumbers: 0
+# CHECK-PDB2YAML:      Characteristics: 1073741888
+# CHECK-PDB2YAML:    - Name:            .pdata
+# CHECK-PDB2YAML:      VirtualSize:     24
+# CHECK-PDB2YAML:      VirtualAddress:  12288
+# CHECK-PDB2YAML:      SizeOfRawData:   512
+# CHECK-PDB2YAML:      PointerToRawData: 2048
+# CHECK-PDB2YAML:      PointerToRelocations: 0
+# CHECK-PDB2YAML:      PointerToLinenumbers: 0
+# CHECK-PDB2YAML:      NumberOfRelocations: 0
+# CHECK-PDB2YAML:      NumberOfLinenumbers: 0
+# CHECK-PDB2YAML:      Characteristics: 1073741888
+
+---
+DbiStream:
+  SectionHeaders:
+    - Name:            .text
+      VirtualSize:     71
+      VirtualAddress:  4096
+      SizeOfRawData:   512
+      PointerToRawData: 1024
+      PointerToRelocations: 0
+      PointerToLinenumbers: 0
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      Characteristics: 1610612768
+    - Name:            .rdata
+      VirtualSize:     100
+      VirtualAddress:  8192
+      SizeOfRawData:   512
+      PointerToRawData: 1536
+      PointerToRelocations: 0
+      PointerToLinenumbers: 0
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      Characteristics: 1073741888
+    - Name:            .pdata
+      VirtualSize:     24
+      VirtualAddress:  12288
+      SizeOfRawData:   512
+      PointerToRawData: 2048
+      PointerToRelocations: 0
+      PointerToLinenumbers: 0
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      Characteristics: 1073741888
+...
diff --git a/llvm/tools/llvm-pdbutil/PdbYaml.cpp b/llvm/tools/llvm-pdbutil/PdbYaml.cpp
@@ -22,6 +22,7 @@ using namespace llvm::pdb;
 using namespace llvm::pdb::yaml;
 using namespace llvm::yaml;
 
+LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::pdb::yaml::CoffSectionHeader)
 LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::pdb::yaml::NamedStreamMapping)
 LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::pdb::yaml::PdbDbiModuleInfo)
 LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::pdb::yaml::StreamBlockList)
@@ -135,6 +136,49 @@ void MappingTraits<msf::SuperBlock>::mapping(IO &IO, msf::SuperBlock &SB) {
   IO.mapOptional("BlockMapAddr", SB.BlockMapAddr, u32(0U));
 }
 
+CoffSectionHeader::CoffSectionHeader() = default;
+
+CoffSectionHeader::CoffSectionHeader(const object::coff_section &Section)
+    : Name(Section.Name), VirtualSize(Section.VirtualSize),
+      VirtualAddress(Section.VirtualAddress),
+      SizeOfRawData(Section.SizeOfRawData),
+      PointerToRawData(Section.PointerToRawData),
+      PointerToRelocations(Section.PointerToRelocations),
+      PointerToLinenumbers(Section.PointerToLinenumbers),
+      NumberOfRelocations(Section.NumberOfRelocations),
+      NumberOfLinenumbers(Section.NumberOfLinenumbers),
+      Characteristics(Section.Characteristics) {}
+
+object::coff_section CoffSectionHeader::toCoffSection() const {
+  object::coff_section Sec;
+  std::memset(Sec.Name, 0, COFF::NameSize);
+  std::memcpy(Sec.Name, Name.data(),
+              std::min(static_cast<size_t>(COFF::NameSize), Name.size()));
+  Sec.VirtualSize = VirtualSize;
+  Sec.VirtualAddress = VirtualAddress;
+  Sec.SizeOfRawData = SizeOfRawData;
+  Sec.PointerToRawData = PointerToRawData;
+  Sec.PointerToRelocations = PointerToRelocations;
+  Sec.PointerToLinenumbers = PointerToLinenumbers;
+  Sec.NumberOfRelocations = NumberOfRelocations;
+  Sec.NumberOfLinenumbers = NumberOfLinenumbers;
+  Sec.Characteristics = Characteristics;
+  return Sec;
+}
+
+void MappingTraits<CoffSectionHeader>::mapping(IO &IO, CoffSectionHeader &Obj) {
+  IO.mapRequired("Name", Obj.Name);
+  IO.mapOptional("VirtualSize", Obj.VirtualSize);
+  IO.mapOptional("VirtualAddress", Obj.VirtualAddress);
+  IO.mapOptional("SizeOfRawData", Obj.SizeOfRawData);
+  IO.mapOptional("PointerToRawData", Obj.PointerToRawData);
+  IO.mapOptional("PointerToRelocations", Obj.PointerToRelocations);
+  IO.mapOptional("PointerToLinenumbers", Obj.PointerToLinenumbers);
+  IO.mapOptional("NumberOfRelocations", Obj.NumberOfRelocations);
+  IO.mapOptional("NumberOfLinenumbers", Obj.NumberOfLinenumbers);
+  IO.mapOptional("Characteristics", Obj.Characteristics);
+}
+
 void MappingTraits<StreamBlockList>::mapping(IO &IO, StreamBlockList &SB) {
   IO.mapRequired("Stream", SB.Blocks);
 }
@@ -163,6 +207,7 @@ void MappingTraits<PdbDbiStream>::mapping(IO &IO, PdbDbiStream &Obj) {
     IO.setContext(&Obj.FakeHeader);
   }
   IO.mapOptional("Modules", Obj.ModInfos);
+  IO.mapOptional("SectionHeaders", Obj.SectionHeaders);
 }
 
 void MappingTraits<PdbTpiStream>::mapping(IO &IO,
diff --git a/llvm/tools/llvm-pdbutil/PdbYaml.h b/llvm/tools/llvm-pdbutil/PdbYaml.h
@@ -18,6 +18,7 @@
 #include "llvm/DebugInfo/PDB/Native/PDBFile.h"
 #include "llvm/DebugInfo/PDB/Native/RawConstants.h"
 #include "llvm/DebugInfo/PDB/PDBTypes.h"
+#include "llvm/Object/COFF.h"
 #include "llvm/ObjectYAML/CodeViewYAMLDebugSections.h"
 #include "llvm/ObjectYAML/CodeViewYAMLSymbols.h"
 #include "llvm/ObjectYAML/CodeViewYAMLTypes.h"
@@ -40,6 +41,24 @@ struct MSFHeaders {
   uint64_t FileSize = 0;
 };
 
+struct CoffSectionHeader {
+  CoffSectionHeader();
+  CoffSectionHeader(const object::coff_section &Section);
+
+  object::coff_section toCoffSection() const;
+
+  StringRef Name;
+  uint32_t VirtualSize = 0;
+  uint32_t VirtualAddress = 0;
+  uint32_t SizeOfRawData = 0;
+  uint32_t PointerToRawData = 0;
+  uint32_t PointerToRelocations = 0;
+  uint32_t PointerToLinenumbers = 0;
+  uint16_t NumberOfRelocations = 0;
+  uint16_t NumberOfLinenumbers = 0;
+  uint32_t Characteristics = 0;
+};
+
 struct StreamBlockList {
   std::vector<uint32_t> Blocks;
 };
@@ -82,6 +101,7 @@ struct PdbDbiStream {
 
   std::vector<PdbDbiModuleInfo> ModInfos;
   COFF::header FakeHeader;
+  std::vector<CoffSectionHeader> SectionHeaders;
 };
 
 struct PdbTpiStream {
@@ -113,6 +133,7 @@ struct PdbObject {
 }
 }
 
+LLVM_YAML_DECLARE_MAPPING_TRAITS_PRIVATE(pdb::yaml::CoffSectionHeader)
 LLVM_YAML_DECLARE_MAPPING_TRAITS_PRIVATE(pdb::yaml::PdbObject)
 LLVM_YAML_DECLARE_MAPPING_TRAITS_PRIVATE(pdb::yaml::MSFHeaders)
 LLVM_YAML_DECLARE_MAPPING_TRAITS_PRIVATE(msf::SuperBlock)
diff --git a/llvm/tools/llvm-pdbutil/YAMLOutputStyle.cpp b/llvm/tools/llvm-pdbutil/YAMLOutputStyle.cpp
@@ -285,6 +285,24 @@ Error YAMLOutputStyle::dumpDbiStream() {
       }
     }
   }
+
+  if (opts::pdb2yaml::DumpSectionHeaders) {
+    for (const auto &Section : DS.getSectionHeaders()) {
+      yaml::CoffSectionHeader Hdr;
+      Hdr.Name = Section.Name;
+      Hdr.VirtualSize = Section.VirtualSize;
+      Hdr.VirtualAddress = Section.VirtualAddress;
+      Hdr.SizeOfRawData = Section.SizeOfRawData;
+      Hdr.PointerToRawData = Section.PointerToRawData;
+      Hdr.PointerToRelocations = Section.PointerToRelocations;
+      Hdr.PointerToLinenumbers = Section.PointerToLinenumbers;
+      Hdr.NumberOfRelocations = Section.NumberOfRelocations;
+      Hdr.NumberOfLinenumbers = Section.NumberOfLinenumbers;
+      Hdr.Characteristics = Section.Characteristics;
+      Obj.DbiStream->SectionHeaders.emplace_back(Hdr);
+    }
+  }
+
   return Error::success();
 }
 
diff --git a/llvm/tools/llvm-pdbutil/llvm-pdbutil.cpp b/llvm/tools/llvm-pdbutil/llvm-pdbutil.cpp
@@ -716,6 +716,10 @@ cl::list<ModuleSubsection> DumpModuleSubsections(
 cl::opt<bool> DumpModuleSyms("module-syms", cl::desc("dump module symbols"),
                              cl::cat(FileOptions),
                              cl::sub(PdbToYamlSubcommand));
+cl::opt<bool> DumpSectionHeaders("section-headers",
+                                 cl::desc("Dump section headers."),
+                                 cl::cat(FileOptions),
+                                 cl::sub(PdbToYamlSubcommand));
 
 cl::list<std::string> InputFilename(cl::Positional,
                                     cl::desc("<input PDB file>"), cl::Required,
@@ -865,6 +869,20 @@ static void yamlToPdb(StringRef Path) {
     }
   }
 
+  std::vector<object::coff_section> Sections;
+  if (!Dbi.SectionHeaders.empty()) {
+    for (const auto &Hdr : Dbi.SectionHeaders)
+      Sections.emplace_back(Hdr.toCoffSection());
+
+    DbiBuilder.createSectionMap(Sections);
+    ExitOnErr(DbiBuilder.addDbgStream(
+        pdb::DbgHeaderType::SectionHdr,
+        // FIXME: Downcasting to an ArrayRef<uint8_t> should use a helper
+        // function in LLVM
+        ArrayRef<uint8_t>{(const uint8_t *)Sections.data(),
+                          Sections.size() * sizeof(object::coff_section)}));
+  }
+
   auto &TpiBuilder = Builder.getTpiBuilder();
   const auto &Tpi = YamlObj.TpiStream.value_or(DefaultTpiStream);
   TpiBuilder.setVersionHeader(Tpi.Version);
@@ -1541,6 +1559,7 @@ int main(int Argc, const char **Argv) {
       opts::pdb2yaml::DumpModules = true;
       opts::pdb2yaml::DumpModuleFiles = true;
       opts::pdb2yaml::DumpModuleSyms = true;
+      opts::pdb2yaml::DumpSectionHeaders = true;
       opts::pdb2yaml::DumpModuleSubsections.push_back(
           opts::ModuleSubsection::All);
     }
@@ -1551,6 +1570,9 @@ int main(int Argc, const char **Argv) {
 
     if (opts::pdb2yaml::DumpModules)
       opts::pdb2yaml::DbiStream = true;
+
+    if (opts::pdb2yaml::DumpSectionHeaders)
+      opts::pdb2yaml::DbiStream = true;
   }
 
   llvm::sys::InitializeCOMRAII COM(llvm::sys::COMThreadingMode::MultiThreaded);
diff --git a/llvm/tools/llvm-pdbutil/llvm-pdbutil.h b/llvm/tools/llvm-pdbutil/llvm-pdbutil.h
@@ -201,6 +201,7 @@ extern llvm::cl::opt<bool> DumpModules;
 extern llvm::cl::opt<bool> DumpModuleFiles;
 extern llvm::cl::list<ModuleSubsection> DumpModuleSubsections;
 extern llvm::cl::opt<bool> DumpModuleSyms;
+extern llvm::cl::opt<bool> DumpSectionHeaders;
 } // namespace pdb2yaml
 
 namespace explain {

Original file line number	Diff line number	Diff line change
`@@ -285,6 +285,24 @@ Error YAMLOutputStyle::dumpDbiStream() {`
`285`	`285`	`}`
`286`	`286`	`}`
`287`	`287`	`}`
	`288`	`+`
	`289`	`+ if (opts::pdb2yaml::DumpSectionHeaders) {`
	`290`	`+ for (const auto &Section : DS.getSectionHeaders()) {`
	`291`	`+ yaml::CoffSectionHeader Hdr;`
	`292`	`+ Hdr.Name = Section.Name;`
	`293`	`+ Hdr.VirtualSize = Section.VirtualSize;`
	`294`	`+ Hdr.VirtualAddress = Section.VirtualAddress;`
	`295`	`+ Hdr.SizeOfRawData = Section.SizeOfRawData;`
	`296`	`+ Hdr.PointerToRawData = Section.PointerToRawData;`
	`297`	`+ Hdr.PointerToRelocations = Section.PointerToRelocations;`
	`298`	`+ Hdr.PointerToLinenumbers = Section.PointerToLinenumbers;`
	`299`	`+ Hdr.NumberOfRelocations = Section.NumberOfRelocations;`
	`300`	`+ Hdr.NumberOfLinenumbers = Section.NumberOfLinenumbers;`
	`301`	`+ Hdr.Characteristics = Section.Characteristics;`
	`302`	`+ Obj.DbiStream->SectionHeaders.emplace_back(Hdr);`
	`303`	`+ }`
	`304`	`+ }`
	`305`	`+`
`288`	`306`	`return Error::success();`
`289`	`307`	`}`
`290`	`308`