[llvm-objcopy] Add support for --add-section for COFF

This patch enables support for --add-section=... option for COFF objects.

Differential Revision: https://reviews.llvm.org/D65040

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367130 91177308-0d34-0410-b5e6-96231b3b80d8

docs/CommandGuide/llvm-objcopy.rst

@@ -36,6 +36,13 @@ multiple file formats.
 
  Add a .gnu_debuglink section for ``<debug-file>`` to the output.
 
+.. option:: --add-section <section=file>
+
+ Add a section named ``<section>`` with the contents of ``<file>`` to the
+ output. For ELF objects the section will be of type `SHT_NOTE`, if the name
+ starts with ".note". Otherwise, it will have type `SHT_PROGBITS`. Can be
+ specified multiple times to add multiple sections.
+
 .. option:: --disable-deterministic-archives, -U
 
  Use real values for UIDs, GIDs and timestamps when updating archive member
@@ -141,13 +148,6 @@ The following options are implemented only for ELF objects. If used with other
 objects, :program:`llvm-objcopy` will either emit an error or silently ignore
 them.
 
-.. option:: --add-section <section=file>
-
- Add a section named ``<section>`` with the contents of ``<file>`` to the
- output. The section will be of type `SHT_NOTE`, if the name starts with
- ".note". Otherwise, it will have type `SHT_PROGBITS`. Can be specified multiple
- times to add multiple sections.
-
 .. option:: --add-symbol <name>=[<section>:]<value>[,<flags>]
 
  Add a new symbol called ``<name>`` to the output symbol table, in the section

test/tools/llvm-objcopy/COFF/add-section.test

@@ -0,0 +1,56 @@
+# RUN: yaml2obj %s > %t
+
+## Test that llvm-objcopy adds a section to the given object with expected
+## contents.
+# RUN: echo DEADBEEF > %t.sec
+# RUN: llvm-objcopy --add-section=.test.section=%t.sec %t %t1
+# RUN: llvm-readobj --file-headers --sections --section-data %t1 | FileCheck %s --check-prefixes=CHECK-ADD
+
+# CHECK-ADD:      SectionCount: 2
+# CHECK-ADD:      Name: .text
+# CHECK-ADD:      Name: .test.section
+# CHECK-ADD:      Characteristics [
+# CHECK-ADD-NEXT:   IMAGE_SCN_ALIGN_1BYTES
+# CHECK-ADD-NEXT:   IMAGE_SCN_CNT_INITIALIZED_DATA
+# CHECK-ADD-NEXT: ]
+# CHECK-ADD:      SectionData (
+# CHECK-ADD-NEXT:  0000: {{.+}}|DEADBEEF{{.+}}|
+# CHECK-ADD-NEXT: )
+
+## Test that llvm-objcopy can add a section with an empty name.
+# RUN: llvm-objcopy --add-section==%t.sec %t %t1.empty.name
+# RUN: llvm-readobj --file-headers --sections --section-data %t1.empty.name | FileCheck %s --check-prefixes=CHECK-ADD-EMPTY-NAME
+
+# CHECK-ADD-EMPTY-NAME:      SectionCount: 2
+# CHECK-ADD-EMPTY-NAME:      Name: .text
+# CHECK-ADD-EMPTY-NAME:      Name: (00 00 00 00 00 00 00 00)
+# CHECK-ADD-EMPTY-NAME:      Characteristics [
+# CHECK-ADD-EMPTY-NAME-NEXT:   IMAGE_SCN_ALIGN_1BYTES
+# CHECK-ADD-EMPTY-NAME-NEXT:   IMAGE_SCN_CNT_INITIALIZED_DATA
+# CHECK-ADD-EMPTY-NAME-NEXT: ]
+# CHECK-ADD-EMPTY-NAME:      SectionData (
+# CHECK-ADD-EMPTY-NAME-NEXT:  0000: {{.+}}|DEADBEEF{{.+}}|
+# CHECK-ADD-EMPTY-NAME-NEXT: )
+
+## Test that llvm-objcopy produces an error if the file with section contents
+## to be added does not exist.
+# RUN: not llvm-objcopy --add-section=.another.section=%t2 %t %t3 2>&1 | FileCheck -DFILE=%t -DFILE1=%t2 %s --check-prefixes=CHECK-ERR1
+
+# CHECK-ERR1: llvm-objcopy{{(.exe)?}}: error: '[[FILE]]': '[[FILE1]]': {{[Nn]}}o such file or directory
+
+## Another negative test for invalid --add-sections command line argument.
+# RUN: not llvm-objcopy --add-section=.another.section %t %t3 2>&1 | FileCheck -DFILE=%t %s --check-prefixes=CHECK-ERR2
+
+# CHECK-ERR2: llvm-objcopy{{(.exe)?}}: error: '[[FILE]]': bad format for --add-section
+
+--- !COFF
+header:
+  Machine:         IMAGE_FILE_MACHINE_AMD64
+  Characteristics: [  ]
+sections:
+  - Name:            .text
+    Characteristics: [  ]
+    Alignment:       4
+    SectionData:     488B0500000000C3
+symbols:
+...

tools/llvm-objcopy/COFF/COFFObjcopy.cpp

@@ -65,26 +65,37 @@ static std::vector<uint8_t> createGnuDebugLinkSectionContents(StringRef File) {
   return Data;
 }
 
-static void addGnuDebugLink(Object &Obj, StringRef DebugLinkFile) {
-  uint32_t StartRVA = getNextRVA(Obj);
+// Adds named section with given contents to the object.
+static void addSection(Object &Obj, StringRef Name, ArrayRef<uint8_t> Contents,
+                       uint32_t Characteristics) {
+  bool NeedVA = Characteristics & (IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ |
+                                   IMAGE_SCN_MEM_WRITE);
 
-  std::vector<Section> Sections;
   Section Sec;
-  Sec.setOwnedContents(createGnuDebugLinkSectionContents(DebugLinkFile));
-  Sec.Name = ".gnu_debuglink";
-  Sec.Header.VirtualSize = Sec.getContents().size();
-  Sec.Header.VirtualAddress = StartRVA;
-  Sec.Header.SizeOfRawData = alignTo(Sec.Header.VirtualSize,
-                                     Obj.IsPE ? Obj.PeHeader.FileAlignment : 1);
+  Sec.setOwnedContents(Contents);
+  Sec.Name = Name;
+  Sec.Header.VirtualSize = NeedVA ? Sec.getContents().size() : 0u;
+  Sec.Header.VirtualAddress = NeedVA ? getNextRVA(Obj) : 0u;
+  Sec.Header.SizeOfRawData =
+      NeedVA ? alignTo(Sec.Header.VirtualSize,
+                       Obj.IsPE ? Obj.PeHeader.FileAlignment : 1)
+             : Sec.getContents().size();
   // Sec.Header.PointerToRawData is filled in by the writer.
   Sec.Header.PointerToRelocations = 0;
   Sec.Header.PointerToLinenumbers = 0;
   // Sec.Header.NumberOfRelocations is filled in by the writer.
   Sec.Header.NumberOfLinenumbers = 0;
-  Sec.Header.Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA |
-                               IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_DISCARDABLE;
-  Sections.push_back(Sec);
-  Obj.addSections(Sections);
+  Sec.Header.Characteristics = Characteristics;
+
+  Obj.addSections(Sec);
+}
+
+static void addGnuDebugLink(Object &Obj, StringRef DebugLinkFile) {
+  std::vector<uint8_t> Contents =
+      createGnuDebugLinkSectionContents(DebugLinkFile);
+  addSection(Obj, ".gnu_debuglink", Contents,
+             IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ |
+                 IMAGE_SCN_MEM_DISCARDABLE);
 }
 
 static Error handleArgs(const CopyConfig &Config, Object &Obj) {
@@ -171,21 +182,40 @@ static Error handleArgs(const CopyConfig &Config, Object &Obj) {
     return false;
   });
 
+  for (const auto &Flag : Config.AddSection) {
+    StringRef SecName, FileName;
+    std::tie(SecName, FileName) = Flag.split("=");
+
+    if (FileName.empty())
+      return createStringError(llvm::errc::invalid_argument,
+                               "bad format for --add-section");
+    auto BufOrErr = MemoryBuffer::getFile(FileName);
+    if (!BufOrErr)
+      return createFileError(FileName, errorCodeToError(BufOrErr.getError()));
+    auto Buf = std::move(*BufOrErr);
+
+    addSection(
+        Obj, SecName,
+        makeArrayRef(reinterpret_cast<const uint8_t *>(Buf->getBufferStart()),
+                     Buf->getBufferSize()),
+        IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_ALIGN_1BYTES);
+  }
+
   if (!Config.AddGnuDebugLink.empty())
     addGnuDebugLink(Obj, Config.AddGnuDebugLink);
 
   if (Config.AllowBrokenLinks || !Config.BuildIdLinkDir.empty() ||
       Config.BuildIdLinkInput || Config.BuildIdLinkOutput ||
       !Config.SplitDWO.empty() || !Config.SymbolsPrefix.empty() ||
-      !Config.AllocSectionsPrefix.empty() || !Config.AddSection.empty() ||
-      !Config.DumpSection.empty() || !Config.KeepSection.empty() ||
-      !Config.SymbolsToGlobalize.empty() || !Config.SymbolsToKeep.empty() ||
-      !Config.SymbolsToLocalize.empty() || !Config.SymbolsToWeaken.empty() ||
-      !Config.SymbolsToKeepGlobal.empty() || !Config.SectionsToRename.empty() ||
-      !Config.SetSectionFlags.empty() || !Config.SymbolsToRename.empty() ||
-      Config.ExtractDWO || Config.KeepFileSymbols || Config.LocalizeHidden ||
-      Config.PreserveDates || Config.StripDWO || Config.StripNonAlloc ||
-      Config.StripSections || Config.Weaken || Config.DecompressDebugSections ||
+      !Config.AllocSectionsPrefix.empty() || !Config.DumpSection.empty() ||
+      !Config.KeepSection.empty() || !Config.SymbolsToGlobalize.empty() ||
+      !Config.SymbolsToKeep.empty() || !Config.SymbolsToLocalize.empty() ||
+      !Config.SymbolsToWeaken.empty() || !Config.SymbolsToKeepGlobal.empty() ||
+      !Config.SectionsToRename.empty() || !Config.SetSectionFlags.empty() ||
+      !Config.SymbolsToRename.empty() || Config.ExtractDWO ||
+      Config.KeepFileSymbols || Config.LocalizeHidden || Config.PreserveDates ||
+      Config.StripDWO || Config.StripNonAlloc || Config.StripSections ||
+      Config.Weaken || Config.DecompressDebugSections ||
       Config.DiscardMode == DiscardType::Locals ||
       !Config.SymbolsToAdd.empty() || Config.EntryExpr) {
     return createStringError(llvm::errc::invalid_argument,

tools/llvm-objcopy/COFF/Writer.cpp

@@ -120,12 +120,12 @@ size_t COFFWriter::finalizeStringTable() {
   StrTabBuilder.finalize();
 
   for (auto &S : Obj.getMutableSections()) {
+    memset(S.Header.Name, 0, sizeof(S.Header.Name));
     if (S.Name.size() > COFF::NameSize) {
-      memset(S.Header.Name, 0, sizeof(S.Header.Name));
       snprintf(S.Header.Name, sizeof(S.Header.Name), "/%d",
                (int)StrTabBuilder.getOffset(S.Name));
     } else {
-      strncpy(S.Header.Name, S.Name.data(), COFF::NameSize);
+      memcpy(S.Header.Name, S.Name.data(), S.Name.size());
     }
   }
   for (auto &S : Obj.getMutableSymbols()) {