[DirectX] Add only-section to llvm-objcopy for DXContainer

Author: inbelic

llvm/lib/ObjCopy/ConfigManager.cpp

@@ -116,14 +116,13 @@ ConfigManager::getDXContainerConfig() const {
       !Common.AllocSectionsPrefix.empty() ||
       Common.DiscardMode != DiscardType::None || !Common.AddSection.empty() ||
       !Common.DumpSection.empty() || !Common.KeepSection.empty() ||
-      !Common.OnlySection.empty() || !Common.SectionsToRename.empty() ||
-      !Common.SetSectionAlignment.empty() || !Common.SetSectionFlags.empty() ||
-      !Common.SetSectionType.empty() || Common.ExtractDWO ||
-      Common.OnlyKeepDebug || Common.StripAllGNU || Common.StripDWO ||
-      Common.StripDebug || Common.StripNonAlloc || Common.StripSections ||
-      Common.StripUnneeded || Common.DecompressDebugSections ||
-      Common.GapFill != 0 || Common.PadTo != 0 ||
-      Common.ChangeSectionLMAValAll != 0 ||
+      !Common.SectionsToRename.empty() || !Common.SetSectionAlignment.empty() ||
+      !Common.SetSectionFlags.empty() || !Common.SetSectionType.empty() ||
+      Common.ExtractDWO || Common.OnlyKeepDebug || Common.StripAllGNU ||
+      Common.StripDWO || Common.StripDebug || Common.StripNonAlloc ||
+      Common.StripSections || Common.StripUnneeded ||
+      Common.DecompressDebugSections || Common.GapFill != 0 ||
+      Common.PadTo != 0 || Common.ChangeSectionLMAValAll != 0 ||
       !Common.ChangeSectionAddress.empty()) {
     return createStringError(
         llvm::errc::invalid_argument,

llvm/lib/ObjCopy/DXContainer/DXContainerObjcopy.cpp

@@ -28,6 +28,13 @@ static Error handleArgs(const CommonConfig &Config, Object &Obj) {
       return Config.ToRemove.matches(P.Name);
     };
 
+  if (!Config.OnlySection.empty())
+    RemovePred = [&Config](const Part &P) {
+      // Explicitly keep these sections regardless of previous removes and
+      // remove everything else.
+      return !Config.OnlySection.matches(P.Name);
+    };
+
   if (auto E = Obj.removeParts(RemovePred))
     return E;
 

llvm/test/tools/llvm-objcopy/DXContainer/only-section-headers.test

@@ -0,0 +1,56 @@
+## Tests that the copied DXContainer correctly retains only the specified
+## headers.
+
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-objcopy --only-section=FKE1 --only-section=FKE4 %t %t.out
+# RUN: obj2yaml %t.out | FileCheck %s
+
+--- !dxcontainer
+Header:
+  Hash:            [ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+                     0x0, 0x0, 0x0, 0x0, 0x0, 0x0 ]
+  Version:
+    Major:           1
+    Minor:           0
+## FileSize = 32 (header)
+##          + 8 (FKE1 content) + 1688 (FKE4 content)
+##          + 8 (2 part offsets) + 16 (2 part headers)
+##          = 1752
+# CHECK: FileSize:       1752
+  FileSize:        1996
+# CHECK-NEXT: PartCount:      2
+  PartCount:       7
+# CHECK-NEXT: PartOffsets:    [ 40, 56 ]
+  PartOffsets:     [ 60, 76, 92, 108, 236, 1932, 1960 ]
+Parts:
+# CHECK-NEXT: Parts
+# CHECK: FKE1
+# CHECK-NOT: FKE2
+# CHECK-NOT: FKE3
+# CHECK: FKE4
+# CHECK-NOT: FKE5
+# CHECK-NOT: DXIL
+  - Name:            FKE0
+    Size:            8
+  - Name:            FKE1
+    Size:            8
+  - Name:            FKE2
+    Size:            8
+  - Name:            FKE3
+    Size:            120
+  - Name:            FKE4
+    Size:            1688
+  - Name:            FKE5
+    Size:            20
+  - Name:            DXIL
+    Size:            28
+    Program:
+      MajorVersion:    6
+      MinorVersion:    5
+      ShaderKind:      5
+      Size:            8
+      DXILMajorVersion: 1
+      DXILMinorVersion: 5
+      DXILSize:        4
+      DXIL:            [ 0x42, 0x43, 0xC0, 0xDE, ]
+...