[llvm] cdd4072 - [llvm-objcopy] [COFF] Consider section flags when adding section

[Martin Storsjö via llvm-commits]

Author: Alfonso Sánchez-Beato
Date: 2021-08-25T23:11:41+03:00
New Revision: cdd407286a9652ec62b33f437a298754fe3ba7ab

URL: https://github.com/llvm/llvm-project/commit/cdd407286a9652ec62b33f437a298754fe3ba7ab
DIFF: https://github.com/llvm/llvm-project/commit/cdd407286a9652ec62b33f437a298754fe3ba7ab.diff

LOG: [llvm-objcopy] [COFF] Consider section flags when adding section

The --set-section-flags option was being ignored when adding a new
section. Take it into account if present.

Fixes https://llvm.org/PR51244

Reviewed By: jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D106942

Added: 
    llvm/test/tools/llvm-objcopy/COFF/add-section-and-set-flags.test

Modified: 
    llvm/tools/llvm-objcopy/COFF/COFFObjcopy.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/test/tools/llvm-objcopy/COFF/add-section-and-set-flags.test b/llvm/test/tools/llvm-objcopy/COFF/add-section-and-set-flags.test
new file mode 100644
index 0000000000000..b5fdcb8f6624f
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/COFF/add-section-and-set-flags.test
@@ -0,0 +1,36 @@
+# RUN: yaml2obj %s -o %t
+
+## Test that llvm-objcopy can add sections and set its flags in the same
+## call.
+# RUN: echo DEADBEEF > %t.sec
+# RUN: llvm-objcopy --set-section-flags=.test.section1=code --add-section=.test.section1=%t.sec --set-section-flags=.test.section2=data --add-section=.test.section2=%t.sec %t %t1
+# RUN: llvm-readobj --sections --section-data %t1 | FileCheck %s
+
+# CHECK:       Name: .test.section1
+# CHECK-NEXT:  VirtualSize: 0x9
+# CHECK-NEXT:  VirtualAddress: 0x0
+# CHECK-NEXT:  RawDataSize: 9
+# CHECK:       Characteristics [
+# CHECK-NEXT:      IMAGE_SCN_CNT_CODE
+# CHECK-NEXT:      IMAGE_SCN_MEM_EXECUTE
+# CHECK-NEXT:      IMAGE_SCN_MEM_READ
+# CHECK-NEXT:      IMAGE_SCN_MEM_WRITE
+# CHECK-NEXT:  ]
+
+# CHECK:       Name: .test.section2
+# CHECK-NEXT:  VirtualSize: 0x9
+# CHECK-NEXT:  VirtualAddress: 0x9
+# CHECK-NEXT:  RawDataSize: 9
+# CHECK:       Characteristics [
+# CHECK-NEXT:    IMAGE_SCN_CNT_INITIALIZED_DATA
+# CHECK-NEXT:    IMAGE_SCN_MEM_READ
+# CHECK-NEXT:    IMAGE_SCN_MEM_WRITE
+# CHECK-NEXT:  ]
+
+--- !COFF
+header:
+  Machine:         IMAGE_FILE_MACHINE_AMD64
+  Characteristics: [ ]
+sections:
+symbols:
+...

diff  --git a/llvm/tools/llvm-objcopy/COFF/COFFObjcopy.cpp b/llvm/tools/llvm-objcopy/COFF/COFFObjcopy.cpp
index e50ac2e12e2f5..38c9cd09433b6 100644
--- a/llvm/tools/llvm-objcopy/COFF/COFFObjcopy.cpp
+++ b/llvm/tools/llvm-objcopy/COFF/COFFObjcopy.cpp
@@ -94,7 +94,7 @@ static Error addGnuDebugLink(Object &Obj, StringRef DebugLinkFile) {
   return Error::success();
 }
 
-static void setSectionFlags(Section &Sec, SectionFlag AllFlags) {
+static uint32_t flagsToCharacteristics(SectionFlag AllFlags, uint32_t OldChar) {
   // Need to preserve alignment flags.
   const uint32_t PreserveMask =
       IMAGE_SCN_ALIGN_1BYTES | IMAGE_SCN_ALIGN_2BYTES | IMAGE_SCN_ALIGN_4BYTES |
@@ -107,8 +107,7 @@ static void setSectionFlags(Section &Sec, SectionFlag AllFlags) {
 
   // Setup new section characteristics based on the flags provided in command
   // line.
-  uint32_t NewCharacteristics =
-      (Sec.Header.Characteristics & PreserveMask) | IMAGE_SCN_MEM_READ;
+  uint32_t NewCharacteristics = (OldChar & PreserveMask) | IMAGE_SCN_MEM_READ;
 
   if ((AllFlags & SectionFlag::SecAlloc) && !(AllFlags & SectionFlag::SecLoad))
     NewCharacteristics |= IMAGE_SCN_CNT_UNINITIALIZED_DATA;
@@ -128,7 +127,7 @@ static void setSectionFlags(Section &Sec, SectionFlag AllFlags) {
   if (AllFlags & SectionFlag::SecExclude)
     NewCharacteristics |= IMAGE_SCN_LNK_REMOVE;
 
-  Sec.Header.Characteristics = NewCharacteristics;
+  return NewCharacteristics;
 }
 
 static Error handleArgs(const CommonConfig &Config, Object &Obj) {
@@ -226,7 +225,8 @@ static Error handleArgs(const CommonConfig &Config, Object &Obj) {
     for (Section &Sec : Obj.getMutableSections()) {
       const auto It = Config.SetSectionFlags.find(Sec.Name);
       if (It != Config.SetSectionFlags.end())
-        setSectionFlags(Sec, It->second.NewFlags);
+        Sec.Header.Characteristics = flagsToCharacteristics(
+            It->second.NewFlags, Sec.Header.Characteristics);
     }
 
   for (const auto &Flag : Config.AddSection) {
@@ -238,11 +238,18 @@ static Error handleArgs(const CommonConfig &Config, Object &Obj) {
       return createFileError(FileName, errorCodeToError(BufOrErr.getError()));
     auto Buf = std::move(*BufOrErr);
 
+    uint32_t Characteristics;
+    const auto It = Config.SetSectionFlags.find(SecName);
+    if (It != Config.SetSectionFlags.end())
+      Characteristics = flagsToCharacteristics(It->second.NewFlags, 0);
+    else
+      Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_ALIGN_1BYTES;
+
     addSection(
         Obj, SecName,
         makeArrayRef(reinterpret_cast<const uint8_t *>(Buf->getBufferStart()),
                      Buf->getBufferSize()),
-        IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_ALIGN_1BYTES);
+        Characteristics);
   }
 
   if (!Config.AddGnuDebugLink.empty())