[lld] r185308 - [PECOFF][Writer] Do not emit the empty section as Windows loader rejects such executable.

[Rui Ueyama]

Author: ruiu
Date: Mon Jul  1 02:32:12 2013
New Revision: 185308

URL: http://llvm.org/viewvc/llvm-project?rev=185308&view=rev
Log:
[PECOFF][Writer] Do not emit the empty section as Windows loader rejects such executable.

Modified:
    lld/trunk/lib/ReaderWriter/PECOFF/WriterPECOFF.cpp
    lld/trunk/test/pecoff/hello.test
    lld/trunk/test/pecoff/trivial.test

Modified: lld/trunk/lib/ReaderWriter/PECOFF/WriterPECOFF.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/PECOFF/WriterPECOFF.cpp?rev=185308&r1=185307&r2=185308&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/PECOFF/WriterPECOFF.cpp (original)
+++ lld/trunk/lib/ReaderWriter/PECOFF/WriterPECOFF.cpp Mon Jul  1 02:32:12 2013
@@ -438,6 +438,11 @@ void SectionHeaderTableChunk::write(uint
   uint64_t offset = 0;
   fileBuffer += fileOffset();
   for (const auto &chunk : _sections) {
+    // Skip the empty section. Windows loader does not like a section
+    // of size zero and rejects such executable.
+    if (chunk->size() == 0)
+      continue;
+
     const llvm::object::coff_section &header = chunk->getSectionHeader();
     std::memcpy(fileBuffer + offset, &header, sizeof(header));
     offset += sizeof(header);
@@ -525,8 +530,12 @@ private:
     uint32_t va = offset;
     for (auto &cp : _chunks) {
       if (SectionChunk *chunk = dyn_cast<SectionChunk>(&*cp)) {
-        numSections++;
         chunk->setVirtualAddress(va);
+
+        // Skip the empty section.
+        if (chunk->size() == 0)
+          continue;
+        numSections++;
         va = llvm::RoundUpToAlignment(va + chunk->size(), PAGE_SIZE);
       }
     }

Modified: lld/trunk/test/pecoff/hello.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/pecoff/hello.test?rev=185308&r1=185307&r2=185308&view=diff
==============================================================================
--- lld/trunk/test/pecoff/hello.test (original)
+++ lld/trunk/test/pecoff/hello.test Mon Jul  1 02:32:12 2013
@@ -25,22 +25,6 @@ CHECK:     ]
 CHECK:   }
 CHECK:   Section {
 CHECK:     Number: 2
-CHECK:     Name: .rdata (2E 72 64 61 74 61 00 00)
-CHECK:     VirtualSize: 0x0
-CHECK:     VirtualAddress: 0x2000
-CHECK:     RawDataSize: 0
-CHECK:     PointerToRawData: 0x400
-CHECK:     PointerToRelocations: 0x0
-CHECK:     PointerToLineNumbers: 0x0
-CHECK:     RelocationCount: 0
-CHECK:     LineNumberCount: 0
-CHECK:     Characteristics [ (0x40000040)
-CHECK:       IMAGE_SCN_CNT_INITIALIZED_DATA (0x40)
-CHECK:       IMAGE_SCN_MEM_READ (0x40000000)
-CHECK:     ]
-CHECK:   }
-CHECK:   Section {
-CHECK:     Number: 3
 CHECK:     Name: .data (2E 64 61 74 61 00 00 00)
 CHECK:     VirtualSize: 0x18
 CHECK:     VirtualAddress: 0x2000

Modified: lld/trunk/test/pecoff/trivial.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/pecoff/trivial.test?rev=185308&r1=185307&r2=185308&view=diff
==============================================================================
--- lld/trunk/test/pecoff/trivial.test (original)
+++ lld/trunk/test/pecoff/trivial.test Mon Jul  1 02:32:12 2013
@@ -10,7 +10,7 @@ FILE: Arch: i386
 FILE: AddressSize: 32bit
 FILE: ImageFileHeader {
 FILE:   Machine: IMAGE_FILE_MACHINE_I386 (0x14C)
-FILE:   SectionCount: 3
+FILE:   SectionCount: 1
 FILE:   TimeDateStamp:
 FILE:   PointerToSymbolTable: 0x0
 FILE:   SymbolCount: 0
@@ -78,37 +78,4 @@ SECTIONS:       IMAGE_SCN_MEM_EXECUTE (0
 SECTIONS:       IMAGE_SCN_MEM_READ (0x40000000)
 SECTIONS:     ]
 SECTIONS:   }
-SECTIONS:   Section {
-SECTIONS:     Number: 2
-SECTIONS:     Name: .rdata (2E 72 64 61 74 61 00 00)
-SECTIONS:     VirtualSize: 0x0
-SECTIONS:     VirtualAddress: 0x2000
-SECTIONS:     RawDataSize: 0
-SECTIONS:     PointerToRawData: 0x400
-SECTIONS:     PointerToRelocations: 0x0
-SECTIONS:     PointerToLineNumbers: 0x0
-SECTIONS:     RelocationCount: 0
-SECTIONS:     LineNumberCount: 0
-SECTIONS:     Characteristics [ (0x40000040)
-SECTIONS:       IMAGE_SCN_CNT_INITIALIZED_DATA (0x40)
-SECTIONS:       IMAGE_SCN_MEM_READ (0x40000000)
-SECTIONS:     ]
-SECTIONS:   }
-SECTIONS:   Section {
-SECTIONS:     Number: 3
-SECTIONS:     Name: .data (2E 64 61 74 61 00 00 00)
-SECTIONS:     VirtualSize: 0x0
-SECTIONS:     VirtualAddress: 0x2000
-SECTIONS:     RawDataSize: 0
-SECTIONS:     PointerToRawData: 0x400
-SECTIONS:     PointerToRelocations: 0x0
-SECTIONS:     PointerToLineNumbers: 0x0
-SECTIONS:     RelocationCount: 0
-SECTIONS:     LineNumberCount: 0
-SECTIONS:     Characteristics [ (0xC0000040)
-SECTIONS:       IMAGE_SCN_CNT_INITIALIZED_DATA (0x40)
-SECTIONS:       IMAGE_SCN_MEM_READ (0x40000000)
-SECTIONS:       IMAGE_SCN_MEM_WRITE (0x80000000)
-SECTIONS:     ]
-SECTIONS:   }
 SECTIONS: ]