COFF: Write import library symbols to a symbol table.

[ruiu]

Summary

Write import library symbols to a symbol table.

[majnemer]

LGTM

[Eugene.Zelenko]

Committed in r243350.

COFF/Writer.h

 //===- Writer.h -----------------------------------------------------------===//
 //
 //                             The LLVM Linker
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLD_COFF_WRITER_H
 #define LLD_COFF_WRITER_H
 
 #include "DLL.h"
 #include "InputFiles.h"
 #include "SymbolTable.h"
+#include "llvm/ADT/Optional.h"
 #include "llvm/Support/FileOutputBuffer.h"
 #include <memory>
 #include <vector>
 
 namespace lld {
 namespace coff {
 
 // Mask for section types (code, data, bss, disacardable, etc.)
private:
   void createSymbolAndStringTable();
   std::error_code openFile(StringRef OutputPath);
   template <typename PEHeaderTy> void writeHeader();
   void fixSafeSEHSymbols();
   void writeSections();
   void sortExceptionTable();
   void applyRelocations();
 
-  coff_symbol16 createSymbol(DefinedRegular *D);
+  llvm::Optional<coff_symbol16> createSymbol(Defined *D);
   size_t addEntryToStringTable(StringRef Str);
 
   OutputSection *findSection(StringRef Name);
   OutputSection *createSection(StringRef Name);
   void addBaserels(OutputSection *Dest);
   void addBaserelBlocks(OutputSection *Dest, std::vector<Baserel> &V);
 
   uint32_t getSizeOfInitializedData();

COFF/Writer.cpp

 size_t Writer::addEntryToStringTable(StringRef Str) {
   assert(Str.size() > COFF::NameSize);
   size_t OffsetOfEntry = Strtab.size() + 4; // +4 for the size field
   Strtab.insert(Strtab.end(), Str.begin(), Str.end());
   Strtab.push_back('\0');
   return OffsetOfEntry;
 }
 
-coff_symbol16 Writer::createSymbol(DefinedRegular *D) {
-  uint64_t RVA = D->getRVA();
-  OutputSection *Sec = nullptr;
-  for (OutputSection *S : OutputSections) {
-    if (S->getRVA() > RVA)
-      break;
-    Sec = S;
-  }
+Optional<coff_symbol16> Writer::createSymbol(Defined *Def) {
+  if (auto *D = dyn_cast<DefinedRegular>(Def))
+    if (!D->isLive())
+      return None;
 
   coff_symbol16 Sym;
-  StringRef Name = D->getName();
+  StringRef Name = Def->getName();
   if (Name.size() > COFF::NameSize) {
     Sym.Name.Offset.Zeroes = 0;
     Sym.Name.Offset.Offset = addEntryToStringTable(Name);
   } else {
     memset(Sym.Name.ShortName, 0, COFF::NameSize);
     memcpy(Sym.Name.ShortName, Name.data(), Name.size());
   }
-  COFFSymbolRef DSymRef = D->getCOFFSymbol();
+
+  if (auto *D = dyn_cast<DefinedCOFF>(Def)) {
+    COFFSymbolRef Ref = D->getCOFFSymbol();
+    Sym.Type = Ref.getType();
+    Sym.StorageClass = Ref.getStorageClass();
+  } else {
+    Sym.Type = IMAGE_SYM_TYPE_NULL;
+    Sym.StorageClass = IMAGE_SYM_CLASS_EXTERNAL;
+  }
+  Sym.NumberOfAuxSymbols = 0;
+
+  switch (Def->kind()) {
+  case SymbolBody::DefinedAbsoluteKind:
+  case SymbolBody::DefinedRelativeKind:
+    Sym.Value = Def->getRVA();
+    Sym.SectionNumber = IMAGE_SYM_ABSOLUTE;
+    break;
+  default: {
+    uint64_t RVA = Def->getRVA();
+    OutputSection *Sec = nullptr;
+    for (OutputSection *S : OutputSections) {
+      if (S->getRVA() > RVA)
+        break;
+      Sec = S;
+    }
     Sym.Value = RVA - Sec->getRVA();
     Sym.SectionNumber = Sec->SectionIndex;
-  Sym.Type = DSymRef.getType();
-  Sym.StorageClass = DSymRef.getStorageClass();
-  Sym.NumberOfAuxSymbols = 0;
+    break;
+  }
+  }
   return Sym;
 }
 
 void Writer::createSymbolAndStringTable() {
   if (!Config->Debug)
     return;
   // Name field in the section table is 8 byte long. Longer names need
   // to be written to the string table. First, construct string table.
   for (OutputSection *Sec : OutputSections) {
     StringRef Name = Sec->getName();
     if (Name.size() <= COFF::NameSize)
       continue;
     Sec->setStringTableOff(addEntryToStringTable(Name));
   }
 
   for (ObjectFile *File : Symtab->ObjectFiles)
     for (SymbolBody *B : File->getSymbols())
-      if (auto *D = dyn_cast<DefinedRegular>(B))
-        if (D->isLive())
-          OutputSymtab.push_back(createSymbol(D));
+      if (auto *D = dyn_cast<Defined>(B))
+        if (Optional<coff_symbol16> Sym = createSymbol(D))
+          OutputSymtab.push_back(*Sym);
+
+  for (ImportFile *File : Symtab->ImportFiles)
+    for (SymbolBody *B : File->getSymbols())
+      if (Optional<coff_symbol16> Sym = createSymbol(cast<Defined>(B)))
+        OutputSymtab.push_back(*Sym);
 
   OutputSection *LastSection = OutputSections.back();
   // We position the symbol table to be adjacent to the end of the last section.
   uint64_t FileOff =
       LastSection->getFileOff() +
       RoundUpToAlignment(LastSection->getRawSize(), FileAlignment);
   if (!OutputSymtab.empty()) {
     PointerToSymbolTable = FileOff;

test/COFF/symtab.test

 # RUN: yaml2obj < %s > %t.obj
-# RUN: lld -flavor link2 /debug /out:%t.exe /entry:main %t.obj
+# RUN: lld -flavor link2 /debug /out:%t.exe /entry:main %t.obj %p/Inputs/std64.lib
 # RUN: llvm-readobj -symbols %t.exe | FileCheck %s
 
 # CHECK:      Symbols [
 # CHECK-NEXT:   Symbol {
 # CHECK-NEXT:     Name: .text
 # CHECK-NEXT:     Value: 0
-# CHECK-NEXT:     Section: .text
+# CHECK-NEXT:     Section: .text (2)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
-# CHECK-NEXT:     StorageClass: Static
+# CHECK-NEXT:     StorageClass: Static (0x3)
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: f
-# CHECK-NEXT:     Value: 2
-# CHECK-NEXT:     Section: .text
+# CHECK-NEXT:     Name: .text2
+# CHECK-NEXT:     Value: 0
+# CHECK-NEXT:     Section: .text (2)
+# CHECK-NEXT:     BaseType: Null (0x0)
+# CHECK-NEXT:     ComplexType: Null (0x0)
+# CHECK-NEXT:     StorageClass: Static (0x3)
+# CHECK-NEXT:     AuxSymbolCount: 0
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: .data
+# CHECK-NEXT:     Value: 0
+# CHECK-NEXT:     Section: .data (1)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
-# CHECK-NEXT:     StorageClass: External
+# CHECK-NEXT:     StorageClass: Static (0x3)
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: g
-# CHECK-NEXT:     Value: 4
-# CHECK-NEXT:     Section: .text
+# CHECK-NEXT:     Name: message
+# CHECK-NEXT:     Value: 6
+# CHECK-NEXT:     Section: .text2 (3)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
-# CHECK-NEXT:     StorageClass:  External
+# CHECK-NEXT:     StorageClass: Static (0x3)
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
 # CHECK-NEXT:     Name: main
 # CHECK-NEXT:     Value: 0
-# CHECK-NEXT:     Section: .text
+# CHECK-NEXT:     Section: .text (2)
+# CHECK-NEXT:     BaseType: Null (0x0)
+# CHECK-NEXT:     ComplexType: Null (0x0)
+# CHECK-NEXT:     StorageClass: External (0x2)
+# CHECK-NEXT:     AuxSymbolCount: 0
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: caption
+# CHECK-NEXT:     Value: 0
+# CHECK-NEXT:     Section: .text2 (3)
+# CHECK-NEXT:     BaseType: Null (0x0)
+# CHECK-NEXT:     ComplexType: Null (0x0)
+# CHECK-NEXT:     StorageClass: Static (0x3)
+# CHECK-NEXT:     AuxSymbolCount: 0
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: abs_symbol
+# CHECK-NEXT:     Value: 2662186735
+# CHECK-NEXT:     Section: IMAGE_SYM_ABSOLUTE (-1)
 # CHECK-NEXT:     BaseType: Null (0x0)
 # CHECK-NEXT:     ComplexType: Null (0x0)
-# CHECK-NEXT:     StorageClass: External
+# CHECK-NEXT:     StorageClass: External (0x2)
+# CHECK-NEXT:     AuxSymbolCount: 0
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: __imp_ExitProcess
+# CHECK-NEXT:     Value: 64
+# CHECK-NEXT:     Section: .idata (4)
+# CHECK-NEXT:     BaseType: Null (0x0)
+# CHECK-NEXT:     ComplexType: Null (0x0)
+# CHECK-NEXT:     StorageClass: External (0x2)
+# CHECK-NEXT:     AuxSymbolCount: 0
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: ExitProcess
+# CHECK-NEXT:     Value: 64
+# CHECK-NEXT:     Section: .text (2)
+# CHECK-NEXT:     BaseType: Null (0x0)
+# CHECK-NEXT:     ComplexType: Null (0x0)
+# CHECK-NEXT:     StorageClass: External (0x2)
+# CHECK-NEXT:     AuxSymbolCount: 0
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: __imp_MessageBoxA
+# CHECK-NEXT:     Value: 72
+# CHECK-NEXT:     Section: .idata (4)
+# CHECK-NEXT:     BaseType: Null (0x0)
+# CHECK-NEXT:     ComplexType: Null (0x0)
+# CHECK-NEXT:     StorageClass: External (0x2)
+# CHECK-NEXT:     AuxSymbolCount: 0
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: MessageBoxA
+# CHECK-NEXT:     Value: 80
+# CHECK-NEXT:     Section: .text (2)
+# CHECK-NEXT:     BaseType: Null (0x0)
+# CHECK-NEXT:     ComplexType: Null (0x0)
+# CHECK-NEXT:     StorageClass: External (0x2)
 # CHECK-NEXT:     AuxSymbolCount: 0
 # CHECK-NEXT:   }
 # CHECK-NEXT: ]
 
 ---
 header:
   Machine:         IMAGE_FILE_MACHINE_AMD64
-  Characteristics: [  ]
+  Characteristics: []
 sections:
   - Name:            .text
     Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       4096
+    SectionData:     B800000000000000005068000000000000000068000000000000000050E8000000000000000050E8000000000000000050E80000000000000000
+    Relocations:
+      - VirtualAddress:  0
+        SymbolName:      abs_symbol
+        Type:            IMAGE_REL_AMD64_ADDR64
+      - VirtualAddress:  7
+        SymbolName:      caption
+        Type:            IMAGE_REL_AMD64_ADDR64
+      - VirtualAddress:  12
+        SymbolName:      message
+        Type:            IMAGE_REL_AMD64_ADDR64
+      - VirtualAddress:  18
+        SymbolName:      MessageBoxA
+        Type:            IMAGE_REL_AMD64_REL32
+      - VirtualAddress:  24
+        SymbolName:      ExitProcess
+        Type:            IMAGE_REL_AMD64_REL32
+      - VirtualAddress:  30
+        SymbolName:      __ImageBase
+        Type:            IMAGE_REL_AMD64_ADDR64
+  - Name:            .text2
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       4096
+    SectionData:     B800000000000000005068000000000000000068000000000000000050E8000000000000000050E8000000000000000050E80000000000000000
+    Relocations:
+      - VirtualAddress:  0
+        SymbolName:      abs_symbol
+        Type:            IMAGE_REL_AMD64_ADDR64
+      - VirtualAddress:  7
+        SymbolName:      caption
+        Type:            IMAGE_REL_AMD64_ADDR64
+      - VirtualAddress:  12
+        SymbolName:      message
+        Type:            IMAGE_REL_AMD64_ADDR64
+      - VirtualAddress:  18
+        SymbolName:      MessageBoxA
+        Type:            IMAGE_REL_AMD64_REL32
+      - VirtualAddress:  24
+        SymbolName:      ExitProcess
+        Type:            IMAGE_REL_AMD64_REL32
+      - VirtualAddress:  30
+        SymbolName:      __ImageBase
+        Type:            IMAGE_REL_AMD64_ADDR64
+  - Name:            .data
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ, IMAGE_SCN_MEM_WRITE ]
     Alignment:       4
-    SectionData:     B82A00
+    SectionData:     48656C6C6F0048656C6C6F20576F726C6400
 symbols:
+  - Name:            "@comp.id"
+    Value:           10394907
+    SectionNumber:   65535
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
   - Name:            .text
     Value:           0
     SectionNumber:   1
     SimpleType:      IMAGE_SYM_TYPE_NULL
     ComplexType:     IMAGE_SYM_DTYPE_NULL
     StorageClass:    IMAGE_SYM_CLASS_STATIC
     SectionDefinition:
-      Length:          6
-      NumberOfRelocations: 0
+      Length:          28
+      NumberOfRelocations: 6
       NumberOfLinenumbers: 0
       CheckSum:        0
       Number:          0
-  - Name:            f
-    Value:           2
+  - Name:            .text2
+    Value:           0
     SectionNumber:   1
     SimpleType:      IMAGE_SYM_TYPE_NULL
     ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          28
+      NumberOfRelocations: 6
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            .data
+    Value:           0
+    SectionNumber:   3
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          18
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            MessageBoxA
+    Value:           0
+    SectionNumber:   0
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
     StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
-  - Name:            g
-    Value:           4
-    SectionNumber:   1
+  - Name:            ExitProcess
+    Value:           0
+    SectionNumber:   0
     SimpleType:      IMAGE_SYM_TYPE_NULL
     ComplexType:     IMAGE_SYM_DTYPE_NULL
     StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            message
+    Value:           6
+    SectionNumber:   2
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
   - Name:            main
     Value:           0
     SectionNumber:   1
     SimpleType:      IMAGE_SYM_TYPE_NULL
     ComplexType:     IMAGE_SYM_DTYPE_NULL
     StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            caption
+    Value:           0
+    SectionNumber:   2
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            abs_symbol
+    Value:           0xDEADBEEF
+    SectionNumber:   -1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            __ImageBase
+    Value:           0
+    SectionNumber:   0
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
 ...