COFF: Set Load Configuration entry in Data Directory.

Load Configuration field points to a structure containing information
for SEH. That data strucutre is not created by the linker but provided
by an external file. What we have to do is just to set __load_config_used
address to the header.

llvm-svn: 242427

lld/COFF/Writer.cpp

@@ -485,6 +485,12 @@ template <typename PEHeaderTy> void Writer::writeHeader() {
       Dir[TLS_TABLE].Size = 40;
     }
   }
+  if (Symbol *Sym = Symtab->find("__load_config_used")) {
+    if (Defined *B = dyn_cast<Defined>(Sym->Body)) {
+      Dir[LOAD_CONFIG_TABLE].RelativeVirtualAddress = B->getRVA();
+      Dir[LOAD_CONFIG_TABLE].Size = 64;
+    }
+  }
 
   // Write section table
   for (OutputSection *Sec : OutputSections) {

lld/test/COFF/loadcfg32.test

@@ -0,0 +1,42 @@
+# RUN: yaml2obj < %s > %t.obj
+# RUN: lld -flavor link2 /out:%t.exe %t.obj /entry:main /subsystem:console
+# RUN: llvm-readobj -file-headers %t.exe | FileCheck %s
+
+# CHECK: LoadConfigTableRVA: 0x1000
+# CHECK: LoadConfigTableSize: 0x40
+
+---
+header:
+  Machine:         IMAGE_FILE_MACHINE_I386
+  Characteristics: []
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       4
+    SectionData:     B82A000000C3
+symbols:
+  - 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
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            _main
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            __load_config_used
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+...