[JITLink][COFF] Implement IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY/LIBRARY.

Implement IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY/LIBRARY characteristics flag.

Since COFFObjectFile class will set undefined flag for symbols with no alias flag, ORC ObjectFileInterface will not pull in this symbol. So, we only need to make sure the scope is local. NOLIBRARY and LIBRARY are handled in the same way for now. (which is what lld does right now)

Reviewed By: lhames

Differential Revision: https://reviews.llvm.org/D129939

llvm/lib/ExecutionEngine/JITLink/COFFLinkGraphBuilder.cpp

@@ -236,15 +236,11 @@ Error COFFLinkGraphBuilder::graphifySymbols() {
             &G->addExternalSymbol(SymbolName, Sym->getValue(), Linkage::Strong);
       GSym = ExternalSymbols[SymbolName];
     } else if (Sym->isWeakExternal()) {
-      COFFSymbolIndex TagIndex =
-          Sym->getAux<object::coff_aux_weak_external>()->TagIndex;
-      assert(Sym->getAux<object::coff_aux_weak_external>()->Characteristics !=
-                 COFF::IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY &&
-             "IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY is not supported.");
-      assert(Sym->getAux<object::coff_aux_weak_external>()->Characteristics !=
-                 COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY &&
-             "IMAGE_WEAK_EXTERN_SEARCH_LIBRARY is not supported.");
-      WeakAliasRequests.push_back({SymIndex, TagIndex, SymbolName});
+      auto *WeakExternal = Sym->getAux<object::coff_aux_weak_external>();
+      COFFSymbolIndex TagIndex = WeakExternal->TagIndex;
+      uint32_t Characteristics = WeakExternal->Characteristics;
+      WeakExternalRequests.push_back(
+          {SymIndex, TagIndex, Characteristics, SymbolName});
     } else {
       Expected<jitlink::Symbol *> NewGSym =
           createDefinedSymbol(SymIndex, SymbolName, *Sym, Sec);
@@ -280,35 +276,41 @@ Error COFFLinkGraphBuilder::graphifySymbols() {
 
 Error COFFLinkGraphBuilder::flushWeakAliasRequests() {
   // Export the weak external symbols and alias it
-  for (auto &WeakAlias : WeakAliasRequests) {
-    if (auto *Target = getGraphSymbol(WeakAlias.Target)) {
+  for (auto &WeakExternal : WeakExternalRequests) {
+    if (auto *Target = getGraphSymbol(WeakExternal.Target)) {
       Expected<object::COFFSymbolRef> AliasSymbol =
-          Obj.getSymbol(WeakAlias.Alias);
+          Obj.getSymbol(WeakExternal.Alias);
       if (!AliasSymbol)
         return AliasSymbol.takeError();
 
+      // FIXME: IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY and
+      // IMAGE_WEAK_EXTERN_SEARCH_LIBRARY are handled in the same way.
+      Scope S =
+          WeakExternal.Characteristics == COFF::IMAGE_WEAK_EXTERN_SEARCH_ALIAS
+              ? Scope::Default
+              : Scope::Local;
+
       // FIXME: Support this when there's a way to handle this.
       if (!Target->isDefined())
         return make_error<JITLinkError>("Weak external symbol with external "
                                         "symbol as alternative not supported.");
 
       jitlink::Symbol *NewSymbol = &G->addDefinedSymbol(
-          Target->getBlock(), Target->getOffset(), WeakAlias.SymbolName,
-          Target->getSize(), Linkage::Weak, Scope::Default,
-          Target->isCallable(), false);
-      setGraphSymbol(AliasSymbol->getSectionNumber(), WeakAlias.Alias,
+          Target->getBlock(), Target->getOffset(), WeakExternal.SymbolName,
+          Target->getSize(), Linkage::Weak, S, Target->isCallable(), false);
+      setGraphSymbol(AliasSymbol->getSectionNumber(), WeakExternal.Alias,
                      *NewSymbol);
       LLVM_DEBUG({
-        dbgs() << "    " << WeakAlias.Alias
+        dbgs() << "    " << WeakExternal.Alias
                << ": Creating weak external symbol for COFF symbol \""
-               << WeakAlias.SymbolName << "\" in section "
+               << WeakExternal.SymbolName << "\" in section "
                << AliasSymbol->getSectionNumber() << "\n";
         dbgs() << "      " << *NewSymbol << "\n";
       });
     } else
       return make_error<JITLinkError>("Weak symbol alias requested but actual "
                                       "symbol not found for symbol " +
-                                      formatv("{0:d}", WeakAlias.Alias));
+                                      formatv("{0:d}", WeakExternal.Alias));
   }
   return Error::success();
 }

llvm/lib/ExecutionEngine/JITLink/COFFLinkGraphBuilder.h

@@ -117,12 +117,13 @@ class COFFLinkGraphBuilder {
 
   // This represents a pending request to create a weak external symbol with a
   // name.
-  struct WeakAliasRequest {
+  struct WeakExternalRequest {
     COFFSymbolIndex Alias;
     COFFSymbolIndex Target;
+    uint32_t Characteristics;
     StringRef SymbolName;
   };
-  std::vector<WeakAliasRequest> WeakAliasRequests;
+  std::vector<WeakExternalRequest> WeakExternalRequests;
 
   // Per COFF section jitlink symbol set sorted by offset.
   // Used for calculating implicit size of defined symbols.

llvm/test/ExecutionEngine/JITLink/X86/COFF_nolibrary_search.s

@@ -0,0 +1,23 @@
+# RUN: rm -rf %t && mkdir -p %t
+# RUN: yaml2obj %S/Inputs/COFF_weak_nolibrary_serach_def.yaml -o %t/COFF_weak.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-windows-msvc %s -o %t/COFF_main.o
+# RUN: not llvm-jitlink -noexec -abs __ImageBase=0xfff00000 \
+# RUN: -slab-allocate 100Kb -slab-address 0xfff00000 -slab-page-size 4096 \
+# RUN: %t/COFF_weak.o %t/COFF_main.o 2>&1 | FileCheck %s
+#
+# Check weak external symbol with IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY Characteristics
+# does not export symbol.
+#
+# CHECK: llvm-jitlink error: Symbols not found: [ func ]
+
+	.text
+
+	.def	main;
+	.scl	2;
+	.type	32;
+	.endef
+	.globl	main
+	.p2align	4, 0x90
+main:
+    callq func
+	retq

llvm/test/ExecutionEngine/JITLink/X86/Inputs/COFF_weak_nolibrary_serach_def.yaml

@@ -0,0 +1,80 @@
+--- !COFF
+header:
+  Machine:         IMAGE_FILE_MACHINE_AMD64
+  Characteristics: [  ]
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       16
+    SectionData:     C3662E0F1F8400000000000F1F440000E800000000C3
+    Relocations:
+      - VirtualAddress:  17
+        SymbolName:      func
+        Type:            IMAGE_REL_AMD64_REL32
+  - Name:            .data
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ, IMAGE_SCN_MEM_WRITE ]
+    Alignment:       4
+    SectionData:     ''
+  - Name:            .bss
+    Characteristics: [ IMAGE_SCN_CNT_UNINITIALIZED_DATA, IMAGE_SCN_MEM_READ, IMAGE_SCN_MEM_WRITE ]
+    Alignment:       4
+    SectionData:     ''
+    SizeOfRawData:   0
+symbols:
+  - Name:            .text
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          22
+      NumberOfRelocations: 1
+      NumberOfLinenumbers: 0
+      CheckSum:        1179995423
+      Number:          1
+  - Name:            .data
+    Value:           0
+    SectionNumber:   2
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          0
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          2
+  - Name:            .bss
+    Value:           0
+    SectionNumber:   3
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          0
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          3
+  - Name:            func
+    Value:           0
+    SectionNumber:   0
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_WEAK_EXTERNAL
+    WeakExternal:
+      TagIndex:        8
+      Characteristics: IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY
+  - Name:            .weak.func.default.main
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            using_func
+    Value:           16
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL