[COFF] Force Symbols containing '.' to be quoted

[loladiro]

Summary

In D87099, the mangler learned to quote export directives that contain
special characters. Only alhpanumerical characters as well as
'_', '$', '.' and '@' were exmpt from this quoting. However, at least
binutils considers an unquoted '.' to be syntax and object files
containing such symbols will cause errors during linking. Fix that
by removing '.' from the list of allowed exemptions.

[mstorsjo]

Can you add a testcase?

[vtjnash]

adding test

llvm/lib/IR/Mangler.cpp

void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
                                 const GlobalValue *GV,
                                 bool CannotUsePrivateLabel) const {
   raw_svector_ostream OS(OutName);
   getNameWithPrefix(OS, GV, CannotUsePrivateLabel);
 }
 
 // Check if the name needs quotes to be safe for the linker to interpret.
 static bool canBeUnquotedInDirective(char C) {
-  return isAlnum(C) || C == '_' || C == '$' || C == '.' || C == '@';
+  return isAlnum(C) || C == '_' || C == '@';
 }
 
 static bool canBeUnquotedInDirective(StringRef Name) {
   if (Name.empty())
     return false;
 
   // If any of the characters in the string is an unacceptable character, force
   // quotes.

llvm/test/CodeGen/X86/dllexport.ll

 @WeakVar1 = weak_odr dllexport global i32 1, align 4
 
 ; CHECK: .weak _WeakVar2
 @WeakVar2 = weak_odr dllexport unnamed_addr constant i32 1
 
 ; CHECK: .globl "_complex-name"
 @"complex-name" = dllexport global i32 1, align 4
 
+; CHECK: .globl _complex.name
+@"complex.name" = dllexport global i32 1, align 4
+
 
 ; Verify items that should not be exported do not appear in the export table.
 ; We use a separate check prefix to avoid confusion between -NOT and -SAME.
 ; NOTEXPORTED: .section .drectve
 ; NOTEXPORTED-NOT: :notExported
 ; NOTEXPORTED-NOT: :notDefined
 
 ; CHECK: .section .drectve
 ; CHECK-CL: .ascii " /EXPORT:_f1"
 ; CHECK-CL: .ascii " /EXPORT:_f2"
 ; CHECK-CL: .ascii " /EXPORT:_stdfun@0"
 ; CHECK-CL: .ascii " /EXPORT:@fastfun@0"
 ; CHECK-CL: .ascii " /EXPORT:_thisfun"
 ; CHECK-CL: .ascii " /EXPORT:_lnk1"
 ; CHECK-CL: .ascii " /EXPORT:_lnk2"
 ; CHECK-CL: .ascii " /EXPORT:_weak1"
 ; CHECK-CL: .ascii " /EXPORT:_Var1,DATA"
 ; CHECK-CL: .ascii " /EXPORT:_Var2,DATA"
 ; CHECK-CL: .ascii " /EXPORT:_Var3,DATA"
 ; CHECK-CL: .ascii " /EXPORT:_WeakVar1,DATA"
 ; CHECK-CL: .ascii " /EXPORT:_WeakVar2,DATA"
 ; CHECK-CL: .ascii " /EXPORT:\"_complex-name\",DATA"
+; CHECK-CL: .ascii " /EXPORT:\"_complex.name\",DATA"
 ; CHECK-CL: .ascii " /EXPORT:_alias"
 ; CHECK-CL: .ascii " /EXPORT:_alias2"
 ; CHECK-CL: .ascii " /EXPORT:_alias3"
 ; CHECK-CL: .ascii " /EXPORT:_weak_alias"
 ; CHECK-GCC: .ascii " -export:f1"
 ; CHECK-GCC: .ascii " -export:f2"
 ; CHECK-GCC: .ascii " -export:stdfun@0"
 ; CHECK-GCC: .ascii " -export:@fastfun@0"
 ; CHECK-GCC: .ascii " -export:thisfun"
 ; CHECK-GCC: .ascii " -export:lnk1"
 ; CHECK-GCC: .ascii " -export:lnk2"
 ; CHECK-GCC: .ascii " -export:weak1"
 ; CHECK-GCC: .ascii " -export:Var1,data"
 ; CHECK-GCC: .ascii " -export:Var2,data"
 ; CHECK-GCC: .ascii " -export:Var3,data"
 ; CHECK-GCC: .ascii " -export:WeakVar1,data"
 ; CHECK-GCC: .ascii " -export:WeakVar2,data"
 ; CHECK-GCC: .ascii " -export:\"complex-name\",data"
+; CHECK-GCC: .ascii " -export:\"complex.name\",data"
 ; CHECK-GCC: .ascii " -export:alias"
 ; CHECK-GCC: .ascii " -export:alias2"
 ; CHECK-GCC: .ascii " -export:alias3"
 ; CHECK-GCC: .ascii " -export:weak_alias"
 
 ; CHECK: .globl _alias
 ; CHECK: .set _alias, _notExported
 @alias = dllexport alias void(), void()* @notExported