Fix warning in MSVC

[giulianobelinassi]

Summary

Currently there is no PrintOnLeft attribute set, which results in an
empty switch-case. When compiling this, MSVC issues a warning saying
that the switch-case is empty. Fix this by using a macro and checking
if this macro is defined or not.

Links to D157394

[erichkeane]

This seems good enough to me. I'll commit it for you as before.

[erichkeane]

Forgot to close the phab review automatically, but: 0323938d3c7a1a48b60a7dea8ec7300e98b4a931

[fdeazeve]

I think this may have broken builds:

worktrees/src1/clang/lib/AST/DeclPrinter.cpp:293:48: error: function definition is not allowed here
static bool mustPrintOnLeftSide(const Attr *A) {

Probably missing a }?

[giulianobelinassi]

In D159490#4643191, @fdeazeve wrote:

I think this may have broken builds:

worktrees/src1/clang/lib/AST/DeclPrinter.cpp:293:48: error: function definition is not allowed here
static bool mustPrintOnLeftSide(const Attr *A) {

Probably missing a }?

No, there is just an extra switch statement that somehow got into the patch. I will fix this in a second.

[erichkeane]

In D159490#4643196, @giulianobelinassi wrote:

In D159490#4643191, @fdeazeve wrote:

I think this may have broken builds:

worktrees/src1/clang/lib/AST/DeclPrinter.cpp:293:48: error: function definition is not allowed here
static bool mustPrintOnLeftSide(const Attr *A) {

Probably missing a }?

No, there is just an extra switch statement that somehow got into the patch. I will fix this in a second.

Yikes, what I get for committing and not building first :) I believe @giulianobelinassi still doesn't have commit access, so I'll just fix it as review-after-commit.

[erichkeane]

Fixed in 6c0b9e357617. I didn't verify ahead of time, but hopefully the bots will yell at ME this time and I'll recognize it right away.

[fdeazeve]

In D159490#4643199, @erichkeane wrote:

Fixed in 6c0b9e357617. I didn't verify ahead of time, but hopefully the bots will yell at ME this time and I'll recognize it right away.

It builds for me, thanks for the quick fix!

[giulianobelinassi]

In D159490#4643199, @erichkeane wrote:

Fixed in 6c0b9e357617. I didn't verify ahead of time, but hopefully the bots will yell at ME this time and I'll recognize it right away.

Thanks for fixing that. This is on me, I should have built it before sending the patch. Sorry about this.

clang/lib/AST/DeclPrinter.cpp

 }
 
 raw_ostream& DeclPrinter::Indent(unsigned Indentation) {
   for (unsigned i = 0; i != Indentation; ++i)
     Out << "  ";
   return Out;
 }
 
+// For CLANG_ATTR_LIST_CanPrintOnLeft macro.
+#include "clang/Basic/AttrLeftSideCanPrintList.inc"
+
+// For CLANG_ATTR_LIST_PrintOnLeft macro.
+#include "clang/Basic/AttrLeftSideMustPrintList.inc"
+
 static bool canPrintOnLeftSide(attr::Kind kind) {
+#ifdef CLANG_ATTR_LIST_CanPrintOnLeft
   switch (kind) {
-#include "clang/Basic/AttrLeftSideCanPrintList.inc"
+  CLANG_ATTR_LIST_CanPrintOnLeft
     return true;
   default:
     return false;
   }
+#else
+  return false;
+#endif
 }
 
 static bool canPrintOnLeftSide(const Attr *A) {
   if (A->isStandardAttributeSyntax())
     return false;
 
   return canPrintOnLeftSide(A->getKind());
 }
 
 static bool mustPrintOnLeftSide(attr::Kind kind) {
   switch (kind) {
-#include "clang/Basic/AttrLeftSideMustPrintList.inc"
+#ifdef CLANG_ATTR_LIST_PrintOnLeft
+  switch (kind) {
+  CLANG_ATTR_LIST_PrintOnLeft
     return true;
   default:
     return false;
   }
+#else
+  return false;
+#endif
 }
 
 static bool mustPrintOnLeftSide(const Attr *A) {
   if (A->isDeclspecAttribute())
     return true;
 
   return mustPrintOnLeftSide(A->getKind());
 }
for (auto *A : Attrs) {
 
           // In case it is a variable declaration with a ctor, then allow
           // printing on the left side for readbility.
         else if (const VarDecl *VD = dyn_cast<VarDecl>(D);
                    VD && VD->getInit() &&
                    VD->getInitStyle() == VarDecl::CallInit)
           AttrLoc = AttrPrintLoc::Left;
       }
-
       // Only print the side matches the user requested.
       if ((Loc & AttrLoc) != AttrPrintLoc::None)
         A->printPretty(Out, Policy);
     }
   }
 }
 
 void DeclPrinter::prettyPrintPragmas(Decl *D) {

clang/utils/TableGen/ClangAttrEmitter.cpp

void EmitClangAttrPrintList(const std::string &FieldName, RecordKeeper &Records,
                             raw_ostream &OS) {
   emitSourceFileHeader(
       "List of attributes that can be print on the left side of a decl", OS);
 
   AttrClassHierarchy Hierarchy(Records);
 
   std::vector<Record *> Attrs = Records.getAllDerivedDefinitions("Attr");
   std::vector<Record *> PragmaAttrs;
+  bool first = false;
+
   for (auto *Attr : Attrs) {
     if (!Attr->getValueAsBit("ASTNode"))
       continue;
 
     if (!Attr->getValueAsBit(FieldName))
       continue;
 
-    OS << "case attr::" << Attr->getName() << ":\n";
+    if (!first) {
+      first = true;
+      OS << "#define CLANG_ATTR_LIST_" << FieldName;
+    }
+
+    OS << " \\\n case attr::" << Attr->getName() << ":";
   }
+
+  OS << '\n';
 }
 
 // Emits the enumeration list for attributes.
 void EmitClangAttrSubjectMatchRuleList(RecordKeeper &Records, raw_ostream &OS) {
   emitSourceFileHeader(
       "List of all attribute subject matching rules that Clang recognizes", OS);
   PragmaClangAttributeSupport &PragmaAttributeSupport =
       getPragmaAttributeSupport(Records);