[clang] eda58ac - Improve the attribute language option interface somewhat; NFCi.

[Aaron Ballman via cfe-commits]

Author: Aaron Ballman
Date: 2020-03-14T15:59:14-04:00
New Revision: eda58ac04cfa95298583223ba6779916e4721550

URL: https://github.com/llvm/llvm-project/commit/eda58ac04cfa95298583223ba6779916e4721550
DIFF: https://github.com/llvm/llvm-project/commit/eda58ac04cfa95298583223ba6779916e4721550.diff

LOG: Improve the attribute language option interface somewhat; NFCi.

The name field is optional if the custom code is supplied, so this updates the
documentation for LangOpt and introduces a tablegen warning if both custom code
and a language option name are supplied.

Added: 
    

Modified: 
    clang/include/clang/Basic/Attr.td
    clang/utils/TableGen/ClangAttrEmitter.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 484691f419c3..c2504ba620e8 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -312,6 +312,7 @@ class SubjectList<list<AttrSubject> subjects, SubjectDiag diag = WarnDiag,
 }
 
 class LangOpt<string name, code customCode = [{}]> {
+  // The language option to test; ignored when custom code is supplied.
   string Name = name;
 
   // A custom predicate, written as an expression evaluated in a context with
@@ -323,15 +324,15 @@ def Borland : LangOpt<"Borland">;
 def CUDA : LangOpt<"CUDA">;
 def HIP : LangOpt<"HIP">;
 def SYCL : LangOpt<"SYCLIsDevice">;
-def COnly : LangOpt<"COnly", "!LangOpts.CPlusPlus">;
+def COnly : LangOpt<"", "!LangOpts.CPlusPlus">;
 def CPlusPlus : LangOpt<"CPlusPlus">;
 def OpenCL : LangOpt<"OpenCL">;
 def RenderScript : LangOpt<"RenderScript">;
 def ObjC : LangOpt<"ObjC">;
 def BlocksSupported : LangOpt<"Blocks">;
 def ObjCAutoRefCount : LangOpt<"ObjCAutoRefCount">;
-def ObjCNonFragileRuntime : LangOpt<"ObjCNonFragileRuntime",
-                                    "LangOpts.ObjCRuntime.allowsClassStubs()">;
+def ObjCNonFragileRuntime
+    : LangOpt<"", "LangOpts.ObjCRuntime.allowsClassStubs()">;
 
 // Language option for CMSE extensions
 def Cmse : LangOpt<"Cmse">;

diff  --git a/clang/utils/TableGen/ClangAttrEmitter.cpp b/clang/utils/TableGen/ClangAttrEmitter.cpp
index 20fb9bc14439..529145efa3d0 100644
--- a/clang/utils/TableGen/ClangAttrEmitter.cpp
+++ b/clang/utils/TableGen/ClangAttrEmitter.cpp
@@ -1980,6 +1980,11 @@ static std::string GenerateTestExpression(ArrayRef<Record *> LangOpts) {
       Test += "(";
       Test += Code;
       Test += ")";
+      if (!E->getValueAsString("Name").empty()) {
+        PrintWarning(
+            E->getLoc(),
+            "non-empty 'Name' field ignored because 'CustomCode' was supplied");
+      }
     } else {
       Test += "LangOpts.";
       Test += E->getValueAsString("Name");