[clang] [Clang] strengthen checks for 'main' function to meet [basic.start.main] p3 requirements (PR #101853)

[via cfe-commits]

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@@ -7353,13 +7353,26 @@ void emitReadOnlyPlacementAttrWarning(Sema &S, const VarDecl *VD) {
   }
 }
 
-// Checks if VD is declared at global scope or with C language linkage.
-static bool isMainVar(DeclarationName Name, VarDecl *VD) {
-  return Name.getAsIdentifierInfo() &&
-         Name.getAsIdentifierInfo()->isStr("main") &&
-         !VD->getDescribedVarTemplate() &&
-         (VD->getDeclContext()->getRedeclContext()->isTranslationUnit() ||
-          VD->isExternC());
+enum MainVarClassificationKind {
+  IMV_NotMain,
+  IMV_GlobalMain,
+  IMV_CLinkageMain,
+};
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Sirraide wrote:

I don’t think this needs to exist:
1. We’re not even using all of these enumerators.
2. We test for them in exactly one place.
3. The test in question ends up being more complex as a result.

It was fine the way it was before, so I’d suggest you just revert this commit.

(Also, for future reference, we prefer scoped enumerations these days.)

https://github.com/llvm/llvm-project/pull/101853