[PATCH] D33437: Emit available_externally vtables opportunistically

[John McCall via Phabricator via cfe-commits]

rjmccall added inline comments.


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Comment at: include/clang/AST/VTableBuilder.h:160
+           "GlobalDecl can be created only from virtual function");
+    if (getKind() == CK_FunctionPointer)
+      return GlobalDecl(getFunctionDecl());
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Please use an exhaustive switch.  You can put llvm_unreachable in the other cases.


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Comment at: lib/CodeGen/CGVTables.cpp:905
+    else
+      OpportunisticVTables.push_back(RD);
 
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I would add a CGM.shouldOpportunisticallyEmitVTables() that can just check the optimization level, and then you can use that to avoid even collecting v-tables like this if you don't need to.


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Comment at: lib/CodeGen/CodeGenModule.cpp:1377
 
+void CodeGenModule::EmitVTablesOpportunistically() {
+  // Only emit speculated vtables with optimizations.
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It's worth adding a header comment to this explaining that it runs after EmitDeferred() and therefore is not allowed to create new references to things that need to be emitted lazily.


https://reviews.llvm.org/D33437