[clang] nolock/noalloc attributes (PR #84983)

[via cfe-commits]

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@@ -10778,6 +10778,101 @@ def warn_imp_cast_drops_unaligned : Warning<
   "implicit cast from type %0 to type %1 drops __unaligned qualifier">,
   InGroup<DiagGroup<"unaligned-qualifier-implicit-cast">>;
 
+def warn_func_effect_allocates : Warning<
+  "'%0' function '%1' must not allocate or deallocate memory">,
+  InGroup<FunctionEffects>;
+
+def note_func_effect_allocates : Note<
+  "'%1' cannot be inferred '%0' because it allocates/deallocates memory">;
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Sirraide wrote:

Checking again, it seems we have a precedent for putting `%1` before `%0` in e.g. `err_alignas_mismatch`. 

One more thing I just remembered though: I don’t think we normally print function names in diagnostics, simply because the diagnostic already points to the function that is the problem, so maybe just ‘%0 function must not...’ and ‘function cannot...’ might be better here, and that’d also solve the 1-before-0 ‘problem’.

https://github.com/llvm/llvm-project/pull/84983