Updated wording in documentation

Author: grigorypas

clang/docs/ReleaseNotes.rst

@@ -351,7 +351,7 @@ Attribute Changes in Clang
   inline calls within the attributed function up to a specified depth. This attribute takes
   a single unsigned integer argument representing the requested depth of inlining. Unlike
   a strict limit, the requested depth is a hint that works cooperatively with other inlining
-  mechanisms:
+  mechanisms, including:
 
   - Functions marked with ``always_inline`` will be inlined even if they exceed the requested depth
   - The compiler's cost model may choose to inline beyond the requested depth for beneficial cases

clang/include/clang/Basic/AttrDocs.td

@@ -4054,7 +4054,7 @@ The actual inlining behavior is subject to several considerations:
 - **Cost model decisions**: The compiler's inlining cost model may choose to
   inline functions beyond the requested depth if doing so is deemed beneficial
   (e.g., trivial wrapper functions or obvious optimization opportunities). This
-  prevents the attribute from becoming a footgun that blocks beneficial optimizations.
+  prevents the attribute from blocking beneficial optimizations.
 
 - **Insufficient call depth**: If the call tree is shallower than the requested
   depth, the attribute simply inlines as far as the call tree allows.

clang/lib/CodeGen/CodeGenModule.cpp

@@ -2755,9 +2755,10 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
   if (const FlattenDepthAttr *FDA = D->getAttr<FlattenDepthAttr>()) {
     Expr *DepthExpr = FDA->getDepthHint();
     Expr::EvalResult Result;
-    if (DepthExpr->EvaluateAsInt(Result, getContext())) {
-      B.addFlattenDepthAttr(Result.Val.getInt().getZExtValue());
-    }
+    [[maybe_unused]] bool Success =
+        DepthExpr->EvaluateAsInt(Result, getContext());
+    assert(Success && "flatten_depth expression should be an integer constant");
+    B.addFlattenDepthAttr(Result.Val.getInt().getZExtValue());
   }
 
   // Track whether we need to add the optnone LLVM attribute,