[clang] nonblocking/nonallocating attributes: 2nd pass caller/callee analysis (PR #99656)

[via cfe-commits]

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+//=== EffectAnalysis.cpp - Sema warnings for function effects -------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements caller/callee analysis for function effects.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/Decl.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/AST/Stmt.h"
+#include "clang/AST/Type.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Sema/SemaInternal.h"
+
+#define DEBUG_TYPE "fxanalysis"
+
+using namespace clang;
+
+namespace {
+
+enum class ViolationID : uint8_t {
+  None = 0, // sentinel for an empty Violation
+  Throws,
+  Catches,
+  CallsObjC,
+  AllocatesMemory,
+  HasStaticLocal,
+  AccessesThreadLocal,
+
+  // These only apply to callees, where the analysis stops at the Decl
+  DeclDisallowsInference,
+
+  CallsDeclWithoutEffect,
+  CallsExprWithoutEffect,
+};
+
+// Represents a violation of the rules, potentially for the entire duration of
+// the analysis phase, in order to refer to it when explaining why a caller has
+// been made unsafe by a callee. Can be transformed into either a Diagnostic
+// (warning or a note), depending on whether the violation pertains to a
+// function failing to be verifed as holding an effect vs. a function failing to
+// be inferred as holding that effect.
+struct Violation {
+  FunctionEffect Effect;
+  FunctionEffect CalleeEffectPreventingInference; // only for certain IDs
+  ViolationID ID = ViolationID::None;
+  SourceLocation Loc;
+  const Decl *Callee = nullptr; // only valid for Calls*
+
+  Violation() = default;
+
+  Violation(const FunctionEffect &Effect, ViolationID ID, SourceLocation Loc,
+            const Decl *Callee = nullptr,
+            const FunctionEffect *CalleeEffect = nullptr)
+      : Effect(Effect), ID(ID), Loc(Loc), Callee(Callee) {
+    if (CalleeEffect != nullptr)
+      CalleeEffectPreventingInference = *CalleeEffect;
+  }
+};
+
+enum class SpecialFuncType : uint8_t { None, OperatorNew, OperatorDelete };
+enum class CallableType {
----------------
Sirraide wrote:

```suggestion
enum class CallableType : uint8_t {
```

https://github.com/llvm/llvm-project/pull/99656