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

[via cfe-commits]

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@@ -1,44 +1,67 @@
-//=== EffectAnalysis.cpp - Sema warnings for function effects -------------===//
+//=== SemaFunctionEffects.cpp - Sema handling of 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.
+// This file implements Sema handling of function effects.
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.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"
+#define DEBUG_TYPE "effectanalysis"
 
 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
+  None = 0, // Sentinel for an empty Violation.
+  // These first few map to a %select{} in a diagnostic.
+  BaseDiagnosticIndex,
+  AllocatesMemory = BaseDiagnosticIndex,
+  ThrowsOrCatchesExceptions,
+  HasStaticLocalVariable,
+  AccessesThreadLocalVariable,
+  AccessesObjCMethodOrProperty,
+
+  // These only apply to callees, where the analysis stops at the Decl.
   DeclDisallowsInference,
 
+  // These both apply to indirect calls. The difference is that sometimes
+  // we have an actual Decl (generally a variable) which is the function
+  // pointer being called, and sometimes, typically due to a cast, we only
+  // have an expression.
   CallsDeclWithoutEffect,
   CallsExprWithoutEffect,
 };
 
+// Information about the AST context in which a violation was found, so
+// that diagnostics can point to the correct source.
+struct ViolationSite {
+  enum class Kind : uint8_t {
+    Default = 0, // Function body.
+    MemberInitializer = 1,
+    DefaultArgExpr = 2
+  };
+
+  Kind VKind = Kind::Default;
+  CXXDefaultArgExpr *DefaultArgExpr = nullptr;
----------------
Sirraide wrote:

We could make smaller by combining the kind and expr using `llvm::PointerIntPair`. Might be worth if we’re expected to have a lot of these instantiated at the same time.

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