1 | //===--- Stack.h - Utilities for dealing with stack space -------*- C++ -*-===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | /// |
9 | /// \file |
10 | /// Defines utilities for dealing with stack allocation and stack space. |
11 | /// |
12 | //===----------------------------------------------------------------------===// |
13 | |
14 | #ifndef LLVM_CLANG_BASIC_STACK_H |
15 | #define LLVM_CLANG_BASIC_STACK_H |
16 | |
17 | #include <cstddef> |
18 | |
19 | #include "llvm/ADT/STLExtras.h" |
20 | #include "llvm/Support/Compiler.h" |
21 | |
22 | namespace clang { |
23 | /// The amount of stack space that Clang would like to be provided with. |
24 | /// If less than this much is available, we may be unable to reach our |
25 | /// template instantiation depth limit and other similar limits. |
26 | constexpr size_t DesiredStackSize = 8 << 20; |
27 | |
28 | /// Call this once on each thread, as soon after starting the thread as |
29 | /// feasible, to note the approximate address of the bottom of the stack. |
30 | void noteBottomOfStack(); |
31 | |
32 | /// Determine whether the stack is nearly exhausted. |
33 | bool isStackNearlyExhausted(); |
34 | |
35 | void runWithSufficientStackSpaceSlow(llvm::function_ref<void()> Diag, |
36 | llvm::function_ref<void()> Fn); |
37 | |
38 | /// Run a given function on a stack with "sufficient" space. If stack space |
39 | /// is insufficient, calls Diag to emit a diagnostic before calling Fn. |
40 | inline void runWithSufficientStackSpace(llvm::function_ref<void()> Diag, |
41 | llvm::function_ref<void()> Fn) { |
42 | #if LLVM_ENABLE_THREADS |
43 | if (LLVM_UNLIKELY(isStackNearlyExhausted())) |
44 | runWithSufficientStackSpaceSlow(Diag, Fn); |
45 | else |
46 | Fn(); |
47 | #else |
48 | if (LLVM_UNLIKELY(isStackNearlyExhausted())) |
49 | Diag(); |
50 | Fn(); |
51 | #endif |
52 | } |
53 | } // end namespace clang |
54 | |
55 | #endif // LLVM_CLANG_BASIC_STACK_H |
56 | |