[PATCH] D158967: [clang][clangd] Ensure the stack bottom before building AST

[Younan Zhang via Phabricator via cfe-commits]

zyounan updated this revision to Diff 554285.
zyounan added a comment.

Oops, something went wrong accidently.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D158967/new/

https://reviews.llvm.org/D158967

Files:
  clang-tools-extra/clangd/support/Threading.cpp
  clang-tools-extra/clangd/test/infinite-instantiation.test
  clang-tools-extra/clangd/tool/Check.cpp
  clang/lib/Frontend/FrontendAction.cpp


Index: clang/lib/Frontend/FrontendAction.cpp
===================================================================
--- clang/lib/Frontend/FrontendAction.cpp
+++ clang/lib/Frontend/FrontendAction.cpp
@@ -15,6 +15,7 @@
 #include "clang/Basic/FileEntry.h"
 #include "clang/Basic/LangStandard.h"
 #include "clang/Basic/Sarif.h"
+#include "clang/Basic/Stack.h"
 #include "clang/Frontend/ASTUnit.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
@@ -1155,6 +1156,10 @@
   CompilerInstance &CI = getCompilerInstance();
   if (!CI.hasPreprocessor())
     return;
+  // This is a fallback: If the client forgets to invoke this, we mark the
+  // current stack as the bottom. Though not optimal, this could help prevent
+  // stack overflow during deep recursion.
+  clang::noteBottomOfStack();
 
   // FIXME: Move the truncation aspect of this into Sema, we delayed this till
   // here so the source manager would be initialized.
Index: clang-tools-extra/clangd/tool/Check.cpp
===================================================================
--- clang-tools-extra/clangd/tool/Check.cpp
+++ clang-tools-extra/clangd/tool/Check.cpp
@@ -57,6 +57,7 @@
 #include "clang/AST/ASTContext.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/LLVM.h"
+#include "clang/Basic/Stack.h"
 #include "clang/Format/Format.h"
 #include "clang/Frontend/CompilerInvocation.h"
 #include "clang/Tooling/CompilationDatabase.h"
@@ -441,6 +442,7 @@
 
 bool check(llvm::StringRef File, const ThreadsafeFS &TFS,
            const ClangdLSPServer::Options &Opts) {
+  clang::noteBottomOfStack();
   std::optional<Range> LineRange;
   if (!CheckFileLines.empty()) {
     uint32_t Begin = 0, End = std::numeric_limits<uint32_t>::max();
Index: clang-tools-extra/clangd/test/infinite-instantiation.test
===================================================================
--- /dev/null
+++ clang-tools-extra/clangd/test/infinite-instantiation.test
@@ -0,0 +1,13 @@
+// RUN: cp %s %t.cpp
+// RUN: not clangd -check=%t.cpp 2>&1 | FileCheck -strict-whitespace %s
+
+// CHECK: [template_recursion_depth_exceeded]
+
+template <typename... T>
+constexpr int f(T... args) {
+  return f(0, args...);
+}
+
+int main() {
+  auto i = f();
+}
Index: clang-tools-extra/clangd/support/Threading.cpp
===================================================================
--- clang-tools-extra/clangd/support/Threading.cpp
+++ clang-tools-extra/clangd/support/Threading.cpp
@@ -8,6 +8,7 @@
 
 #include "support/Threading.h"
 #include "support/Trace.h"
+#include "clang/Basic/Stack.h"
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/Support/Threading.h"
 #include "llvm/Support/thread.h"
@@ -98,6 +99,9 @@
   auto Task = [Name = Name.str(), Action = std::move(Action),
                Cleanup = std::move(CleanupTask)]() mutable {
     llvm::set_thread_name(Name);
+    // Mark the bottom of the stack for clang to be aware of the stack usage and
+    // prevent stack overflow.
+    clang::noteBottomOfStack();
     Action();
     // Make sure function stored by ThreadFunc is destroyed before Cleanup runs.
     Action = nullptr;


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