[C-index] Fix annotate-deep-statements test in Debug target

[aganea]

Summary

As per title: previously, running the test clang/test/Index/annotate-deep-statements.cpp and SemaTemplate/stack-exhaustion.cpp used to fail because of stack overflow (Debug target on Windows compiled with clang-cl)

[rnk]

lgtm

I was wondering if Richard would add something since he created this stack size management code, but in the absence of that, this looks right to me.

[aganea]

Thanks Reid!

clang/lib/Sema/SemaChecking.cpp

public:
   void VisitCallExpr(CallExpr *CE) {
     // C++11 [intro.execution]p15:
     //   When calling a function [...], every value computation and side effect
     //   associated with any argument expression, or with the postfix expression
     //   designating the called function, is sequenced before execution of every
     //   expression or statement in the body of the function [and thus before
     //   the value computation of its result].
     SequencedSubexpression Sequenced(*this);
-    Base::VisitCallExpr(CE);
+    SemaRef.runWithSufficientStackSpace(CE->getExprLoc(),
+                                        [&] { Base::VisitCallExpr(CE); });
 
     // FIXME: CXXNewExpr and CXXDeleteExpr implicitly call functions.
   }
 
   void VisitCXXConstructExpr(CXXConstructExpr *CCE) {
     // This is a call, so all subexpressions are sequenced before the result.
     SequencedSubexpression Sequenced(*this);
 

clang/tools/libclang/CIndex.cpp

clang_parseTranslationUnit(CXIndex CIdx,
   return TU;
 }
 
 enum CXErrorCode clang_parseTranslationUnit2(
     CXIndex CIdx, const char *source_filename,
     const char *const *command_line_args, int num_command_line_args,
     struct CXUnsavedFile *unsaved_files, unsigned num_unsaved_files,
     unsigned options, CXTranslationUnit *out_TU) {
+  noteBottomOfStack();
   SmallVector<const char *, 4> Args;
   Args.push_back("clang");
   Args.append(command_line_args, command_line_args + num_command_line_args);
   return clang_parseTranslationUnit2FullArgv(
       CIdx, source_filename, Args.data(), Args.size(), unsaved_files,
       num_unsaved_files, options, out_TU);
 }
 
 enum CXErrorCode clang_parseTranslationUnit2FullArgv(
     CXIndex CIdx, const char *source_filename,
     const char *const *command_line_args, int num_command_line_args,
     struct CXUnsavedFile *unsaved_files, unsigned num_unsaved_files,
     unsigned options, CXTranslationUnit *out_TU) {
   LOG_FUNC_SECTION {
     *Log << source_filename << ": ";
     for (int i = 0; i != num_command_line_args; ++i)
       *Log << command_line_args[i] << " ";
   }
 
   if (num_unsaved_files && !unsaved_files)
     return CXError_InvalidArguments;
 
   CXErrorCode result = CXError_Failure;
   auto ParseTranslationUnitImpl = [=, &result] {
+    noteBottomOfStack();
     result = clang_parseTranslationUnit_Impl(
         CIdx, source_filename, command_line_args, num_command_line_args,
         llvm::makeArrayRef(unsaved_files, num_unsaved_files), options, out_TU);
   };
 
   llvm::CrashRecoveryContext CRC;
 
   if (!RunSafely(CRC, ParseTranslationUnitImpl)) {

 
 void clang_enableStackTraces(void) {
   // FIXME: Provide an argv0 here so we can find llvm-symbolizer.
   llvm::sys::PrintStackTraceOnErrorSignal(StringRef());
 }
 
 void clang_executeOnThread(void (*fn)(void*), void *user_data,
                            unsigned stack_size) {
-  llvm::llvm_execute_on_thread(
-      fn, user_data,
-      stack_size == 0 ? llvm::None : llvm::Optional<unsigned>(stack_size));
+  llvm::llvm_execute_on_thread(fn, user_data,
+                               stack_size == 0
+                                   ? clang::DesiredStackSize
+                                   : llvm::Optional<unsigned>(stack_size));
 }
 
 //===----------------------------------------------------------------------===//
 // Token-based Operations.
 //===----------------------------------------------------------------------===//
 
 /* CXToken layout:
  *   int_data[0]: a CXTokenKind