1 files changed, 158 insertions, 0 deletions
diff --git a/lib/AST/Interp/State.cpp b/lib/AST/Interp/State.cpp
new file mode 100644
index 000000000000..692cc2e8d69b
--- /dev/null
+++ b/lib/AST/Interp/State.cpp
@@ -0,0 +1,158 @@
+//===--- State.cpp - State chain for the VM and AST Walker ------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "State.h"
+#include "Frame.h"
+#include "Program.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/CXXInheritance.h"
+
+using namespace clang;
+using namespace clang::interp;
+
+State::~State() {}
+
+OptionalDiagnostic State::FFDiag(SourceLocation Loc, diag::kind DiagId,
+                                 unsigned ExtraNotes) {
+  return diag(Loc, DiagId, ExtraNotes, false);
+}
+
+OptionalDiagnostic State::FFDiag(const Expr *E, diag::kind DiagId,
+                                 unsigned ExtraNotes) {
+  if (getEvalStatus().Diag)
+    return diag(E->getExprLoc(), DiagId, ExtraNotes, false);
+  setActiveDiagnostic(false);
+  return OptionalDiagnostic();
+}
+
+OptionalDiagnostic State::FFDiag(const SourceInfo &SI, diag::kind DiagId,
+                                 unsigned ExtraNotes) {
+  if (getEvalStatus().Diag)
+    return diag(SI.getLoc(), DiagId, ExtraNotes, false);
+  setActiveDiagnostic(false);
+  return OptionalDiagnostic();
+}
+
+OptionalDiagnostic State::CCEDiag(SourceLocation Loc, diag::kind DiagId,
+                                  unsigned ExtraNotes) {
+  // Don't override a previous diagnostic. Don't bother collecting
+  // diagnostics if we're evaluating for overflow.
+  if (!getEvalStatus().Diag || !getEvalStatus().Diag->empty()) {
+    setActiveDiagnostic(false);
+    return OptionalDiagnostic();
+  }
+  return diag(Loc, DiagId, ExtraNotes, true);
+}
+
+OptionalDiagnostic State::CCEDiag(const Expr *E, diag::kind DiagId,
+                                  unsigned ExtraNotes) {
+  return CCEDiag(E->getExprLoc(), DiagId, ExtraNotes);
+}
+
+OptionalDiagnostic State::CCEDiag(const SourceInfo &SI, diag::kind DiagId,
+                                  unsigned ExtraNotes) {
+  return CCEDiag(SI.getLoc(), DiagId, ExtraNotes);
+}
+
+OptionalDiagnostic State::Note(SourceLocation Loc, diag::kind DiagId) {
+  if (!hasActiveDiagnostic())
+    return OptionalDiagnostic();
+  return OptionalDiagnostic(&addDiag(Loc, DiagId));
+}
+
+void State::addNotes(ArrayRef<PartialDiagnosticAt> Diags) {
+  if (hasActiveDiagnostic()) {
+    getEvalStatus().Diag->insert(getEvalStatus().Diag->end(), Diags.begin(),
+                                 Diags.end());
+  }
+}
+
+DiagnosticBuilder State::report(SourceLocation Loc, diag::kind DiagId) {
+  return getCtx().getDiagnostics().Report(Loc, DiagId);
+}
+
+/// Add a diagnostic to the diagnostics list.
+PartialDiagnostic &State::addDiag(SourceLocation Loc, diag::kind DiagId) {
+  PartialDiagnostic PD(DiagId, getCtx().getDiagAllocator());
+  getEvalStatus().Diag->push_back(std::make_pair(Loc, PD));
+  return getEvalStatus().Diag->back().second;
+}
+
+OptionalDiagnostic State::diag(SourceLocation Loc, diag::kind DiagId,
+                               unsigned ExtraNotes, bool IsCCEDiag) {
+  Expr::EvalStatus &EvalStatus = getEvalStatus();
+  if (EvalStatus.Diag) {
+    if (hasPriorDiagnostic()) {
+      return OptionalDiagnostic();
+    }
+
+    unsigned CallStackNotes = getCallStackDepth() - 1;
+    unsigned Limit = getCtx().getDiagnostics().getConstexprBacktraceLimit();
+    if (Limit)
+      CallStackNotes = std::min(CallStackNotes, Limit + 1);
+    if (checkingPotentialConstantExpression())
+      CallStackNotes = 0;
+
+    setActiveDiagnostic(true);
+    setFoldFailureDiagnostic(!IsCCEDiag);
+    EvalStatus.Diag->clear();
+    EvalStatus.Diag->reserve(1 + ExtraNotes + CallStackNotes);
+    addDiag(Loc, DiagId);
+    if (!checkingPotentialConstantExpression()) {
+      addCallStack(Limit);
+    }
+    return OptionalDiagnostic(&(*EvalStatus.Diag)[0].second);
+  }
+  setActiveDiagnostic(false);
+  return OptionalDiagnostic();
+}
+
+const LangOptions &State::getLangOpts() const { return getCtx().getLangOpts(); }
+
+void State::addCallStack(unsigned Limit) {
+  // Determine which calls to skip, if any.
+  unsigned ActiveCalls = getCallStackDepth() - 1;
+  unsigned SkipStart = ActiveCalls, SkipEnd = SkipStart;
+  if (Limit && Limit < ActiveCalls) {
+    SkipStart = Limit / 2 + Limit % 2;
+    SkipEnd = ActiveCalls - Limit / 2;
+  }
+
+  // Walk the call stack and add the diagnostics.
+  unsigned CallIdx = 0;
+  Frame *Top = getCurrentFrame();
+  const Frame *Bottom = getBottomFrame();
+  for (Frame *F = Top; F != Bottom; F = F->getCaller(), ++CallIdx) {
+    SourceLocation CallLocation = F->getCallLocation();
+
+    // Skip this call?
+    if (CallIdx >= SkipStart && CallIdx < SkipEnd) {
+      if (CallIdx == SkipStart) {
+        // Note that we're skipping calls.
+        addDiag(CallLocation, diag::note_constexpr_calls_suppressed)
+            << unsigned(ActiveCalls - Limit);
+      }
+      continue;
+    }
+
+    // Use a different note for an inheriting constructor, because from the
+    // user's perspective it's not really a function at all.
+    if (auto *CD = dyn_cast_or_null<CXXConstructorDecl>(F->getCallee())) {
+      if (CD->isInheritingConstructor()) {
+        addDiag(CallLocation, diag::note_constexpr_inherited_ctor_call_here)
+            << CD->getParent();
+        continue;
+      }
+    }
+
+    SmallVector<char, 128> Buffer;
+    llvm::raw_svector_ostream Out(Buffer);
+    F->describe(Out);
+    addDiag(CallLocation, diag::note_constexpr_call_here) << Out.str();
+  }
+}