Add driver arguments -ftemplate-depth=N and -fconstexpr-depth=N, with the same

semantics and defaults as the corresponding g++ arguments. The historical g++
argument -ftemplate-depth-N is kept for compatibility, but modern g++ versions
no longer document that option.

Add -cc1 argument -fconstexpr-depth N to implement the corresponding
functionality.

The -ftemplate-depth=N part of this fixes PR9890.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145045 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 22 insertions, 10 deletions

diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index d602be4581..81fe7e3a4e 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -257,9 +257,6 @@ namespace {
     /// CurrentCall - The top of the constexpr call stack.
     CallStackFrame *CurrentCall;
 
-    /// NumCalls - The number of calls we've evaluated so far.
-    unsigned NumCalls;
-
     /// CallStackDepth - The number of calls in the call stack right now.
     unsigned CallStackDepth;
 
@@ -282,7 +279,7 @@ namespace {
 
 
     EvalInfo(const ASTContext &C, Expr::EvalStatus &S)
-      : Ctx(C), EvalStatus(S), CurrentCall(0), NumCalls(0), CallStackDepth(0),
+      : Ctx(C), EvalStatus(S), CurrentCall(0), CallStackDepth(0),
         BottomFrame(*this, 0, 0), EvaluatingDecl(0), EvaluatingDeclValue(0) {}
 
     const CCValue *getOpaqueValue(const OpaqueValueExpr *e) const {
@@ -296,7 +293,11 @@ namespace {
       EvaluatingDeclValue = &Value;
     }
 
-    const LangOptions &getLangOpts() { return Ctx.getLangOptions(); }
+    const LangOptions &getLangOpts() const { return Ctx.getLangOptions(); }
+
+    bool atCallLimit() const {
+      return CallStackDepth > getLangOpts().ConstexprCallDepth;
+    }
   };
 
   CallStackFrame::CallStackFrame(EvalInfo &Info, const LValue *This,
@@ -1278,8 +1279,7 @@ static bool EvaluateArgs(ArrayRef<const Expr*> Args, ArgVector &ArgValues,
 static bool HandleFunctionCall(const LValue *This, ArrayRef<const Expr*> Args,
                                const Stmt *Body, EvalInfo &Info,
                                CCValue &Result) {
-  // FIXME: Implement a proper call limit, along with a command-line flag.
-  if (Info.NumCalls >= 1000000 || Info.CallStackDepth >= 512)
+  if (Info.atCallLimit())
     return false;
 
   ArgVector ArgValues(Args.size());
@@ -1296,7 +1296,7 @@ static bool HandleConstructorCall(const LValue &This,
                                   const CXXConstructorDecl *Definition,
                                   EvalInfo &Info,
                                   APValue &Result) {
-  if (Info.NumCalls >= 1000000 || Info.CallStackDepth >= 512)
+  if (Info.atCallLimit())
     return false;
 
   ArgVector ArgValues(Args.size());
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 4229987f52..918b4551c5 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1619,11 +1619,17 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
-  if (Arg *A = Args.getLastArg(options::OPT_ftemplate_depth_)) {
+  if (Arg *A = Args.getLastArg(options::OPT_ftemplate_depth_,
+                               options::OPT_ftemplate_depth_EQ)) {
     CmdArgs.push_back("-ftemplate-depth");
     CmdArgs.push_back(A->getValue(Args));
   }
 
+  if (Arg *A = Args.getLastArg(options::OPT_fconstexpr_depth_EQ)) {
+    CmdArgs.push_back("-fconstexpr-depth");
+    CmdArgs.push_back(A->getValue(Args));
+  }
+
   if (Arg *A = Args.getLastArg(options::OPT_Wlarge_by_value_copy_EQ,
                                options::OPT_Wlarge_by_value_copy_def)) {
     CmdArgs.push_back("-Wlarge-by-value-copy");
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 738facf069..34080908c0 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -789,6 +789,10 @@ static void LangOptsToArgs(const LangOptions &Opts,
     Res.push_back("-ftemplate-depth");
     Res.push_back(llvm::utostr(Opts.InstantiationDepth));
   }
+  if (Opts.ConstexprCallDepth != DefaultLangOpts.ConstexprCallDepth) {
+    Res.push_back("-fconstexpr-depth");
+    Res.push_back(llvm::utostr(Opts.ConstexprCallDepth));
+  }
   if (!Opts.ObjCConstantStringClass.empty()) {
     Res.push_back("-fconstant-string-class");
     Res.push_back(Opts.ObjCConstantStringClass);
@@ -1777,7 +1781,9 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   Opts.ElideConstructors = !Args.hasArg(OPT_fno_elide_constructors);
   Opts.MathErrno = Args.hasArg(OPT_fmath_errno);
   Opts.InstantiationDepth = Args.getLastArgIntValue(OPT_ftemplate_depth, 1024,
-                                               Diags);
+                                                    Diags);
+  Opts.ConstexprCallDepth = Args.getLastArgIntValue(OPT_fconstexpr_depth, 512,
+                                                    Diags);
   Opts.DelayedTemplateParsing = Args.hasArg(OPT_fdelayed_template_parsing);
   Opts.NumLargeByValueCopy = Args.getLastArgIntValue(OPT_Wlarge_by_value_copy,
                                                     0, Diags);