Implement support for varargs functions without any fixed
parameters in the CBE by implicitly adding a fixed argument.
This allows eliminating a work-around from DAE. Patch by
Sylvere Teissier!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100944 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/CBackend/CBackend.cpp b/lib/Target/CBackend/CBackend.cpp
index 5e16a08..67f513b 100644
--- a/lib/Target/CBackend/CBackend.cpp
+++ b/lib/Target/CBackend/CBackend.cpp
@@ -473,8 +473,9 @@
PrintedType = true;
}
if (FTy->isVarArg()) {
- if (PrintedType)
- FunctionInnards << ", ...";
+ if (!PrintedType)
+ FunctionInnards << " int"; //dummy argument for empty vararg functs
+ FunctionInnards << ", ...";
} else if (!PrintedType) {
FunctionInnards << "void";
}
@@ -568,8 +569,9 @@
++Idx;
}
if (FTy->isVarArg()) {
- if (FTy->getNumParams())
- FunctionInnards << ", ...";
+ if (!FTy->getNumParams())
+ FunctionInnards << " int"; //dummy argument for empty vaarg functs
+ FunctionInnards << ", ...";
} else if (!FTy->getNumParams()) {
FunctionInnards << "void";
}
@@ -2237,12 +2239,16 @@
}
}
+ if (!PrintedArg && FT->isVarArg()) {
+ FunctionInnards << "int vararg_dummy_arg";
+ PrintedArg = true;
+ }
+
// Finish printing arguments... if this is a vararg function, print the ...,
// unless there are no known types, in which case, we just emit ().
//
if (FT->isVarArg() && PrintedArg) {
- if (PrintedArg) FunctionInnards << ", ";
- FunctionInnards << "..."; // Output varargs portion of signature!
+ FunctionInnards << ",..."; // Output varargs portion of signature!
} else if (!FT->isVarArg() && !PrintedArg) {
FunctionInnards << "void"; // ret() -> ret(void) in C.
}
@@ -2928,6 +2934,12 @@
Out << '(';
+ bool PrintedArg = false;
+ if(FTy->isVarArg() && !FTy->getNumParams()) {
+ Out << "0 /*dummy arg*/";
+ PrintedArg = true;
+ }
+
unsigned NumDeclaredParams = FTy->getNumParams();
CallSite::arg_iterator AI = I.op_begin()+1, AE = I.op_end();
@@ -2937,7 +2949,7 @@
++ArgNo;
}
- bool PrintedArg = false;
+
for (; AI != AE; ++AI, ++ArgNo) {
if (PrintedArg) Out << ", ";
if (ArgNo < NumDeclaredParams &&
@@ -2987,15 +2999,10 @@
writeOperand(I.getOperand(1));
Out << ", ";
// Output the last argument to the enclosing function.
- if (I.getParent()->getParent()->arg_empty()) {
- std::string msg;
- raw_string_ostream Msg(msg);
- Msg << "The C backend does not currently support zero "
- << "argument varargs functions, such as '"
- << I.getParent()->getParent()->getName() << "'!";
- report_fatal_error(Msg.str());
- }
- writeOperand(--I.getParent()->getParent()->arg_end());
+ if (I.getParent()->getParent()->arg_empty())
+ Out << "vararg_dummy_arg";
+ else
+ writeOperand(--I.getParent()->getParent()->arg_end());
Out << ')';
return true;
case Intrinsic::vaend: