[clang] Fix pretty-printing for variables declared in a for-loop condition

[vaithak]

rebased on the latest changes

[MaskRay]

Thanks! Node->getConditionVariableDeclStmt() is how StmtPrinter::VisitWhileStmt prints the declaration in the condition.

https://reviews.llvm.org/D102502 added PCH/for-loop-init-ternary-operator-statement.cpp

[vaithak]

Please land this change for me as I don't have commit access. Thanks 👍
My details: "Vaibhav Thakkar" <vaibhav.thakkar.22.12.99 at gmail.com>

clang/lib/AST/StmtPrinter.cpp

 }
 
 void StmtPrinter::VisitForStmt(ForStmt *Node) {
   Indent() << "for (";
   if (Node->getInit())
     PrintInitStmt(Node->getInit(), 5);
   else
     OS << (Node->getCond() ? "; " : ";");
-  if (Node->getCond())
+  if (const DeclStmt *DS = Node->getConditionVariableDeclStmt())
+    PrintRawDeclStmt(DS);
+  else if (Node->getCond())
     PrintExpr(Node->getCond());
   OS << ";";
   if (Node->getInc()) {
     OS << " ";
     PrintExpr(Node->getInc());
   }
   OS << ")";
   PrintControlledStmt(Node->getBody());

clang/test/PCH/for-loop-init-ternary-operator-statement.cpp

 // RUN: %clang_cc1 -emit-pch -o %t %s
 // RUN: %clang_cc1 -x ast -ast-print %t | FileCheck %s
 
 int f() {
-  // CHECK: for (int i = 0; x; i++) {
+  // CHECK: for (int i = 0; int x = i < 2 ? 1 : 0; i++) {
   for (int i = 0; int x = i < 2 ? 1 : 0; i++) {
     return x;
   }
   return 0;
 }
 

clang/test/SemaCXX/ast-print.cpp

 void test1() {
     Reference r;
     (r->method());
 }
 
 // CHECK: if (int a = 1)
 // CHECK:  while (int a = 1)
 // CHECK:  switch (int a = 1)
+// CHECK:  for (; int a = 1;)
 
 void test2()
 {
     if (int a = 1) { }
     while (int a = 1) { }
     switch (int a = 1) { }
+    for(; int a = 1; ) { }
 }
 
 // CHECK: new (1) int;
 void *operator new (typeof(sizeof(1)), int, int = 2);
 void test3() {
   new (1) int;
 }