[clang] Fix ternary operator in the second for loop statement

Fix ternary operator in for loop argument, it was by mistake not set as CanBeForRangeDecl and led to incorrect codegen. It fixes https://bugs.llvm.org/show_bug.cgi?id=50038. I don't have commit rights. Danila Kutenin. [email protected]

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D102502

Author: danlark1

clang/lib/Parse/ParseExprCXX.cpp

@@ -2033,6 +2033,8 @@ Sema::ConditionResult Parser::ParseCXXCondition(StmtResult *InitStmt,
     DeclGroupPtrTy DG = ParseSimpleDeclaration(DeclaratorContext::ForInit,
                                                DeclEnd, attrs, false, FRI);
     FRI->LoopVar = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation());
+    assert((FRI->ColonLoc.isValid() || !DG) &&
+           "cannot find for range declaration");
     return Sema::ConditionResult();
   }
 

clang/lib/Parse/ParseTentative.cpp

@@ -353,8 +353,8 @@ struct Parser::ConditionDeclarationOrInitStatementState {
       if (CanBeForRangeDecl) {
         // Skip until we hit a ')', ';', or a ':' with no matching '?'.
         // The final case is a for range declaration, the rest are not.
+        unsigned QuestionColonDepth = 0;
         while (true) {
-          unsigned QuestionColonDepth = 0;
           P.SkipUntil({tok::r_paren, tok::semi, tok::question, tok::colon},
                       StopBeforeMatch);
           if (P.Tok.is(tok::question))

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

@@ -0,0 +1,42 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm %s -o - | FileCheck %s
+
+// CHECK-LABEL: @_Z1fv(
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[RETVAL:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[I:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    [[X:%.*]] = alloca i32, align 4
+// CHECK-NEXT:    store i32 0, i32* [[I]], align 4
+// CHECK-NEXT:    br label [[FOR_COND:%.*]]
+// CHECK:       for.cond:
+// CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* [[I]], align 4
+// CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[TMP0]], 2
+// CHECK-NEXT:    [[TMP1:%.*]] = zext i1 [[CMP]] to i64
+// CHECK-NEXT:    [[COND:%.*]] = select i1 [[CMP]], i32 1, i32 0
+// CHECK-NEXT:    store i32 [[COND]], i32* [[X]], align 4
+// CHECK-NEXT:    [[TMP2:%.*]] = load i32, i32* [[X]], align 4
+// CHECK-NEXT:    [[TOBOOL:%.*]] = icmp ne i32 [[TMP2]], 0
+// CHECK-NEXT:    br i1 [[TOBOOL]], label [[FOR_BODY:%.*]], label [[FOR_END:%.*]]
+// CHECK:       for.body:
+// CHECK-NEXT:    [[TMP3:%.*]] = load i32, i32* [[X]], align 4
+// CHECK-NEXT:    store i32 [[TMP3]], i32* [[RETVAL]], align 4
+// CHECK-NEXT:    br label [[RETURN:%.*]]
+// CHECK:       for.inc:
+// CHECK-NEXT:    [[TMP4:%.*]] = load i32, i32* [[I]], align 4
+// CHECK-NEXT:    [[INC:%.*]] = add nsw i32 [[TMP4]], 1
+// CHECK-NEXT:    store i32 [[INC]], i32* [[I]], align 4
+// CHECK-NEXT:    br label [[FOR_COND]], !llvm.loop [[LOOP2:![0-9]+]]
+// CHECK:       for.end:
+// CHECK-NEXT:    store i32 0, i32* [[RETVAL]], align 4
+// CHECK-NEXT:    br label [[RETURN]]
+// CHECK:       return:
+// CHECK-NEXT:    [[TMP5:%.*]] = load i32, i32* [[RETVAL]], align 4
+// CHECK-NEXT:    ret i32 [[TMP5]]
+//
+int f() {
+  for (int i = 0; int x = i < 2 ? 1 : 0; i++) {
+    return x;
+  }
+  return 0;
+}
+

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

@@ -0,0 +1,11 @@
+// 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++) {
+  for (int i = 0; int x = i < 2 ? 1 : 0; i++) {
+    return x;
+  }
+  return 0;
+}
+

clang/test/Parser/cxx2a-init-statement.cpp

@@ -15,6 +15,8 @@ void f() {
   int A<0>::*arr2[3];
   for (int n = 5; int A<true ? 0 : 1>::*x : arr2) {}
 
+  for (int i = 0; int x = i < 2 ? 1 : 0; i++) {}
+
   F (*arr3[3])(int);
   for (int n = 5; F (*p)(int n) : arr3) {}
   for (int n = 5; F (*p)(int (n)) : arr3) {}