[flang]Verify C7107, C7108, C7109 from - Clause 7 constraint checks for f18.

[sameeranjoshi]

Summary

1. Annotate the sources with constraint numbers.
2. Add tests for
   
   *C7107 (R765) digit shall have one of the values 0 or 1. *C7108 (R766) digit shall have one of the values 0 through 7. *C7109 (R764) A boz-literal-constant shall appear only as a data-stmt-constant in a DATA statement, or where explicitly allowed in 16.9 as an actual argument of an intrinsic procedure.

[sameeranjoshi]

flang/test/Semantics/boz-literal-constants.f90

36

Seems like this 8.6.7(11) was missing a test.
Current llvm-trunk flang outputs below error:

"DATA statement value could not be converted to the type 'COMPLEX(4)' of the object 'rescmplx'"

Is the error (with this patch) expected to be printed here(i.e is that getting ignored due to above error)?

50

Is error below a more proper one?

Typeless (BOZ) not allowed for both 'i=' & 'j=' arguments.

16.9.65(3)

J shall be of type integer or a boz-literal-constant. If both I and J are of type integer, they shall have the same kind type parameter. I and J shall not both be boz-literal-constants

restricts variables I and J when both are boz-literal-constants, whereas the current error with flang trunk assumes 'i' to be wrong, and which might not give proper information to the user.

[PeteSteinfeld]

Thanks for working on this!

Please update the messages and the test results. Also, please add a reference to C7109 in the source code where that constraint is enforced.

flang/test/Semantics/boz-literal-constants.f90

36

I suspect that the error message produced in this instance changed when I committed the fix for D83917. In that change, I give the normally typeless BOZ literal constants the type INTEGER. The new error message seems OK to me, but you should update the test results.

50

I would say:

Typeless (BOZ) not allowed for either 'i=' & 'j=' arguments.

[sameeranjoshi]

Address review comments.

[sameeranjoshi]

Add missing constraint number in sources.

[PeteSteinfeld]

flang/lib/Evaluate/intrinsics.cpp

1134–1135

Sorry for not noticing this earlier, but the message should say:

Typeless (BOZ) not allowed for either '%s=' or '%s=' arguments

flang/test/Semantics/boz-literal-constants.f90

50

The message also needs to be corrected here.

[tskeith]

flang/test/Semantics/boz-literal-constants.f90

50

I think @sameeranjoshi's version of this message is right. They can't both be BOZ literals but either one can be.

[PeteSteinfeld]

flang/test/Semantics/boz-literal-constants.f90

50

Good catch, Tim. I just re-read the standard, and you're correct.

[sameeranjoshi]

Revert to older message.

[PeteSteinfeld]

All builds, tests, and looks good!

[sameeranjoshi]

Changes in commit message for using arc.

flang/lib/Evaluate/intrinsics.cpp

for (std::size_t j{0}; j < dummies; ++j) {
     if (!type) {
       CHECK(arg->Rank() == 0);
       const Expr<SomeType> &expr{DEREF(arg->UnwrapExpr())};
       if (std::holds_alternative<BOZLiteralConstant>(expr.u)) {
         if (d.typePattern.kindCode == KindCode::typeless ||
             d.rank == Rank::elementalOrBOZ) {
           continue;
         } else {
+          const IntrinsicDummyArgument &nextParam{dummy[j + 1]};
           messages.Say(
-              "Typeless (BOZ) not allowed for '%s=' argument"_err_en_US,
-              d.keyword);
+              "Typeless (BOZ) not allowed for both '%s=' & '%s=' arguments"_err_en_US, // C7109
+              d.keyword, nextParam.keyword);
         }
       } else {
         // NULL(), procedure, or procedure pointer
         CHECK(IsProcedurePointer(expr));
         if (d.typePattern.kindCode == KindCode::addressable ||
             d.rank == Rank::reduceOperation) {
           continue;
         } else {

flang/lib/Semantics/expression.cpp

case 'x':
     break;
   default:
     CRASH_NO_CASE;
   }
   CHECK(*p == '"');
   ++p;
   auto value{BOZLiteralConstant::Read(p, base, false /*unsigned*/)};
   if (*p != '"') {
-    Say("Invalid digit ('%c') in BOZ literal '%s'"_err_en_US, *p, x.v);
+    Say("Invalid digit ('%c') in BOZ literal '%s'"_err_en_US, *p,
+        x.v); // C7107, C7108
     return std::nullopt;
   }
   if (value.overflow) {
     Say("BOZ literal '%s' too large"_err_en_US, x.v);
     return std::nullopt;
   }
   return AsGenericExpr(std::move(value.value));
 }

flang/test/Semantics/boz-literal-constants.f90

+! RUN: %S/test_errors.sh %s %t %f18
+! Confirm enforcement of constraints and restrictions in 7.7
+! C7107, C7108, C7109
+
+subroutine bozchecks
+  ! Type declaration statements
+  integer :: f, realpart = B"0101", img = B"1111", resint
+  logical :: resbit
+  complex :: rescmplx
+  real :: dbl, e
+  ! C7107
+  !ERROR: Invalid digit ('a') in BOZ literal 'b"110a"'
+  integer, parameter :: a = B"110A"
+  !ERROR: Invalid digit ('2') in BOZ literal 'b"1232"'
+  integer, parameter :: b = B"1232"
+  !ERROR: BOZ literal 'b"010101010101010101010101011111111111111111111111111111111111111111111111111111111111111111111111111111111111000000000000000000000000000000000000"' too large
+  integer, parameter :: b1 = B"010101010101010101010101011111111111111111111&
+                              &111111111111111111111111111111111111111111111&
+                              &111111111111111111000000000000000000000000000&
+                              &000000000"
+  ! C7108
+  !ERROR: Invalid digit ('8') in BOZ literal 'o"8"'
+  integer :: c = O"8"
+  !ERROR: Invalid digit ('a') in BOZ literal 'o"a"'
+  integer :: d = O"A"
+
+  ! C7109
+  !    A) can appear only in data statement
+  !    B) Argument to intrinsics listed from 16.9 below
+  !       BGE, BGT, BLE, BLT, CMPLX, DBLE, DSHIFTL,
+  !       DSHIFTR, IAND, IEOR, INT, IOR, MERGE_BITS, REAL
+
+  ! part A
+  data f / Z"AA" / ! OK
+  !ERROR: DATA statement value could not be converted to the type 'COMPLEX(4)' of the object 'rescmplx'
+  data rescmplx / B"010101" /
+  ! part B
+  resbit = BGE(B"0101", B"1111")
+  resbit = BGT(Z"0101", B"1111")
+  resbit = BLE(B"0101", B"1111")
+  resbit = BLT(B"0101", B"1111")
+
+  res = CMPLX (realpart, img, 4)
+  res = CMPLX (B"0101", B"1111", 4)
+
+  dbl = DBLE(B"1111")
+  dbl = DBLE(realpart)
+
+  !ERROR: Typeless (BOZ) not allowed for both 'i=' & 'j=' arguments
+  dbl = DSHIFTL(B"0101",B"0101",2)
+  !ERROR: Typeless (BOZ) not allowed for both 'i=' & 'j=' arguments
+  dbl = DSHIFTR(B"1010",B"1010",2)
+  dbl = DSHIFTL(B"0101",5,2) ! OK
+  dbl = DSHIFTR(B"1010",5,2) ! OK
+
+  !ERROR: Typeless (BOZ) not allowed for both 'i=' & 'j=' arguments
+  resint = IAND(B"0001", B"0011")
+  resint = IAND(B"0001", 3)
+
+  !ERROR: Typeless (BOZ) not allowed for both 'i=' & 'j=' arguments
+  resint = IEOR(B"0001", B"0011")
+  resint = IEOR(B"0001", 3)
+
+  resint = INT(B"1010")
+
+  !ERROR: Typeless (BOZ) not allowed for both 'i=' & 'j=' arguments
+  res = IOR(B"0101", B"0011")
+  res = IOR(B"0101", 3)
+
+  res = MERGE_BITS(13,3,11)
+  res = MERGE_BITS(B"1101",3,11)
+  !ERROR: Typeless (BOZ) not allowed for both 'i=' & 'j=' arguments
+  res = MERGE_BITS(B"1101",B"0011",11)
+  !ERROR: Typeless (BOZ) not allowed for both 'i=' & 'j=' arguments
+  res = MERGE_BITS(B"1101",B"0011",B"1011")
+  res = MERGE_BITS(B"1101",3,B"1011")
+
+  res = REAL(B"1101")
+end subroutine