From 1eb9948f02560912c67757e18d105d18609935ce Mon Sep 17 00:00:00 2001
From: Peter Klausler <pklausler@nvidia.com>
Date: Wed, 15 Mar 2023 17:57:58 -0700
Subject: [PATCH] [flang] Catch more bad DATA statement objects

The data statement variable checker is missing some cases, like expressions
that are not variables.  Run the checker first to enjoy its very specific
error messages, but when it finds no problems, still apply a general
check that an expression is a "variable" and also not a constant expression
at the top level as a backstop.

Differential Revision: https://reviews.llvm.org/D146580
---
 flang/lib/Semantics/check-data.cpp | 35 +++++++++++++++++++++--------------
 flang/test/Semantics/data03.f90    | 10 ++++++----
 2 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/flang/lib/Semantics/check-data.cpp b/flang/lib/Semantics/check-data.cpp
index 955998b..f33258e 100644
--- a/flang/lib/Semantics/check-data.cpp
+++ b/flang/lib/Semantics/check-data.cpp
@@ -179,24 +179,27 @@ private:
   bool isFirstSymbol_{true};
 };
 
+static bool IsValidDataObject(const SomeExpr &expr) { // C878, C879
+  return !evaluate::IsConstantExpr(expr) &&
+      (evaluate::IsVariable(expr) || evaluate::IsProcedurePointer(expr));
+}
+
 void DataChecker::Leave(const parser::DataIDoObject &object) {
   if (const auto *designator{
           std::get_if<parser::Scalar<common::Indirection<parser::Designator>>>(
               &object.u)}) {
     if (MaybeExpr expr{exprAnalyzer_.Analyze(*designator)}) {
       auto source{designator->thing.value().source};
-      if (evaluate::IsConstantExpr(*expr)) { // C878,C879
-        exprAnalyzer_.context().Say(
-            source, "Data implied do object must be a variable"_err_en_US);
-      } else {
-        DataVarChecker checker{exprAnalyzer_.context(), source};
-        if (checker(*expr)) {
-          if (checker.HasComponentWithoutSubscripts()) { // C880
-            exprAnalyzer_.context().Say(source,
-                "Data implied do structure component must be subscripted"_err_en_US);
-          } else {
-            return;
-          }
+      DataVarChecker checker{exprAnalyzer_.context(), source};
+      if (checker(*expr)) {
+        if (checker.HasComponentWithoutSubscripts()) { // C880
+          exprAnalyzer_.context().Say(source,
+              "Data implied do structure component must be subscripted"_err_en_US);
+        } else if (!IsValidDataObject(*expr)) {
+          exprAnalyzer_.context().Say(
+              source, "Data implied do object must be a variable"_err_en_US);
+        } else {
+          return;
         }
       }
     }
@@ -211,9 +214,13 @@ void DataChecker::Leave(const parser::DataStmtObject &dataObject) {
           },
           [&](const auto &var) {
             auto expr{exprAnalyzer_.Analyze(var)};
+            auto source{parser::FindSourceLocation(dataObject)};
             if (!expr ||
-                !DataVarChecker{exprAnalyzer_.context(),
-                    parser::FindSourceLocation(dataObject)}(*expr)) {
+                !DataVarChecker{exprAnalyzer_.context(), source}(*expr)) {
+              currentSetHasFatalErrors_ = true;
+            } else if (!IsValidDataObject(*expr)) {
+              exprAnalyzer_.context().Say(
+                  source, "Data statement object must be a variable"_err_en_US);
               currentSetHasFatalErrors_ = true;
             }
           },
diff --git a/flang/test/Semantics/data03.f90 b/flang/test/Semantics/data03.f90
index b3ed338..d9bead7 100644
--- a/flang/test/Semantics/data03.f90
+++ b/flang/test/Semantics/data03.f90
@@ -1,5 +1,5 @@
 ! RUN: %python %S/test_errors.py %s %flang_fc1
-!Testing data constraints : C874 - C875, C878 - C881 
+!Testing data constraints : C874 - C875, C878 - C881
 module m
     integer, target :: modarray(1)
   contains
@@ -8,7 +8,7 @@ module m
       integer, pointer :: f
       f => modarray(i)
     end
-    subroutine CheckObject 
+    subroutine CheckObject
       type specialNumbers
         integer one
         integer numbers(5)
@@ -34,6 +34,8 @@ module m
       integer :: d(10, 10)
       character :: name(12)
       integer :: ind = 2
+      !ERROR: Data statement object must be a variable
+      DATA name%len / 666 /
       !C874
       !ERROR: Data object must not be a coindexed variable
       DATA a[1] / 1 /
@@ -77,7 +79,7 @@ module m
       !C881
       !ERROR: Data object must have constant subscripts
       DATA(b(x), i = 1, 5) / 5 * 1 /
-      !C881 
+      !C881
       !OK: Correct use
       DATA(nums % numbers(i), i = 1, 5) / 5 * 1 /
       !C881
@@ -86,5 +88,5 @@ module m
       !C881
       !OK: Correct use
       DATA(d(i, 1), i = 1, 10) / 10 * 1 /
-    end 
+    end
   end
-- 
2.7.4