TableGen: Handle nontrivial foreach range bounds

This allows using anything that isn't a literal integer as the bounds
for a foreach. Some of the diagnostics aren't perfect, but nobody ever
accused tablegen of having good errors. For example, the existing
wording suggests a bitrange is valid, but as far as I can tell this
has never worked.

Fixes bug 41958.

llvm-svn: 361434

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/test/TableGen/foreach-range-parse-errors0.td b/llvm/test/TableGen/foreach-range-parse-errors0.td
new file mode 100644
index 00000000000..a3e6a9eb975
--- /dev/null
+++ b/llvm/test/TableGen/foreach-range-parse-errors0.td
@@ -0,0 +1,19 @@
+// RUN: not llvm-tblgen %s 2>&1 | FileCheck -DFILE=%s %s
+
+class ConstantsImpl {
+  int Zero = 0;
+  int One = 1;
+  int Two = 2;
+  int Three = 3;
+  int Five = 5;
+}
+
+def Constants : ConstantsImpl;
+
+// CHECK-NOT:  error: Unknown token when parsing a value
+// CHECK: [[FILE]]:[[@LINE+3]]:22: error: Unknown token when parsing a value
+// CHECK: [[FILE]]:[[@LINE+2]]:22: error: expected integer value as end of range
+// CHECK: [[FILE]]:[[@LINE+1]]:22: error: expected declaration in for
+foreach Index = 0 -  in {
+
+}