[FileCheck] Fix PR49531: invalid use of string var

FileCheck string substitution block parsing code only report an invalid
variable name in a string variable use if it starts with a forbidden
character. It does not report anything if there are unparsed characters
after the variable name, i.e. [[X-Y]] is parsed as [[X]] and no error is
returned. This commit fixes that.

Reviewed By: jdenny, jhenderson

Differential Revision: https://reviews.llvm.org/D98691

1 files changed, 8 insertions, 1 deletions

diff --git a/llvm/lib/FileCheck/FileCheck.cpp b/llvm/lib/FileCheck/FileCheck.cpp
index bcf828d..12a0ae6 100644
--- a/llvm/lib/FileCheck/FileCheck.cpp
+++ b/llvm/lib/FileCheck/FileCheck.cpp
@@ -1083,8 +1083,15 @@ bool Pattern::parsePattern(StringRef PatternStr, StringRef Prefix,
           if (IsPseudo) {
             MatchStr = OrigMatchStr;
             IsLegacyLineExpr = IsNumBlock = true;
-          } else
+          } else {
+            if (!MatchStr.empty()) {
+              SM.PrintMessage(SMLoc::getFromPointer(Name.data()),
+                              SourceMgr::DK_Error,
+                              "invalid name in string variable use");
+              return true;
+            }
             SubstStr = Name;
+          }
         }
       }