From 28db0415f3e47cb2ef0678d0c797b6f5f39baa4b Mon Sep 17 00:00:00 2001
From: Thomas Preud'homme <thomasp@graphcore.ai>
Date: Tue, 16 Mar 2021 10:19:52 +0000
Subject: [PATCH] [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
---
 lib/FileCheck/FileCheck.cpp           |  9 ++++++++-
 test/FileCheck/simple-var-capture.txt | 12 ++++++++++++
 unittests/FileCheck/FileCheckTest.cpp |  3 +++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/lib/FileCheck/FileCheck.cpp b/lib/FileCheck/FileCheck.cpp
index bcf828d20ee..12a0ae63419 100644
--- a/lib/FileCheck/FileCheck.cpp
+++ b/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;
+          }
         }
       }
 
diff --git a/test/FileCheck/simple-var-capture.txt b/test/FileCheck/simple-var-capture.txt
index a487baaa531..d9f456130e0 100644
--- a/test/FileCheck/simple-var-capture.txt
+++ b/test/FileCheck/simple-var-capture.txt
@@ -11,3 +11,15 @@ op4 r30, r18, r21
 ; CHECK-NEXT:   op4 {{r[0-9]+}}, [[REGa]], [[REGb]]
 
 
+// RUN: %ProtectFileCheckOutput \
+// RUN: not FileCheck --check-prefixes INVALID-VARNAME --input-file %s %s 2>&1 \
+// RUN:   | FileCheck --check-prefix INVALID-VARNAME-MSG --strict-whitespace %s
+
+5
+4
+; INVALID-VARNAME: [[X:]]
+; INVALID-VARNAME-NEXT: [[Y:]]
+; INVALID-VARNAME-NEXT: [[X-Y]]
+; INVALID-VARNAME-MSG: simple-var-capture.txt:[[#@LINE-1]]:27: error: invalid name in string variable use
+; INVALID-VARNAME-MSG-NEXT: ; {{I}}NVALID-VARNAME-NEXT: {{\[\[X-Y\]\]}}
+; INVALID-VARNAME-MSG-NEXT:    {{^}}                          ^{{$}}
diff --git a/unittests/FileCheck/FileCheckTest.cpp b/unittests/FileCheck/FileCheckTest.cpp
index 299fbb8a798..f54b940d68c 100644
--- a/unittests/FileCheck/FileCheckTest.cpp
+++ b/unittests/FileCheck/FileCheckTest.cpp
@@ -1343,6 +1343,9 @@ TEST_F(FileCheckTest, ParsePattern) {
   // Collision with numeric variable.
   EXPECT_TRUE(Tester.parsePattern("[[FOO:]]"));
 
+  // Invalid use of string variable.
+  EXPECT_TRUE(Tester.parsePattern("[[FOO-BAR]]"));
+
   // Valid use of string variable.
   EXPECT_FALSE(Tester.parsePattern("[[BAR]]"));