Fix @line variables

Author: CodaFi

Sources/FileCheck/FileCheck.swift

@@ -118,9 +118,10 @@ public func fileCheckOutput(of FD : FileCheckFD = .stdout, withPrefixes prefixes
   let buf = contents.cString(using: .utf8)?.withUnsafeBufferPointer { buffer in
     return readCheckStrings(in: buffer, withPrefixes: validPrefixes, checkNot: checkNot, options: options, prefixRE)
   }
-  guard let checkStrings = buf else {
+  guard let checkStrings = buf, !checkStrings.isEmpty else {
     return false
   }
+
   return check(input: input, against: checkStrings, options: options)
 }
 

Sources/FileCheck/Pattern.swift

@@ -178,7 +178,7 @@ final class Pattern {
         let diagLoc = CheckLoc.inBuffer(pattern.baseAddress!, buf)
         for (i, c) in name.characters.enumerated() {
           if i == 0 && c == "@" {
-            if nameEnd == nil {
+            if nameEnd != nil {
               diagnose(.error, at: diagLoc, with: "invalid name in named regex definition", options: options)
               return nil
             }

Tests/FileCheckTests/FileCheckSpec.swift

@@ -92,6 +92,8 @@ class FileCheckSpec : XCTestCase {
 
   #if !os(macOS)
   static var allTests = testCase([
+    ("testWhitespace", testWhitespace),
+    ("testSame", testSame),
     ("testImplicitCheckNot", testImplicitCheckNot),
   ])
   #endif

Tests/FileCheckTests/LineCountSpec.swift

@@ -0,0 +1,37 @@
+// THIS TEST IS LINE-COUNT DEPENDENT.  DO NOT RE-INDENT.
+import FileCheck
+import XCTest
+import Foundation
+
+class LineCountSpec : XCTestCase {
+  func testLineCount() {
+    let txt = [
+      "9",
+      "10 aaa",
+      "11 bbb",
+      "12 ccc",
+      "13 CHECK-LINECOUNT: [[@LINE-3]] {{a}}aa",
+      "14 CHECK-LINECOUNT: [[@LINE-3]] {{b}}bb",
+      "15 CHECK-LINECOUNT: [[@LINE-3]] {{c}}cc",
+      "16 foobar",
+      "17 CHECK-LINECOUNT: [[@LINE-1]] {{foo}}bar",
+      "18",
+      "19 arst CHECK-LINECOUNT: [[@LINE]] {{a}}rst",
+      "20",
+      "21 BAD-CHECK-LINECOUNT: [[@LINE:cant-have-regex]]",
+    ].joined(separator: "\n")
+
+    XCTAssert(fileCheckOutput(of: .stdout, withPrefixes: ["CHECK-LINECOUNT"]) {
+      print(txt)
+    })
+
+    XCTAssertFalse(fileCheckOutput(of: .stdout, withPrefixes: ["BAD-CHECK-LINECOUNT"]) {
+      print(txt)
+    })
+  }
+  #if !os(macOS)
+  static var allTests = testCase([
+    ("testLineCount", testLineCount),
+  ])
+  #endif
+}

Tests/LinuxMain.swift

@@ -5,5 +5,6 @@ import XCTest
 #if !os(macOS)
 XCTMain([
   FileCheckSpec.allTests,
+  LineCountSpec.allTests,
 ])
 #endif