Check for ninja_required_version when $^ escape is used

Author: ildus

src/lexer.cc

@@ -22,6 +22,10 @@
 
 using namespace std;
 
+// $^ supported starting this version
+const int minNewlineEscapeVersionMajor = 1;
+const int minNewlineEscapeVersionMinor = 14;
+
 bool Lexer::Error(const string& message, string* err) {
   // Compute line/column.
   int line = 1;
@@ -753,6 +757,16 @@ bool Lexer::ReadEvalString(EvalString* eval, bool path, string* err) {
 yy81:
 	++p;
 	{
+      if (!newline_version_checked_)
+      {
+        if ((manifest_version_major < minNewlineEscapeVersionMajor) ||
+            (manifest_version_major = minNewlineEscapeVersionMajor &&
+             manifest_version_minor < minNewlineEscapeVersionMinor))
+        {
+          return Error("using $^ escape requires specifying 'ninja_required_version' with version greater or equal 1.14", err);
+        }
+        newline_version_checked_ = true;
+      }
       eval->AddText(StringPiece("\n", 1));
       continue;
     }

src/lexer.h

@@ -90,6 +90,10 @@ struct Lexer {
   /// Construct an error message with context.
   bool Error(const std::string& message, std::string* err);
 
+  /// Parsed 'ninja_required_version' from the manifest.
+  int manifest_version_major = 0;
+  int manifest_version_minor = 0;
+
 private:
   /// Skip past whitespace (called after each read token/ident/etc.).
   void EatWhitespace();
@@ -101,6 +105,9 @@ struct Lexer {
   StringPiece input_;
   const char* ofs_;
   const char* last_token_;
+
+  /// Holds true if ninja_required_version checked for $^ (newline) escape.
+  bool newline_version_checked_ = false;
 };
 
 #endif // NINJA_LEXER_H_

src/lexer.in.cc

@@ -21,6 +21,10 @@
 
 using namespace std;
 
+// $^ supported starting this version
+const int minNewlineEscapeVersionMajor = 1;
+const int minNewlineEscapeVersionMinor = 14;
+
 bool Lexer::Error(const string& message, string* err) {
   // Compute line/column.
   int line = 1;
@@ -260,6 +264,16 @@ bool Lexer::ReadEvalString(EvalString* eval, bool path, string* err) {
       continue;
     }
     "$^" {
+      if (!newline_version_checked_)
+      {
+        if ((manifest_version_major < minNewlineEscapeVersionMajor) ||
+            (manifest_version_major = minNewlineEscapeVersionMajor &&
+             manifest_version_minor < minNewlineEscapeVersionMinor))
+        {
+          return Error("using $^ escape requires specifying 'ninja_required_version' with version greater or equal 1.14", err);
+        }
+        newline_version_checked_ = true;
+      }
       eval->AddText(StringPiece("\n", 1));
       continue;
     }

src/lexer_test.cc

@@ -101,6 +101,14 @@ TEST(Lexer, EscapedNewlines) {
   Lexer lexer("foo$\nbar$^newline foo\n");
   EvalString eval;
   string err;
+  EXPECT_FALSE(lexer.ReadVarValue(&eval, &err));
+  EXPECT_EQ("input:1: using $^ escape requires specifying 'ninja_required_version' with version greater or equal 1.14\n", err);
+
+  lexer.manifest_version_major = 1;
+  lexer.manifest_version_minor = 14;
+
+  eval.Clear();
+  err = "";
   EXPECT_TRUE(lexer.ReadVarValue(&eval, &err));
   EXPECT_EQ("", err);
   EXPECT_EQ("[foobar\nnewline foo]", eval.Serialize());

src/manifest_parser.cc

@@ -68,7 +68,7 @@ bool ManifestParser::Parse(const string& filename, const string& input,
       // Check ninja_required_version immediately so we can exit
       // before encountering any syntactic surprises.
       if (name == "ninja_required_version")
-        CheckNinjaVersion(value);
+        CheckNinjaVersion(value, lexer_.manifest_version_major, lexer_.manifest_version_minor);
       env_->AddBinding(name, value);
       break;
     }

src/version.cc

@@ -33,10 +33,9 @@ void ParseVersion(const string& version, int* major, int* minor) {
   }
 }
 
-void CheckNinjaVersion(const string& version) {
+void CheckNinjaVersion(const string& version, int &file_major, int &file_minor) {
   int bin_major, bin_minor;
   ParseVersion(kNinjaVersion, &bin_major, &bin_minor);
-  int file_major, file_minor;
   ParseVersion(version, &file_major, &file_minor);
 
   if (bin_major > file_major) {

src/version.h

@@ -26,6 +26,7 @@ void ParseVersion(const std::string& version, int* major, int* minor);
 
 /// Check whether \a version is compatible with the current Ninja version,
 /// aborting if not.
-void CheckNinjaVersion(const std::string& required_version);
+void CheckNinjaVersion(const std::string& required_version, int &file_major,
+    int &file_minor);
 
 #endif  // NINJA_VERSION_H_