Merge branch 'master' into stack-graphs-integration

tool/playground/T.g

@@ -1,8 +1,34 @@
 grammar T;
+s   :   stat ;
+stat:   expr[0] NEWLINE               
+    |   ID '=' expr[0] NEWLINE       
+    |   NEWLINE                     
+    ;
 
-s : ID b ;
+expr[int _p]
-b : INT ;
+    :   ( INT
+        | ID
+        | '(' expr[0] ')'
+        )
+        ( {5 >= $_p}? ('*'|'/') expr[6]
+        | {4 >= $_p}? ('+'|'-') expr[5]
+        )*
+    ;
 
-ID  :   [a-zA-Z]+ ;
+/*
-INT :   [0-9]+ ;
+expr:   expr ('*'|'/') expr      # MulDiv
-WS  :   [ \t\n\r]+ -> skip ;
+    |   expr ('+'|'-') expr      # AddSub
+    |   INT                      # int
+    |   ID                       # id
+    |   '(' expr ')'             # parens
+    ;
+*/
+
+MUL :   '*' ; // assigns token name to '*' used above in grammar
+DIV :   '/' ;
+ADD :   '+' ;
+SUB :   '-' ;
+ID  :   [a-zA-Z]+ ;      // match identifiers
+INT :   [0-9]+ ;         // match integers
+NEWLINE:'\r'? '\n' ;     // return newlines to parser (is end-statement signal)
+WS  :   [ \t]+ -> skip ; // toss out whitespace

tool/playground/TestT.java

@@ -1,6 +1,7 @@
 import org.antlr.v4.runtime.CharStream;
 import org.antlr.v4.runtime.CommonTokenFactory;
 import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.DiagnosticErrorListener;
 import org.antlr.v4.runtime.ParserRuleContext;
 import org.antlr.v4.runtime.UnbufferedCharStream;
 
@@ -23,8 +24,9 @@ public class TestT {
 		CommonTokenStream tokens = new CommonTokenStream(lex);
 		TParser parser = new TParser(tokens);
 
-		ParserRuleContext tree = parser.s();
+		parser.addErrorListener(new DiagnosticErrorListener());
-		tree.save(parser, "/tmp/t.ps");
 
+		ParserRuleContext tree = parser.s();
+//		tree.save(parser, "/tmp/t.ps");
 	}
 }

tool/test/org/antlr/v4/test/TestLeftRecursion.java

@@ -297,31 +297,19 @@ public class TestLeftRecursion extends BaseTest {
 	@Test
 	public void testAmbigLR() throws Exception {
 		String grammar =
-			"// START: g\n" +
 			"grammar Expr;\n" +
-			"// END: g\n" +
-			"\n" +
-			"// START:stat\n" +
 			"prog:   stat ;\n" +
-			"\n" +
 			"stat:   expr NEWLINE                # printExpr\n" +
 			"    |   ID '=' expr NEWLINE         # assign\n" +
 			"    |   NEWLINE                     # blank\n" +
 			"    ;\n" +
-			"// END:stat\n" +
-			"\n" +
-			"// START:expr\n" +
 			"expr:   expr ('*'|'/') expr      # MulDiv\n" +
 			"    |   expr ('+'|'-') expr      # AddSub\n" +
 			"    |   INT                      # int\n" +
 			"    |   ID                       # id\n" +
 			"    |   '(' expr ')'             # parens\n" +
 			"    ;\n" +
-			"// END:expr\n" +
 			"\n" +
-			"// show marginal cost of adding a clear/wipe command for memory\n" +
-			"\n" +
-			"// START:tokens\n" +
 			"MUL :   '*' ; // assigns token name to '*' used above in grammar\n" +
 			"DIV :   '/' ;\n" +
 			"ADD :   '+' ;\n" +
@@ -329,8 +317,7 @@ public class TestLeftRecursion extends BaseTest {
 			"ID  :   [a-zA-Z]+ ;      // match identifiers\n" +
 			"INT :   [0-9]+ ;         // match integers\n" +
 			"NEWLINE:'\\r'? '\\n' ;     // return newlines to parser (is end-statement signal)\n" +
-			"WS  :   [ \\t]+ -> skip ; // toss out whitespace\n" +
+			"WS  :   [ \\t]+ -> skip ; // toss out whitespace\n";
-			"// END:tokens\n";
 		String result = execParser("Expr.g4", grammar, "ExprParser", "ExprLexer", "prog", "1\n", true);
 		assertNull(stderrDuringParse);
 

tool/test/org/antlr/v4/test/TestParserExec.java

@@ -164,32 +164,33 @@ public class TestParserExec extends BaseTest {
 
 
 	/**
-	 * This test is meant to detect regressions of bug antlr/antlr4#41.
+	 * Related to https://github.com/antlr/antlr4/issues/41.  EOF is
-	 * https://github.com/antlr/antlr4/issues/41
+	 * not viable after "if x" since EOF not viable after stat.
 	 */
 	@Test
 	public void testOptional() throws Exception {
 		String grammar =
 			"grammar T;\n" +
-			"s : a | 'x';\n" +
+			"stat : ifstat | 'x';\n" +
-			"a : 'a' s ('b' s)?;\n"
+			"ifstat : 'if' stat ('else' stat)?;\n" +
+			"WS : [ \\n\\t]+ -> skip ;"
 			;
 
-		String found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "x", false);
+		String found = execParser("T.g4", grammar, "TParser", "TLexer", "stat", "x", false);
 		assertEquals("", found);
 		assertNull(this.stderrDuringParse);
 
-		found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "axbx", false);
+		found = execParser("T.g4", grammar, "TParser", "TLexer", "stat", "if x else x", false);
 		assertEquals("", found);
 		assertNull(this.stderrDuringParse);
 
-		found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "ax", false);
+		found = execParser("T.g4", grammar, "TParser", "TLexer", "stat", "if x", false);
 		assertEquals("", found);
-		assertNull(this.stderrDuringParse);
+		assertEquals("line 1:4 no viable alternative at input '<EOF>'\n", this.stderrDuringParse);
 
-		found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "aaxbx", false);
+		found = execParser("T.g4", grammar, "TParser", "TLexer", "stat", "if if x else x", false);
 		assertEquals("", found);
-		assertNull(this.stderrDuringParse);
+		assertEquals("line 1:14 no viable alternative at input '<EOF>'\n", this.stderrDuringParse);
 	}
 
 	/**
@@ -200,6 +201,7 @@ public class TestParserExec extends BaseTest {
 	public void testIfIfElse() throws Exception {
 		String grammar =
 			"grammar T;\n" +
+			"s : stmt EOF ;\n" +
 			"stmt : ifStmt | ID;\n" +
 			"ifStmt : 'if' ID stmt ('else' stmt | {_input.LA(1) != ELSE}?);\n" +
 			"ELSE : 'else';\n" +
@@ -207,11 +209,12 @@ public class TestParserExec extends BaseTest {
 			"WS : (' ' | '\\t')+ -> skip;\n"
 			;
 
-		String found = execParser("T.g4", grammar, "TParser", "TLexer", "stmt",
+		String found = execParser("T.g4", grammar, "TParser", "TLexer", "s",
 								  "if x if x a else b", true);
 		String expecting = "";
 		assertEquals(expecting, found);
-		assertNull(this.stderrDuringParse);
+		assertEquals("line 1:12 reportAttemptingFullContext d=1, input='else'\n",
+					 this.stderrDuringParse);
 	}
 
 }