Merge pull request #2291 from guwirth/fix-2286

fix parsing error with right angle bracket detection

Author: guwirth

cxx-squid/src/main/java/org/sonar/cxx/channels/RightAngleBracketsChannel.java

@@ -43,29 +43,45 @@
  */
 public class RightAngleBracketsChannel extends Channel<Lexer> {
 
-  private int angleBracketLevel = 0;
-  private int parentheseLevel = 0;
+  private int angleBracketLevel = 0; // angle brackets <  >
+  private int parentheseLevel = 0;   // parentheses / round brackets ( )
 
   @Override
   public boolean consume(CodeReader code, Lexer output) {
     var ch = (char) code.peek();
     var consumed = false;
 
-    if (ch == '<') {
-      if (parentheseLevel == 0) {
-        var next = code.charAt(1);
-        if ((next != '<') && (next != '=')) { // not <<, <=, <<=, <=>,
-          angleBracketLevel++;
+    switch (ch) {
+      case '(':
+        parentheseLevel++;
+        break;
+      case ')':
+        if (parentheseLevel > 0) {
+          parentheseLevel--;
         }
-      }
-    } else if (angleBracketLevel > 0) {
-      switch (ch) {
-        case ';': // end of expression => reset
-          angleBracketLevel = 0;
-          parentheseLevel = 0;
-          break;
-        case '>':
-          if (parentheseLevel == 0) {
+        break;
+      case ';': // end of expression => reset
+        angleBracketLevel = 0;
+        parentheseLevel = 0;
+        break;
+
+      case '<':
+        if (parentheseLevel == 0) {
+          var next = code.charAt(1);
+          if ((next != '<') && (next != '=')) { // not <<, <=, <<=, <=>
+            angleBracketLevel++;
+          }
+        }
+        break;
+
+      case '>':
+        if (angleBracketLevel > 0) {
+          var consume = parentheseLevel == 0;
+          var next = code.charAt(1);
+          consume = consume && !(next == '='); // not >=
+          consume = consume && !((next == '>') && (angleBracketLevel == 1)); // not dangling >>
+
+          if (consume) {
             output.addToken(Token.builder()
               .setLine(code.getLinePosition())
               .setColumn(code.getColumnPosition())
@@ -74,20 +90,12 @@ public boolean consume(CodeReader code, Lexer output) {
               .setType(CxxPunctuator.GT)
               .build());
             code.pop();
+
+            angleBracketLevel--;
             consumed = true;
           }
-          angleBracketLevel = Math.max(0, angleBracketLevel - 1);
-          if (angleBracketLevel == 0) {
-            parentheseLevel = 0;
-          }
-          break;
-        case '(':
-          parentheseLevel++;
-          break;
-        case ')':
-          parentheseLevel = Math.max(0, parentheseLevel - 1);
-          break;
-      }
+        }
+        break;
     }
 
     return consumed;

cxx-squid/src/main/java/org/sonar/cxx/parser/CxxGrammarImpl.java

@@ -713,7 +713,7 @@ private static void expressions(LexerfulGrammarBuilder b) {
     ).skipIfOneChild();
 
     b.rule(cudaKernel).is(
-      b.sequence("<<", "<", b.optional(expressionList), ">", ">>") // CUDA
+      b.sequence("<<", "<", b.optional(expressionList), ">>", ">") // CUDA
     );
 
     b.rule(typeIdEnclosed).is( // todo

cxx-squid/src/test/java/org/sonar/cxx/parser/StatementTest.java

@@ -71,6 +71,28 @@ public void statement_reallife() {
       .matches("friend class SmartPtr<T>;");
   }
 
+  @Test
+  public void expressionStatement_reallife() {
+    setRootRule(CxxGrammarImpl.expressionStatement);
+
+    assertThatParser()
+      // fix #2286: use expressionStatement with ; at the end to reset RightAngleBracketsChannel after each matches
+      .matches("a() < 0 || c >= 1;")
+      .matches("a() < 0 || c > 1;")
+      .matches("a() < 0 || c >> 1;");
+  }
+
+  @Test
+  public void selectionStatement_reallife() {
+    setRootRule(CxxGrammarImpl.selectionStatement);
+
+    assertThatParser()
+      // fix #2286
+      .matches("if(a() < 0 || c >= 1) {}")
+      .matches("if(a() < 0 || c > 1) {}")
+      .matches("if(a() < 0 || c >> 1) {}");
+  }
+
   @Test
   public void labeledStatement() {
     setRootRule(CxxGrammarImpl.labeledStatement);

cxx-squid/src/test/java/org/sonar/cxx/parser/TemplatesTest.java

@@ -199,7 +199,13 @@ public void simpleTemplateId_reallife() {
       .matches("A<(X>Y)>")
       .matches("A<(X<Y)>")
       .matches("vector<std::vector<bool>>")
-      .matches("Y<X<(6>>1)>>");
+      .matches("Y<X<(6>1)>>")
+      .matches("Y<X<(6<1)>>")
+      .matches("Y<X<(6>=1)>>")
+      .matches("Y<X<(6<=1)>>")
+      .matches("Y<X<(6>>1)>>")
+      .matches("Y<X<(6<<1)>>")
+      .matches("Y<X<(6<=>1)>>");
   }
 
   @Test