Display ignored -Xjit and -Xaot args in IGNOREDARGS list

Author: luke-li-2003

runtime/rasdump/javadump.cpp

@@ -1468,19 +1468,102 @@ JavaCoreDumpWriter::writeEnvUserArgsHelper(J9VMInitArgs *vmArgs)
 	}
 
 	{
-		/* write ignored options */
-		bool anyIgnored = false;
+		/* Write ignored options.
+		 *
+		 * An option is printed as ignored if it has been consumed or if it is an -Xjit or
+		 * -Xaot option that fall under the rules below.
+		 *
+		 * Ignored options for -Xjit and -Xaot follows these rules:
+		 * 1. If -Xjit is followed by -Xint or -Xnojit,
+		 *    then any -Xjit:optionString beforehand appears as ignored.
+		 * 2. If -XX:+MergeCompilerOptions is present,
+		 *    then all -Xjit options after -Xint or -Xnojit should not be ignored.
+		 * 3. If multiple -Xjit strings appear, all but the last one will appear as ignored.
+		 *
+		 * Similar rules apply for -Xaot.
+		 */
+
+		jint numXjit = 0;
+		jint numXaot = 0;
+		bool hasXXMerge = false;
+
+		/* These indices ensure all the options before them will be printed as ignored. */
+		jint ignoreXjitBefore = 0;
+		jint ignoreXaotBefore = 0;
 
 		for (jint i = 0; i < args->nOptions; i++) {
+			const char *optionString = args->options[i].optionString;
+
+			if (0 == strncmp(optionString, "-Xint", 6)) {
+				/* Case 1: ignore all options before. */
+				ignoreXjitBefore = numXjit;
+				ignoreXaotBefore = numXaot;
+			} else if (0 == strncmp(optionString, "-Xnojit", 8)) {
+				/* Case 1: ignore all -Xjit options before. */
+				ignoreXjitBefore = numXjit;
+			} else if (0 == strncmp(optionString, "-Xnoaot", 8)) {
+				/* Case 1: ignore all -Xaot options before. */
+				ignoreXaotBefore = numXaot;
+			} else if (0 == strncmp(optionString, "-XX:+MergeCompilerOptions", 26)) {
+				/* Case 2. */
+				hasXXMerge = true;
+			} else if (0 == strncmp(optionString, "-XX:-MergeCompilerOptions", 26)) {
+				/* If -XX:-MergeCompilerOptions is encountered after
+				 * -XX:+MergeCompilerOptions, the latter is overriden.
+				 */
+				hasXXMerge = false;
+			} else if (0 == strncmp(optionString, "-Xjit:", 6)) {
+				/* Case 3. */
+				numXjit += 1;
+			} else if (0 == strncmp(optionString, "-Xaot:", 6)) {
+				/* Case 3. */
+				numXaot += 1;
+			}
+		}
+
+		bool anyIgnored = false;
+		jint countXjit = 0;
+		jint countXaot = 0;
+		for (jint i = 0; i < args->nOptions; i++) {
+			bool optionIgnored = false;
+			const char *optionString = args->options[i].optionString;
+
 			if (IS_CONSUMABLE(vmArgs, i) && !IS_CONSUMED(vmArgs, i)) {
+				/* Argument consumed. */
+				optionIgnored = true;
+			} else if (0 == strncmp(optionString, "-Xjit:", 6)) {
+				countXjit += 1;
+				if (countXjit <= ignoreXjitBefore) {
+					/* Case 1: Anything before -Xint/-Xnojit is ignored. */
+					optionIgnored = true;
+				} else {
+					/* Cases 2 & 3: Only the last option is not ignored
+					 * unless -XX:+MergeCompilerOptions is in effect.
+					 */
+					optionIgnored = (!hasXXMerge) && (countXjit < numXjit);
+				}
+			} else if (0 == strncmp(optionString, "-Xaot:", 6)) {
+				countXaot += 1;
+				if (countXaot <= ignoreXaotBefore) {
+					/* Case 1: Anything before -Xint/-Xnoaot is ignored. */
+					optionIgnored = true;
+				} else {
+					/* Cases 2 & 3: Only the last option is not ignored
+					 * unless -XX:+MergeCompilerOptions is in effect.
+					 */
+					optionIgnored = (!hasXXMerge) && (countXaot < numXaot);
+				}
+			}
+
+			if (optionIgnored) {
 				if (!anyIgnored) {
 					_OutputStream.writeCharacters("NULL\n");
 					_OutputStream.writeCharacters(ignoredArgsHeader);
 					anyIgnored = true;
 				}
 
 				_OutputStream.writeCharacters(singleIgnoredArgHeader);
-				_OutputStream.writeCharacters(args->options[i].optionString);
+				_OutputStream.writeCharacters(optionString);
 				_OutputStream.writeCharacters("\n");
 			}
 		}