diff --git a/core/org.eclipse.cdt.core.tests/misc/org/eclipse/cdt/utils/CommandLineUtilTest.java b/core/org.eclipse.cdt.core.tests/misc/org/eclipse/cdt/utils/CommandLineUtilTest.java
index 062df03642f..c198af409d3 100644
--- a/core/org.eclipse.cdt.core.tests/misc/org/eclipse/cdt/utils/CommandLineUtilTest.java
+++ b/core/org.eclipse.cdt.core.tests/misc/org/eclipse/cdt/utils/CommandLineUtilTest.java
@@ -35,11 +35,24 @@ public class CommandLineUtilTest extends TestCase {
 		return CommandLineUtil.argumentsToArray(line);
 	}
 
+	private String join(String[] line) {
+		return CommandLineUtil.argumentsToStringBash(line, false);
+	}
+
+	private String joinWin(String[] line) {
+		return CommandLineUtil.argumentsToStringWindowsCreateProcess(line, false);
+	}
+
+	private String joinU(String[] line) {
+		return CommandLineUtil.argumentsToString(line, false);
+	}
+
 	public void testArgumentsToArraySimple() {
 		String[] args = parse("A=B C");
 		assertEquals(2, args.length);
 		assertEquals("A=B", args[0]);
 		assertEquals("C", args[1]);
+		assertEquals("A=B C", join(args));
 	}
 
 	public void testArgumentsToArraySpaces() {
@@ -48,6 +61,7 @@ public class CommandLineUtilTest extends TestCase {
 		assertEquals(2, args.length);
 		assertEquals("A=B", args[0]);
 		assertEquals("C", args[1]);
+		assertEquals("A=B C", join(args));
 	}
 
 	public void testArgumentsToArraySpaces2() {
@@ -56,6 +70,7 @@ public class CommandLineUtilTest extends TestCase {
 		assertEquals(2, args.length);
 		assertEquals("A=B", args[0]);
 		assertEquals("C", args[1]);
+		assertEquals("A=B C", join(args));
 	}
 
 	public void testArgumentsToArrayDoubleQuotes() {
@@ -63,6 +78,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("Arg=\"a b c\"");
 		assertEquals(1, args.length);
 		assertEquals("Arg=a b c", args[0]);
+		assertEquals("'Arg=a b c'", join(args));
 	}
 
 	public void testArgumentsToArrayDoubleQuotes2() {
@@ -70,6 +86,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("Arg=\"\\\"quoted\\\"\"");
 		assertEquals(1, args.length);
 		assertEquals("Arg=\"quoted\"", args[0]);
+		assertEquals("'Arg=\"quoted\"'", join(args));
 	}
 
 	public void testArgumentsToArraySingleQuotes() {
@@ -77,6 +94,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("Arg='\"quoted\"'");
 		assertEquals(1, args.length);
 		assertEquals("Arg=\"quoted\"", args[0]);
+		assertEquals("'Arg=\"quoted\"'", join(args));
 	}
 
 	public void testArgumentsToArrayQuote() {
@@ -84,6 +102,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("\\\"");
 		assertEquals(1, args.length);
 		assertEquals("\"", args[0]);
+		assertEquals("'\"'", join(args));
 	}
 
 	public void testArgumentsToArrayQuotSpaces() {
@@ -91,6 +110,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("  \\\"");
 		assertEquals(1, args.length);
 		assertEquals("\"", args[0]);
+		assertEquals("'\"'", join(args));
 	}
 
 	public void testArgumentsToArrayOnlySpaces() {
@@ -98,6 +118,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("\"   \"");
 		assertEquals(1, args.length);
 		assertEquals("   ", args[0]);
+		assertEquals("'   '", join(args));
 	}
 
 	public void testArgumentsToArrayJumbledString() {
@@ -105,6 +126,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("\"a b\"-c");
 		assertEquals(1, args.length);
 		assertEquals("a b-c", args[0]);
+		assertEquals("'a b-c'", join(args));
 	}
 
 	public void testArgumentsToArrayJumbledString2() {
@@ -113,6 +135,7 @@ public class CommandLineUtilTest extends TestCase {
 		assertEquals(2, args.length);
 		assertEquals("x", args[0]);
 		assertEquals("a b-c", args[1]);
+		assertEquals("x 'a b-c'", join(args));
 	}
 
 	public void testArgumentsToArrayJumbledSQ() {
@@ -121,6 +144,7 @@ public class CommandLineUtilTest extends TestCase {
 		assertEquals(2, args.length);
 		assertEquals("x x", args[0]);
 		assertEquals("y", args[1]);
+		assertEquals("'x x' y", join(args));
 	}
 
 	public void testArgumentsToArrayEmptyString() {
@@ -128,6 +152,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("\"\"");
 		assertEquals(1, args.length);
 		assertEquals("", args[0]);
+		assertEquals("''", join(args));
 	}
 
 	public void testArgumentsToArrayEmptyString2() {
@@ -135,6 +160,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("''");
 		assertEquals(1, args.length);
 		assertEquals("", args[0]);
+		assertEquals("''", join(args));
 	}
 
 	public void testArgumentsToArrayEmpty3() {
@@ -143,6 +169,7 @@ public class CommandLineUtilTest extends TestCase {
 		assertEquals(2, args.length);
 		assertEquals("", args[0]);
 		assertEquals("a", args[1]);
+		assertEquals("'' a", join(args));
 	}
 
 	public void testArgumentsToArrayQuot1() {
@@ -150,6 +177,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("'\"'");
 		assertEquals(1, args.length);
 		assertEquals("\"", args[0]);
+		assertEquals("'\"'", join(args));
 	}
 
 	public void testArgumentsToArrayQuot2() {
@@ -157,24 +185,28 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("\"\\\"\"");
 		assertEquals(1, args.length);
 		assertEquals("\"", args[0]);
+		assertEquals("'\"'", join(args));
 	}
 
 	public void testArgumentsToArrayNull() {
 		// []
 		String[] args = parse(null);
 		assertEquals(0, args.length);
+		assertEquals("", join(args));
 	}
 
 	public void testArgumentsToArrayEmpty() {
 		// []
 		String[] args = parse("");
 		assertEquals(0, args.length);
+		assertEquals("", join(args));
 	}
 
 	public void testArgumentsToArrayEmptySpaces() {
 		// [   ]
 		String[] args = parse("   ");
 		assertEquals(0, args.length);
+		assertEquals("", join(args));
 	}
 
 	public void testArgumentsToArrayTabs() {
@@ -182,6 +214,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("a \tb");
 		assertEquals(2, args.length);
 		assertEquals("a", args[0]);
+		assertEquals("a b", join(args));
 	}
 
 	public void testArgumentsToArrayNL() {
@@ -189,6 +222,7 @@ public class CommandLineUtilTest extends TestCase {
 		String[] args = parse("\"a\\nb\"");
 		assertEquals(1, args.length);
 		assertEquals("a\nb", args[0]);
+		assertEquals("'a\nb'", join(args));
 	}
 
 	public void testArgumentsToArraySimpleWin() {
@@ -196,24 +230,28 @@ public class CommandLineUtilTest extends TestCase {
 		assertEquals(2, args.length);
 		assertEquals("A=B", args[0]);
 		assertEquals("C", args[1]);
+		assertEquals("A=B C", joinWin(args));
 	}
 
 	public void testArgumentsToArrayWindowsFiles() {
 		String[] args = parseWin("my\\file\\path");
 		assertEquals(1, args.length);
 		assertEquals("my\\file\\path", args[0]);
+		assertEquals("my\\file\\path", joinWin(args));
 	}
 
 	public void testArgumentsToArrayWindowsSpaces() {
 		String[] args = parseWin("\"my\\file\\path space\"");
 		assertEquals(1, args.length);
 		assertEquals("my\\file\\path space", args[0]);
+		assertEquals("\"my\\file\\path space\"", joinWin(args));
 	}
 
 	public void testArgumentsToArrayWindowsEmpty() {
 		String[] args = parseWin("\"\"");
 		assertEquals(1, args.length);
 		assertEquals("", args[0]);
+		assertEquals("\"\"", joinWin(args));
 	}
 
 	public void testArgumentsToArrayWindowsQuotes() {
@@ -221,6 +259,7 @@ public class CommandLineUtilTest extends TestCase {
 		assertEquals(2, args.length);
 		assertEquals("\"a", args[0]);
 		assertEquals("b\"", args[1]);
+		assertEquals("\"\\\"a\" \"b\\\"\"", joinWin(args));
 	}
 
 	public void testArgumentsToArraySimpleUniversal() {
@@ -229,5 +268,6 @@ public class CommandLineUtilTest extends TestCase {
 		assertEquals("A=B", args[0]);
 		assertEquals("C", args[1]);
 		assertEquals("D", args[2]);
+		assertEquals("A=B C D", joinU(args));
 	}
 }
diff --git a/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/CommandLineUtil.java b/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/CommandLineUtil.java
index 5d91d7faa10..4b8b903cf46 100644
--- a/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/CommandLineUtil.java
+++ b/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/CommandLineUtil.java
@@ -346,20 +346,24 @@ public class CommandLineUtil {
 				builder.append(' ');
 			}
 
-			builder.append('\'');
-			for (int j = 0; j < arg.length(); j++) {
-				char c = arg.charAt(j);
-				if (c == '\'') {
-					builder.append("'\"'\"'"); //$NON-NLS-1$
-				} else if (c == '\r' && encodeNewline) {
-					builder.append("'$'\\r''"); //$NON-NLS-1$
-				} else if (c == '\n' && encodeNewline) {
-					builder.append("'$'\\n''"); //$NON-NLS-1$
-				} else {
-					builder.append(c);
+			if (needsQuoting(arg)) {
+				builder.append('\'');
+				for (int j = 0; j < arg.length(); j++) {
+					char c = arg.charAt(j);
+					if (c == '\'') {
+						builder.append("'\"'\"'"); //$NON-NLS-1$
+					} else if (c == '\r' && encodeNewline) {
+						builder.append("'$'\\r''"); //$NON-NLS-1$
+					} else if (c == '\n' && encodeNewline) {
+						builder.append("'$'\\n''"); //$NON-NLS-1$
+					} else {
+						builder.append(c);
+					}
 				}
+				builder.append('\'');
+			} else {
+				builder.append(arg);
 			}
-			builder.append('\'');
 		}
 
 		return builder.toString();
@@ -386,39 +390,50 @@ public class CommandLineUtil {
 				builder.append(' ');
 			}
 
-			builder.append('"');
-			for (int j = 0; j < arg.length(); j++) {
-				/*
-				 * backslashes are special if and only if they are followed by a
-				 * double-quote (") therefore doubling them depends on what is
-				 * next
-				 */
-				int numBackslashes = 0;
-				for (; j < arg.length() && arg.charAt(j) == '\\'; j++) {
-					numBackslashes++;
-				}
-				if (j == arg.length()) {
-					appendNBackslashes(builder, numBackslashes * 2);
-				} else if (arg.charAt(j) == '"') {
-					appendNBackslashes(builder, numBackslashes * 2);
-					builder.append('"');
-				} else if ((arg.charAt(j) == '\n' || arg.charAt(j) == '\r') && encodeNewline) {
-					builder.append(' ');
-				} else {
+			if (needsQuoting(arg)) {
+				builder.append('"');
+				for (int j = 0; j < arg.length(); j++) {
 					/*
-					 * this really is numBackslashes (no missing * 2), that is
-					 * because next character is not a double-quote (")
+					 * backslashes are special if and only if they are followed by a
+					 * double-quote (") therefore doubling them depends on what is
+					 * next
 					 */
-					appendNBackslashes(builder, numBackslashes);
-					builder.append(arg.charAt(j));
+					int numBackslashes = 0;
+					for (; j < arg.length() && arg.charAt(j) == '\\'; j++) {
+						numBackslashes++;
+					}
+					if (j == arg.length()) {
+						appendNBackslashes(builder, numBackslashes * 2);
+					} else if (arg.charAt(j) == '"') {
+						appendNBackslashes(builder, numBackslashes * 2);
+						builder.append('\\');
+						builder.append('"');
+					} else if ((arg.charAt(j) == '\n' || arg.charAt(j) == '\r') && encodeNewline) {
+						builder.append(' ');
+					} else {
+						/*
+						 * this really is numBackslashes (no missing * 2), that is
+						 * because next character is not a double-quote (")
+						 */
+						appendNBackslashes(builder, numBackslashes);
+						builder.append(arg.charAt(j));
+					}
 				}
+				builder.append('"');
+			} else {
+				builder.append(arg);
 			}
-			builder.append('"');
 		}
 
 		return builder.toString();
 	}
 
+	private static boolean needsQuoting(String arg) {
+		boolean needsQuoting = arg.isBlank() || arg.chars().mapToObj(i -> (char) i)
+				.anyMatch(c1 -> Character.isWhitespace(c1) || c1 == '"' || c1 == '\'');
+		return needsQuoting;
+	}
+
 	private static void appendNBackslashes(StringBuilder builder, int numBackslashes) {
 		for (int i = 0; i < numBackslashes; i++) {
 			builder.append('\\');