MOVE ME to patch and re-describe: GT-3569

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/assembler/sleigh/parse/AssemblyParseErrorResult.java

@@ -15,13 +15,20 @@
  */
 package ghidra.app.plugin.assembler.sleigh.parse;
 
-import java.util.Collections;
-import java.util.Set;
+import java.util.*;
+
+import org.apache.commons.collections4.IterableUtils;
 
 /**
  * An unsuccessful result from parsing
  */
 public class AssemblyParseErrorResult extends AssemblyParseResult {
+	/**
+	 * The maximum number of suggestions to print when describing this error, e.g., when reported in
+	 * exception messages.
+	 */
+	private static final int SUGGESTIONS_THRESHOLD = 10;
+
 	private final String buffer;
 	private final Set<String> suggestions;
 
@@ -40,15 +47,28 @@ public class AssemblyParseErrorResult extends AssemblyParseResult {
 
 	/**
 	 * Get a description of the error
+	 * 
 	 * @return a description
 	 */
 	public String describeError() {
-		return "Syntax Error: Expected " + suggestions + ". Got " + buffer;
+		Collection<String> truncSuggestions;
+		if (suggestions.size() <= SUGGESTIONS_THRESHOLD) {
+			truncSuggestions = suggestions;
+		}
+		else {
+			truncSuggestions = new ArrayList<>();
+			for (String s : IterableUtils.boundedIterable(suggestions, SUGGESTIONS_THRESHOLD)) {
+				truncSuggestions.add(s);
+			}
+			truncSuggestions.add("...");
+		}
+		return "Syntax Error: Expected " + truncSuggestions + ". Got " + buffer;
 	}
 
 	/**
 	 * Get a set of suggested tokens that would have allowed parsing to continue
-	 * @return the set
+	 * 
+	 * @return the token set
 	 */
 	public Set<String> getSuggestions() {
 		return Collections.unmodifiableSet(suggestions);
@@ -56,7 +76,8 @@ public class AssemblyParseErrorResult extends AssemblyParseResult {
 
 	/**
 	 * Get the leftover contents of the input buffer when the error occurred
-	 * @return
+	 * 
+	 * @return the remaining buffer contents
 	 */
 	public String getBuffer() {
 		return buffer;

Ghidra/Framework/SoftwareModeling/src/test/java/ghidra/app/plugin/assembler/sleigh/AbstractAssemblyTest.java

@@ -202,7 +202,7 @@ public abstract class AbstractAssemblyTest extends AbstractGenericTest {
 			long addr, String ctxstr) {
 		final AssemblyPatternBlock ctx =
 			(ctxstr == null ? context.getDefault() : AssemblyPatternBlock.fromString(ctxstr))
-				.fillMask();
+					.fillMask();
 		dbg.println("Checking each: " + disassembly + " ctx:" + ctx);
 		boolean gotOne = false;
 		boolean failedOne = false;
@@ -303,7 +303,7 @@ public abstract class AbstractAssemblyTest extends AbstractGenericTest {
 	/**
 	 * Run a test with the given checks
 	 *
-	 * @param assembly the text to assembly
+	 * @param assembly the text to assemble
 	 * @param instr an instruction pattern that must appear in the results
 	 * @param disassembly a set of acceptable disassembly texts
 	 * @param addr the address for assembly and disassembly
@@ -326,7 +326,7 @@ public abstract class AbstractAssemblyTest extends AbstractGenericTest {
 			}
 			final AssemblyPatternBlock ctx =
 				(ctxstr == null ? context.getDefault() : AssemblyPatternBlock.fromString(ctxstr))
-					.fillMask();
+						.fillMask();
 			try {
 				String disstr;
 				PseudoInstruction psins = disassemble(addr, ins.getVals(), ctx.getVals());
@@ -398,7 +398,7 @@ public abstract class AbstractAssemblyTest extends AbstractGenericTest {
 	/**
 	 * Run a test where one result must match a given instruction pattern, and all others must
 	 * disassemble exactly to the input
-	 *
+	 * 
 	 * @param assembly the input assembly
 	 * @param instr the instruction pattern
 	 * @see AssemblyPatternBlock#fromString(String)

Ghidra/Framework/SoftwareModeling/src/test/java/ghidra/app/plugin/assembler/sleigh/x86AssemblyTest.java

@@ -15,6 +15,9 @@
  */
 package ghidra.app.plugin.assembler.sleigh;
 
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
 import org.junit.Test;
 
 import ghidra.app.plugin.assembler.*;
@@ -31,6 +34,20 @@ public class x86AssemblyTest extends AbstractAssemblyTest {
 		return new LanguageID("x86:LE:64:default");
 	}
 
+	@Test
+	public void testReasonableErrorMessageLength() throws AssemblySemanticException {
+		Assembler assembler = Assemblers.getAssembler(lang);
+		Address addr = lang.getDefaultSpace().getAddress(DEFAULT_ADDR);
+		try {
+			assembler.assembleLine(addr, "UNLIKELY qword ptr [RAX],RBX");
+			fail(); // The exception must be thrown
+		}
+		catch (AssemblySyntaxException e) {
+			Msg.info(this, "Got expected syntax error: " + e);
+			assertTrue(e.getMessage().length() < 1000);
+		}
+	}
+
 	@Test
 	public void testAssemble_ADD_m0x12_RAXm_RBX() {
 		// Again, a little odd. Imm8 does not have the I+R form.