Improve debugging of EvalException
--
MOS_MIGRATED_REVID=101679755
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/EvalException.java b/src/main/java/com/google/devtools/build/lib/syntax/EvalException.java
index 0382079..e7073bb 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/EvalException.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/EvalException.java
@@ -14,7 +14,9 @@
package com.google.devtools.build.lib.syntax;
+import com.google.common.base.Joiner;
import com.google.common.base.Preconditions;
+import com.google.common.base.Throwables;
import com.google.devtools.build.lib.events.Location;
import com.google.devtools.build.lib.util.LoggingUtil;
@@ -36,6 +38,9 @@
private final String message;
private final boolean dueToIncompleteAST;
+ private static final Joiner LINE_JOINER = Joiner.on("\n").skipNulls();
+ private static final Joiner FIELD_JOINER = Joiner.on(": ").skipNulls();
+
/**
* @param location the location where evaluation/execution failed.
* @param message the error message.
@@ -65,22 +70,18 @@
public EvalException(Location location, String message, Throwable cause) {
super(cause);
this.location = location;
- // This is only used from Skylark, it's useful for debugging. Note that this only happens
- // when the Precondition below kills the execution anyway.
- if (message == null) {
- message = "";
- }
- if (cause != null) {
- String causeMsg = cause.getMessage();
- if (causeMsg != null && !message.contains(causeMsg)) {
- message = message + (message.isEmpty() ? "" : ": ") + causeMsg;
+ // This is only used from Skylark, it's useful for debugging.
+ this.message = FIELD_JOINER.join(message, getCauseMessage(message));
+ if (this.message.isEmpty()) {
+ String details;
+ if (cause == null) {
+ details = "Invalid EvalException: no cause given!";
+ } else {
+ details = "Invalid EvalException:\n" + Throwables.getStackTraceAsString(cause);
}
+ LoggingUtil.logToRemote(Level.SEVERE, details, cause);
+ throw new IllegalArgumentException(details);
}
- if (message.isEmpty()) {
- LoggingUtil.logToRemote(Level.SEVERE, "Invalid EvalException", cause);
- throw new IllegalArgumentException("Invalid EvalException");
- }
- this.message = message;
this.dueToIncompleteAST = false;
}
@@ -92,19 +93,33 @@
* Returns the error message with location info if exists.
*/
public String print() { // TODO(bazel-team): do we also need a toString() method?
- return (getLocation() == null ? "" : getLocation()) + ": "
- + (message == null ? "" : message + "\n")
- + (dueToIncompleteAST ? "due to incomplete AST\n" : "")
- + getCauseMessage();
+ return LINE_JOINER.join("\n", FIELD_JOINER.join(getLocation(), message),
+ (dueToIncompleteAST ? "due to incomplete AST" : ""),
+ getCauseMessage(message));
}
-
- private String getCauseMessage() {
+
+ /**
+ * @param message the message of this exception, so far.
+ * @return a message for the cause of the exception, if the main message (passed as argument)
+ * doesn't already contain this cause; return null if no new information is available.
+ */
+ private String getCauseMessage(String message) {
Throwable cause = getCause();
if (cause == null) {
- return "";
+ return null;
}
String causeMessage = cause.getMessage();
- return (causeMessage == null || message.contains(causeMessage)) ? "" : causeMessage;
+ if (causeMessage == null) {
+ return null;
+ }
+ if (message == null) {
+ return causeMessage;
+ }
+ // Skip the cause if it is redundant with the message so far.
+ if (message.contains(causeMessage)) {
+ return null;
+ }
+ return causeMessage;
}
/**
