Changeset 35245 in webkit for trunk/JavaScriptCore/VM/CodeBlock.cpp

Timestamp:

Jul 18, 2008, 6:44:24 PM (17 years ago)

Author:

[email protected]

Message:

Bug 18774: SQUIRRELFISH: print meaningful error messages <​https://bugs.webkit.org/show_bug.cgi?id=18774>
<rdar://problem/5769353> SQUIRRELFISH: JavaScript error messages are missing informative text

Reviewed by Cameron Zwarich

Add support for decent error messages in JavaScript. This patch achieves this by providing
ensuring the common errors and exceptions have messages that provide the text of expression
that trigger the exception. In addition it attaches a number of properties to the exception
object detailing where in the source the expression came from.

File:

• trunk/JavaScriptCore/VM/CodeBlock.cpp (modified) (2 diffs)

trunk/JavaScriptCore/VM/CodeBlock.cpp

@@ -655 +655 @@
 int CodeBlock::lineNumberForVPC(const Instruction* vPC)
 {
+    ASSERT(lineInfo.size());    
     unsigned instructionOffset = vPC - instructions.begin();
     ASSERT(instructionOffset < instructions.size());
@@ -670 +671 @@
             high = mid;
     }
-
     return lineInfo[low - 1].lineNumber;
 }
 
+int CodeBlock::expressionRangeForVPC(const Instruction* vPC, int& divot, int& startOffset, int& endOffset)
+{
+    unsigned instructionOffset = vPC - instructions.begin();
+    ASSERT(instructionOffset < instructions.size());
+
+    if (!expressionInfo.size()) {
+        // We didn't think anything could throw.  Apparently we were wrong.
+        startOffset = 0;
+        endOffset = 0;
+        divot = 0;
+        return lineNumberForVPC(vPC);
+    }
+
+    int low = 0;
+    int high = expressionInfo.size();
+    while (low < high) {
+        int mid = low + (high - low) / 2;
+        if (expressionInfo[mid].instructionOffset <= instructionOffset)
+            low = mid + 1;
+        else
+            high = mid;
+    }
+    
+    ASSERT(low);
+    if (!low) {
+        startOffset = 0;
+        endOffset = 0;
+        divot = 0;
+        return lineNumberForVPC(vPC);
+    }
+
+    startOffset = expressionInfo[low - 1].startOffset;
+    endOffset = expressionInfo[low - 1].endOffset;
+    divot = expressionInfo[low - 1].divotPoint + sourceOffset;
+    return lineNumberForVPC(vPC);
+}
+
 } // namespace KJS