[source-map] Fix sourceIndex in mapping entries for index source maps

We "sourceIndex" to mapping entries to resolve inlined source positions
via "scopes" proposal. This CL fixes the "sourceIndex" for index
source maps: These are source maps that contain a set of other
source maps describing different parts of a bundle.

For index source maps we concatenate all the "sources" arrays from
all the "child source maps". The "sourceIndex" is then an index
into the concatenated "sources" list.

[email protected]

Bug: 390337576
Change-Id: I7a450ae466a7ce89516895a137289c4db2c391ac
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6182123
Commit-Queue: Simon Zünd <[email protected]>
Reviewed-by: Kim-Anh Tran <[email protected]>

Author: szuend

front_end/core/sdk/SourceMap.test.ts

@@ -341,8 +341,8 @@ describeWithEnvironment('SourceMap', () => {
     assert.lengthOf(sourceMap.sourceURLs(), 3, 'unexpected number of original source URLs');
     assertMapping(sourceMap.findEntry(0, 0), 0, 'source1.js', 0, 0);
     assertMapping(sourceMap.findEntry(0, 1), 0, 'source1.js', 2, 1);
-    assertMapping(sourceMap.findEntry(2, 10), 0, 'source3.js', 0, 0);
-    assertMapping(sourceMap.findEntry(2, 11), 0, 'source3.js', 2, 1);
+    assertMapping(sourceMap.findEntry(2, 10), 2, 'source3.js', 0, 0);
+    assertMapping(sourceMap.findEntry(2, 11), 2, 'source3.js', 2, 1);
   });
 
   it('can parse source maps with ClosureScript names', () => {

front_end/core/sdk/SourceMap.ts

@@ -457,18 +457,20 @@ export class SourceMap {
     }
   }
 
-  private eachSection(callback: (arg0: SourceMapV3Object, arg1: number, arg2: number) => void): void {
+  private eachSection(callback: (arg0: SourceMapV3Object, arg1: number, arg2: number, arg3: number) => void): void {
     if (!this.#json) {
       return;
     }
     if ('sections' in this.#json) {
+      let sourcesIndex = 0;
       for (const section of this.#json.sections) {
         if ('map' in section) {
-          callback(section.map, section.offset.line, section.offset.column);
+          callback(section.map, sourcesIndex, section.offset.line, section.offset.column);
+          sourcesIndex += section.map.sources.length;
         }
       }
     } else {
-      callback(this.#json, 0, 0);
+      callback(this.#json, 0, 0, 0);
     }
   }
 
@@ -503,7 +505,7 @@ export class SourceMap {
     sourceMapToSourceList.set(sourceMap, sourcesList);
   }
 
-  private parseMap(map: SourceMapV3Object, lineNumber: number, columnNumber: number): void {
+  private parseMap(map: SourceMapV3Object, baseSourceIndex: number, lineNumber: number, columnNumber: number): void {
     let sourceIndex = 0;
     let sourceLineNumber = 0;
     let sourceColumnNumber = 0;
@@ -550,14 +552,15 @@ export class SourceMap {
       sourceColumnNumber += tokenIter.nextVLQ();
 
       if (!tokenIter.hasNext() || this.isSeparator(tokenIter.peek())) {
-        this.mappings().push(
-            new SourceMapEntry(lineNumber, columnNumber, sourceIndex, sourceURL, sourceLineNumber, sourceColumnNumber));
+        this.mappings().push(new SourceMapEntry(
+            lineNumber, columnNumber, baseSourceIndex + sourceIndex, sourceURL, sourceLineNumber, sourceColumnNumber));
         continue;
       }
 
       nameIndex += tokenIter.nextVLQ();
       this.mappings().push(new SourceMapEntry(
-          lineNumber, columnNumber, sourceIndex, sourceURL, sourceLineNumber, sourceColumnNumber, names[nameIndex]));
+          lineNumber, columnNumber, baseSourceIndex + sourceIndex, sourceURL, sourceLineNumber, sourceColumnNumber,
+          names[nameIndex]));
     }
 
     if (Root.Runtime.experiments.isEnabled(Root.Runtime.ExperimentName.USE_SOURCE_MAP_SCOPES)) {