import: callgrind.ts: Improved collection of file names associated wi…

…th functions

When called function is within an inlined code block, it should use file names
provided by 'fi' or 'fe' commands.

Also, when 'fn' command is called, it sets the current file name to the value
provided in the previous 'fl' call.

Also, the file associated with 'fn' should be stored separately so that
it is not overwritten by new 'fl' calls (Callgrind does not tell whether
there can be multiple 'fl' calls without following 'fn' calls, and this
should guard the parser from associating the wrong new file name with the
previous 'fn' function).

This modification fixes detached call stacks, which were created when one
function has been called from inline block without the file source update,
which led to duplicated entries, which were later not removed when
determining root functions.

Signed-off-by: Grzegorz Latosinski <[email protected]>

src/import/callgrind.ts

@@ -342,6 +342,8 @@ class CallgrindParser {
 
   private filename: string | null = null
   private functionName: string | null = null
+  private functionFile: string | null = null
+  private currentFunctionFile: string | null = null
   private calleeFilename: string | null = null
   private calleeFunctionName: string | null = null
 
@@ -396,7 +398,7 @@ class CallgrindParser {
   }
 
   private frameInfo(): FrameInfo {
-    const file = this.filename || '(unknown)'
+    const file = this.functionFile || '(unknown)'
     const name = this.functionName || '(unknown)'
     const key = `${file}:${name}`
     return {key, name, file}
@@ -445,23 +447,29 @@ class CallgrindParser {
       case 'fe':
       case 'fi': {
         // fe/fi are used to indicate the source-file of a function definition
-        // changed mid-definition. This is for inlined code, but doesn't
-        // indicate that we've actually switched to referring to a different
-        // function, so we mostly ignore it.
-        //
-        // We still need to do the parseNameWithCompression call in case a name
-        // is defined and then referenced later on for name compression.
-        this.parseNameWithCompression(value, this.savedFileNames)
+        // changed mid-definition. This is for inlined code, but when a function
+        // is called from within the inlined code, it is indicated that it
+        // comes from file marked by fe/fi.
+        this.filename = this.parseNameWithCompression(value, this.savedFileNames)
         break
       }
 
       case 'fl': {
         this.filename = this.parseNameWithCompression(value, this.savedFileNames)
+        // The 'fl' needs to be stored in order to reset current filename upon
+        // consecutive 'fn' calls
+        this.currentFunctionFile = this.filename
         break
       }
 
       case 'fn': {
+        // the file for a function defined with 'fn' always comes from 'fl'
+        // It also resets the current filename to previous 'fl' value, as in KCacheGrind:
+        // https://github.com/KDE/kcachegrind/blob/ea4314db2785cb8f279fe884ee7f82445642b692/libcore/cachegrindloader.cpp#L808
+        if (this.filename !== this.currentFunctionFile) this.filename = this.currentFunctionFile
         this.functionName = this.parseNameWithCompression(value, this.savedFunctionNames)
+        // store function file associated with 'fn' function
+        this.functionFile = this.filename
         break
       }