VM profiler (#14833)

* Crude VM profiler

* Added --profileVM flag, refactoring

* fixed FileLine hash

* Use TLineInfo instead of own FileLine, updated formatting

* Refactoring, moved PStackFrame to vmdefs for cleaner data structure

* Moved vmprofiler to separate file

* Simplified TLineInfo hash, use toFileLineCol for output

* Hash

* Moved profile data into Config, dump only once at end of run

* Changed profile output header to show '#instr' instead of 'count'

* Do not accumulate instrcount for non-top frames

Co-authored-by: Ico Doornekamp <git@zevv.nl>

compiler/options.nim

@@ -9,7 +9,7 @@
 
 import
   os, strutils, strtabs, sets, lineinfos, platform,
-  prefixmatches, pathutils, nimpaths
+  prefixmatches, pathutils, nimpaths, tables
 
 from terminal import isatty
 from times import utc, fromUnix, local, getTime, format, DateTime
@@ -95,6 +95,7 @@ type                          # please make sure we have under 32 options
     optPanics                 # turn panics (sysFatal) into a process termination
     optNimV1Emulation         # emulate Nim v1.0
     optSourcemap
+    optProfileVM              # enable VM profiler
 
   TGlobalOptions* = set[TGlobalOption]
 
@@ -217,6 +218,13 @@ type
     version*: int
   Suggestions* = seq[Suggest]
 
+  ProfileInfo* = object
+    time*: float
+    count*: int
+
+  ProfileData* = ref object
+    data*: TableRef[TLineInfo, ProfileInfo]
+
   ConfigRef* = ref object ## every global configuration
                           ## fields marked with '*' are subject to
                           ## the incremental compilation mechanisms
@@ -314,6 +322,7 @@ type
     structuredErrorHook*: proc (config: ConfigRef; info: TLineInfo; msg: string;
                                 severity: Severity) {.closure, gcsafe.}
     cppCustomNamespace*: string
+    vmProfileData*: ProfileData
 
 proc assignIfDefault*[T](result: var T, val: T, def = default(T)) =
   ## if `result` was already assigned to a value (that wasn't `def`), this is a noop.
@@ -390,6 +399,9 @@ template newPackageCache*(): untyped =
                  else:
                    modeCaseSensitive)
 
+proc newProfileData(): ProfileData =
+  ProfileData(data: newTable[TLineInfo, ProfileInfo]())
+
 proc newConfigRef*(): ConfigRef =
   result = ConfigRef(
     selectedGC: gcRefc,
@@ -442,6 +454,7 @@ proc newConfigRef*(): ConfigRef =
     arguments: "",
     suggestMaxResults: 10_000,
     maxLoopIterationsVM: 10_000_000,
+    vmProfileData: newProfileData(),
   )
   setTargetFromSystem(result.target)
   # enable colors by default on terminals