# Nimbus
# Copyright (c) 2018-2024 Status Research & Development GmbH
# Licensed under either of
#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
#    http://www.apache.org/licenses/LICENSE-2.0)
#  * MIT license ([LICENSE-MIT](LICENSE-MIT) or
#    http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed except
# according to those terms.

import strutils

const currentDir = currentSourcePath()[0 .. ^(len("config.nims") + 1)]

if getEnv("NIMBUS_BUILD_SYSTEM") == "yes" and
   # BEWARE
   # In Nim 1.6, config files are evaluated with a working directory
   # matching where the Nim command was invocated. This means that we
   # must do all file existance checks with full absolute paths:
   system.fileExists(currentDir & "nimbus-build-system.paths"):
  include "nimbus-build-system.paths"

const nimCachePathOverride {.strdefine.} = ""
when nimCachePathOverride == "":
  when defined(release):
    let nimCachePath = "nimcache/release/" & projectName()
  else:
    let nimCachePath = "nimcache/debug/" & projectName()
else:
  let nimCachePath = nimCachePathOverride
switch("nimcache", nimCachePath)

# `-flto` gives a significant improvement in processing speed, specially hash tree and state transition (basically any CPU-bound code implemented in nim)
# With LTO enabled, optimization flags should be passed to both compiler and linker!
if defined(release) and not defined(disableLTO):
  # "-w" is not passed to the compiler during linking, so we need to disable
  # some warnings by hand.
  switch("passL", "-Wno-stringop-overflow -Wno-stringop-overread")

  if defined(macosx): # Clang
    switch("passC", "-flto=thin")
    switch("passL", "-flto=thin -Wl,-object_path_lto," & nimCachePath & "/lto")
  elif defined(linux):
    switch("passC", "-flto=auto")
    switch("passL", "-flto=auto")
    switch("passC", "-finline-limit=100000")
    switch("passL", "-finline-limit=100000")
  else:
    # On windows, LTO needs more love and attention so "gcc-ar" and "gcc-ranlib" are
    # used for static libraries.
    discard

# Hidden visibility allows for better position-independent codegen - it also
# resolves a build issue in BLST where otherwise private symbols would require
# an unsupported relocation on PIE-enabled distros such as ubuntu - BLST itself
# solves this via a linker script which is messy
switch("passC", "-fvisibility=hidden")

if defined(windows):
  # disable timestamps in Windows PE headers - https://wiki.debian.org/ReproducibleBuilds/TimestampsInPEBinaries
  switch("passL", "-Wl,--no-insert-timestamp")
  # increase stack size, unless something else is setting the stack size
  if not defined(windowsNoSetStack):
    switch("passL", "-Wl,--stack,8388608")
  # https://github.com/nim-lang/Nim/issues/4057
  --tlsEmulation:off
  if defined(i386):
    # set the IMAGE_FILE_LARGE_ADDRESS_AWARE flag so we can use PAE, if enabled, and access more than 2 GiB of RAM
    switch("passL", "-Wl,--large-address-aware")

  # Colors are disabled for Windows, see issue:
  # https://github.com/status-im/nim-chronicles/issues/130
  switch("define", "chronicles_colors=off")

  # Avoid some rare stack corruption while using exceptions with a SEH-enabled
  # toolchain: https://github.com/status-im/nimbus-eth2/issues/3121
  switch("define", "nimRawSetjmp")

# This helps especially for 32-bit x86, which sans SSE2 and newer instructions
# requires quite roundabout code generation for cryptography, and other 64-bit
# and larger arithmetic use cases, along with register starvation issues. When
# engineering a more portable binary release, this should be tweaked but still
# use at least -msse2 or -msse3.
#
# https://github.com/status-im/nimbus-eth2/blob/stable/docs/cpu_features.md#ssse3-supplemental-sse3
# suggests that SHA256 hashing with SSSE3 is 20% faster than without SSSE3, so
# given its near-ubiquity in the x86 installed base, it renders a distribution
# build more viable on an overall broader range of hardware.
#
if defined(disableMarchNative):
  if defined(i386) or defined(amd64):
    if defined(macosx):
      # https://support.apple.com/en-us/102861
      # "macOS Ventura is compatible with these computers" lists current oldest
      # supported x86 models, all of which have Kaby Lake or newer CPUs.
      switch("passC", "-march=skylake -mtune=generic")
      switch("passL", "-march=skylake -mtune=generic")
    else:
      switch("passC", "-mssse3")
      switch("passL", "-mssse3")
elif defined(macosx) and defined(arm64):
  # Apple's Clang can't handle "-march=native" on M1: https://github.com/status-im/nimbus-eth2/issues/2758
  switch("passC", "-mcpu=apple-a14")
  switch("passL", "-mcpu=apple-a14")
else:
  switch("passC", "-march=native")
  switch("passL", "-march=native")
  if defined(windows):
    # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65782
    # ("-fno-asynchronous-unwind-tables" breaks Nim's exception raising, sometimes)
    switch("passC", "-mno-avx512f")
    switch("passL", "-mno-avx512f")

# Omitting frame pointers in nim breaks the GC:
# https://github.com/nim-lang/Nim/issues/10625
if not defined(windows):
  # ...except on Windows where the Nim bug doesn't manifest and the option
  # crashes GCC in some Mingw-w64 versions:
  # https://sourceforge.net/p/mingw-w64/bugs/880/
  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86593
  switch("passC", "-fno-omit-frame-pointer")
  switch("passL", "-fno-omit-frame-pointer")

--threads:on
--opt:speed
--excessiveStackTrace:on
# enable metric collection
--define:metrics
# for heap-usage-by-instance-type metrics and object base-type strings
--define:nimTypeNames
--styleCheck:usages
--styleCheck:error
--mm:refc

switch("define", "withoutPCRE")

when not defined(disable_libbacktrace):
  --define:nimStackTraceOverride
  switch("import", "libbacktrace")
else:
  --stacktrace:on
  --linetrace:on

var canEnableDebuggingSymbols = true
if defined(macosx):
  # The default open files limit is too low on macOS (512), breaking the
  # "--debugger:native" build. It can be increased with `ulimit -n 1024`.
  let openFilesLimitTarget = 1024
  var openFilesLimit = 0
  try:
    openFilesLimit = staticExec("ulimit -n").strip(chars = Whitespace + Newlines).parseInt()
    if openFilesLimit < openFilesLimitTarget:
      echo "Open files limit too low to enable debugging symbols and lightweight stack traces."
      echo "Increase it with \"ulimit -n " & $openFilesLimitTarget & "\""
      canEnableDebuggingSymbols = false
  except:
    echo "ulimit error"
# We ignore this resource limit on Windows, where a default `ulimit -n` of 256
# in Git Bash is apparently ignored by the OS, and on Linux where the default of
# 1024 is good enough for us.

if canEnableDebuggingSymbols:
  # add debugging symbols and original files and line numbers
  --debugger:native

--define:nimOldCaseObjects # https://github.com/status-im/nim-confutils/issues/9

# `switch("warning[CaseTransition]", "off")` fails with "Error: invalid command line option: '--warning[CaseTransition]'"
switch("warning", "CaseTransition:off")

# nim-kzg shipping their own blst, nimbus-eth1 too.
# disable nim-kzg's blst
switch("define", "kzgExternalBlst")

# We lock down rocksdb to a particular version
# TODO self-build rocksdb dll on windows
when not defined(use_system_rocksdb) and not defined(windows):
  switch("define", "rocksdb_static_linking")

  # use the C++ linker profile because it's a C++ library
  when defined(macosx):
    switch("clang.linkerexe", "clang++")
  else:
    switch("gcc.linkerexe", "g++")

  switch("dynlibOverride", "rocksdb")
  switch("dynlibOverride", "lz4")
  switch("dynlibOverride", "zstd")

# This applies per-file compiler flags to C files
# which do not support {.localPassC: "...".}
# Unfortunately this is filename based instead of path-based
# Assumes GCC

# -fomit-frame-pointer for https://github.com/status-im/nimbus-eth1/issues/2127
put("secp256k1.always", "-fno-lto -fomit-frame-pointer")

# ############################################################
#
#                    No LTO for crypto
#
# ############################################################

# This applies per-file compiler flags to C files
# which do not support {.localPassC: "-fno-lto".}
# Unfortunately this is filename based instead of path-based
# Assumes GCC

# BLST
put("server.always", "-fno-lto")
put("assembly.always", "-fno-lto")


# BearSSL - only RNGs
put("aesctr_drbg.always", "-fno-lto")
put("hmac_drbg.always", "-fno-lto")
put("sysrng.always", "-fno-lto")

# ############################################################
#
#                    Spurious warnings
#
# ############################################################

# sqlite3.c: In function ‘sqlite3SelectNew’:
# vendor/nim-sqlite3-abi/sqlite3.c:124500: warning: function may return address of local variable [-Wreturn-local-addr]
put("sqlite3.always", "-fno-lto") # -Wno-return-local-addr