config/external/wasm2c_sandbox_compiler/preprocess_wasm2c_config.py

   1 # -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
   2 # vim: set filetype=python:
   3 # This Souce Code Form is subject to the terms of the Mozilla Public
   4 # License, v. 2.0. If a copy of the MPL was not distibuted with this
   5 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   6
   7 import itertools
   8
   9 # The wasm2c source relies on CMAKE to generate a config file to be used to build the project
  10 # Since we do not use cmake, this script automates the generation of a similar config suitable
  11 # for firefox builds
  12 # The script has a list of known variables it can replace and throws an error if it encounters a
  13 # new variable (for instance when the in-tree source is updated)
  14
  15 # This python script knows how to replace the following variables normally configured by cmake for
  16 # the wasm2c source
  17 known_vars = [
  18     '#cmakedefine WABT_VERSION_STRING "@WABT_VERSION_STRING@"',
  19     "#cmakedefine WABT_DEBUG @WABT_DEBUG@",
  20     "#cmakedefine01 HAVE_ALLOCA_H",
  21     "#cmakedefine01 HAVE_UNISTD_H",
  22     "#cmakedefine01 HAVE_SNPRINTF",
  23     "#cmakedefine01 HAVE_SSIZE_T",
  24     "#cmakedefine01 HAVE_STRCASECMP",
  25     "#cmakedefine01 HAVE_WIN32_VT100",
  26     "#cmakedefine01 WABT_BIG_ENDIAN",
  27     "#cmakedefine01 HAVE_OPENSSL_SHA_H",
  28     "#cmakedefine01 COMPILER_IS_CLANG",
  29     "#cmakedefine01 COMPILER_IS_GNU",
  30     "#cmakedefine01 COMPILER_IS_MSVC",
  31     "#cmakedefine01 WITH_EXCEPTIONS",
  32     "#define SIZEOF_SIZE_T @SIZEOF_SIZE_T@",
  33 ]
  34
  35 # The above variables are replaced with the code shown below
  36 replaced_variables = """
  37 // mozilla-config.h defines the following which is used
  38 // - HAVE_ALLOCA_H
  39 // - HAVE_UNISTD_H
  40 #include "mozilla-config.h"
  41
  42 #define WABT_VERSION_STRING "Firefox-in-tree-version"
  43
  44 #define WABT_DEBUG 0
  45
  46 /* We don't require color printing of wasm2c errors on any platform */
  47 #define HAVE_WIN32_VT100 0
  48
  49 #ifdef _WIN32
  50   // Ignore whatever is set in mozilla-config.h wrt alloca because it is
  51   // wrong when cross-compiling on Windows.
  52   #undef HAVE_ALLOCA_H
  53   // It is wrong when cross-compiling on Windows.
  54   #undef HAVE_UNISTD_H
  55   /* Whether ssize_t is defined by stddef.h */
  56   #define HAVE_SSIZE_T 0
  57   /* Whether strcasecmp is defined by strings.h */
  58   #define HAVE_STRCASECMP 0
  59 #else
  60   #define HAVE_SSIZE_T 1
  61   #define HAVE_STRCASECMP 1
  62 #endif
  63
  64 #if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && defined(__ORDER_BIG_ENDIAN__)
  65 #  if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
  66 #    define WABT_BIG_ENDIAN 0
  67 #  elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
  68 #    define WABT_BIG_ENDIAN 1
  69 #  else
  70 #    error "Can't handle mixed-endian architectures"
  71 #  endif
  72 #else
  73 #  error "Don't know how to determine endianness"
  74 #endif
  75
  76 /* Use internal Pico-SHA. Never use OpenSSL */
  77 #define HAVE_OPENSSL_SHA_H 0
  78
  79 /* Whether snprintf is defined by stdio.h */
  80 #define HAVE_SNPRINTF 1
  81
  82 #if defined(_MSC_VER)
  83   #define COMPILER_IS_GNU 0
  84   #define COMPILER_IS_CLANG 0
  85   #define COMPILER_IS_MSVC 1
  86 #elif defined(__GNUC__)
  87   #if defined(__clang__)
  88     #define COMPILER_IS_GNU 0
  89     #define COMPILER_IS_CLANG 1
  90     #define COMPILER_IS_MSVC 0
  91   #else
  92     #define COMPILER_IS_GNU 1
  93     #define COMPILER_IS_CLANG 0
  94     #define COMPILER_IS_MSVC 0
  95   #endif
  96 #else
  97   #error "Unknown compiler"
  98 #endif
  99
 100 #define WITH_EXCEPTIONS 0
 101
 102 #if SIZE_MAX == 0xffffffffffffffff
 103   #define SIZEOF_SIZE_T 8
 104 #elif SIZE_MAX == 0xffffffff
 105   #define SIZEOF_SIZE_T 4
 106 #else
 107   #error "Unknown size of size_t"
 108 #endif
 109 """
 110
 111
 112 def generate_config(output, config_h_in):
 113     file_config_h_in = open(config_h_in, "r")
 114     lines = file_config_h_in.readlines()
 115
 116     # Remove the known cmake variables
 117     for known_var in known_vars:
 118         lines = [x for x in lines if not x.startswith(known_var)]
 119
 120     # Do a sanity check to make sure there are no unknown variables
 121     remaining_vars = [x for x in lines if x.startswith("#cmakedefine") or "@" in x]
 122     if len(remaining_vars) > 0:
 123         raise BaseException("Unknown cmake variables: " + str(remaining_vars))
 124
 125     pos = lines.index("#define WABT_CONFIG_H_\n")
 126     skipped = itertools.takewhile(
 127         lambda x: not (x.strip()) or x.startswith("#include "), lines[pos + 1 :]
 128     )
 129     pos += len(list(skipped))
 130     pre_include_lines = lines[0:pos]
 131     post_include_lines = lines[pos:]
 132     output_str = (
 133         "".join(pre_include_lines)
 134         + "\n"
 135         + replaced_variables
 136         + "\n"
 137         + "".join(post_include_lines)
 138     )
 139     output.write(output_str)