Beginning work on GN build

build/config/win/BUILD.gn

Index: build/config/win/BUILD.gn
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+# Copyright (c) 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/compiler/compiler.gni")
+import("//build/config/sanitizers/sanitizers.gni")
+import("//build/config/win/visual_studio_version.gni")
+import("//build/toolchain/toolchain.gni")
+
+assert(is_win)
+
+declare_args() {
+  # Set this to true to enable static analysis through Visual Studio's
+  # /analyze. This dramatically slows compiles and reports thousands of
+  # warnings, so normally this is done on a build machine and only the new
+  # warnings are examined.
+  use_vs_code_analysis = false
+}
+
+# This is included by reference in the //build/config/compiler config that
+# is applied to all targets. It is here to separate out the logic that is
+# Windows-only.
+config("compiler") {
+  if (current_cpu == "x86") {
+    asmflags = [
+      # When /safeseh is specified, the linker will only produce an image if it
+      # can also produce a table of the image's safe exception handlers. This
+      # table specifies for the operating system which exception handlers are
+      # valid for the image. Note that /SAFESEH isn't accepted on the command
+      # line, only /safeseh. This is only accepted by ml.exe, not ml64.exe.
+      "/safeseh",
+    ]
+  }
+
+  cflags = [
+    "/Gy",  # Enable function-level linking.
+    "/FS",  # Preserve previous PDB behavior.
+    "/bigobj",  # Some of our files are bigger than the regular limits.
+
+    # Tell the compiler to crash on failures. This is undocumented
+    # and unsupported but very handy.
+    "/d2FastFail",
+  ]
+
+  # Force C/C++ mode for the given GN detected file type. This is necessary
+  # for precompiled headers where the same source file is compiled in both
+  # modes.
+  cflags_c = [ "/TC" ]
+  cflags_cc = [ "/TP" ]
+
+  if (visual_studio_version == "2015") {
+    cflags += [
+      # Work around crbug.com/526851, bug in VS 2015 RTM compiler.
+      "/Zc:sizedDealloc-",
+
+      # Disable thread-safe statics to avoid overhead and because
+      # they are disabled on other platforms. See crbug.com/587210
+      # and -fno-threadsafe-statics.
+      "/Zc:threadSafeInit-",
+    ]
+  }
+
+  # Building with Clang on Windows is a work in progress and very
+  # experimental. See crbug.com/82385.
+  # Keep this in sync with the similar block in build/common.gypi
+  if (is_clang) {
+    cflags += [
+      # Many files use intrinsics without including this header.
+      # TODO(hans): Fix those files, or move this to sub-GYPs.
+      "/FIIntrin.h",
+    ]
+
+    if (visual_studio_version == "2013") {
+      cflags += [ "-fmsc-version=1800" ]
+    } else if (visual_studio_version == "2015") {
+      cflags += [ "-fmsc-version=1900" ]
+    }
+
+    if (current_cpu == "x86") {
+      cflags += [ "-m32" ]
+    } else {
+      cflags += [ "-m64" ]
+    }
+
+    if (exec_script("//build/win/use_ansi_codes.py", [], "trim string") ==
+        "True") {
+      cflags += [
+        # cmd.exe doesn't understand ANSI escape codes by default,
+        # so only enable them if something emulating them is around.
+        "-fansi-escape-codes",
+      ]
+    }
+
+    # Clang runtime libraries, such as the sanitizer runtimes, live here.
+    lib_dirs = [ "//third_party/llvm-build/Release+Asserts/lib/clang/$clang_version/lib/windows" ]
+  }
+
+  if (is_syzyasan) {
+    # SyzyAsan needs /PROFILE turned on to produce appropriate pdbs.
+    assert(!is_win_fastlink, "/PROFILE and /DEBUG:FASTLINK are incompatible")
+    ldflags = [ "/PROFILE" ]
+  }
+
+  # arflags apply only to static_libraries. The normal linker configs are only
+  # set for executable and shared library targets so arflags must be set
+  # elsewhere. Since this is relatively contained, we just apply them in this
+  # more general config and they will only have an effect on static libraries.
+  arflags = [
+    # "No public symbols found; archive member will be inaccessible." This
+    # means that one or more object files in the library can never be
+    # pulled in to targets that link to this library. It's just a warning that
+    # the source file is a no-op.
+    "/ignore:4221",
+  ]
+}
+
+config("vs_code_analysis") {
+  if (use_vs_code_analysis) {
+    # When use_vs_code_analysis is specified add the /analyze switch to enable
+    # static analysis. Specifying /analyze:WX- says that /analyze warnings
+    # should not be treated as errors.
+    cflags = [ "/analyze:WX-" ]
+
+    # Also, disable various noisy warnings that have low value.
+    cflags += [
+      "/wd6011",  # Dereferencing NULL pointer
+
+      # C6285 is ~16% of raw warnings and has low value
+      "/wd6285",  # non-zero constant || non-zero constant
+      "/wd6308",  # realloc might return null pointer
+
+      # Possible infinite loop: use of the constant
+      # EXCEPTION_CONTINUE_EXECUTION in the exception-filter
+      "/wd6312",
+
+      "/wd6322",  # Empty _except block
+      "/wd6330",  # 'char' used instead of 'unsigned char' for istype() call
+
+      # C6334 is ~80% of raw warnings and has low value
+      "/wd6334",  # sizeof applied to an expression with an operator
+      "/wd6326",  # Potential comparison of constant with constant
+      "/wd6340",  # Sign mismatch in function parameter
+      "/wd28159",  # Consider using 'GetTickCount64'
+      "/wd28196",  # The precondition is not satisfied
+      "/wd28204",  # Inconsistent SAL annotations
+      "/wd28251",  # Inconsistent SAL annotations
+      "/wd28252",  # Inconsistent SAL annotations
+      "/wd28253",  # Inconsistent SAL annotations
+      "/wd28278",  # Function appears with no prototype in scope
+      "/wd28285",  # syntax error in SAL annotation (in algorithm)
+      "/wd28301",  # Inconsistent SAL annotations
+      "/wd28182",  # Dereferencing NULL pointer
+    ]
+  }
+}
+
+# This is included by reference in the //build/config/compiler:runtime_library
+# config that is applied to all targets. It is here to separate out the logic
+# that is Windows-only. Please see that target for advice on what should go in
+# :runtime_library vs. :compiler.
+config("runtime_library") {
+  cflags = []
+
+  # Defines that set up the CRT.
+  defines = [
+    "__STD_C",
+    "_CRT_RAND_S",
+    "_CRT_SECURE_NO_DEPRECATE",
+    "_HAS_EXCEPTIONS=0",
+    "_SCL_SECURE_NO_DEPRECATE",
+  ]
+
+  # Defines that set up the Windows SDK.
+  defines += [
+    "_ATL_NO_OPENGL",
+    "_WINDOWS",
+    "CERT_CHAIN_PARA_HAS_EXTRA_FIELDS",
+    "NTDDI_VERSION=0x0A000000",
+    "PSAPI_VERSION=1",
+    "WIN32",
+    "_SECURE_ATL",
+  ]
+
+  if (!use_vs_code_analysis) {
+    # This is required for ATL to use XP-safe versions of its functions.
+    # However it is prohibited when using /analyze
+    defines += [ "_USING_V110_SDK71_" ]
+  }
+
+  if (is_component_build) {
+    # Component mode: dynamic CRT. Since the library is shared, it requires
+    # exceptions or will give errors about things not matching, so keep
+    # exceptions on.
+    if (is_debug) {
+      cflags += [ "/MDd" ]
+    } else {
+      cflags += [ "/MD" ]
+    }
+  } else {
+    if (current_os != "win") {
+      # WindowsRT: use the dynamic CRT.
+      if (is_debug) {
+        cflags += [ "/MDd" ]
+      } else {
+        cflags += [ "/MD" ]
+      }
+    } else {
+      # Desktop Windows: static CRT.
+      if (is_debug) {
+        cflags += [ "/MTd" ]
+      } else {
+        cflags += [ "/MT" ]
+      }
+    }
+  }
+}
+
+# Sets the default Windows build version. This is separated because some
+# targets need to manually override it for their compiles.
+config("winver") {
+  defines = [
+    "_WIN32_WINNT=0x0A00",
+    "WINVER=0x0A00",
+  ]
+}
+
+# Linker flags for Windows SDK setup, this is applied only to EXEs and DLLs.
+config("sdk_link") {
+  if (current_cpu == "x64") {
+    ldflags = [ "/MACHINE:X64" ]
+    lib_dirs = [
+      "$windows_sdk_path\Lib\winv6.3\um\x64",
+      "$visual_studio_path\VC\lib\amd64",
+      "$visual_studio_path\VC\atlmfc\lib\amd64",
+    ]
+  } else {
+    ldflags = [
+      "/MACHINE:X86",
+      "/SAFESEH",  # Not compatible with x64 so use only for x86.
+      "/largeaddressaware",
+    ]
+    lib_dirs = [
+      "$windows_sdk_path\Lib\winv6.3\um\x86",
+      "$visual_studio_path\VC\lib",
+      "$visual_studio_path\VC\atlmfc\lib",
+    ]
+  }
+}
+
+# This default linker setup is provided separately from the SDK setup so
+# targets who want different library configurations can remove this and specify
+# their own.
+config("common_linker_setup") {
+  ldflags = [
+    "/FIXED:NO",
+    "/ignore:4199",
+    "/ignore:4221",
+    "/NXCOMPAT",
+
+    # Suggested by Microsoft Devrel to avoid
+    #   LINK : fatal error LNK1248: image size (80000000)
+    #   exceeds maximum allowable size (80000000)
+    # which started happening more regularly after VS2013 Update 4.
+    # Needs to be a bit lower for VS2015, or else errors out.
+    "/maxilksize:0x7ff00000",
+
+    # Tell the linker to crash on failures.
+    "/fastfail",
+  ]
+
+  # ASLR makes debugging with windbg difficult because Chrome.exe and
+  # Chrome.dll share the same base name. As result, windbg will name the
+  # Chrome.dll module like chrome_<base address>, where <base address>
+  # typically changes with each launch. This in turn means that breakpoints in
+  # Chrome.dll don't stick from one launch to the next. For this reason, we
+  # turn ASLR off in debug builds.
+  if (is_debug) {
+    ldflags += [ "/DYNAMICBASE:NO" ]
+  } else {
+    ldflags += [ "/DYNAMICBASE" ]
+  }
+}
+
+# Subsystem --------------------------------------------------------------------
+
+# This is appended to the subsystem to specify a minimum version.
+if (current_cpu == "x64") {
+  # The number after the comma is the minimum required OS version.
+  # 5.02 = Windows Server 2003.
+  subsystem_version_suffix = ",5.02"
+} else {
+  # 5.01 = Windows XP.
+  subsystem_version_suffix = ",5.01"
+}
+
+config("console") {
+  ldflags = [ "/SUBSYSTEM:CONSOLE$subsystem_version_suffix" ]
+}
+config("windowed") {
+  ldflags = [ "/SUBSYSTEM:WINDOWS$subsystem_version_suffix" ]
+}
+
+# Incremental linking ----------------------------------------------------------
+
+incremental_linking_on_switch = [ "/INCREMENTAL" ]
+incremental_linking_off_switch = [ "/INCREMENTAL:NO" ]
+
+# Disable incremental linking for syzyasan
+if (is_debug && !is_syzyasan) {
+  default_incremental_linking_switch = incremental_linking_on_switch
+} else {
+  default_incremental_linking_switch = incremental_linking_off_switch
+}
+
+# Applies incremental linking or not depending on the current configuration.
+config("default_incremental_linking") {
+  ldflags = default_incremental_linking_switch
+}
+
+# Explicitly on or off incremental linking
+config("incremental_linking") {
+  ldflags = incremental_linking_on_switch
+}
+config("no_incremental_linking") {
+  ldflags = incremental_linking_off_switch
+}
+
+# Some large modules can't handle incremental linking in some situations. This
+# config should be applied to large modules to turn off incremental linking
+# when it won't work.
+config("default_large_module_incremental_linking") {
+  if (symbol_level > 0 && (current_cpu == "x86" || !is_component_build)) {
+    # When symbols are on, things get so large that the tools fail due to the
+    # size of the .ilk files.
+    ldflags = incremental_linking_off_switch
+  } else {
+    # Otherwise just do the default incremental linking for this build type.
+    ldflags = default_incremental_linking_switch
+  }
+}
+
+# Character set ----------------------------------------------------------------
+
+# Not including this config means "ansi" (8-bit system codepage).
+config("unicode") {
+  defines = [
+    "_UNICODE",
+    "UNICODE",
+  ]
+}
+
+# Lean and mean ----------------------------------------------------------------
+
+# Some third party code might not compile with WIN32_LEAN_AND_MEAN so we have
+# to have a separate config for it. Remove this config from your target to
+# get the "bloaty and accomodating" version of windows.h.
+config("lean_and_mean") {
+  defines = [ "WIN32_LEAN_AND_MEAN" ]
+}
+
+# Nominmax --------------------------------------------------------------------
+
+# Some third party code defines NOMINMAX before including windows.h, which
+# then causes warnings when it's been previously defined on the command line.
+# For such targets, this config can be removed.
+
+config("nominmax") {
+  defines = [ "NOMINMAX" ]
+}
+
+# Target WinRT ----------------------------------------------------------------
+
+# When targeting Windows Runtime, certain compiler/linker flags are necessary.
+
+config("target_winrt") {
+  defines = [
+    "WINRT",
+    "WINAPI_FAMILY=WINAPI_FAMILY_PC_APP",
+  ]
+  cflags_cc = [
+    "/ZW",
+    "/EHsc",
+  ]
+}
+
+# Internal stuff --------------------------------------------------------------
+
+# Config used by the MIDL template to disable warnings.
+config("midl_warnings") {
+  if (is_clang) {
+    # MIDL generates code like "#endif !_MIDL_USE_GUIDDEF_".
+    cflags = [ "-Wno-extra-tokens" ]
+  }
+}