Make generate_export_header.bzl work for Windows. (#1355)
* Make generate_export_header.bzl work for Windows.
While I'm here, bring the generated code slightly closer to what CMake
would generate nowadays.
Fixes #1351.
* Fix define.
* Fix export_import_condition.
* Fix guard.
diff --git a/BUILD.bazel b/BUILD.bazel
index dce4d64..4bf5bfc 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -55,6 +55,10 @@
":windows": [],
"//conditions:default": posix_copts,
}),
+ local_defines = select({
+ ":windows": ["benchmark_EXPORTS"],
+ "//conditions:default": [],
+ }),
)
cc_library(
diff --git a/WORKSPACE b/WORKSPACE
index 949eb98..bb44e7b 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -4,6 +4,15 @@
load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
http_archive(
+ name = "platforms",
+ sha256 = "379113459b0feaf6bfbb584a91874c065078aa673222846ac765f86661c27407",
+ urls = [
+ "https://mirror.bazel.build/github.com/bazelbuild/platforms/releases/download/0.0.5/platforms-0.0.5.tar.gz",
+ "https://github.com/bazelbuild/platforms/releases/download/0.0.5/platforms-0.0.5.tar.gz",
+ ],
+)
+
+http_archive(
name = "com_google_absl",
sha256 = "f41868f7a938605c92936230081175d1eae87f6ea2c248f41077c8f88316f111",
strip_prefix = "abseil-cpp-20200225.2",
diff --git a/config/generate_export_header.bzl b/config/generate_export_header.bzl
index 0d0b671..35e9871 100644
--- a/config/generate_export_header.bzl
+++ b/config/generate_export_header.bzl
@@ -36,33 +36,44 @@
#
# -*- python -*-
-def _make_identifier(s):
- result = ""
- for i in range(len(s)):
- result += s[i] if s[i].isalnum() else "_"
-
- return result
-
# Defines the implementation actions to generate_export_header.
def _generate_export_header_impl(ctx):
+ windows_constraint = ctx.attr._windows_constraint[platform_common.ConstraintValueInfo]
output = ctx.outputs.out
- guard = _make_identifier(output.basename.upper())
+ if ctx.target_platform_has_constraint(windows_constraint):
+ export_attr = "__declspec(dllexport)"
+ import_attr = "__declspec(dllimport)"
+ no_export_attr = ""
+ deprecated_attr = "__declspec(deprecated)"
+ else:
+ export_attr = "__attribute__((visibility(\"default\")))"
+ import_attr = "__attribute__((visibility(\"default\")))"
+ no_export_attr = "__attribute__((visibility(\"hidden\")))"
+ deprecated_attr = "__attribute__((__deprecated__))"
content = [
- "#ifndef %s" % guard,
- "#define %s" % guard,
+ "#ifndef %s_H" % ctx.attr.export_macro_name,
+ "#define %s_H" % ctx.attr.export_macro_name,
"",
"#ifdef %s" % ctx.attr.static_define,
"# define %s" % ctx.attr.export_macro_name,
"# define %s" % ctx.attr.no_export_macro_name,
"#else",
- "# define %s __attribute__((visibility(\"default\")))" % ctx.attr.export_macro_name, # noqa
- "# define %s __attribute__((visibility(\"hidden\")))" % ctx.attr.no_export_macro_name, # noqa
+ "# ifndef %s" % ctx.attr.export_macro_name,
+ "# ifdef %s" % ctx.attr.export_import_condition,
+ "# define %s %s" % (ctx.attr.export_macro_name, export_attr),
+ "# else",
+ "# define %s %s" % (ctx.attr.export_macro_name, import_attr),
+ "# endif",
+ "# endif",
+ "# ifndef %s" % ctx.attr.no_export_macro_name,
+ "# define %s %s" % (ctx.attr.no_export_macro_name, no_export_attr),
+ "# endif",
"#endif",
"",
"#ifndef %s" % ctx.attr.deprecated_macro_name,
- "# define %s __attribute__ ((__deprecated__))" % ctx.attr.deprecated_macro_name, # noqa
+ "# define %s %s" % (ctx.attr.deprecated_macro_name, deprecated_attr),
"#endif",
"",
"#ifndef %s" % ctx.attr.export_deprecated_macro_name,
@@ -82,12 +93,14 @@
_generate_export_header_gen = rule(
attrs = {
"out": attr.output(mandatory = True),
+ "export_import_condition": attr.string(),
"export_macro_name": attr.string(),
"deprecated_macro_name": attr.string(),
"export_deprecated_macro_name": attr.string(),
"no_export_macro_name": attr.string(),
"no_export_deprecated_macro_name": attr.string(),
"static_define": attr.string(),
+ "_windows_constraint": attr.label(default = "@platforms//os:windows"),
},
output_to_genfiles = True,
implementation = _generate_export_header_impl,
@@ -97,6 +110,7 @@
lib = None,
name = None,
out = None,
+ export_import_condition = None,
export_macro_name = None,
deprecated_macro_name = None,
export_deprecated_macro_name = None,
@@ -121,6 +135,9 @@
name = "__%s_export_h" % lib
if out == None:
out = "%s_export.h" % lib
+ if export_import_condition == None:
+ # CMake does not uppercase the <lib>_EXPORTS define.
+ export_import_condition = "%s_EXPORTS" % lib
if export_macro_name == None:
export_macro_name = "%s_EXPORT" % lib.upper()
if deprecated_macro_name == None:
@@ -138,6 +155,7 @@
_generate_export_header_gen(
name = name,
out = out,
+ export_import_condition = export_import_condition,
export_macro_name = export_macro_name,
deprecated_macro_name = deprecated_macro_name,
export_deprecated_macro_name = export_deprecated_macro_name,
