Actually support the C++ stdlib

Now that we're downloading arbitrary versions of clang, if we want to actually use the C++ standard library in cross-compilation environments, we need to compile it too. bazel doesn't make that super easy for now, as there is no facility for transitioning between a no-stdlib-C++ compiler and a with-stdlib-C++ compiler automatically. Thus we currently require cc_binary nodes to manually link in the libcxx label.
mjbots · Apr 11, 2019 · 6e90762 · 6e90762
1 parent 267da15
commit 6e90762
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Showing 8 changed files with 153 additions and 16 deletions.
diff --git a/example/BUILD b/example/BUILD
@@ -17,5 +17,6 @@
 cc_binary(
     name = "example1",
     srcs = ["example1.cc"],
+    deps = ["@org_llvm_libcxx//:libcxx"],
     linkstatic = 1,
 )
diff --git a/example/example1.cc b/example/example1.cc
@@ -12,11 +12,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <stdio.h>
+#include <iostream>
+#include <string>
 
 extern "C" {
 int main(int, char**) {
-  printf("hello there!\n");
+  std::string stuff = "hello there!";
+
+  std::cout << "yo: " << stuff << "\n";
+
   return 0;
 }
 

diff --git a/tools/cc_toolchain/BUILD b/tools/cc_toolchain/BUILD
@@ -50,6 +50,8 @@ filegroup(
         "@org_llvm_clang//:includes",
         "@org_llvm_clang//:runtime_libs",
         "@org_llvm_clang//:static_libs",
+        "@org_llvm_libcxx//:raw_headers",
+        "@org_llvm_libcxxabi//:raw_headers",
     ],
 )
 
@@ -58,7 +60,7 @@ cc_toolchain(
     name = "cc_toolchain_linux",
     toolchain_identifier = "clang-x86_64",
     all_files = ":clang_all",
-    compiler_files = ":clang_wrappers",
+    compiler_files = ":clang_all",
     cpu = "k8",
     dwp_files = ":clang_wrappers",
     dynamic_runtime_libs = ["@org_llvm_clang//:runtime_libs"],

diff --git a/tools/cc_toolchain/CROSSTOOL b/tools/cc_toolchain/CROSSTOOL
@@ -33,7 +33,7 @@ toolchain {
   abi_version: "local"
   abi_libc_version: "local"
   builtin_sysroot: ""
-  compiler: "compiler"
+  compiler: "clang"
   host_system_name: "local"
   target_libc: "local"
   target_cpu: "k8"
@@ -69,8 +69,16 @@ toolchain {
   linker_flag: "-Wno-unused-command-line-argument"
 
   cxx_flag: "-std=c++17"
-  cxx_flag: "-stdlib=libc++"
-  linker_flag: "-stdlib=libc++"
+
+  # We rely on a compiled version of libcxx, which for now users must
+  # manually specify when linking applications (but not compiling).
+  cxx_flag: "-nostdinc++"
+  linker_flag: "-nostdinc++"
+  linker_flag: "-nostdlib++"
+  cxx_flag: "-isystem"
+  cxx_flag: "external/org_llvm_libcxx/include"
+  cxx_flag: "-isystem"
+  cxx_flag: "external/org_llvm_libcxxabi/include"
 
   linker_flag: "-fuse-ld=lld"
   linker_flag: "-rtlib=compiler-rt"
@@ -201,11 +209,6 @@ toolchain {
   needsPic: true
 
 
-  cxx_builtin_include_directory: "external/raspberry_pi/sysroot/usr/include/c++/5"
-  cxx_builtin_include_directory: "external/raspberry_pi/sysroot/usr/include/arm-linux-gnueabihf/c++/5"
-  cxx_builtin_include_directory: "external/raspberry_pi/sysroot/usr/include/c++/5/backward"
-  cxx_builtin_include_directory: "external/raspberry_pi/sysroot/usr/lib/gcc/arm-linux-gnueabihf/5/include"
-  cxx_builtin_include_directory: "external/raspberry_pi/sysroot/usr/lib/gcc/arm-linux-gnueabihf/5/include-fixed"
   cxx_builtin_include_directory: "external/raspberry_pi/sysroot/usr/include/arm-linux-gnueabihf"
   cxx_builtin_include_directory: "external/raspberry_pi/sysroot/usr/include"
   cxx_builtin_include_directory: "external/org_llvm_clang/include/"
@@ -217,8 +220,16 @@ toolchain {
   linker_flag: "-Wno-unused-command-line-argument"
 
   cxx_flag: "-std=c++17"
-  cxx_flag: "-stdlib=libc++"
-  linker_flag: "-stdlib=libc++"
+
+  # We rely on a compiled version of libcxx, which for now users must
+  # manually specify when linking applications (but not compiling).
+  cxx_flag: "-nostdinc++"
+  linker_flag: "-nostdinc++"
+  linker_flag: "-nostdlib++"
+  cxx_flag: "-isystem"
+  cxx_flag: "external/org_llvm_libcxx/include"
+  cxx_flag: "-isystem"
+  cxx_flag: "external/org_llvm_libcxxabi/include"
 
   linker_flag: "-fuse-ld=lld"
   linker_flag: "-lm"

diff --git a/tools/workspace/clang/libcxx.BUILD b/tools/workspace/clang/libcxx.BUILD
@@ -0,0 +1,56 @@
+# -*- python -*-
+
+# Copyright 2019 Josh Pieper, jjp@pobox.com.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "raw_headers",
+    srcs = glob(["include/**"]),
+)
+
+cc_library(
+    name = "headers",
+    hdrs = [":raw_headers"],
+)
+
+cc_library(
+    name = "libcxx",
+    hdrs = glob(["include/**"]),
+    srcs = glob([
+        "src/*.cpp",
+        "src/include/*.h",
+        "filesystem/*.cpp",
+        "filesystem/*.h",
+    ]),
+    textual_hdrs = glob([
+        "src/support/runtime/**",
+    ]),
+    copts = [
+        "-Iexternal/org_llvm_libcxx/src/include",
+        "-Iexternal/org_llvm_libcxx/src",
+        "-D_LIBCPP_BUILDING_LIBRARY",
+        "-D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER",
+        "-DLIBCXX_BUILDING_LIBCXXABI",
+        "-DLIBCXX_CXX_ABI=libstdc++",
+        "-DNDEBUG",
+        "-fvisibility-inlines-hidden",
+    ],
+    includes = ["include"],
+    deps = [
+        ":headers",
+        "@org_llvm_libcxxabi//:libcxxabi",
+    ],
+)
diff --git a/tools/workspace/clang/libcxxabi.BUILD b/tools/workspace/clang/libcxxabi.BUILD
@@ -0,0 +1,45 @@
+# -*- python -*-
+
+# Copyright 2019 Josh Pieper, jjp@pobox.com.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "raw_headers",
+    srcs = glob(["include/**"]),
+)
+
+cc_library(
+    name = "libcxxabi",
+    hdrs = [":raw_headers"],
+    srcs = glob([
+        "src/*.cpp",
+        "src/*.hpp",
+        "src/*.h",
+        "src/include/*.h",
+        "src/demangle/*.h",
+    ], exclude = [
+        "src/stdlib_new_delete.cpp",
+        "src/cxa_noexception.cpp",
+    ]),
+    copts = [
+        "-Iexternal/org_llvm_libcxx/include",
+        "-D_LIBCPP_BUILDING_LIBRARY",
+        "-DNDEBUG",
+        "-fvisibility-inlines-hidden",
+    ],
+    includes = ["include"],
+    deps = ["@org_llvm_libcxx//:headers"],
+)
diff --git a/tools/workspace/clang/repository.bzl b/tools/workspace/clang/repository.bzl
@@ -17,13 +17,31 @@
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 
-def clang_repository(name):
+def clang_repository():
     http_archive(
-        name = name,
+        name = "org_llvm_clang",
         urls = [
             "http://releases.llvm.org/7.0.0/clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-16.04.tar.xz",
         ],
         sha256 = "69b85c833cd28ea04ce34002464f10a6ad9656dd2bba0f7133536a9927c660d2",
         strip_prefix = "clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-16.04",
         build_file = Label("//tools/workspace/clang:package.BUILD"),
     )
+    http_archive(
+        name = "org_llvm_libcxx",
+        urls = [
+            "http://releases.llvm.org/7.0.0/libcxx-7.0.0.src.tar.xz",
+        ],
+        sha256 = "9b342625ba2f4e65b52764ab2061e116c0337db2179c6bce7f9a0d70c52134f0",
+        strip_prefix = "libcxx-7.0.0.src",
+        build_file = Label("//tools/workspace/clang:libcxx.BUILD"),
+    )
+    http_archive(
+        name = "org_llvm_libcxxabi",
+        urls = [
+            "http://releases.llvm.org/7.0.1/libcxxabi-7.0.1.src.tar.xz",
+        ],
+        sha256 = "9b45c759ff397512eae4d938ff82827b1bd7ccba49920777e5b5e460baeb245f",
+        strip_prefix = "libcxxabi-7.0.0.src",
+        build_file = Label("//tools/workspace/clang:libcxxabi.BUILD"),
+    )
diff --git a/tools/workspace/default.bzl b/tools/workspace/default.bzl
@@ -19,6 +19,6 @@ load("//tools/workspace/raspberry_pi:repository.bzl", "raspberry_pi_repository")
 
 def add_default_repositories(excludes = []):
     if "clang" not in excludes:
-        clang_repository(name = "org_llvm_clang")
+        clang_repository()
     if "raspberry_pi" not in excludes:
         raspberry_pi_repository(name = "raspberry_pi")