[gn] Support for building libunwind

This change introduces support for building libuwind. The library
build should be complete, but not all CMake options have been
replicated in GN. We also don't support tests yet.

We only support two stage build at the moment.

Differential Revision: https://reviews.llvm.org/D60370

llvm-svn: 359804

3 files changed, 133 insertions, 1 deletions

diff --git a/llvm/utils/gn/secondary/BUILD.gn b/llvm/utils/gn/secondary/BUILD.gn
index 5fbddf93168..af0c85711c4 100644
--- a/llvm/utils/gn/secondary/BUILD.gn
+++ b/llvm/utils/gn/secondary/BUILD.gn
@@ -11,7 +11,10 @@ group("default") {
     "//llvm/test",
   ]
   if (current_os == "linux") {
-    deps += [ "//compiler-rt" ]
+    deps += [
+      "//compiler-rt",
+      "//libunwind",
+    ]
   }
   if (current_os == "linux" || current_os == "android") {
     deps += [ "//compiler-rt/test/hwasan" ]
diff --git a/llvm/utils/gn/secondary/libunwind/BUILD.gn b/llvm/utils/gn/secondary/libunwind/BUILD.gn
new file mode 100644
index 00000000000..b55d9c75808
--- /dev/null
+++ b/llvm/utils/gn/secondary/libunwind/BUILD.gn
@@ -0,0 +1,5 @@
+group("libunwind") {
+  deps = [
+    "//libunwind/src(//llvm/utils/gn/build/toolchain:stage2_unix)",
+  ]
+}
diff --git a/llvm/utils/gn/secondary/libunwind/src/BUILD.gn b/llvm/utils/gn/secondary/libunwind/src/BUILD.gn
new file mode 100644
index 00000000000..1e96b5643ad
--- /dev/null
+++ b/llvm/utils/gn/secondary/libunwind/src/BUILD.gn
@@ -0,0 +1,124 @@
+import("//clang/runtimes.gni")
+
+declare_args() {
+  # Build libunwind as a shared library.
+  libunwind_enable_shared = true
+
+  # Build libunwind as a static library.
+  libunwind_enable_static = true
+
+  # Do not export any symbols from the static library.
+  libunwind_hermetic_static_library = true
+}
+
+unwind_headers = [
+  "../include/libunwind.h",
+  "../include/unwind.h",
+]
+if (target_os == "mac") {
+  unwind_headers += [
+    # This comment prevents `gn format` from putting the file on the same line
+    # as `sources +=`, for sync_source_lists_from_cmake.py.
+    "../include/mach-o/compact_unwind_encoding.h",
+  ]
+}
+
+unwind_sources = [
+  "libunwind.cpp",
+  "Unwind-EHABI.cpp",
+  "Unwind-seh.cpp",
+  "UnwindLevel1.c",
+  "UnwindLevel1-gcc-ext.c",
+  "Unwind-sjlj.c",
+  "UnwindRegistersRestore.S",
+  "UnwindRegistersSave.S",
+  "AddressSpace.hpp",
+  "assembly.h",
+  "CompactUnwinder.hpp",
+  "config.h",
+  "dwarf2.h",
+  "DwarfInstructions.hpp",
+  "DwarfParser.hpp",
+  "libunwind_ext.h",
+  "Registers.hpp",
+  "RWMutex.hpp",
+  "UnwindCursor.hpp",
+]
+if (target_os == "mac") {
+  unwind_sources += [ "src/Unwind_AppleExtras.cpp" ]
+}
+
+config("unwind_config") {
+  cflags = []
+  cflags_c = [ "-std=c99" ]
+  cflags_cc = [ "-fno-rtti" ]
+  include_dirs = [ "//libunwind/include" ]
+  if (target_os == "mac") {
+    cflags += [ "-U__STRICT_ANSI__" ]
+  }
+}
+
+if (libunwind_enable_shared) {
+  shared_library("unwind_shared") {
+    output_dir = runtimes_dir
+    output_name = "unwind"
+    if (target_os == "linux" || target_os == "mac") {
+      cflags = [ "-fPIC" ]
+      ldflags = [ "-nostdlib++" ]
+      libs = [
+        "dl",
+        "pthread",
+      ]
+    }
+    if (target_os == "mac") {
+      ldflags += [
+        "-compatibility_version 1",
+        "-install_name /usr/lib/libunwind.1.dylib",
+      ]
+    }
+    sources = unwind_sources
+    public = unwind_headers
+    deps = [
+      "//compiler-rt/lib/builtins",
+    ]
+    configs += [ ":unwind_config" ]
+    configs -= [
+      "//llvm/utils/gn/build:no_exceptions",
+      "//llvm/utils/gn/build:no_rtti",
+    ]
+  }
+}
+
+if (libunwind_enable_static) {
+  static_library("unwind_static") {
+    output_dir = runtimes_dir
+    output_name = "unwind"
+    complete_static_lib = true
+    configs -= [ "//llvm/utils/gn/build:thin_archive" ]
+    sources = unwind_sources
+    public = unwind_headers
+    if (libunwind_hermetic_static_library) {
+      cflags = [ "-fvisibility=hidden" ]
+      cflags_cc = [ "-fvisibility-global-new-delete-hidden" ]
+      defines = [ "_LIBUNWIND_DISABLE_VISIBILITY_ANNOTATIONS" ]
+    }
+    deps = [
+      "//compiler-rt/lib/builtins",
+    ]
+    configs += [ ":unwind_config" ]
+    configs -= [
+      "//llvm/utils/gn/build:no_exceptions",
+      "//llvm/utils/gn/build:no_rtti",
+    ]
+  }
+}
+
+group("src") {
+  deps = []
+  if (libunwind_enable_shared) {
+    deps += [ ":unwind_shared" ]
+  }
+  if (libunwind_enable_static) {
+    deps += [ ":unwind_static" ]
+  }
+}