Merge pull request #2523 from xmake-io/lto

Add better LTO support

2 files changed, 98 insertions, 0 deletions

diff --git a/xmake/rules/c++/build_optimization/load.lua b/xmake/rules/c++/build_optimization/load.lua
new file mode 100644
index 000000000..bd1831778
--- /dev/null
+++ b/xmake/rules/c++/build_optimization/load.lua
@@ -0,0 +1,66 @@
+--!A cross-platform build utility based on Lua
+--
+-- 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.
+--
+-- Copyright (C) 2015-present, TBOOX Open Source Group.
+--
+-- @author      ruki
+-- @file        load.lua
+--
+
+-- imports
+import("core.tool.compiler")
+import("core.project.project")
+
+-- add lto optimization
+function _add_lto_optimization(target, sourcekind)
+
+    -- add cflags
+    local _, cc = target:tool(sourcekind)
+    local cflag = sourcekind == "cxx" and "cxxflags" or "cflags"
+    if cc == "cl" then
+        target:add(cflag, "-GL")
+    elseif cc == "clang" or cc == "clangxx" then
+        target:add(cflag, "-flto=thin")
+    elseif cc == "gcc" or cc == "gxx" then
+        target:add(cflag, "-flto")
+    end
+
+    -- add ldflags and shflags
+    local _, ld = target:tool("ld")
+    if ld == "link" then
+        target:add("ldflags", "-LTCG")
+        target:add("shflags", "-LTCG")
+    elseif ld == "clang" or ld == "clangxx" then
+        target:add("ldflags", "-flto=thin")
+        target:add("shflags", "-flto=thin")
+    elseif ld == "gcc" or ld == "gxx" then
+        target:add("ldflags", "-flto")
+        target:add("shflags", "-flto")
+        -- to use the link-time optimizer, -flto and optimization options should be specified at compile time and during the final link.
+        -- @see https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
+        local optimize = target:get("optimize")
+        if optimize then
+            local optimize_flags = compiler.map_flags(sourcekind == "cc" and "c" or "cxx", "optimize", optimize)
+            target:add("ldflags", optimize_flags)
+            target:add("shflags", optimize_flags)
+        end
+    end
+end
+
+function main(target, sourcekind)
+    if target:policy("build.optimization.lto") or
+        project.policy("build.optimization.lto") then
+        _add_lto_optimization(target, sourcekind)
+    end
+end
diff --git a/xmake/rules/c++/build_optimization/xmake.lua b/xmake/rules/c++/build_optimization/xmake.lua
new file mode 100644
index 000000000..c08b74141
--- /dev/null
+++ b/xmake/rules/c++/build_optimization/xmake.lua
@@ -0,0 +1,32 @@
+--!A cross-platform build utility based on Lua
+--
+-- 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.
+--
+-- Copyright (C) 2015-present, TBOOX Open Source Group.
+--
+-- @author      ruki
+-- @file        xmake.lua
+--
+
+-- define rule: c.build.optimization
+rule("c.build.optimization")
+    on_config(function (target)
+        import("load")(target, "cc")
+    end)
+
+-- define rule: c++.build.optimization
+rule("c++.build.optimization")
+    on_config(function (target)
+        import("load")(target, "cxx")
+    end)
+