From 72df804d8e649950ef082034e147bd8fc5ee162d Mon Sep 17 00:00:00 2001 From: Michael Woerister Date: Fri, 6 Jul 2018 13:58:25 +0200 Subject: [PATCH] When doing linker-plugin based LTO, write LLVM bitcode obj-files instead of embedding the bitcode into the regular object file. --- src/librustc/session/config.rs | 2 +- src/librustc_codegen_llvm/back/write.rs | 8 ++-- .../run-make-fulldeps/cross-lang-lto/Makefile | 42 +++++++++---------- 3 files changed, 24 insertions(+), 28 deletions(-) diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs index c349def865a..ba1249215cc 100644 --- a/src/librustc/session/config.rs +++ b/src/librustc/session/config.rs @@ -104,7 +104,7 @@ pub enum CrossLangLto { } impl CrossLangLto { - pub fn embed_bitcode(&self) -> bool { + pub fn enabled(&self) -> bool { match *self { CrossLangLto::LinkerPlugin(_) | CrossLangLto::LinkerPluginAuto | diff --git a/src/librustc_codegen_llvm/back/write.rs b/src/librustc_codegen_llvm/back/write.rs index baab3c618be..42b772b8a5d 100644 --- a/src/librustc_codegen_llvm/back/write.rs +++ b/src/librustc_codegen_llvm/back/write.rs @@ -288,10 +288,10 @@ impl ModuleConfig { self.no_builtins = no_builtins || sess.target.target.options.no_builtins; self.time_passes = sess.time_passes(); self.inline_threshold = sess.opts.cg.inline_threshold; - self.obj_is_bitcode = sess.target.target.options.obj_is_bitcode; + self.obj_is_bitcode = sess.target.target.options.obj_is_bitcode || + sess.opts.debugging_opts.cross_lang_lto.enabled(); let embed_bitcode = sess.target.target.options.embed_bitcode || - sess.opts.debugging_opts.embed_bitcode || - sess.opts.debugging_opts.cross_lang_lto.embed_bitcode(); + sess.opts.debugging_opts.embed_bitcode; if embed_bitcode { match sess.opts.optimize { config::OptLevel::No | @@ -1365,7 +1365,7 @@ fn execute_work_item(cgcx: &CodegenContext, // Don't run LTO passes when cross-lang LTO is enabled. The linker // will do that for us in this case. let needs_lto = needs_lto && - !cgcx.opts.debugging_opts.cross_lang_lto.embed_bitcode(); + !cgcx.opts.debugging_opts.cross_lang_lto.enabled(); if needs_lto { Ok(WorkItemResult::NeedsLTO(module)) diff --git a/src/test/run-make-fulldeps/cross-lang-lto/Makefile b/src/test/run-make-fulldeps/cross-lang-lto/Makefile index f5480178db0..cdc429d1f99 100644 --- a/src/test/run-make-fulldeps/cross-lang-lto/Makefile +++ b/src/test/run-make-fulldeps/cross-lang-lto/Makefile @@ -1,53 +1,49 @@ # min-llvm-version 4.0 -# ignore-mingw +# ignore-msvc -include ../tools.mk -# This test makes sure that the expected .llvmbc sections for use by -# linker-based LTO are available in object files when compiling with -# -Z cross-lang-lto +# This test makes sure that the object files we generate are actually +# LLVM bitcode files (as used by linker LTO plugins) when compiling with +# -Z cross-lang-lto. -LLVMBC_SECTION_NAME=\\.llvmbc +ASSERT_IS_BITCODE_OBJ=llvm-bcanalyzer # this only succeeds for bitcode files +EXTRACT_OBJS=(cd $(TMPDIR); rm -f ./*.o; llvm-ar x $(1)) -ifeq ($(UNAME),Darwin) - LLVMBC_SECTION_NAME=__bitcode -endif - - -OBJDUMP=llvm-objdump -SECTION_HEADERS=$(OBJDUMP) -section-headers - -BUILD_LIB=$(RUSTC) lib.rs -Copt-level=2 -Z cross-lang-lto=no-link -Ccodegen-units=1 - -BUILD_EXE=$(RUSTC) main.rs -Copt-level=2 -Z cross-lang-lto=no-link -Ccodegen-units=1 --emit=obj +BUILD_LIB=$(RUSTC) lib.rs -Copt-level=2 -Z cross-lang-lto=on -Ccodegen-units=1 +BUILD_EXE=$(RUSTC) main.rs -Copt-level=2 -Z cross-lang-lto=on -Ccodegen-units=1 --emit=obj all: staticlib staticlib-fat-lto staticlib-thin-lto rlib exe cdylib rdylib staticlib: lib.rs $(BUILD_LIB) --crate-type=staticlib -o $(TMPDIR)/liblib.a - [ "$$($(SECTION_HEADERS) $(TMPDIR)/liblib.a | grep -c $(LLVMBC_SECTION_NAME))" -ne "0" ] + $(call EXTRACT_OBJS, liblib.a) + $(ASSERT_IS_BITCODE_OBJ) $(TMPDIR)/liblib.lib0.rcgu.o staticlib-fat-lto: lib.rs $(BUILD_LIB) --crate-type=staticlib -o $(TMPDIR)/liblib-fat-lto.a -Clto=fat - [ "$$($(SECTION_HEADERS) $(TMPDIR)/liblib-fat-lto.a | grep -c $(LLVMBC_SECTION_NAME))" -ne "0" ] + $(call EXTRACT_OBJS, liblib-fat-lto.a) + $(ASSERT_IS_BITCODE_OBJ) $(TMPDIR)/liblib-fat-lto.lib0.rcgu.o staticlib-thin-lto: lib.rs $(BUILD_LIB) --crate-type=staticlib -o $(TMPDIR)/liblib-thin-lto.a -Clto=thin - [ "$$($(SECTION_HEADERS) $(TMPDIR)/liblib-thin-lto.a | grep -c $(LLVMBC_SECTION_NAME))" -ne "0" ] + $(call EXTRACT_OBJS, liblib-thin-lto.a) + $(ASSERT_IS_BITCODE_OBJ) $(TMPDIR)/liblib-thin-lto.lib0.rcgu.o rlib: lib.rs $(BUILD_LIB) --crate-type=rlib -o $(TMPDIR)/liblib.rlib - [ "$$($(SECTION_HEADERS) $(TMPDIR)/liblib.rlib | grep -c $(LLVMBC_SECTION_NAME))" -ne "0" ] + $(call EXTRACT_OBJS, liblib.rlib) + $(ASSERT_IS_BITCODE_OBJ) $(TMPDIR)/liblib.lib0.rcgu.o cdylib: lib.rs $(BUILD_LIB) --crate-type=cdylib --emit=obj -o $(TMPDIR)/cdylib.o - [ "$$($(SECTION_HEADERS) $(TMPDIR)/cdylib.o | grep -c $(LLVMBC_SECTION_NAME))" -ne "0" ] + $(ASSERT_IS_BITCODE_OBJ) $(TMPDIR)/cdylib.o rdylib: lib.rs $(BUILD_LIB) --crate-type=dylib --emit=obj -o $(TMPDIR)/rdylib.o - [ "$$($(SECTION_HEADERS) $(TMPDIR)/rdylib.o | grep -c $(LLVMBC_SECTION_NAME))" -ne "0" ] + $(ASSERT_IS_BITCODE_OBJ) $(TMPDIR)/rdylib.o exe: lib.rs $(BUILD_EXE) -o $(TMPDIR)/exe.o - [ "$$($(SECTION_HEADERS) $(TMPDIR)/exe.o | grep -c $(LLVMBC_SECTION_NAME))" -ne "0" ] + $(ASSERT_IS_BITCODE_OBJ) $(TMPDIR)/exe.o