Auto merge of #38117 - michaelwoerister:hidden-symbols, r=alexcrichton

Improve symbol visibility handling for dynamic libraries.

This will hopefully fix issue https://github.com/rust-lang/rust/issues/37530 and maybe also https://github.com/rust-lang/rust/issues/32887.

I'm relying on @m4b to post some numbers on how awesome the improvement for cdylibs is `:)`

cc @rust-lang/compiler @rust-lang/tools @cuviper @froydnj
r? @alexcrichton

src/test/run-make/sepcomp-inlining/Makefile

@@ -10,5 +10,5 @@ all:
 	$(RUSTC) foo.rs --emit=llvm-ir -C codegen-units=3
 	[ "$$(cat "$(TMPDIR)"/foo.?.ll | grep -c define\ i32\ .*inlined)" -eq "0" ]
 	[ "$$(cat "$(TMPDIR)"/foo.?.ll | grep -c define\ internal\ i32\ .*inlined)" -eq "2" ]
-	[ "$$(cat "$(TMPDIR)"/foo.?.ll | grep -c define\ i32\ .*normal)" -eq "1" ]
-	[ "$$(cat "$(TMPDIR)"/foo.?.ll | grep -c declare\ i32\ .*normal)" -eq "2" ]
+	[ "$$(cat "$(TMPDIR)"/foo.?.ll | grep -c define\ hidden\ i32\ .*normal)" -eq "1" ]
+	[ "$$(cat "$(TMPDIR)"/foo.?.ll | grep -c declare\ hidden\ i32\ .*normal)" -eq "2" ]

src/test/run-make/symbol-visibility/Makefile

@@ -0,0 +1,50 @@
+include ../tools.mk
+
+ifdef IS_WINDOWS
+# Do nothing on MSVC.
+# On MINGW the --version-script, --dynamic-list, and --retain-symbol args don't
+# seem to work reliably.
+all:
+	exit 0
+else
+
+NM=nm -D
+DYLIB_EXT=so
+CDYLIB_NAME=liba_cdylib.so
+RDYLIB_NAME=liba_rust_dylib.so
+EXE_NAME=an_executable
+
+ifeq ($(UNAME),Darwin)
+NM=nm -gU
+DYLIB_EXT=dylib
+CDYLIB_NAME=liba_cdylib.dylib
+RDYLIB_NAME=liba_rust_dylib.dylib
+EXE_NAME=an_executable
+endif
+
+all:
+	$(RUSTC) an_rlib.rs
+	$(RUSTC) a_cdylib.rs
+	$(RUSTC) a_rust_dylib.rs
+	$(RUSTC) an_executable.rs
+
+	# Check that a cdylib exports its public #[no_mangle] functions
+	[ "$$($(NM) $(TMPDIR)/$(CDYLIB_NAME) | grep -c public_c_function_from_cdylib)" -eq "1" ]
+	# Check that a cdylib exports the public #[no_mangle] functions of dependencies
+	[ "$$($(NM) $(TMPDIR)/$(CDYLIB_NAME) | grep -c public_c_function_from_rlib)" -eq "1" ]
+	# Check that a cdylib DOES NOT export any public Rust functions
+	[ "$$($(NM) $(TMPDIR)/$(CDYLIB_NAME) | grep -c _ZN.*h.*E)" -eq "0" ]
+
+	# Check that a Rust dylib exports its monomorphic functions
+	[ "$$($(NM) $(TMPDIR)/$(RDYLIB_NAME) | grep -c public_c_function_from_rust_dylib)" -eq "1" ]
+	[ "$$($(NM) $(TMPDIR)/$(RDYLIB_NAME) | grep -c _ZN.*public_rust_function_from_rust_dylib.*E)" -eq "1" ]
+
+	# Check that a Rust dylib exports the monomorphic functions from its dependencies
+	[ "$$($(NM) $(TMPDIR)/$(RDYLIB_NAME) | grep -c public_c_function_from_rlib)" -eq "1" ]
+	[ "$$($(NM) $(TMPDIR)/$(RDYLIB_NAME) | grep -c public_rust_function_from_rlib)" -eq "1" ]
+
+	# Check that an executable does not export any dynamic symbols
+	[ "$$($(NM) $(TMPDIR)/$(EXE_NAME) | grep -c public_c_function_from_rlib)" -eq "0" ]
+	[ "$$($(NM) $(TMPDIR)/$(EXE_NAME) | grep -c public_rust_function_from_exe)" -eq "0" ]
+
+endif

src/test/run-make/symbol-visibility/a_cdylib.rs

@@ -0,0 +1,22 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type="cdylib"]
+
+extern crate an_rlib;
+
+// This should not be exported
+pub fn public_rust_function_from_cdylib() {}
+
+// This should be exported
+#[no_mangle]
+pub extern "C" fn public_c_function_from_cdylib() {
+    an_rlib::public_c_function_from_rlib();
+}

src/test/run-make/symbol-visibility/a_rust_dylib.rs

@@ -0,0 +1,20 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type="dylib"]
+
+extern crate an_rlib;
+
+// This should be exported
+pub fn public_rust_function_from_rust_dylib() {}
+
+// This should be exported
+#[no_mangle]
+pub extern "C" fn public_c_function_from_rust_dylib() {}

src/test/run-make/symbol-visibility/an_executable.rs

@@ -0,0 +1,17 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type="bin"]
+
+extern crate an_rlib;
+
+pub fn public_rust_function_from_exe() {}
+
+fn main() {}

src/test/run-make/symbol-visibility/an_rlib.rs

@@ -0,0 +1,16 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type="rlib"]
+
+pub fn public_rust_function_from_rlib() {}
+
+#[no_mangle]
+pub extern "C" fn public_c_function_from_rlib() {}