Add a way to generate a list of symbols for dynamic linkage, resolves #…

…907

src/bindgen/bindings.rs

@@ -7,7 +7,7 @@ use std::cell::RefCell;
 use std::collections::HashMap;
 use std::fs;
 use std::fs::File;
-use std::io::{Read, Write};
+use std::io::{BufWriter, Read, Write};
 use std::path;
 use std::rc::Rc;
 
@@ -129,6 +129,28 @@ impl Bindings {
         fields
     }
 
+    /// Lists the exported symbols that can be dynamically linked, i.e. globals and functions.
+    pub fn dynamic_symbols_names(&self) -> impl Iterator<Item = &str> {
+        use crate::bindgen::ir::Item;
+
+        let function_names = self.functions.iter().map(|f| f.path().name());
+        let global_names = self.globals.iter().map(|g| g.export_name());
+        function_names.chain(global_names)
+    }
+
+    pub fn generate_symfile<P: AsRef<path::Path>>(&self, symfile_path: P) {
+        if let Some(dir) = symfile_path.as_ref().parent() {
+            std::fs::create_dir_all(dir).unwrap();
+        }
+        let mut symfile = File::create(symfile_path).unwrap();
+        let mut writer = BufWriter::new(symfile);
+        write!(&mut writer, "{{\n").expect("writing symbol file header failed");
+        for symbol in self.dynamic_symbols_names() {
+            write!(&mut symfile, "{};\n", symbol).expect("writing symbol failed");
+        }
+        write!(&mut writer, "}};").expect("writing symbol file footer failed");
+    }
+
     pub fn generate_depfile<P: AsRef<path::Path>>(&self, header_path: P, depfile_path: P) {
         if let Some(dir) = depfile_path.as_ref().parent() {
             if !dir.exists() {

src/main.rs

@@ -298,6 +298,17 @@ fn main() {
                     This option is ignored if `--out` is missing."
                 )
         )
+        .arg(
+            Arg::new("symfile")
+                .value_name("PATH")
+                .long("symfile")
+                .num_args(1)
+                .required(false)
+                .help("Generate a list of symbols at the given Path. This list can be \
+                    given to a linker in order to compile an application that exposes \
+                    dynamic symbols. Useful when creating a plugin system with a C interface."
+                )
+        )
         .get_matches();
 
     if matches.get_flag("verify") && !matches.contains_id("out") {
@@ -343,7 +354,10 @@ fn main() {
                 std::process::exit(2);
             }
             if let Some(depfile) = matches.get_one("depfile") {
-                bindings.generate_depfile(file, depfile)
+                bindings.generate_depfile(file, depfile);
+            }
+            if let Some(symfile) = matches.get_one::<String>("symfile") {
+                bindings.generate_symfile(symfile);
             }
         }
         _ => {

tests/expectations-symbols/abi_string.c.sym

@@ -0,0 +1,4 @@
+{
+c;
+c_unwind;
+};

tests/expectations-symbols/alias.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/annotation.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/array.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/asserted_cast.c.sym

@@ -0,0 +1,3 @@
+{
+foo;
+};

tests/expectations-symbols/assoc_constant.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/associated_in_body.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/bitfield.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/bitflags.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/body.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/box.c.sym

@@ -0,0 +1,5 @@
+{
+root;
+drop_box;
+drop_box_opt;
+};

tests/expectations-symbols/cdecl.c.sym

@@ -0,0 +1,4 @@
+{
+O;
+root;
+};

tests/expectations-symbols/cell.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/cfg.c.sym

@@ -0,0 +1,5 @@
+{
+root;
+root;
+cond;
+};

tests/expectations-symbols/cfg_2.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/char.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/const_generics.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/const_generics_arrayvec.c.sym

@@ -0,0 +1,3 @@
+{
+push;
+};

tests/expectations-symbols/const_generics_bool.c.sym

@@ -0,0 +1,6 @@
+{
+new_set;
+set_for_each;
+new_map;
+map_for_each;
+};

tests/expectations-symbols/const_generics_byte.c.sym

@@ -0,0 +1,5 @@
+{
+init_parens_parser;
+destroy_parens_parser;
+init_braces_parser;
+};

tests/expectations-symbols/const_generics_char.c.sym

@@ -0,0 +1,3 @@
+{
+until_nul;
+};

tests/expectations-symbols/const_generics_constant.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/const_generics_thru.c.sym

@@ -0,0 +1,4 @@
+{
+one;
+two;
+};

tests/expectations-symbols/constant.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/constant_sort_name.c.sym

@@ -0,0 +1,4 @@
+{
+C;
+D;
+};

tests/expectations-symbols/constant_sort_none.c.sym

@@ -0,0 +1,4 @@
+{
+D;
+C;
+};

tests/expectations-symbols/custom_header.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/decl_name_conflicting.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/dep_v2.c.sym

@@ -0,0 +1,3 @@
+{
+get_x;
+};

tests/expectations-symbols/deprecated.c.sym

@@ -0,0 +1,8 @@
+{
+deprecated_without_note;
+deprecated_without_bracket;
+deprecated_with_note;
+deprecated_with_note_and_since;
+deprecated_with_note_which_requires_to_be_escaped;
+dummy;
+};

tests/expectations-symbols/derive_eq.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/derive_ostream.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/destructor_and_copy_ctor.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/display_list.c.sym

@@ -0,0 +1,3 @@
+{
+push_item;
+};

tests/expectations-symbols/doclength_short.c.sym

@@ -0,0 +1,4 @@
+{
+root;
+trunk;
+};

tests/expectations-symbols/docstyle_auto.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/docstyle_c99.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/docstyle_doxy.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/documentation.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/documentation_attr.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/enum.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/enum_discriminant.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/enum_self.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/euclid.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/exclude_generic_monomorph.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/expand.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/expand_default_features.c.sym

@@ -0,0 +1,4 @@
+{
+extra_debug_fn;
+root;
+};

tests/expectations-symbols/expand_dep.c.sym

@@ -0,0 +1,3 @@
+{
+get_x;
+};

tests/expectations-symbols/expand_dep_v2.c.sym

@@ -0,0 +1,3 @@
+{
+get_x;
+};

tests/expectations-symbols/expand_features.c.sym

@@ -0,0 +1,5 @@
+{
+extra_debug_fn;
+cbindgen;
+root;
+};

tests/expectations-symbols/expand_no_default_features.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/export_name.c.sym

@@ -0,0 +1,3 @@
+{
+do_the_thing_with_export_name;
+};

tests/expectations-symbols/extern.c.sym

@@ -0,0 +1,4 @@
+{
+foo;
+bar;
+};

tests/expectations-symbols/extern_2.c.sym

@@ -0,0 +1,4 @@
+{
+first;
+second;
+};

tests/expectations-symbols/external_workspace_child.c.sym

@@ -0,0 +1,3 @@
+{
+consume_ext;
+};

tests/expectations-symbols/fns.c.sym

@@ -0,0 +1,4 @@
+{
+root;
+no_return;
+};

tests/expectations-symbols/forward_declaration.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/function_args.c.sym

@@ -0,0 +1,5 @@
+{
+unnamed;
+pointer_test;
+print_from_rust;
+};

tests/expectations-symbols/function_noreturn.c.sym

@@ -0,0 +1,4 @@
+{
+loop_forever;
+normal_return;
+};

tests/expectations-symbols/function_ptr.c.sym

@@ -0,0 +1,3 @@
+{
+my_function;
+};

tests/expectations-symbols/function_sort_name.c.sym

@@ -0,0 +1,6 @@
+{
+A;
+B;
+C;
+D;
+};

tests/expectations-symbols/function_sort_none.c.sym

@@ -0,0 +1,6 @@
+{
+C;
+B;
+D;
+A;
+};

tests/expectations-symbols/generic_pointer.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/global_variable.c.sym

@@ -0,0 +1,4 @@
+{
+MUT_GLOBAL_ARRAY;
+CONST_GLOBAL_ARRAY;
+};

tests/expectations-symbols/ignore.c.sym

@@ -0,0 +1,3 @@
+{
+no_ignore_root;
+};

tests/expectations-symbols/include_guard.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/inner_mod.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/item_types.c.sym

@@ -0,0 +1,3 @@
+{
+;
+};

tests/expectations-symbols/item_types_renamed.c.sym

@@ -0,0 +1,3 @@
+{
+;
+};

tests/expectations-symbols/lifetime_arg.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/linestyle_cr.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/linestyle_crlf.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/linestyle_lf.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};

tests/expectations-symbols/mangle.c.sym

@@ -0,0 +1,3 @@
+{
+root;
+};