Enable -rpath flag

src/lib/libdylink.js

@@ -447,7 +447,7 @@ var LibraryDylink = {
       name = getString();
     }
 
-    var customSection = { neededDynlibs: [], tlsExports: new Set(), weakImports: new Set() };
+    var customSection = { neededDynlibs: [], tlsExports: new Set(), weakImports: new Set(), runtimePaths: [] };
     if (name == 'dylink') {
       customSection.memorySize = getLEB();
       customSection.memoryAlign = getLEB();
@@ -457,7 +457,7 @@ var LibraryDylink = {
       // current module could resolve its imports. (see tools/shared.py
       // WebAssembly.make_shared_library() for "dylink" section extension format)
       var neededDynlibsCount = getLEB();
-      for (var i = 0; i < neededDynlibsCount; ++i) {
+      while (neededDynlibsCount--) {
         var libname = getString();
         customSection.neededDynlibs.push(libname);
       }
@@ -467,6 +467,7 @@ var LibraryDylink = {
       var WASM_DYLINK_NEEDED = 0x2;
       var WASM_DYLINK_EXPORT_INFO = 0x3;
       var WASM_DYLINK_IMPORT_INFO = 0x4;
+      var WASM_DYLINK_RUNTIME_PATH = 0x5;
       var WASM_SYMBOL_TLS = 0x100;
       var WASM_SYMBOL_BINDING_MASK = 0x3;
       var WASM_SYMBOL_BINDING_WEAK = 0x1;
@@ -480,8 +481,8 @@ var LibraryDylink = {
           customSection.tableAlign = getLEB();
         } else if (subsectionType === WASM_DYLINK_NEEDED) {
           var neededDynlibsCount = getLEB();
-          for (var i = 0; i < neededDynlibsCount; ++i) {
-            libname = getString();
+          while (neededDynlibsCount--) {
+            var libname = getString();
             customSection.neededDynlibs.push(libname);
           }
         } else if (subsectionType === WASM_DYLINK_EXPORT_INFO) {
@@ -503,6 +504,12 @@ var LibraryDylink = {
               customSection.weakImports.add(symname);
             }
           }
+        } else if (subsectionType === WASM_DYLINK_RUNTIME_PATH) {
+          var runtimePathsCount = getLEB();
+          while (runtimePathsCount--) {
+            var path = getString();
+            customSection.runtimePaths.push(path);
+          }
         } else {
 #if ASSERTIONS
           err(`unknown dylink.0 subsection: ${subsectionType}`)

test/other/codesize/test_codesize_hello_dylink.gzsize

@@ -1 +1 @@
-5907
+5911

test/other/codesize/test_codesize_hello_dylink.jssize

@@ -1 +1 @@
-13048
+13085

test/test_other.py

@@ -2357,6 +2357,55 @@ def test_dylink_dependencies(self):
     self.run_process(cmd + ['-L.'])
     self.run_js('a.out.js')
 
+  def test_dylink_dependencies_rpath(self):
+    create_file('side1.c', r'''
+    #include <stdio.h>
+    #include <stdlib.h>
+
+    void side2();
+
+    void side1() {
+        printf("side1\n");
+        side2();
+    }
+    ''')
+    create_file('side2.c', r'''
+    #include <stdio.h>
+    #include <stdlib.h>
+
+    void side2() {
+        printf("side2\n");
+    }
+    ''')
+    create_file('main.c', '''
+    void side1();
+
+    int main() {
+        side1();
+        return 0;
+    }
+    ''')
+    self.emcc('side2.c', ['-fPIC', '-sSIDE_MODULE', '-olibside2.so'])
+    self.emcc('side1.c', ['-fPIC', '-sSIDE_MODULE', '-Wl,-rpath,$ORIGIN', '-olibside1.so', 'libside2.so'])
+    cmd = [EMCC, 'main.c', '-fPIC', '-sMAIN_MODULE=2', 'libside1.so']
+
+    # Unless `.` is added to the library path the libside2.so won't be found.
+    err = self.expect_fail(cmd)
+    self.assertContained('emcc: error: libside1.so: shared library dependency not found in library path: `libside2.so`.', err)
+
+    # Adding -L. to the library path makes it work.
+    self.run_process(cmd + ['-L.', '-Wl,-rpath,$ORIGIN'])
+    self.run_js('a.out.js')
+
+    def get_runtime_paths(path):
+      with webassembly.Module(path) as module:
+        dylink_section = module.parse_dylink_section()
+        return dylink_section.runtime_paths
+
+    self.assertEqual(get_runtime_paths('libside2.so'), [])
+    self.assertEqual(get_runtime_paths('libside1.so'), ['$ORIGIN'])
+    self.assertEqual(get_runtime_paths('a.out.wasm'), ['$ORIGIN'])
+
   def test_dylink_LEGACY_GL_EMULATION(self):
     # LEGACY_GL_EMULATION wraps JS library functions. This test ensure that when it does
     # so it preserves the `.sig` attributes needed by dynamic linking.
@@ -12415,9 +12464,6 @@ def test_missing_stdlibs(self):
     self.run_process([EMCC, test_file('hello_world.c'), '-lm', '-ldl', '-lrt', '-lpthread'])
 
   def test_supported_linker_flags(self):
-    out = self.run_process([EMCC, test_file('hello_world.c'), '-Wl,-rpath=foo'], stderr=PIPE).stderr
-    self.assertContained('warning: ignoring unsupported linker flag: `-rpath=foo`', out)
-
     out = self.run_process([EMCC, test_file('hello_world.c'), '-Wl,-rpath-link,foo'], stderr=PIPE).stderr
     self.assertContained('warning: ignoring unsupported linker flag: `-rpath-link`', out)
 
@@ -12437,7 +12483,7 @@ def test_supported_linker_flags(self):
   def test_supported_linker_flag_skip_next(self):
     # Regression test for a bug where skipping an unsupported linker flag
     # could skip the next unrelated linker flag.
-    err = self.expect_fail([EMCC, test_file('hello_world.c'), '-Wl,-rpath=foo', '-lbar'])
+    err = self.expect_fail([EMCC, test_file('hello_world.c'), '-Wl,-version-script,foo', '-lbar'])
     self.assertContained('error: unable to find library -lbar', err)
 
   def test_linker_flags_pass_through(self):

tools/link.py

@@ -61,7 +61,8 @@
     '--start-group', '--end-group',
     '-(', '-)',
     '--whole-archive', '--no-whole-archive',
-    '-whole-archive', '-no-whole-archive'
+    '-whole-archive', '-no-whole-archive',
+    '-rpath',
 )
 
 # Unsupported LLD flags which we will ignore.
@@ -72,7 +73,6 @@
     # wasm-ld doesn't support soname or other dynamic linking flags (yet).   Ignore them
     # in order to aid build systems that want to pass these flags.
     '-allow-shlib-undefined': False,
-    '-rpath': True,
     '-rpath-link': True,
     '-version-script': True,
     '-install_name': True,

tools/webassembly.py

@@ -149,6 +149,7 @@ class DylinkType(IntEnum):
   NEEDED = 2
   EXPORT_INFO = 3
   IMPORT_INFO = 4
+  RUNTIME_PATH = 5
 
 
 class TargetFeaturePrefix(IntEnum):
@@ -165,7 +166,7 @@ class InvalidWasmError(BaseException):
 Import = namedtuple('Import', ['kind', 'module', 'field', 'type'])
 Export = namedtuple('Export', ['name', 'kind', 'index'])
 Global = namedtuple('Global', ['type', 'mutable', 'init'])
-Dylink = namedtuple('Dylink', ['mem_size', 'mem_align', 'table_size', 'table_align', 'needed', 'export_info', 'import_info'])
+Dylink = namedtuple('Dylink', ['mem_size', 'mem_align', 'table_size', 'table_align', 'needed', 'export_info', 'import_info', 'runtime_paths'])
 Table = namedtuple('Table', ['elem_type', 'limits'])
 FunctionBody = namedtuple('FunctionBody', ['offset', 'size'])
 DataSegment = namedtuple('DataSegment', ['flags', 'init', 'offset', 'size'])
@@ -313,6 +314,7 @@ def parse_dylink_section(self):
     needed = []
     export_info = {}
     import_info = {}
+    runtime_paths = []
     self.read_string()  # name
 
     if dylink_section.name == 'dylink':
@@ -359,6 +361,12 @@ def parse_dylink_section(self):
             import_info.setdefault(module, {})
             import_info[module][field] = flags
             count -= 1
+        elif subsection_type == DylinkType.RUNTIME_PATH:
+          count = self.read_uleb()
+          while count:
+            rpath = self.read_string()
+            runtime_paths.append(rpath)
+            count -= 1
         else:
           print(f'unknown subsection: {subsection_type}')
           # ignore unknown subsections
@@ -367,7 +375,7 @@ def parse_dylink_section(self):
     else:
       utils.exit_with_error('error parsing shared library')
 
-    return Dylink(mem_size, mem_align, table_size, table_align, needed, export_info, import_info)
+    return Dylink(mem_size, mem_align, table_size, table_align, needed, export_info, import_info, runtime_paths)
 
   @memoize
   def get_exports(self):