[mach-o] Add support for -force_load option

The darwin linker has two ways to force all members of an archive to be loaded.
The -all_load option applies to all static libraries.  The -force_load takes
a path to a library and just that library's members are force loaded.

llvm-svn: 221477

3 files changed, 45 insertions, 0 deletions

diff --git a/lld/lib/Driver/DarwinLdDriver.cpp b/lld/lib/Driver/DarwinLdDriver.cpp
index 645a3efb650..723b6509395 100644
--- a/lld/lib/Driver/DarwinLdDriver.cpp
+++ b/lld/lib/Driver/DarwinLdDriver.cpp
@@ -658,6 +658,9 @@ bool DarwinLdDriver::parse(int argc, const char *argv[],
     case OPT_upward_library:
       addFile(arg->getValue(), inputGraph, ctx, false, true);
       break;
+    case OPT_force_load:
+      addFile(arg->getValue(), inputGraph, ctx, true, false);
+      break;
     case OPT_l:
     case OPT_upward_l:
       upward = (arg->getOption().getID() == OPT_upward_l);
diff --git a/lld/lib/Driver/DarwinLdOptions.td b/lld/lib/Driver/DarwinLdOptions.td
index d819c03aac0..eefb2c7b92d 100644
--- a/lld/lib/Driver/DarwinLdOptions.td
+++ b/lld/lib/Driver/DarwinLdOptions.td
@@ -107,6 +107,10 @@ def Z : Flag<["-"], "Z">,
 def all_load : Flag<["-"], "all_load">,
      HelpText<"Forces all members of all static libraries to be loaded">,
      Group<grp_libs>;
+def force_load : Separate<["-"], "force_load">,
+     MetaVarName<"<library-path>">,
+     HelpText<"Forces all members of specified static libraries to be loaded">,
+     Group<grp_libs>;
 def syslibroot : Separate<["-"], "syslibroot">, MetaVarName<"<dir>">,
      HelpText<"Add path to SDK to all absolute library search paths">,
      Group<grp_libs>;
diff --git a/lld/test/mach-o/force_load-x86_64.yaml b/lld/test/mach-o/force_load-x86_64.yaml
new file mode 100644
index 00000000000..35905effd2c
--- /dev/null
+++ b/lld/test/mach-o/force_load-x86_64.yaml
@@ -0,0 +1,38 @@
+# RUN: lld -flavor darwin -arch x86_64  %s %p/Inputs/libSystem.yaml \
+# RUN:      %p/Inputs/libfoo.a %p/Inputs/libbar.a -o %t1
+# RUN: llvm-nm -m -n %t1 | FileCheck %s
+#
+# RUN: lld -flavor darwin -arch x86_64  %s %p/Inputs/libSystem.yaml \
+# RUN:      -force_load %p/Inputs/libfoo.a %p/Inputs/libbar.a -o %t2
+# RUN: llvm-nm -m -n %t2 | FileCheck --check-prefix=CHECKF %s
+#
+# Test that -force_load causes members of static library to be loaded.
+#
+
+--- !mach-o
+arch:            x86_64
+file-type:       MH_OBJECT
+flags:           [ MH_SUBSECTIONS_VIA_SYMBOLS ]
+has-UUID:        false
+OS:              unknown
+sections:        
+  - segment:         __TEXT
+    section:         __text
+    type:            S_REGULAR
+    attributes:      [ S_ATTR_PURE_INSTRUCTIONS, S_ATTR_SOME_INSTRUCTIONS ]
+    address:         0x0000000000000000
+    content:         [ 0xC3 ]
+global-symbols:  
+  - name:            _main
+    type:            N_SECT
+    scope:           [ N_EXT ]
+    sect:            1
+    value:           0x0000000000000000
+...
+
+# CHECK:      {{[0-9a-f]+}} (__TEXT,__text) external _main
+# CHECK-NOT:	{{[0-9a-f]+}} (__TEXT,__text) external _main
+
+# CHECKF:     {{[0-9a-f]+}} (__TEXT,__text) external _main
+# CHECKF:     {{[0-9a-f]+}} (__TEXT,__text) external _foo
+# CHECKF-NOT: {{[0-9a-f]+}} (__TEXT,__text) external _bar