Remove BITCODE_TOUCH_SYMBOL_MAP

This was a workaround for a ld64 bug that has been fixed as far back as Xcode 10.x. The logic (from Xcode 10.2) is now: ``` int ret = ::stat(fReverseMapPath, &statbuf); if ( ret == 0 && S_ISDIR(statbuf.st_mode)) { ``` Closes #12379. PiperOrigin-RevId: 341880058
bazelbuild · Nov 11, 2020 · a1471a8 · a1471a8
1 parent c7df294
commit a1471a8
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Showing 3 changed files with 3 additions and 21 deletions.
diff --git a/src/test/java/com/google/devtools/build/lib/packages/util/mock/osx_cc_toolchain_config.bzl b/src/test/java/com/google/devtools/build/lib/packages/util/mock/osx_cc_toolchain_config.bzl
@@ -5961,7 +5961,7 @@ def _impl(ctx):
                                 "-Xlinker",
                                 "-bitcode_symbol_map",
                                 "-Xlinker",
-                                "BITCODE_TOUCH_SYMBOL_MAP=%{bitcode_symbol_map_path}",
+                                "%{bitcode_symbol_map_path}",
                             ],
                         ),
                     ],

diff --git a/tools/osx/crosstool/cc_toolchain_config.bzl b/tools/osx/crosstool/cc_toolchain_config.bzl
@@ -6009,7 +6009,7 @@ def _impl(ctx):
                                 "-Xlinker",
                                 "-bitcode_symbol_map",
                                 "-Xlinker",
-                                "BITCODE_TOUCH_SYMBOL_MAP=%{bitcode_symbol_map_path}",
+                                "%{bitcode_symbol_map_path}",
                             ],
                             expand_if_available = "bitcode_symbol_map_path",
                         ),

diff --git a/tools/osx/crosstool/wrapped_clang.cc b/tools/osx/crosstool/wrapped_clang.cc
@@ -23,18 +23,6 @@
 // "DSYM_HINT_LINKED_BINARY": Workspace-relative path to binary output of the
 //    link action generating the dsym file.
 // "DSYM_HINT_DSYM_PATH": Workspace-relative path to dSYM dwarf file.
-//
-// Likewise, this wrapper also contains a workaround for a bug in ld that causes
-// flaky builds when using Bitcode symbol maps. ld allows the
-// -bitcode_symbol_map to be either a directory (into which the file will be
-// written) or a file, but the return value of the call to ::stat is never
-// checked so examining the S_ISDIR bit of the struct afterwards returns
-// true/false randomly depending on what data happened to be in memory at the
-// time it was called:
-// https://github.com/michaelweiser/ld64/blob/9c3700b64ed03e2d55ba094176bf6a172bf2bc6b/src/ld/Options.cpp#L3261
-// To address this, we prepend a special "BITCODE_TOUCH_SYMBOL_MAP=" flag to the
-// symbol map filename and touch it before passing it along to clang, forcing
-// the file to exist.
 
 #include <libgen.h>
 #include <spawn.h>
@@ -191,7 +179,7 @@ int main(int argc, char *argv[]) {
 
   std::vector<std::string> processed_args = {"/usr/bin/xcrun", tool_name};
 
-  std::string linked_binary, dsym_path, bitcode_symbol_map;
+  std::string linked_binary, dsym_path;
   std::string dest_dir;
 
   std::unique_ptr<char, decltype(std::free) *> cwd{getcwd(nullptr, 0),
@@ -211,12 +199,6 @@ int main(int argc, char *argv[]) {
     if (SetArgIfFlagPresent(arg, "DSYM_HINT_DSYM_PATH", &dsym_path)) {
       continue;
     }
-    if (SetArgIfFlagPresent(arg, "BITCODE_TOUCH_SYMBOL_MAP",
-                            &bitcode_symbol_map)) {
-      // Touch bitcode_symbol_map.
-      std::ofstream bitcode_symbol_map_file(bitcode_symbol_map);
-      arg = bitcode_symbol_map;
-    }
     if (arg.compare("OSO_PREFIX_MAP_PWD") == 0) {
       arg = "-Wl,-oso_prefix," + std::string(cwd.get()) + "/";
     }