From ada2c55dcc106cd55bafbbe5d9a966e21e4770e0 Mon Sep 17 00:00:00 2001
From: Keith Smiley <keithbsmiley@gmail.com>
Date: Fri, 13 Sep 2019 08:09:31 -0700
Subject: [PATCH] Add explicit --sdk argument to xcrun calls

Xcode 11 (and possibly earlier versions) has a bug where, when you don't
pass `-sdk macosx`, it can either pick the global
`/Library/Developer/CommandLineTools` SDK path, or the SDK path bundled
within Xcode itself. This seems to depend on if you have other versions
of Xcode installed, and which versions of the command line tools you
have installed. Passing `-sdk macosx` seems to always force it to pick
the Xcode bundled version, which is what we prefer. This fixes issues
with remote cache misses caused by these tools not being the same
because of this difference. At least 2 apple bugs have been filed
about this FB7147521 FB7253366

You can see which path it's picking by running:

```
env -i xcrun -l -n clang
```

Closes #9371.

PiperOrigin-RevId: 268906772
---
 scripts/bootstrap/compile.sh   | 2 +-
 src/tools/xcode/realpath/BUILD | 2 +-
 tools/cpp/osx_cc_configure.bzl | 2 ++
 tools/osx/BUILD                | 2 +-
 tools/osx/xcode_configure.bzl  | 2 ++
 5 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/scripts/bootstrap/compile.sh b/scripts/bootstrap/compile.sh
index 06a98546cc7e32..dcc98b40d83bdc 100755
--- a/scripts/bootstrap/compile.sh
+++ b/scripts/bootstrap/compile.sh
@@ -398,7 +398,7 @@ cp $OUTPUT_DIR/libblaze.jar ${ARCHIVE_DIR}
 # TODO(b/28965185): Remove when xcode-locator is no longer required in embedded_binaries.
 log "Compiling xcode-locator..."
 if [[ $PLATFORM == "darwin" ]]; then
-  run /usr/bin/xcrun clang -fobjc-arc -framework CoreServices -framework Foundation -o ${ARCHIVE_DIR}/_embedded_binaries/xcode-locator tools/osx/xcode_locator.m
+  run /usr/bin/xcrun --sdk macosx clang -fobjc-arc -framework CoreServices -framework Foundation -o ${ARCHIVE_DIR}/_embedded_binaries/xcode-locator tools/osx/xcode_locator.m
 else
   cp tools/osx/xcode_locator_stub.sh ${ARCHIVE_DIR}/_embedded_binaries/xcode-locator
 fi
diff --git a/src/tools/xcode/realpath/BUILD b/src/tools/xcode/realpath/BUILD
index 8642f9c7c7cb1b..14d1745d8f40c1 100644
--- a/src/tools/xcode/realpath/BUILD
+++ b/src/tools/xcode/realpath/BUILD
@@ -5,7 +5,7 @@ genrule(
     name = "realpath_genrule",
     srcs = ["realpath.c"],
     outs = ["realpath"],
-    cmd = "/usr/bin/xcrun clang -o $@ $<",
+    cmd = "/usr/bin/xcrun --sdk macosx clang -o $@ $<",
     output_to_bindir = 1,
     visibility = ["//visibility:public"],
 )
diff --git a/tools/cpp/osx_cc_configure.bzl b/tools/cpp/osx_cc_configure.bzl
index 9434c168b2f06f..7202d499e95997 100644
--- a/tools/cpp/osx_cc_configure.bzl
+++ b/tools/cpp/osx_cc_configure.bzl
@@ -108,6 +108,8 @@ def configure_osx_toolchain(repository_ctx, overriden_tools):
             "env",
             "-i",
             "xcrun",
+            "--sdk",
+            "macosx",
             "clang",
             "-std=c++11",
             "-lc++",
diff --git a/tools/osx/BUILD b/tools/osx/BUILD
index b1326e27af5f32..b3568dc30419a9 100644
--- a/tools/osx/BUILD
+++ b/tools/osx/BUILD
@@ -18,7 +18,7 @@ exports_files([
 ])
 
 DARWIN_XCODE_LOCATOR_COMPILE_COMMAND = """
-  /usr/bin/xcrun clang -fobjc-arc -framework CoreServices \
+  /usr/bin/xcrun --sdk macosx clang -fobjc-arc -framework CoreServices \
       -framework Foundation -o $@ $<
 """
 
diff --git a/tools/osx/xcode_configure.bzl b/tools/osx/xcode_configure.bzl
index 6136bcd7b1f6a3..509c16553bb5b8 100644
--- a/tools/osx/xcode_configure.bzl
+++ b/tools/osx/xcode_configure.bzl
@@ -117,6 +117,8 @@ def run_xcode_locator(repository_ctx, xcode_locator_src_label):
         "env",
         "-i",
         "xcrun",
+        "--sdk",
+        "macosx",
         "clang",
         "-fobjc-arc",
         "-framework",