[compiler-rt] b16dfbe - [Darwin] Fix OS version checks inside simulators

[Julian Lettner via llvm-commits]

Author: Julian Lettner
Date: 2020-07-16T10:48:04-07:00
New Revision: b16dfbead21a458799a0dab96599eb15f5d9b7ea

URL: https://github.com/llvm/llvm-project/commit/b16dfbead21a458799a0dab96599eb15f5d9b7ea
DIFF: https://github.com/llvm/llvm-project/commit/b16dfbead21a458799a0dab96599eb15f5d9b7ea.diff

LOG: [Darwin] Fix OS version checks inside simulators

compiler-rt checks OS versions by querying the Darwin kernel version.
This is not necessarily correct inside the simulators if the simulator
runtime is not aligned with the host macOS.  Let's instead check the
`SIMULATOR_RUNTIME_VERSION` env var.

Note that we still use the old code path as a fallback in case the
`SIMULATOR_RUNTIME_VERSION` environment variable isn't set.

rdar://63031937

Reviewers: delcypher

Differential Revision: https://reviews.llvm.org/D79979

Added: 
    

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp
    compiler-rt/lib/sanitizer_common/tests/sanitizer_mac_test.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp
index 7a3dfbcc2760..eb9c662190e7 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp
@@ -606,9 +606,32 @@ HandleSignalMode GetHandleSignalMode(int signum) {
   return result;
 }
 
+void ParseVersion(const char *vers, u16 *major, u16 *minor) {
+  // Format: <major>.<minor>[.<patch>]\0
+  CHECK_GE(internal_strlen(vers), 3);
+  const char *p = vers;
+  *major = internal_simple_strtoll(p, &p, /*base=*/10);
+  CHECK_EQ(*p, '.');
+  p += 1;
+  *minor = internal_simple_strtoll(p, &p, /*base=*/10);
+}
+
+// Aligned versions example:
+// Darwin 19 -- macOS 10.15 -- iOS 13 -- tvOS 13 -- watchOS 6
+static u16 GetDarwinKernelMajorFromOSMajor(u16 os_major) {
+  u16 offset;
+  if (SANITIZER_IOS || SANITIZER_TVOS)
+    offset = 6;
+  else if (SANITIZER_WATCHOS)
+    offset = 13;
+  else  // macOS
+    UNREACHABLE("GetDarwinKernelMajorFromOSMajor() does not support macOS");
+
+  return os_major + offset;
+}
+
 // This corresponds to Triple::getMacOSXVersion() in the Clang driver.
-static MacosVersion GetMacosAlignedVersionInternal() {
-  u16 kernel_major = GetDarwinKernelVersion().major;
+static MacosVersion GetMacosVersionFromDarwinMajor(u16 kernel_major) {
   // Darwin 0-3  -> unsupported
   // Darwin 4-19 -> macOS 10.x
   // Darwin 20+  -> macOS 11+
@@ -624,6 +647,22 @@ static MacosVersion GetMacosAlignedVersionInternal() {
   return MacosVersion(major, minor);
 }
 
+static MacosVersion GetMacosAlignedVersionInternal() {
+  if (SANITIZER_IOSSIM) {
+    if (auto vers = GetEnv("SIMULATOR_RUNTIME_VERSION")) {
+      u16 major, minor;
+      ParseVersion(vers, &major, &minor);
+      u16 kernel_major = GetDarwinKernelMajorFromOSMajor(major);
+      return GetMacosVersionFromDarwinMajor(kernel_major);
+    }
+    Report("WARNING: Running in simulator but SIMULATOR_RUNTIME_VERSION env "
+           "var is not set.\n");
+  }
+
+  u16 kernel_major = GetDarwinKernelVersion().major;
+  return GetMacosVersionFromDarwinMajor(kernel_major);
+}
+
 static_assert(sizeof(MacosVersion) == sizeof(atomic_uint32_t::Type),
               "MacosVersion cache size");
 static atomic_uint32_t cached_macos_version;
@@ -639,24 +678,14 @@ MacosVersion GetMacosAlignedVersion() {
   return *reinterpret_cast<MacosVersion *>(&result);
 }
 
-void ParseVersion(const char *vers, u16 *major, u16 *minor) {
-  // Format: <major>.<minor>.<patch>\0
-  CHECK_GE(internal_strlen(vers), 5);
-  const char *p = vers;
-  *major = internal_simple_strtoll(p, &p, /*base=*/10);
-  CHECK_EQ(*p, '.');
-  p += 1;
-  *minor = internal_simple_strtoll(p, &p, /*base=*/10);
-}
-
 DarwinKernelVersion GetDarwinKernelVersion() {
-  char buf[100];
-  size_t len = sizeof(buf);
-  int res = internal_sysctlbyname("kern.osrelease", buf, &len, nullptr, 0);
+  char vers[100];
+  size_t len = sizeof(vers);
+  int res = internal_sysctlbyname("kern.osrelease", vers, &len, nullptr, 0);
   CHECK_EQ(res, 0);
 
   u16 major, minor;
-  ParseVersion(buf, &major, &minor);
+  ParseVersion(vers, &major, &minor);
 
   return DarwinKernelVersion(major, minor);
 }

diff  --git a/compiler-rt/lib/sanitizer_common/tests/sanitizer_mac_test.cpp b/compiler-rt/lib/sanitizer_common/tests/sanitizer_mac_test.cpp
index c8658ea55d03..db5cbce7cbee 100644
--- a/compiler-rt/lib/sanitizer_common/tests/sanitizer_mac_test.cpp
+++ b/compiler-rt/lib/sanitizer_common/tests/sanitizer_mac_test.cpp
@@ -22,6 +22,35 @@
 
 namespace __sanitizer {
 
+void ParseVersion(const char *vers, u16 *major, u16 *minor);
+
+TEST(SanitizerMac, ParseVersion) {
+  u16 major, minor;
+
+  ParseVersion("11.22.33", &major, &minor);
+  EXPECT_EQ(major, 11); EXPECT_EQ(minor, 22);
+
+  ParseVersion("1.2", &major, &minor);
+  EXPECT_EQ(major, 1); EXPECT_EQ(minor, 2);
+}
+
+#if SANITIZER_IOSSIM
+TEST(SanitizerMac, GetMacosAlignedVersion) {
+  const char *vers_str;
+  if (SANITIZER_IOS || SANITIZER_TVOS) {
+    vers_str = "13.0";
+  } else if (SANITIZER_WATCHOS) {
+    vers_str = "6.5";
+  } else {
+    FAIL() << "unsupported simulator runtime";
+  }
+  setenv("SIMULATOR_RUNTIME_VERSION", vers_str, /*overwrite=*/1);
+
+  MacosVersion vers = GetMacosAlignedVersion();
+  EXPECT_EQ(vers.major, 10);
+  EXPECT_EQ(vers.minor, 15);
+}
+#else
 TEST(SanitizerMac, GetMacosAlignedVersion) {
   MacosVersion vers = GetMacosAlignedVersion();
   u16 kernel_major = GetDarwinKernelVersion().major;
@@ -31,15 +60,7 @@ TEST(SanitizerMac, GetMacosAlignedVersion) {
   EXPECT_EQ(vers.major, expected_major);
   EXPECT_EQ(vers.minor, expected_minor);
 }
-
-void ParseVersion(const char *vers, u16 *major, u16 *minor);
-
-TEST(SanitizerMac, ParseVersion) {
-  u16 major, minor;
-  ParseVersion("11.22.33", &major, &minor);
-  EXPECT_EQ(major, 11);
-  EXPECT_EQ(minor, 22);
-}
+#endif
 
 TEST(SanitizerMac, GetDarwinKernelVersion) {
   DarwinKernelVersion vers = GetDarwinKernelVersion();