[CodeGenFunction] Fix emission of implicit syncs before returns for r…

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -394,7 +394,8 @@ void CodeGenFunction::FinishFunction(SourceLocation EndLoc) {
 
     PopCleanupBlocks(PrologueCleanupDepth, {}, CompilingCilk);
     SyncEmitted = true;
-  } else if (CompilingCilk && Builder.GetInsertBlock()) {
+  } else if (CompilingCilk && Builder.GetInsertBlock() &&
+             ReturnBlock.getBlock()->use_empty()) {
     // If we're compiling Cilk, emit an implicit sync for the function.
     EmitImplicitSyncCleanup();
     SyncEmitted = true;

clang/test/Cilk/early-return-while.c

@@ -0,0 +1,43 @@
+// RUN: %clang_cc1 %s -triple x86_64-unknown-linux-gnu -fcilkplus -verify -ftapir=none -S -emit-llvm -o - | FileCheck %s
+// expected-no-diagnostics
+
+void bar();
+int baz(int);
+
+void foo(int p) {
+  while (p) {
+    if (baz(p))
+      return;
+    _Cilk_spawn bar();
+    --p;
+  }
+  bar();
+}
+
+// CHECK-LABEL: define {{.*}}void @foo(
+
+// CHECK: br i1 %{{.+}}, label %[[WHILE_BODY:.+]], label %[[WHILE_END:.+]]
+
+// CHECK: [[WHILE_BODY]]:
+// CHECK: br i1 %{{.+}}, label %[[THEN:.+]], label %[[END:.+]]
+
+// CHECK: [[THEN]]:
+// CHECK-NEXT: br label %[[RETURN:.+]]
+
+// CHECK: detach within %[[SYNCREG:.+]], label %[[DETACHED:.+]], label %[[CONTINUE:.+]]
+
+// CHECK: [[DETACHED]]:
+// CHECK: call void {{.*}}@bar()
+// CHECK: reattach within %[[SYNCREG]], label %[[CONTINUE]]
+
+// CHECK: [[CONTINUE]]:
+// CHECK: br
+
+// CHECK: [[WHILE_END]]:
+// CHECK-NEXT: call void {{.*}}@bar()
+// CHECK-NEXT: br label %[[RETURN]]
+
+// CHECK: [[RETURN]]:
+// CHECK-NEXT: sync within %[[SYNCREG]]
+
+// CHECK: ret void

clang/test/Cilk/early-return.c

@@ -25,7 +25,8 @@ void foo(int p) {
 
 // CHECK: [[END]]:
 // CHECK-NEXT: call void {{.*}}@bar()
-// CHECK-NEXT: sync within %[[SYNCREG]]
+
+// CHECK: sync within %[[SYNCREG]]
 
 // CHECK: ret void
 

compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc

@@ -842,6 +842,7 @@ POST_SYSCALL(statfs)(long res, const void *path, void *buf) {
   }
 }
 
+#if !SANITIZER_MAC
 PRE_SYSCALL(statfs64)(const void *path, long sz, void *buf) {
   if (path)
     PRE_READ(path, __sanitizer::internal_strlen((const char *)path) + 1);
@@ -852,6 +853,7 @@ POST_SYSCALL(statfs64)(long res, const void *path, long sz, void *buf) {
     if (buf) POST_WRITE(buf, struct_statfs64_sz);
   }
 }
+#endif
 
 PRE_SYSCALL(fstatfs)(long fd, void *buf) {}
 
@@ -861,13 +863,15 @@ POST_SYSCALL(fstatfs)(long res, long fd, void *buf) {
   }
 }
 
+#if !SANITIZER_MAC
 PRE_SYSCALL(fstatfs64)(long fd, long sz, void *buf) {}
 
 POST_SYSCALL(fstatfs64)(long res, long fd, long sz, void *buf) {
   if (res >= 0) {
     if (buf) POST_WRITE(buf, struct_statfs64_sz);
   }
 }
+#endif
 #endif // !SANITIZER_ANDROID
 
 PRE_SYSCALL(lstat)(const void *filename, void *statbuf) {

compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h

@@ -341,7 +341,7 @@
 #define SANITIZER_INTERCEPT_STATFS \
   (SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_STATFS64 \
-  ((SI_MAC && !SI_IOS) || SI_LINUX_NOT_ANDROID)
+  (SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_STATVFS \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_STATVFS64 SI_LINUX_NOT_ANDROID

compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cpp

@@ -170,9 +170,9 @@ typedef struct user_fpregs elf_fpregset_t;
 namespace __sanitizer {
   unsigned struct_utsname_sz = sizeof(struct utsname);
   unsigned struct_stat_sz = sizeof(struct stat);
-#if !SANITIZER_IOS
+#if !SANITIZER_MAC
   unsigned struct_stat64_sz = sizeof(struct stat64);
-#endif // !SANITIZER_IOS
+#endif // !SANITIZER_MAC
   unsigned struct_rusage_sz = sizeof(struct rusage);
   unsigned struct_tm_sz = sizeof(struct tm);
   unsigned struct_passwd_sz = sizeof(struct passwd);
@@ -196,10 +196,6 @@ namespace __sanitizer {
   unsigned struct_regex_sz = sizeof(regex_t);
   unsigned struct_regmatch_sz = sizeof(regmatch_t);
 
-#if SANITIZER_MAC && !SANITIZER_IOS
-  unsigned struct_statfs64_sz = sizeof(struct statfs64);
-#endif // SANITIZER_MAC && !SANITIZER_IOS
-
 #if !SANITIZER_ANDROID
   unsigned struct_fstab_sz = sizeof(struct fstab);
   unsigned struct_statfs_sz = sizeof(struct statfs);