[compiler-rt] Make the ASan OS X DYLD_INSERT_LIBRARIES detection path-independent

[kubamracek]

Summary

ASan on Darwin during launch reads DYLD_INSERT_LIBRARIES env. variable and if it's not set or if the ASan dylib is not present in there, it relaunches the process. The check whether the dylib is present in the variable is now trying to find a full path in there. This fails in the scenarios where we want to copy the dylib to the executable's directory or somewhere else and set the DYLD_INSERT_LIBRARIES manually, see http://reviews.llvm.org/D6018.

Let's change the search in DYLD_INSERT_LIBRARIES to only look for the filename of the dylib and not the full path.

[glider]

LGTM

test/asan/TestCases/Darwin/dyld_insert_libraries_reexec.cc

11

How do you make sure you do not reexec?
Maybe do that explicitly by running with verbosity=1?

[kubamracek]

Adding an explicit check whether we reexec using verbosity=1.

[glider]

LGTM

test/asan/TestCases/Darwin/dyld_insert_libraries_reexec.cc

6

Note: you can wrap long lines using '\'

[kubamracek]

Splitting long lines.

[kubamracek]

Landed in r222297.

lib/asan/asan_mac.cc

       internal_strlen(dyld_insert_libraries) : 0;
   uptr fname_len = internal_strlen(info.dli_fname);
   if (!dyld_insert_libraries ||
-      !REAL(strstr)(dyld_insert_libraries, info.dli_fname)) {
+      !REAL(strstr)(dyld_insert_libraries, StripModuleName(info.dli_fname))) {
     // DYLD_INSERT_LIBRARIES is not set or does not contain the runtime
     // library.
     char program_name[1024];

test/asan/TestCases/Darwin/dyld_insert_libraries_reexec.cc

+// When DYLD-inserting the ASan dylib from a different location than the
+// original, make sure we don't try to reexec.
+
+// RUN: mkdir -p %T/dyld_insert_libraries_reexec
+// RUN: cp `%clang_asan %s -fsanitize=address -### 2>&1 \
+// RUN:   | grep "libclang_rt.asan_osx_dynamic.dylib" \
+// RUN:   | sed -e 's/.*"\(.*libclang_rt.asan_osx_dynamic.dylib\)".*/\1/'` \
+// RUN:   %T/dyld_insert_libraries_reexec/libclang_rt.asan_osx_dynamic.dylib
+// RUN: %clangxx_asan %s -o %T/dyld_insert_libraries_reexec/a.out
+// RUN: DYLD_INSERT_LIBRARIES=@executable_path/libclang_rt.asan_osx_dynamic.dylib \
+// RUN:   ASAN_OPTIONS=verbosity=1 %run %T/dyld_insert_libraries_reexec/a.out 2>&1 \
+// RUN:   | FileCheck %s
+// RUN: ASAN_OPTIONS=verbosity=1 %run %T/dyld_insert_libraries_reexec/a.out 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NOINSERT %s
+
+#include <stdio.h>
+
+int main() {
+  printf("Passed\n");
+  return 0;
+}
+
+// CHECK-NOINSERT: Parsed ASAN_OPTIONS: verbosity=1
+// CHECK-NOINSERT: exec()-ing the program with
+// CHECK-NOINSERT: DYLD_INSERT_LIBRARIES
+// CHECK-NOINSERT: to enable ASan wrappers.
+// CHECK-NOINSERT: Passed
+
+// CHECK: Parsed ASAN_OPTIONS: verbosity=1
+// CHECK-NOT: exec()-ing the program with
+// CHECK-NOT: DYLD_INSERT_LIBRARIES
+// CHECK-NOT: to enable ASan wrappers.
+// CHECK: Passed