[MemProf] Add interface to dump profile

[tejohnson]

Summary

Add an interface so that the profile can be dumped on demand.

compiler-rt/include/sanitizer/memprof_interface.h

 ///
 /// You can provide your own implementation of this function to return a string
 /// containing MemProf runtime options (for example,
 /// <c>verbosity=1:print_stats=1</c>).
 ///
 /// \returns Default options string.
 const char *__memprof_default_options(void);
 
+/// Prints the memory profile to the current profile file.
+///
+/// \returns 0 on success.
+int __memprof_profile_dump(void);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif
 
 #endif // SANITIZER_MEMPROF_INTERFACE_H

compiler-rt/lib/memprof/memprof_allocator.cpp

 
 int __sanitizer_get_ownership(const void *p) {
   return memprof_malloc_usable_size(p, 0, 0) != 0;
 }
 
 uptr __sanitizer_get_allocated_size(const void *p) {
   return memprof_malloc_usable_size(p, 0, 0);
 }
+
+int __memprof_profile_dump() {
+  instance.FinishAndPrint();
+  // In the future we may want to return non-zero if there are any errors
+  // detected during the dumping process.
+  return 0;
+}

compiler-rt/lib/memprof/memprof_interface_internal.h

 SANITIZER_INTERFACE_ATTRIBUTE
 const char *__memprof_default_options();
 
 SANITIZER_INTERFACE_ATTRIBUTE
 extern uptr __memprof_shadow_memory_dynamic_address;
 
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE extern char
     __memprof_profile_filename[1];
+SANITIZER_INTERFACE_ATTRIBUTE int __memprof_profile_dump();
 
 SANITIZER_INTERFACE_ATTRIBUTE void __memprof_load(uptr p);
 SANITIZER_INTERFACE_ATTRIBUTE void __memprof_store(uptr p);
 
 SANITIZER_INTERFACE_ATTRIBUTE
 void *__memprof_memcpy(void *dst, const void *src, uptr size);
 SANITIZER_INTERFACE_ATTRIBUTE
 void *__memprof_memset(void *s, int c, uptr n);
 SANITIZER_INTERFACE_ATTRIBUTE
 void *__memprof_memmove(void *dest, const void *src, uptr n);
 } // extern "C"
 
 #endif // MEMPROF_INTERFACE_INTERNAL_H

compiler-rt/test/memprof/TestCases/log_path_test.cpp

 // Note we use an invalid path since that is sufficient for checking that the
 // specified __memprof_profile_filename value is passed through to the runtime.
 // Using an automatically generated name via %t can cause weird issues with
 // unexpected macro expansion if the path includes tokens that match a build
 // system macro (e.g. "linux").
 // RUN: %clangxx_memprof  %s -o %t -DPROFILE_NAME_VAR="/dev/null/INVALID"
 // RUN: not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-INVALID --dump-input=always
 
+#include <sanitizer/memprof_interface.h>
+
 #ifdef PROFILE_NAME_VAR
 #define xstr(s) str(s)
 #define str(s) #s
 char __memprof_profile_filename[] = xstr(PROFILE_NAME_VAR);
 #endif
 
 #include <stdlib.h>
 #include <string.h>
 int main(int argc, char **argv) {
   char *x = (char *)malloc(10);
   memset(x, 0, 10);
   free(x);
+  __memprof_profile_dump();
   return 0;
 }
 // CHECK-GOOD: Memory allocation stack id
 // CHECK-INVALID: ERROR: Can't open file: /dev/null/INVALID
 // CHECK-LONG: ERROR: Path is too long: 01234

compiler-rt/test/memprof/TestCases/memprof_profile_dump.cpp

+// RUN: %clangxx_memprof  %s -o %t
+
+// RUN: %env_memprof_opts=log_path=stdout %run %t | FileCheck %s
+
+#include <sanitizer/memprof_interface.h>
+#include <stdlib.h>
+#include <string.h>
+int main(int argc, char **argv) {
+  char *x = (char *)malloc(10);
+  memset(x, 0, 10);
+  free(x);
+  __memprof_profile_dump();
+  x = (char *)malloc(10);
+  memset(x, 0, 10);
+  free(x);
+  return 0;
+}
+// We should get 2 rounds of profile info, one from the explicit dump request,
+// and one at exit.
+// CHECK: Memory allocation stack id
+// CHECK: Stack for id
+// CHECK: Memory allocation stack id
+// CHECK: Stack for id