[MemProf] Allow the binary to specify the profile output filename

[tejohnson]

Summary

This will allow the output directory to be specified by a build time
option, similar to the directory specified for regular PGO profiles via
-fprofile-generate=. The memory profiling instrumentation pass will
set up the variable. This is the same mechanism used by the PGO
instrumentation and runtime.

Depends on D87120 and D89629.

[davidxl]

Profile runtime has 4 ways of setting output: 1) default 2) compiler command line arg 3) environment variable at runtime; and 4) user invocation of runtime API at runtime. The order of the precedence is 4> 3 > 2 > 1. Is the behavior here consistent with that?

[vitalybuka]

LGTM but I have no opinion on David's request.

compiler-rt/lib/memprof/memprof_rtl.cpp

31

not needed?

compiler-rt/lib/sanitizer_common/sanitizer_file.cpp

71–92 ↗

(On Diff #297091)

looks correct, but it would be nice to have sanitizer_common as a separate patch

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

4 ↗

(On Diff #297091)

It's not clear why this is needed before reading patch description.
Seems unrelated to __memprof_profile_filename and can be a separate patch.

[tejohnson]

In D89086#2322033, @davidxl wrote:

Profile runtime has 4 ways of setting output: 1) default 2) compiler command line arg 3) environment variable at runtime; and 4) user invocation of runtime API at runtime. The order of the precedence is 4> 3 > 2 > 1. Is the behavior here consistent with that?

The runtime I recently upstreamed has #3, and this patch adds #1 (well there is a default in the already upstreamed stuff, but it is stderr) and #2. A follow on patch will add #4. The order of precedence will be the same as in the profile runtime (it is already 3>2>1).

compiler-rt/lib/memprof/memprof_rtl.cpp

31

This is to ensure that the if below at line 182 will fail when the compiler has not set up a strong version of this variable.

compiler-rt/lib/sanitizer_common/sanitizer_file.cpp

71–92 ↗

(On Diff #297091)

Ok, I can split this out.

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

4 ↗

(On Diff #297091)

I can just move this to the follow on patch that changes the compiler which affects the defaults, requiring this change.

[vitalybuka]

compiler-rt/lib/memprof/memprof_rtl.cpp

31

Sorry, I asked if initialization is needed. "={0}" I'd expect it's already zeroes.

[tejohnson]

compiler-rt/lib/memprof/memprof_rtl.cpp

31

You're right. The global should get zero initialized so the init isn't really necessary. I can remove it.

[tejohnson]

Address comments.

compiler-rt/lib/memprof/memprof_interface_internal.h

 SANITIZER_INTERFACE_ATTRIBUTE void __memprof_print_accumulated_stats();
 
 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 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/lib/memprof/memprof_rtl.cpp

 #include "sanitizer_common/sanitizer_atomic.h"
 #include "sanitizer_common/sanitizer_flags.h"
 #include "sanitizer_common/sanitizer_libc.h"
 #include "sanitizer_common/sanitizer_symbolizer.h"
 #include <ctime>
 
 uptr __memprof_shadow_memory_dynamic_address; // Global interface symbol.
 
+// Allow the user to specify a profile output file via the binary.
+SANITIZER_WEAK_ATTRIBUTE char __memprof_profile_filename[1];
+
 namespace __memprof {
 
 static void MemprofDie() {
   static atomic_uint32_t num_calls;
   if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
     // Don't die twice - run a busy loop.
     while (1) {
     }
static void MemprofInitInternal() {
 
   // Make sure we are not statically linked.
   MemprofDoesNotSupportStaticLinkage();
 
   // Install tool-specific callbacks in sanitizer_common.
   AddDieCallback(MemprofDie);
   SetCheckFailedCallback(MemprofCheckFailed);
 
+  // Use profile name specified via the binary itself if it exists, and hasn't
+  // been overrriden by a flag at runtime.
+  if (__memprof_profile_filename[0] != 0 && !common_flags()->log_path)
+    __sanitizer_set_report_path(__memprof_profile_filename);
+  else
     __sanitizer_set_report_path(common_flags()->log_path);
 
   __sanitizer::InitializePlatformEarly();
 
   // Re-exec ourselves if we need to set additional env or command line args.
   MaybeReexec();
 
   // Setup internal allocator callback.
   SetLowLevelAllocateMinAlignment(SHADOW_GRANULARITY);

compiler-rt/lib/memprof/weak_symbols.txt

-___memprof_default_options
+___memprof_default_options __memprof_profile_filename

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

 // RUN: %env_memprof_opts=log_path=/dev/null/INVALID not %run %t 2> %t.out
 // RUN: FileCheck %s --check-prefix=CHECK-INVALID < %t.out
 
 // Too long log_path.
 // RUN: %env_memprof_opts=log_path=`for((i=0;i<10000;i++)); do echo -n $i; done` \
 // RUN:   not %run %t 2> %t.out
 // RUN: FileCheck %s --check-prefix=CHECK-LONG < %t.out
 
+// Specifying the log name via the __memprof_profile_filename variable.
+// RUN: %clangxx_memprof  %s -o %t -DPROFILE_NAME_VAR="%t.log2"
+// RUN: rm -f %t.log2.*
+// RUN: %run %t 2> %t.out
+// RUN: FileCheck %s --check-prefix=CHECK-GOOD < %t.log2.*
+
+// Check that the log_path option overrides the log name set via the
+// __memprof_profile_filename variable.
+// RUN: rm -f %t.log.*
+// RUN: %env_memprof_opts=log_path=%t.log %run %t 2> %t.out
+// RUN: FileCheck %s --check-prefix=CHECK-GOOD < %t.log.*
+
+#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);
   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