diff --git a/compiler-rt/lib/profile/InstrProfilingFile.c b/compiler-rt/lib/profile/InstrProfilingFile.c --- a/compiler-rt/lib/profile/InstrProfilingFile.c +++ b/compiler-rt/lib/profile/InstrProfilingFile.c @@ -638,34 +638,38 @@ } } - int Fileno = fileno(File); - - /* Determine how much padding is needed before/after the counters and after - * the names. */ - uint64_t PaddingBytesBeforeCounters, PaddingBytesAfterCounters, - PaddingBytesAfterNames; - __llvm_profile_get_padding_sizes_for_counters( - DataSize, CountersSize, NamesSize, &PaddingBytesBeforeCounters, - &PaddingBytesAfterCounters, &PaddingBytesAfterNames); - - uint64_t PageAlignedCountersLength = - (CountersSize * sizeof(uint64_t)) + PaddingBytesAfterCounters; - uint64_t FileOffsetToCounters = - CurrentFileOffset + sizeof(__llvm_profile_header) + - (DataSize * sizeof(__llvm_profile_data)) + PaddingBytesBeforeCounters; - - uint64_t *CounterMmap = (uint64_t *)mmap( - (void *)CountersBegin, PageAlignedCountersLength, PROT_READ | PROT_WRITE, - MAP_FIXED | MAP_SHARED, Fileno, FileOffsetToCounters); - if (CounterMmap != CountersBegin) { - PROF_ERR( - "Continuous counter sync mode is enabled, but mmap() failed (%s).\n" - " - CountersBegin: %p\n" - " - PageAlignedCountersLength: %" PRIu64 "\n" - " - Fileno: %d\n" - " - FileOffsetToCounters: %" PRIu64 "\n", - strerror(errno), CountersBegin, PageAlignedCountersLength, Fileno, - FileOffsetToCounters); + /* mmap() the profile counters so long as there is at least one counter. + * If there aren't any counters, mmap() would fail with EINVAL. */ + if (CountersSize > 0) { + int Fileno = fileno(File); + + /* Determine how much padding is needed before/after the counters and after + * the names. */ + uint64_t PaddingBytesBeforeCounters, PaddingBytesAfterCounters, + PaddingBytesAfterNames; + __llvm_profile_get_padding_sizes_for_counters( + DataSize, CountersSize, NamesSize, &PaddingBytesBeforeCounters, + &PaddingBytesAfterCounters, &PaddingBytesAfterNames); + + uint64_t PageAlignedCountersLength = + (CountersSize * sizeof(uint64_t)) + PaddingBytesAfterCounters; + uint64_t FileOffsetToCounters = + CurrentFileOffset + sizeof(__llvm_profile_header) + + (DataSize * sizeof(__llvm_profile_data)) + PaddingBytesBeforeCounters; + + uint64_t *CounterMmap = (uint64_t *)mmap( + (void *)CountersBegin, PageAlignedCountersLength, PROT_READ | PROT_WRITE, + MAP_FIXED | MAP_SHARED, Fileno, FileOffsetToCounters); + if (CounterMmap != CountersBegin) { + PROF_ERR( + "Continuous counter sync mode is enabled, but mmap() failed (%s).\n" + " - CountersBegin: %p\n" + " - PageAlignedCountersLength: %" PRIu64 "\n" + " - Fileno: %d\n" + " - FileOffsetToCounters: %" PRIu64 "\n", + strerror(errno), CountersBegin, PageAlignedCountersLength, Fileno, + FileOffsetToCounters); + } } if (ProfileRequiresUnlock) diff --git a/compiler-rt/test/profile/ContinuousSyncMode/image-with-no-counters.c b/compiler-rt/test/profile/ContinuousSyncMode/image-with-no-counters.c new file mode 100644 --- /dev/null +++ b/compiler-rt/test/profile/ContinuousSyncMode/image-with-no-counters.c @@ -0,0 +1,11 @@ +// REQUIRES: darwin + +// RUN: echo "static void dead_code(void) {}" > %t.dso.c +// RUN: %clang_profgen -fcoverage-mapping -O3 -dynamiclib -o %t.dso.dylib %t.dso.c +// RUN: %clang_profgen -fcoverage-mapping -O3 -o %t.exe %s %t.dso.dylib +// RUN: env LLVM_PROFILE_FILE="%c%t.profraw" %run %t.exe 2>&1 | count 0 +// RUN: llvm-profdata show --counts --all-functions %t.profraw | FileCheck %s + +// CHECK: Total functions: 1 + +int main() {}