InstrProf: If libc is available, use it; no functionality change

It was misguided to plan to rely on __llvm_profile_write_buffer() in
__llvm_profile_write_file().  It's less complex to duplicate the writing
logic than to mmap the file.

Since it's here to stay, move `FILE*`-based writing logic into
InstrProfilingFile.c.

<rdar://problem/15943240>

llvm-svn: 204498

1 files changed, 42 insertions, 1 deletions

diff --git a/compiler-rt/lib/profile/InstrProfilingFile.c b/compiler-rt/lib/profile/InstrProfilingFile.c
index 505d748f77c..27fa92611e6 100644
--- a/compiler-rt/lib/profile/InstrProfilingFile.c
+++ b/compiler-rt/lib/profile/InstrProfilingFile.c
@@ -12,6 +12,47 @@
 #include <stdlib.h>
 #include <string.h>
 
+static int writeFile(FILE *File) {
+  const __llvm_profile_data *DataBegin = __llvm_profile_data_begin();
+  const __llvm_profile_data *DataEnd = __llvm_profile_data_end();
+  const uint64_t *CountersBegin = __llvm_profile_counters_begin();
+  const uint64_t *CountersEnd   = __llvm_profile_counters_end();
+  const char *NamesBegin = __llvm_profile_names_begin();
+  const char *NamesEnd   = __llvm_profile_names_end();
+
+  /* Calculate size of sections. */
+  const uint64_t DataSize = DataEnd - DataBegin;
+  const uint64_t CountersSize = CountersEnd - CountersBegin;
+  const uint64_t NamesSize = NamesEnd - NamesBegin;
+
+  /* Get rest of header data. */
+  const uint64_t Magic = __llvm_profile_get_magic();
+  const uint64_t Version = __llvm_profile_get_version();
+  const uint64_t CountersDelta = (uint64_t)CountersBegin;
+  const uint64_t NamesDelta = (uint64_t)NamesBegin;
+
+#define CHECK_fwrite(Data, Size, Length, File) \
+  do { if (fwrite(Data, Size, Length, File) != Length) return -1; } while (0)
+
+  /* Write the header. */
+  CHECK_fwrite(&Magic,         sizeof(uint64_t), 1, File);
+  CHECK_fwrite(&Version,       sizeof(uint64_t), 1, File);
+  CHECK_fwrite(&DataSize,      sizeof(uint64_t), 1, File);
+  CHECK_fwrite(&CountersSize,  sizeof(uint64_t), 1, File);
+  CHECK_fwrite(&NamesSize,     sizeof(uint64_t), 1, File);
+  CHECK_fwrite(&CountersDelta, sizeof(uint64_t), 1, File);
+  CHECK_fwrite(&NamesDelta,    sizeof(uint64_t), 1, File);
+
+  /* Write the data. */
+  CHECK_fwrite(DataBegin, sizeof(__llvm_profile_data), DataSize, File);
+  CHECK_fwrite(CountersBegin, sizeof(uint64_t), CountersSize, File);
+  CHECK_fwrite(NamesBegin, sizeof(char), NamesSize, File);
+
+#undef CHECK_fwrite
+
+   return 0;
+}
+
 static int writeFileWithName(const char *OutputName) {
   int RetVal;
   FILE *OutputFile;
@@ -21,7 +62,7 @@ static int writeFileWithName(const char *OutputName) {
   if (!OutputFile)
     return -1;
 
-  RetVal = __llvm_profile_write_buffer(OutputFile);
+  RetVal = writeFile(OutputFile);
 
   fclose(OutputFile);
   return RetVal;