Support Qualcomm Hexagon DSP targets.

PiperOrigin-RevId: 544438364
Change-Id: I22d461f2d0aa8638a0e640eebecdc7e5e2b49ea3

absl/base/config.h

@@ -487,6 +487,8 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #elif defined(__Fuchsia__)
 // Signals don't exist on fuchsia.
 #elif defined(__native_client__)
+// Signals don't exist on hexagon/QuRT
+#elif defined(__hexagon__)
 #else
 // other standard libraries
 #define ABSL_HAVE_ALARM 1

absl/base/internal/sysinfo.cc

@@ -190,7 +190,13 @@ static double GetNominalCPUFrequency() {
 // and the memory location pointed to by value is set to the value read.
 static bool ReadLongFromFile(const char *file, long *value) {
   bool ret = false;
-  int fd = open(file, O_RDONLY | O_CLOEXEC);
+#if defined(_POSIX_C_SOURCE)
+  const int file_mode = (O_RDONLY | O_CLOEXEC);
+#else
+  const int file_mode = O_RDONLY;
+#endif
+
+  int fd = open(file, file_mode);
   if (fd != -1) {
     char line[1024];
     char *err;

absl/base/internal/thread_identity.cc

@@ -80,7 +80,7 @@ void SetCurrentThreadIdentity(ThreadIdentity* identity,
   absl::call_once(init_thread_identity_key_once, AllocateThreadIdentityKey,
                   reclaimer);
 
-#if defined(__EMSCRIPTEN__) || defined(__MINGW32__)
+#if defined(__EMSCRIPTEN__) || defined(__MINGW32__) || defined(__hexagon__)
   // Emscripten and MinGW pthread implementations does not support signals.
   // See https://kripken.github.io/emscripten-site/docs/porting/pthreads.html
   // for more information.

absl/debugging/internal/elf_mem_image.h

@@ -34,7 +34,7 @@
 #if defined(__ELF__) && !defined(__OpenBSD__) && !defined(__QNX__) && \
     !defined(__native_client__) && !defined(__asmjs__) &&             \
     !defined(__wasm__) && !defined(__HAIKU__) && !defined(__sun) &&   \
-    !defined(__VXWORKS__)
+    !defined(__VXWORKS__) && !defined(__hexagon__)
 #define ABSL_HAVE_ELF_MEM_IMAGE 1
 #endif
 

absl/log/internal/conditions.h

@@ -23,7 +23,7 @@
 #ifndef ABSL_LOG_INTERNAL_CONDITIONS_H_
 #define ABSL_LOG_INTERNAL_CONDITIONS_H_
 
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__hexagon__)
 #include <cstdlib>
 #else
 #include <unistd.h>

absl/log/internal/nullstream.h

@@ -102,7 +102,9 @@ class NullStreamMaybeFatal final : public NullStream {
   explicit NullStreamMaybeFatal(absl::LogSeverity severity)
       : fatal_(severity == absl::LogSeverity::kFatal) {}
   ~NullStreamMaybeFatal() {
-    if (fatal_) _exit(1);
+    if (fatal_) {
+      _exit(1);
+    }
   }
 
  private: