rts: use HAVE_GETPID to guard subprocess related logic

We've previously added detection of getpid() in autoconf. This patch
uses HAVE_GETPID to guard some subprocess related logic in the RTS.
This is required for certain targets like wasm32-wasi, where there
isn't a process model at all.

3 files changed, 20 insertions, 2 deletions

diff --git a/rts/Hpc.c b/rts/Hpc.c
index 13f2ab87a2..c236cdd07f 100644
--- a/rts/Hpc.c
+++ b/rts/Hpc.c
@@ -203,7 +203,9 @@ startupHpc(void)
     return;
   }
   hpc_inited = 1;
+#if defined(HAVE_GETPID)
   hpc_pid    = getpid();
+#endif
   hpc_tixdir = getenv("HPCTIXDIR");
   hpc_tixfile = getenv("HPCTIXFILE");
 
@@ -387,7 +389,12 @@ exitHpc(void) {
   // Any sub-process from use of fork from inside Haskell will
   // not clobber the .tix file.
 
-  if (hpc_pid == getpid()) {
+#if defined(HAVE_GETPID)
+  bool is_subprocess = hpc_pid != getpid();
+#else
+  bool is_subprocess = false;
+#endif
+  if (!is_subprocess) {
     FILE *f = __rts_fopen(tixFilename,"w+");
     writeTix(f);
   }
diff --git a/rts/Trace.c b/rts/Trace.c
index 30db2a704c..18bb827cc4 100644
--- a/rts/Trace.c
+++ b/rts/Trace.c
@@ -485,11 +485,14 @@ void traceWallClockTime_(void) {
 
 void traceOSProcessInfo_(void) {
     if (eventlog_enabled) {
+
+#if defined(HAVE_GETPID)
         postCapsetEvent(EVENT_OSPROCESS_PID,
                         CAPSET_OSPROCESS_DEFAULT,
                         getpid());
+#endif
 
-#if !defined(mingw32_HOST_OS)
+#if !defined(mingw32_HOST_OS) && defined(HAVE_GETPID)
 /* Windows has no strong concept of process hierarchy, so no getppid().
  * In any case, this trace event is mainly useful for tracing programs
  * that use 'forkProcess' which Windows doesn't support anyway.
@@ -605,7 +608,11 @@ void traceTaskCreate_ (Task       *task,
 #endif
     {
         EventTaskId         taskid = serialisableTaskId(task);
+#if !defined(HAVE_GETPID)
+        EventKernelThreadId tid    = 0;
+#else
         EventKernelThreadId tid    = kernelThreadId();
+#endif
         postTaskCreateEvent(taskid, cap->no, tid);
     }
 }
diff --git a/rts/eventlog/EventLogWriter.c b/rts/eventlog/EventLogWriter.c
index daa6dc3c9d..984b2afb5d 100644
--- a/rts/eventlog/EventLogWriter.c
+++ b/rts/eventlog/EventLogWriter.c
@@ -68,6 +68,9 @@ static char *outputFileName(void)
                                         + 10 /* .eventlog */,
                                         "initEventLogFileWriter");
 
+#if !defined(HAVE_GETPID)
+            sprintf(filename, "%s.eventlog", prog);
+#else
         if (event_log_pid == -1) { // #4512
             // Single process
             sprintf(filename, "%s.eventlog", prog);
@@ -82,6 +85,7 @@ static char *outputFileName(void)
             sprintf(filename, "%s.%" FMT_Word64 ".eventlog",
                     prog, (StgWord64)event_log_pid);
         }
+#endif
         stgFree(prog);
         return filename;
     }