Add '-p file' command line syntax for VMProfile

Now it is possible to enable VMProfile trace profiling to a file from
the command line.

src/lj_vmprofile.c

@@ -41,6 +41,21 @@ int vmprofile_get_profile_size() {
   return sizeof(VMProfile);
 }
 
+/* Open a counter file on disk and returned the mmapped data structure. */
+void *vmprofile_open_file(const char *filename)
+{
+  int fd;
+  void *ptr = MAP_FAILED;
+  if (((fd = open(filename, O_RDWR|O_CREAT, 0666)) != -1) &&
+      ((ftruncate(fd, sizeof(VMProfile))) != -1) &&
+      ((ptr = mmap(NULL, sizeof(VMProfile), PROT_READ|PROT_WRITE,
+                   MAP_SHARED, fd, 0)) != MAP_FAILED)) {
+    memset(ptr, 0, sizeof(VMProfile));
+  }
+  if (fd != -1) close(fd);
+  return ptr == MAP_FAILED ? NULL : ptr;
+}
+
 /* Set the memory where the next samples will be counted. 
    Size of the memory must match vmprofile_get_profile_size(). */
 void vmprofile_set_profile(void *counters) {
@@ -122,20 +137,12 @@ static void stop_timer()
 
 LUA_API int luaJIT_vmprofile_open(lua_State *L, const char *str)
 {
-  int fd;
   void *ptr;
-  if (((fd = open(str, O_RDWR|O_CREAT, 0666)) != -1) &&
-      ((ftruncate(fd, sizeof(VMProfile))) != -1) &&
-      ((ptr = mmap(NULL, sizeof(VMProfile), PROT_READ|PROT_WRITE,
-                   MAP_SHARED, fd, 0)) != MAP_FAILED)) {
-    memset(ptr, 0, sizeof(VMProfile));
+  if ((ptr = vmprofile_open_file(str)) != NULL) {
     setlightudV(L->base, checklightudptr(L, ptr));
   } else {
     setnilV(L->base);
   }
-  if (fd != -1) {
-    close(fd);
-  }
   return 1;
 }
 

src/lj_vmprofile.h

@@ -6,6 +6,9 @@
 #ifndef _LJ_VMPROFILE_H
 #define _LJ_VMPROFILE_H
 
+#include <stdint.h>
+#include "lj_obj.h"
+
 /* Counters are 64-bit to avoid overflow even in long running processes. */
 typedef uint64_t VMProfileCount;
 
@@ -30,6 +33,7 @@ typedef struct VMProfile {
 
 /* Functions that should be accessed via FFI. */
 
+void *vmprofile_open_file(const char *filename);
 void vmprofile_set_profile(void *counters);
 int vmprofile_get_profile_size();
 

src/luajit.c

@@ -16,6 +16,7 @@
 #include "lauxlib.h"
 #include "lualib.h"
 #include "luajit.h"
+#include "lj_vmprofile.h"
 
 #include "lj_arch.h"
 
@@ -56,6 +57,7 @@ static void print_usage(void)
   "  -j cmd    Perform LuaJIT control command.\n"
   "  -O[opt]   Control LuaJIT optimizations.\n"
   "  -i        Enter interactive mode after executing " LUA_QL("script") ".\n"
+  "  -p file   Enable trace profiling to a VMProfile file.\n"
   "  -v        Show version information.\n"
   "  -E        Ignore environment variables.\n"
   "  --        Stop handling options.\n"
@@ -404,6 +406,7 @@ static int collectargs(char **argv, int *flags)
       *flags |= FLAGS_EXEC;
     case 'j':  /* LuaJIT extension */
     case 'l':
+    case 'p':  /* RaptorJIT extension */
       *flags |= FLAGS_OPTION;
       if (argv[i][2] == '\0') {
 	i++;
@@ -461,6 +464,17 @@ static int runargs(lua_State *L, char **argv, int argn)
       break;
     case 'b':  /* LuaJIT extension. */
       return dobytecode(L, argv+i);
+    case 'p': {
+      void *ptr;
+      if ((ptr = vmprofile_open_file(argv[++i])) != NULL) {
+        vmprofile_set_profile(ptr);
+        luaJIT_vmprofile_start(L);
+      } else {
+        fprintf(stderr, "unable to open vmprofile\n");
+        fflush(stderr);
+      }
+      break;
+      }
     default: break;
     }
   }