Move global state in timevar.c to a new "timer" class

gcc/ChangeLog:
	* timevar.c (timevar_enable): Delete in favor of...
	(g_timer): New global.
	(struct timevar_def): Move to timevar.h inside class timer.
	(struct timevar_stack_def): Likewise.
	(timevars): Delete global in favor of field "m_timevars" within
	class timer in timevar.h
	(stack): Likewise, in favor of field "m_stack".
	(unused_stack_instances): Likewise, in favor of field
	"m_unused_stack_instances".
	(start_time): Likewise, in favor of field "m_start_time".
	(get_time): Eliminate check for timevar_enable.
	(timer::timer): New function, built from part of timevar_init.
	(timevar_init): Rewrite idempotency test from using
	"timevar_enable" bool to using dynamic allocation of "g_timer".
	Move rest of implementation into timer's constructor.
	(timevar_push_1): Rename to...
	(timer::push): ...this, adding "m_" prefixes to variables that
	are now fields of timer.
	(timevar_pop_1): Likewise, rename to...
	(timer::pop): ...this, and add "m_" prefixes.
	(timevar_start): Replace test for "timevar_enable" with one for
	"g_timer", and move bulk of implementation to...
	(timer::start): ...here, adding "m_" prefixes.
	(timevar_stop): Likewise, from here...
	(timer::stop): ...to here.
	(timevar_cond_start): Likewise, from here...
	(timer::cond_start): ...to here.
	(timevar_cond_stop): Likewise, from here...
	(timer::cond_stop): ...to here.
	(validate_phases): Rename to...
	(timer::validate_phases): ...this, and add "m_" prefixes.  Make
	locals "total" and "tv" const.
	(timevar_print): Rename to...
	(timer::print): ...this, and add "m_" prefixes.  Make locals
	"total" and "tv" const.  Eliminate test for timevar_enable.
	* timevar.h (timevar_enable): Eliminate.
	(g_timer): New declaration.
	(timevar_push_1): Eliminate.
	(timevar_pop_1): Eliminate.
	(timevar_print): Eliminate.
	(class timer): New class.
	(timevar_push): Rewrite to use g_timer.
	(timevar_pop): Likewise.
	* toplev.c (toplev::~toplev): Likewise.

From-SVN: r223092

4 files changed, 241 insertions, 123 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 80e9033c220..2e423a45151 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,50 @@
+2015-05-12  David Malcolm  <dmalcolm@redhat.com>
+
+	* timevar.c (timevar_enable): Delete in favor of...
+	(g_timer): New global.
+	(struct timevar_def): Move to timevar.h inside class timer.
+	(struct timevar_stack_def): Likewise.
+	(timevars): Delete global in favor of field "m_timevars" within
+	class timer in timevar.h
+	(stack): Likewise, in favor of field "m_stack".
+	(unused_stack_instances): Likewise, in favor of field
+	"m_unused_stack_instances".
+	(start_time): Likewise, in favor of field "m_start_time".
+	(get_time): Eliminate check for timevar_enable.
+	(timer::timer): New function, built from part of timevar_init.
+	(timevar_init): Rewrite idempotency test from using
+	"timevar_enable" bool to using dynamic allocation of "g_timer".
+	Move rest of implementation into timer's constructor.
+	(timevar_push_1): Rename to...
+	(timer::push): ...this, adding "m_" prefixes to variables that
+	are now fields of timer.
+	(timevar_pop_1): Likewise, rename to...
+	(timer::pop): ...this, and add "m_" prefixes.
+	(timevar_start): Replace test for "timevar_enable" with one for
+	"g_timer", and move bulk of implementation to...
+	(timer::start): ...here, adding "m_" prefixes.
+	(timevar_stop): Likewise, from here...
+	(timer::stop): ...to here.
+	(timevar_cond_start): Likewise, from here...
+	(timer::cond_start): ...to here.
+	(timevar_cond_stop): Likewise, from here...
+	(timer::cond_stop): ...to here.
+	(validate_phases): Rename to...
+	(timer::validate_phases): ...this, and add "m_" prefixes.  Make
+	locals "total" and "tv" const.
+	(timevar_print): Rename to...
+	(timer::print): ...this, and add "m_" prefixes.  Make locals
+	"total" and "tv" const.  Eliminate test for timevar_enable.
+	* timevar.h (timevar_enable): Eliminate.
+	(g_timer): New declaration.
+	(timevar_push_1): Eliminate.
+	(timevar_pop_1): Eliminate.
+	(timevar_print): Eliminate.
+	(class timer): New class.
+	(timevar_push): Rewrite to use g_timer.
+	(timevar_pop): Likewise.
+	* toplev.c (toplev::~toplev): Likewise.
+
 2015-05-12  Richard Earnshaw  <rearnsha@arm.com>
 
 	* arm-protos.h (arm_sched_autopref): Delete.
diff --git a/gcc/timevar.c b/gcc/timevar.c
index 123402dcde3..76ad22ac9ef 100644
--- a/gcc/timevar.c
+++ b/gcc/timevar.c
@@ -99,10 +99,10 @@ static double clocks_to_msec;
 #define CLOCKS_TO_MSEC (1 / (double)CLOCKS_PER_SEC)
 #endif
 
-/* True if timevars should be used.  In GCC, this happens with
+/* Non-NULL if timevars should be used.  In GCC, this happens with
    the -ftime-report flag.  */
 
-bool timevar_enable;
+timer *g_timer;
 
 /* Total amount of memory allocated by garbage collector.  */
 
@@ -115,57 +115,6 @@ size_t timevar_ggc_mem_total;
 
 /* See timevar.h for an explanation of timing variables.  */
 
-/* A timing variable.  */
-
-struct timevar_def
-{
-  /* Elapsed time for this variable.  */
-  struct timevar_time_def elapsed;
-
-  /* If this variable is timed independently of the timing stack,
-     using timevar_start, this contains the start time.  */
-  struct timevar_time_def start_time;
-
-  /* The name of this timing variable.  */
-  const char *name;
-
-  /* Nonzero if this timing variable is running as a standalone
-     timer.  */
-  unsigned standalone : 1;
-
-  /* Nonzero if this timing variable was ever started or pushed onto
-     the timing stack.  */
-  unsigned used : 1;
-};
-
-/* An element on the timing stack.  Elapsed time is attributed to the
-   topmost timing variable on the stack.  */
-
-struct timevar_stack_def
-{
-  /* The timing variable at this stack level.  */
-  struct timevar_def *timevar;
-
-  /* The next lower timing variable context in the stack.  */
-  struct timevar_stack_def *next;
-};
-
-/* Declared timing variables.  Constructed from the contents of
-   timevar.def.  */
-static struct timevar_def timevars[TIMEVAR_LAST];
-
-/* The top of the timing stack.  */
-static struct timevar_stack_def *stack;
-
-/* A list of unused (i.e. allocated and subsequently popped)
-   timevar_stack_def instances.  */
-static struct timevar_stack_def *unused_stack_instances;
-
-/* The time at which the topmost element on the timing stack was
-   pushed.  Time elapsed since then is attributed to the topmost
-   element.  */
-static struct timevar_time_def start_time;
-
 static void get_time (struct timevar_time_def *);
 static void timevar_accumulate (struct timevar_time_def *,
 				struct timevar_time_def *,
@@ -183,9 +132,6 @@ get_time (struct timevar_time_def *now)
   now->wall = 0;
   now->ggc_mem = timevar_ggc_mem_total;
 
-  if (!timevar_enable)
-    return;
-
   {
 #ifdef USE_TIMES
     struct tms tms;
@@ -218,25 +164,24 @@ timevar_accumulate (struct timevar_time_def *timer,
   timer->ggc_mem += stop_time->ggc_mem - start_time->ggc_mem;
 }
 
-/* Initialize timing variables.  */
+/* Class timer's constructor.  */
 
-void
-timevar_init (void)
+timer::timer () :
+  m_stack (NULL),
+  m_unused_stack_instances (NULL),
+  m_start_time ()
 {
-  if (timevar_enable)
-    return;
-
-  timevar_enable = true;
-
   /* Zero all elapsed times.  */
-  memset (timevars, 0, sizeof (timevars));
+  memset (m_timevars, 0, sizeof (m_timevars));
 
   /* Initialize the names of timing variables.  */
 #define DEFTIMEVAR(identifier__, name__) \
-  timevars[identifier__].name = name__;
+  m_timevars[identifier__].name = name__;
 #include "timevar.def"
 #undef DEFTIMEVAR
 
+  /* Initialize configuration-specific state.
+     Ideally this would be one-time initialization.  */
 #ifdef USE_TIMES
   ticks_to_msec = TICKS_TO_MSEC;
 #endif
@@ -245,6 +190,17 @@ timevar_init (void)
 #endif
 }
 
+/* Initialize timing variables.  */
+
+void
+timevar_init (void)
+{
+  if (g_timer)
+    return;
+
+  g_timer = new timer ();
+}
+
 /* Push TIMEVAR onto the timing stack.  No further elapsed time is
    attributed to the previous topmost timing variable on the stack;
    subsequent elapsed time is attributed to TIMEVAR, until it is
@@ -253,9 +209,9 @@ timevar_init (void)
    TIMEVAR cannot be running as a standalone timer.  */
 
 void
-timevar_push_1 (timevar_id_t timevar)
+timer::push (timevar_id_t timevar)
 {
-  struct timevar_def *tv = &timevars[timevar];
+  struct timevar_def *tv = &m_timevars[timevar];
   struct timevar_stack_def *context;
   struct timevar_time_def now;
 
@@ -270,27 +226,27 @@ timevar_push_1 (timevar_id_t timevar)
 
   /* If the stack isn't empty, attribute the current elapsed time to
      the old topmost element.  */
-  if (stack)
-    timevar_accumulate (&stack->timevar->elapsed, &start_time, &now);
+  if (m_stack)
+    timevar_accumulate (&m_stack->timevar->elapsed, &m_start_time, &now);
 
   /* Reset the start time; from now on, time is attributed to
      TIMEVAR.  */
-  start_time = now;
+  m_start_time = now;
 
   /* See if we have a previously-allocated stack instance.  If so,
      take it off the list.  If not, malloc a new one.  */
-  if (unused_stack_instances != NULL)
+  if (m_unused_stack_instances != NULL)
     {
-      context = unused_stack_instances;
-      unused_stack_instances = unused_stack_instances->next;
+      context = m_unused_stack_instances;
+      m_unused_stack_instances = m_unused_stack_instances->next;
     }
   else
     context = XNEW (struct timevar_stack_def);
 
   /* Fill it in and put it on the stack.  */
   context->timevar = tv;
-  context->next = stack;
-  stack = context;
+  context->next = m_stack;
+  m_stack = context;
 }
 
 /* Pop the topmost timing variable element off the timing stack.  The
@@ -300,30 +256,30 @@ timevar_push_1 (timevar_id_t timevar)
    timing variable.  */
 
 void
-timevar_pop_1 (timevar_id_t timevar)
+timer::pop (timevar_id_t timevar)
 {
   struct timevar_time_def now;
-  struct timevar_stack_def *popped = stack;
+  struct timevar_stack_def *popped = m_stack;
 
-  gcc_assert (&timevars[timevar] == stack->timevar);
+  gcc_assert (&m_timevars[timevar] == m_stack->timevar);
 
   /* What time is it?  */
   get_time (&now);
 
   /* Attribute the elapsed time to the element we're popping.  */
-  timevar_accumulate (&popped->timevar->elapsed, &start_time, &now);
+  timevar_accumulate (&popped->timevar->elapsed, &m_start_time, &now);
 
   /* Reset the start time; from now on, time is attributed to the
      element just exposed on the stack.  */
-  start_time = now;
+  m_start_time = now;
 
   /* Take the item off the stack.  */
-  stack = stack->next;
+  m_stack = m_stack->next;
 
   /* Don't delete the stack element; instead, add it to the list of
      unused elements for later use.  */
-  popped->next = unused_stack_instances;
-  unused_stack_instances = popped;
+  popped->next = m_unused_stack_instances;
+  m_unused_stack_instances = popped;
 }
 
 /* Start timing TIMEVAR independently of the timing stack.  Elapsed
@@ -333,11 +289,19 @@ timevar_pop_1 (timevar_id_t timevar)
 void
 timevar_start (timevar_id_t timevar)
 {
-  struct timevar_def *tv = &timevars[timevar];
-
-  if (!timevar_enable)
+  if (!g_timer)
     return;
 
+  g_timer->start (timevar);
+}
+
+/* See timevar_start above.  */
+
+void
+timer::start (timevar_id_t timevar)
+{
+  struct timevar_def *tv = &m_timevars[timevar];
+
   /* Mark this timing variable as used.  */
   tv->used = 1;
 
@@ -355,12 +319,20 @@ timevar_start (timevar_id_t timevar)
 void
 timevar_stop (timevar_id_t timevar)
 {
-  struct timevar_def *tv = &timevars[timevar];
-  struct timevar_time_def now;
-
-  if (!timevar_enable)
+  if (!g_timer)
     return;
 
+  g_timer->stop (timevar);
+}
+
+/* See timevar_stop above.  */
+
+void
+timer::stop (timevar_id_t timevar)
+{
+  struct timevar_def *tv = &m_timevars[timevar];
+  struct timevar_time_def now;
+
   /* TIMEVAR must have been started via timevar_start.  */
   gcc_assert (tv->standalone);
   tv->standalone = 0; /* Enable a restart.  */
@@ -379,11 +351,19 @@ timevar_stop (timevar_id_t timevar)
 bool
 timevar_cond_start (timevar_id_t timevar)
 {
-  struct timevar_def *tv = &timevars[timevar];
-
-  if (!timevar_enable)
+  if (!g_timer)
     return false;
 
+  return g_timer->cond_start (timevar);
+}
+
+/* See timevar_cond_start above.  */
+
+bool
+timer::cond_start (timevar_id_t timevar)
+{
+  struct timevar_def *tv = &m_timevars[timevar];
+
   /* Mark this timing variable as used.  */
   tv->used = 1;
 
@@ -406,13 +386,21 @@ timevar_cond_start (timevar_id_t timevar)
 void
 timevar_cond_stop (timevar_id_t timevar, bool running)
 {
+  if (!g_timer || running)
+    return;
+
+  g_timer->cond_stop (timevar);
+}
+
+/* See timevar_cond_stop above.  */
+
+void
+timer::cond_stop (timevar_id_t timevar)
+{
   struct timevar_def *tv;
   struct timevar_time_def now;
 
-  if (!timevar_enable || running)
-    return;
-
-  tv = &timevars[timevar];
+  tv = &m_timevars[timevar];
 
   /* TIMEVAR must have been started via timevar_cond_start.  */
   gcc_assert (tv->standalone);
@@ -425,11 +413,11 @@ timevar_cond_stop (timevar_id_t timevar, bool running)
 
 /* Validate that phase times are consistent.  */
 
-static void
-validate_phases (FILE *fp)
+void
+timer::validate_phases (FILE *fp) const
 {
   unsigned int /* timevar_id_t */ id;
-  struct timevar_time_def *total = &timevars[TV_TOTAL].elapsed;
+  const timevar_time_def *total = &m_timevars[TV_TOTAL].elapsed;
   double phase_user = 0.0;
   double phase_sys = 0.0;
   double phase_wall = 0.0;
@@ -439,7 +427,7 @@ validate_phases (FILE *fp)
 
   for (id = 0; id < (unsigned int) TIMEVAR_LAST; ++id)
     {
-      struct timevar_def *tv = &timevars[(timevar_id_t) id];
+      const timevar_def *tv = &m_timevars[(timevar_id_t) id];
 
       /* Don't evaluate timing variables that were never used.  */
       if (!tv->used)
@@ -480,17 +468,14 @@ validate_phases (FILE *fp)
    for normalizing the others, and is displayed last.  */
 
 void
-timevar_print (FILE *fp)
+timer::print (FILE *fp)
 {
   /* Only print stuff if we have some sort of time information.  */
 #if defined (HAVE_USER_TIME) || defined (HAVE_SYS_TIME) || defined (HAVE_WALL_TIME)
   unsigned int /* timevar_id_t */ id;
-  struct timevar_time_def *total = &timevars[TV_TOTAL].elapsed;
+  const timevar_time_def *total = &m_timevars[TV_TOTAL].elapsed;
   struct timevar_time_def now;
 
-  if (!timevar_enable)
-    return;
-
   /* Update timing information in case we're calling this from GDB.  */
 
   if (fp == 0)
@@ -501,17 +486,17 @@ timevar_print (FILE *fp)
 
   /* If the stack isn't empty, attribute the current elapsed time to
      the old topmost element.  */
-  if (stack)
-    timevar_accumulate (&stack->timevar->elapsed, &start_time, &now);
+  if (m_stack)
+    timevar_accumulate (&m_stack->timevar->elapsed, &m_start_time, &now);
 
   /* Reset the start time; from now on, time is attributed to
      TIMEVAR.  */
-  start_time = now;
+  m_start_time = now;
 
   fputs ("\nExecution times (seconds)\n", fp);
   for (id = 0; id < (unsigned int) TIMEVAR_LAST; ++id)
     {
-      struct timevar_def *tv = &timevars[(timevar_id_t) id];
+      const timevar_def *tv = &m_timevars[(timevar_id_t) id];
       const double tiny = 5e-3;
 
       /* Don't print the total execution time here; that goes at the
diff --git a/gcc/timevar.h b/gcc/timevar.h
index c06025deed7..71a814a7d60 100644
--- a/gcc/timevar.h
+++ b/gcc/timevar.h
@@ -79,35 +79,118 @@ typedef enum
 timevar_id_t;
 #undef DEFTIMEVAR
 
-/* True if timevars should be used.  In GCC, this happens with
-   the -ftime-report flag.  */
-extern bool timevar_enable;
+/* A class to hold all state relating to timing.  */
+
+class timer;
+
+/* The singleton instance of timing state.
+
+   This is non-NULL if timevars should be used.  In GCC, this happens with
+   the -ftime-report flag.  Hence this is NULL for the common,
+   needs-to-be-fast case, with an early reject happening for this being
+   NULL.  */
+extern timer *g_timer;
 
 /* Total amount of memory allocated by garbage collector.  */
 extern size_t timevar_ggc_mem_total;
 
 extern void timevar_init (void);
-extern void timevar_push_1 (timevar_id_t);
-extern void timevar_pop_1 (timevar_id_t);
 extern void timevar_start (timevar_id_t);
 extern void timevar_stop (timevar_id_t);
 extern bool timevar_cond_start (timevar_id_t);
 extern void timevar_cond_stop (timevar_id_t, bool);
-extern void timevar_print (FILE *);
+
+/* The public (within GCC) interface for timing.  */
+
+class timer
+{
+ public:
+  timer ();
+  ~timer ();
+
+  void start (timevar_id_t tv);
+  void stop (timevar_id_t tv);
+  void push (timevar_id_t tv);
+  void pop (timevar_id_t tv);
+  bool cond_start (timevar_id_t tv);
+  void cond_stop (timevar_id_t tv);
+
+  void print (FILE *fp);
+
+ private:
+  /* Private member functions.  */
+  void validate_phases (FILE *fp) const;
+
+ private:
+
+  /* Private type: a timing variable.  */
+  struct timevar_def
+  {
+    /* Elapsed time for this variable.  */
+    struct timevar_time_def elapsed;
+
+    /* If this variable is timed independently of the timing stack,
+       using timevar_start, this contains the start time.  */
+    struct timevar_time_def start_time;
+
+    /* The name of this timing variable.  */
+    const char *name;
+
+    /* Nonzero if this timing variable is running as a standalone
+       timer.  */
+    unsigned standalone : 1;
+
+    /* Nonzero if this timing variable was ever started or pushed onto
+       the timing stack.  */
+    unsigned used : 1;
+  };
+
+  /* Private type: an element on the timing stack
+     Elapsed time is attributed to the topmost timing variable on the
+     stack.  */
+  struct timevar_stack_def
+  {
+    /* The timing variable at this stack level.  */
+    struct timevar_def *timevar;
+
+    /* The next lower timing variable context in the stack.  */
+    struct timevar_stack_def *next;
+  };
+
+ private:
+
+  /* Data members (all private).  */
+
+  /* Declared timing variables.  Constructed from the contents of
+     timevar.def.  */
+  timevar_def m_timevars[TIMEVAR_LAST];
+
+  /* The top of the timing stack.  */
+  timevar_stack_def *m_stack;
+
+  /* A list of unused (i.e. allocated and subsequently popped)
+     timevar_stack_def instances.  */
+  timevar_stack_def *m_unused_stack_instances;
+
+  /* The time at which the topmost element on the timing stack was
+     pushed.  Time elapsed since then is attributed to the topmost
+     element.  */
+  timevar_time_def m_start_time;
+};
 
 /* Provided for backward compatibility.  */
 static inline void
 timevar_push (timevar_id_t tv)
 {
-  if (timevar_enable)
-    timevar_push_1 (tv);
+  if (g_timer)
+    g_timer->push (tv);
 }
 
 static inline void
 timevar_pop (timevar_id_t tv)
 {
-  if (timevar_enable)
-    timevar_pop_1 (tv);
+  if (g_timer)
+    g_timer->pop (tv);
 }
 
 // This is a simple timevar wrapper class that pushes a timevar in its
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 27736c29d08..9b1151b0186 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -2095,8 +2095,11 @@ toplev::toplev (bool use_TV_TOTAL, bool init_signals)
 
 toplev::~toplev ()
 {
-  timevar_stop (TV_TOTAL);
-  timevar_print (stderr);
+  if (g_timer)
+    {
+      g_timer->stop (TV_TOTAL);
+      g_timer->print (stderr);
+    }
 }
 
 void