The patch re-factors libgcov.c to make it better modulelized.

2013-11-12  Rong Xu  <xur@google.com>

The patch re-factors libgcov.c to make it better modulelized.
It contains two pieces of work:
1. break gcov_exit() into the following structure:
   gcov_exit()
      --> gcov_exit_compute_summary()
      --> allocate_filename_struct()
          for gi_ptr in gcov_list
            --> gcov_exit_dump_gcov()
                   --> gcov_exit_open_gcda_file()
                   --> gcov_exit_merge_gcda ()
                   --> gcov_exit_merge_summary ()
                   --> gcov_exit_write_gcda ()
2. split libgcov.c into the following files:
     libgcov-profiler.c
     libgcov-merge.c
     libgcov-interface.c
     libgcov-driver.c
       libgcov-driver-system.c (source included into libgcov-driver.c)

	* libgcc/libgcov.c: Delete as part of re-factoring.
	* gcc/gcov-io.h (__gcov_indirect_call_profiler): Add the decl to
        avoid warning.
	* libgcc/libgcov-interface.c (init_mx): Moved from libgcov.c.
	(init_mx_once): Ditto.
	(__gcov_flush): Ditto.
	(__gcov_reset): Ditto.
	(__gcov_dump): Ditto.
	(__gcov_fork): Ditto.
	(__gcov_execl): Ditto.
	(__gcov_execlp): Ditto.
	(__gcov_execle): Ditto.
	(__gcov_execv): Ditto.
	(__gcov_execvp): Ditto.
	(__gcov_execve): Ditto.
        * libgcc/libgcov-merge.c (__gcov_merge_time_profile): Moved from
        libgcov.c.
	(__gcov_merge_add): Ditto.
	(__gcov_merge_ior): Ditto.
	(__gcov_merge_single): Ditto.
	(__gcov_merge_delta): Ditto.
	* libgcc/libgcov-profiler.c 
	(__gcov_interval_profiler): Ditto.
	(__gcov_pow2_profiler): Ditto.
	(__gcov_one_value_profiler_body): Ditto.
	(__gcov_one_value_profiler): Ditto.
	(__gcov_indirect_call_profiler): Ditto.
	(__gcov_indirect_call_profiler_v2): Ditto.
	(__gcov_time_profiler): Ditto.
	(__gcov_average_profiler): Ditto.
	(__gcov_ior_profiler): Ditto.
	* libgcc/libgcov-driver.c (set_gcov_list): New.
	(get_gcov_dump_complete): Ditto.
	(set_gcov_dump_complete):Ditto.
	(reset_gcov_dump_complete):Ditto.
	(gcov_exit_compute_summary): New function split from gcov_exit().
	(gcov_exit_merge_gcda): Ditto.
	(gcov_exit_write_gcda): Ditto.
	(gcov_exit_merge_summary): Ditto.
	(gcov_exit_dump_gcov): Ditto.
	(struct gcov_fn_buffer): Moved from libgcov.c
	(struct gcov_summary_buffer): Ditto.
	(free_fn_data): Ditto.
	(buffer_fn_data): Ditto.
	(crc32_unsigned): Ditto.
	(gcov_version): Ditto.
	(gcov_histogram_insert): Ditto.
	(gcov_compute_histogram): Ditto.
	(gcov_exit): Ditto.
	(gcov_clear): Ditto.
	(__gcov_init): Ditto.
        (this_prg): Make it file scope static variable.
        (all_prg): Ditto.
        (crc32): Ditto.
        (gi_filename): Ditto.
        (fn_buffer): Ditto.
        (sum_buffer): Ditto.
        (struct gcov_filename_aux): New types to store auxiliary information
        for gi_filename.
	* libgcc/libgcov-driver-system.c (gcov_error): New utility function.
	(allocate_filename_struct): New function split from gcov_exit().
	(gcov_exit_open_gcda_file): Ditto.
	(create_file_directory): Moved from libgcov.c
	* libgcc/Makefile.in: Change to build newly added files.

From-SVN: r204730
diff --git a/libgcc/libgcov-profiler.c b/libgcc/libgcov-profiler.c
new file mode 100644
index 0000000..6ba1bcf
--- /dev/null
+++ b/libgcc/libgcov-profiler.c
@@ -0,0 +1,223 @@
+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+
+#if !defined(inhibit_libc)
+#define IN_LIBGCOV 1
+#include "gcov-io.h"
+
+#ifdef L_gcov_interval_profiler
+/* If VALUE is in interval <START, START + STEPS - 1>, then increases the
+   corresponding counter in COUNTERS.  If the VALUE is above or below
+   the interval, COUNTERS[STEPS] or COUNTERS[STEPS + 1] is increased
+   instead.  */
+
+void
+__gcov_interval_profiler (gcov_type *counters, gcov_type value,
+                          int start, unsigned steps)
+{
+  gcov_type delta = value - start;
+  if (delta < 0)
+    counters[steps + 1]++;
+  else if (delta >= steps)
+    counters[steps]++;
+  else
+    counters[delta]++;
+}
+#endif
+
+#ifdef L_gcov_pow2_profiler
+/* If VALUE is a power of two, COUNTERS[1] is incremented.  Otherwise
+   COUNTERS[0] is incremented.  */
+
+void
+__gcov_pow2_profiler (gcov_type *counters, gcov_type value)
+{
+  if (value & (value - 1))
+    counters[0]++;
+  else
+    counters[1]++;
+}
+#endif
+
+/* Tries to determine the most common value among its inputs.  Checks if the
+   value stored in COUNTERS[0] matches VALUE.  If this is the case, COUNTERS[1]
+   is incremented.  If this is not the case and COUNTERS[1] is not zero,
+   COUNTERS[1] is decremented.  Otherwise COUNTERS[1] is set to one and
+   VALUE is stored to COUNTERS[0].  This algorithm guarantees that if this
+   function is called more than 50% of the time with one value, this value
+   will be in COUNTERS[0] in the end.
+
+   In any case, COUNTERS[2] is incremented.  */
+
+static inline void
+__gcov_one_value_profiler_body (gcov_type *counters, gcov_type value)
+{
+  if (value == counters[0])
+    counters[1]++;
+  else if (counters[1] == 0)
+    {
+      counters[1] = 1;
+      counters[0] = value;
+    }
+  else
+    counters[1]--;
+  counters[2]++;
+}
+
+#ifdef L_gcov_one_value_profiler
+void
+__gcov_one_value_profiler (gcov_type *counters, gcov_type value)
+{
+  __gcov_one_value_profiler_body (counters, value);
+}
+#endif
+
+#ifdef L_gcov_indirect_call_profiler
+/* This function exist only for workaround of binutils bug 14342.
+   Once this compatibility hack is obsolette, it can be removed.  */
+
+/* By default, the C++ compiler will use function addresses in the
+   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
+   tells the compiler to use function descriptors instead.  The value
+   of this macro says how many words wide the descriptor is (normally 2),
+   but it may be dependent on target flags.  Since we do not have access
+   to the target flags here we just check to see if it is set and use
+   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
+
+   It is assumed that the address of a function descriptor may be treated
+   as a pointer to a function.  */
+
+#ifdef TARGET_VTABLE_USES_DESCRIPTORS
+#define VTABLE_USES_DESCRIPTORS 1
+#else
+#define VTABLE_USES_DESCRIPTORS 0
+#endif
+
+/* Tries to determine the most common value among its inputs. */
+void
+__gcov_indirect_call_profiler (gcov_type* counter, gcov_type value,
+                               void* cur_func, void* callee_func)
+{
+  /* If the C++ virtual tables contain function descriptors then one
+     function may have multiple descriptors and we need to dereference
+     the descriptors to see if they point to the same function.  */
+  if (cur_func == callee_func
+      || (VTABLE_USES_DESCRIPTORS && callee_func
+          && *(void **) cur_func == *(void **) callee_func))
+    __gcov_one_value_profiler_body (counter, value);
+}
+
+#endif
+#ifdef L_gcov_indirect_call_profiler_v2
+
+/* These two variables are used to actually track caller and callee.  Keep
+   them in TLS memory so races are not common (they are written to often).
+   The variables are set directly by GCC instrumented code, so declaration
+   here must match one in tree-profile.c  */
+
+#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
+__thread
+#endif
+void * __gcov_indirect_call_callee;
+#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
+__thread
+#endif
+gcov_type * __gcov_indirect_call_counters;
+
+/* By default, the C++ compiler will use function addresses in the
+   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
+   tells the compiler to use function descriptors instead.  The value
+   of this macro says how many words wide the descriptor is (normally 2),
+   but it may be dependent on target flags.  Since we do not have access
+   to the target flags here we just check to see if it is set and use
+   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
+
+   It is assumed that the address of a function descriptor may be treated
+   as a pointer to a function.  */
+
+#ifdef TARGET_VTABLE_USES_DESCRIPTORS
+#define VTABLE_USES_DESCRIPTORS 1
+#else
+#define VTABLE_USES_DESCRIPTORS 0
+#endif
+
+/* Tries to determine the most common value among its inputs. */
+void
+__gcov_indirect_call_profiler_v2 (gcov_type value, void* cur_func)
+{
+  /* If the C++ virtual tables contain function descriptors then one
+     function may have multiple descriptors and we need to dereference
+     the descriptors to see if they point to the same function.  */
+  if (cur_func == __gcov_indirect_call_callee
+      || (VTABLE_USES_DESCRIPTORS && __gcov_indirect_call_callee
+          && *(void **) cur_func == *(void **) __gcov_indirect_call_callee))
+    __gcov_one_value_profiler_body (__gcov_indirect_call_counters, value);
+}
+#endif
+
+#ifdef L_gcov_time_profiler
+
+/* Counter for first visit of each function.  */
+static gcov_type function_counter;
+
+/* Sets corresponding COUNTERS if there is no value.  */
+
+void
+__gcov_time_profiler (gcov_type* counters)
+{
+  if (!counters[0])
+    counters[0] = ++function_counter;
+}
+#endif
+
+#ifdef L_gcov_average_profiler
+/* Increase corresponding COUNTER by VALUE.  FIXME: Perhaps we want
+   to saturate up.  */
+
+void
+__gcov_average_profiler (gcov_type *counters, gcov_type value)
+{
+  counters[0] += value;
+  counters[1] ++;
+}
+#endif
+
+#ifdef L_gcov_ior_profiler
+/* Bitwise-OR VALUE into COUNTER.  */
+
+void
+__gcov_ior_profiler (gcov_type *counters, gcov_type value)
+{
+  *counters |= value;
+}
+#endif
+
+#endif /* inhibit_libc */