When using -fprofile-generate=/some/path mangle absolute path of file (PR lto/85759).

2018-06-29  Martin Liska  <mliska@suse.cz>

	PR lto/85759
	* coverage.c (coverage_init): Mangle full path name.
	* doc/invoke.texi: Document the change.
	* gcov-io.c (mangle_path): New.
	* gcov-io.h (mangle_path): Likewise.
	* gcov.c (mangle_name): Use mangle_path for path mangling.

From-SVN: r262251

gcc/ChangeLog

+2018-06-29  Martin Liska  <mliska@suse.cz>
+
+	PR lto/85759
+	* coverage.c (coverage_init): Mangle full path name.
+	* doc/invoke.texi: Document the change.
+	* gcov-io.c (mangle_path): New.
+	* gcov-io.h (mangle_path): Likewise.
+	* gcov.c (mangle_name): Use mangle_path for path mangling.
+
 2018-06-29  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* config/arm/arm.c (output_move_double): Don't allow STRD instructions

gcc/coverage.c

@@ -1220,8 +1220,24 @@ coverage_init (const char *filename)
     g->get_passes ()->get_pass_profile ()->static_pass_number;
   g->get_dumps ()->dump_start (profile_pass_num, NULL);
 
-  if (!profile_data_prefix && !IS_ABSOLUTE_PATH (filename))
-    profile_data_prefix = getpwd ();
+  if (!IS_ABSOLUTE_PATH (filename))
+    {
+      /* When a profile_data_prefix is provided, then mangle full path
+	 of filename in order to prevent file path clashing.  */
+      if (profile_data_prefix)
+	{
+#if HAVE_DOS_BASED_FILE_SYSTEM
+	  const char separator = "\\";
+#else
+	  const char *separator = "/";
+#endif
+	  filename = concat (getpwd (), separator, filename, NULL);
+	  filename = mangle_path (filename);
+	  len = strlen (filename);
+	}
+      else
+	profile_data_prefix = getpwd ();
+    }
 
   if (profile_data_prefix)
     prefix_len = strlen (profile_data_prefix);

gcc/doc/invoke.texi

@@ -11352,6 +11352,9 @@ and used by @option{-fprofile-use} and @option{-fbranch-probabilities}
 and its related options.  Both absolute and relative paths can be used.
 By default, GCC uses the current directory as @var{path}, thus the
 profile data file appears in the same directory as the object file.
+In order to prevent filename clashing, if object file name is not an absolute
+path, we mangle absolute path of @file{@var{sourcename}.gcda} file and
+use it as file name of a @file{.gcda} file.
 
 When an executable is run in a massive parallel environment, it is recommended
 to save profile to different folders.  That can be done with variables

gcc/gcov-io.c

@@ -566,6 +566,55 @@ gcov_read_counter (void)
   return value;
 }
 
+/* Mangle filename path of BASE and output new allocated pointer with
+   mangled path.  */
+
+char *
+mangle_path (char const *base)
+{
+  /* Convert '/' to '#', convert '..' to '^',
+     convert ':' to '~' on DOS based file system.  */
+  const char *probe;
+  char *buffer = (char *)xmalloc (strlen (base) + 10);
+  char *ptr = buffer;
+
+#if HAVE_DOS_BASED_FILE_SYSTEM
+  if (base[0] && base[1] == ':')
+    {
+      ptr[0] = base[0];
+      ptr[1] = '~';
+      ptr += 2;
+      base += 2;
+    }
+#endif
+  for (; *base; base = probe)
+    {
+      size_t len;
+
+      for (probe = base; *probe; probe++)
+	if (*probe == '/')
+	  break;
+      len = probe - base;
+      if (len == 2 && base[0] == '.' && base[1] == '.')
+	*ptr++ = '^';
+      else
+	{
+	  memcpy (ptr, base, len);
+	  ptr += len;
+	}
+      if (*probe)
+	{
+	  *ptr++ = '#';
+	  probe++;
+	}
+    }
+
+  /* Terminate the string.  */
+  *ptr = '\0';
+
+  return buffer;
+}
+
 /* We need to expose the below function when compiling for gcov-tool.  */
 
 #if !IN_LIBGCOV || defined (IN_GCOV_TOOL)

gcc/gcov-io.h

@@ -371,6 +371,7 @@ GCOV_LINKAGE void gcov_read_summary (struct gcov_summary *) ATTRIBUTE_HIDDEN;
 GCOV_LINKAGE const char *gcov_read_string (void);
 GCOV_LINKAGE void gcov_sync (gcov_position_t /*base*/,
 			     gcov_unsigned_t /*length */);
+char *mangle_path (char const *base);
 
 #if !IN_GCOV
 /* Available outside gcov */

gcc/gcov.c

@@ -2461,42 +2461,7 @@ mangle_name (char const *base, char *ptr)
       ptr += len;
     }
   else
-    {
-      /* Convert '/' to '#', convert '..' to '^',
-	 convert ':' to '~' on DOS based file system.  */
-      const char *probe;
-
-#if HAVE_DOS_BASED_FILE_SYSTEM
-      if (base[0] && base[1] == ':')
-	{
-	  ptr[0] = base[0];
-	  ptr[1] = '~';
-	  ptr += 2;
-	  base += 2;
-	}
-#endif
-      for (; *base; base = probe)
-	{
-	  size_t len;
-
-	  for (probe = base; *probe; probe++)
-	    if (*probe == '/')
-	      break;
-	  len = probe - base;
-	  if (len == 2 && base[0] == '.' && base[1] == '.')
-	    *ptr++ = '^';
-	  else
-	    {
-	      memcpy (ptr, base, len);
-	      ptr += len;
-	    }
-	  if (*probe)
-	    {
-	      *ptr++ = '#';
-	      probe++;
-	    }
-	}
-    }
+    ptr = mangle_path (base);
 
   return ptr;
 }