Remove some unneeded headers (#680)

* Removed unneeded headers

This removes some unneeded headers from the headers.

* Remove use of std::string

This stack allocates and copies a c-string to replace the calls to std::string.

src/snmalloc/backend_helpers/largebuddyrange.h

@@ -6,8 +6,6 @@
 #include "empty_range.h"
 #include "range_helpers.h"
 
-#include <string>
-
 namespace snmalloc
 {
   /**

src/snmalloc/ds/combininglock.h

@@ -4,7 +4,6 @@
 #include "../pal/pal.h"
 
 #include <atomic>
-#include <functional>
 
 namespace snmalloc
 {

src/snmalloc/ds/flaglock.h

@@ -4,7 +4,6 @@
 #include "../pal/pal.h"
 
 #include <atomic>
-#include <functional>
 
 namespace snmalloc
 {

src/snmalloc/ds/singleton.h

@@ -3,9 +3,7 @@
 #include "../ds_core/ds_core.h"
 #include "flaglock.h"
 
-#include <array>
 #include <atomic>
-#include <string_view>
 #include <type_traits>
 
 namespace snmalloc

src/snmalloc/ds_core/helpers.h

@@ -4,8 +4,8 @@
 
 #include <array>
 #include <atomic>
-#include <functional>
 #include <string_view>
+#include <tuple>
 #include <type_traits>
 
 namespace snmalloc

src/snmalloc/ds_core/redblacktree.h

@@ -3,7 +3,6 @@
 #include <array>
 #include <cstddef>
 #include <cstdint>
-#include <string>
 
 namespace snmalloc
 {
@@ -439,9 +438,27 @@ namespace snmalloc
           depth);
         if (!(get_dir(true, curr).is_null() && get_dir(false, curr).is_null()))
         {
-          auto s_indent = std::string(indent);
-          print(get_dir(true, curr), (s_indent + "|").c_str(), depth + 1);
-          print(get_dir(false, curr), (s_indent + " ").c_str(), depth + 1);
+          // As the tree should be balanced, the depth should not exceed 128 if
+          // there are 2^64 elements in the tree. This is a debug feature, and
+          // it would be impossible to debug something of this size, so this is
+          // considerably larger than required.
+          // If there is a bug that leads to an unbalanced tree, this might be
+          // insufficient to accurately display the tree, but it will still be
+          // memory safe as the search code is bounded by the string size.
+          static constexpr size_t max_depth = 128;
+          char s_indent[max_depth];
+          size_t end = 0;
+          for (; end < max_depth - 1; end++)
+          {
+            if (indent[end] == 0)
+              break;
+            s_indent[end] = indent[end];
+          }
+          s_indent[end] = '|';
+          s_indent[end + 1] = 0;
+          print(get_dir(true, curr), s_indent, depth + 1);
+          s_indent[end] = ' ';
+          print(get_dir(false, curr), s_indent, depth + 1);
         }
       }
     }

src/snmalloc/mem/freelist_queue.h

@@ -3,7 +3,6 @@
 #include "../ds/ds.h"
 #include "freelist.h"
 
-#include <array>
 #include <atomic>
 
 namespace snmalloc

src/snmalloc/mem/remoteallocator.h

@@ -2,6 +2,8 @@
 
 #include "freelist_queue.h"
 
+#include <new>
+
 namespace snmalloc
 {
   class RemoteMessageAssertions;

src/snmalloc/pal/pal_consts.h

@@ -3,7 +3,6 @@
 #include "../ds_core/ds_core.h"
 
 #include <atomic>
-#include <functional>
 
 namespace snmalloc
 {

src/snmalloc/pal/pal_ds.h

@@ -3,7 +3,6 @@
 #include "../ds_core/ds_core.h"
 
 #include <atomic>
-#include <functional>
 
 namespace snmalloc
 {

src/test/func/redblack/redblack.cc

@@ -4,7 +4,6 @@
 #include "test/xoroshiro.h"
 
 #include <algorithm>
-#include <array>
 #include <iostream>
 #include <vector>
 

src/test/perf/startup/startup.cc

@@ -3,6 +3,7 @@
 #include "test/usage.h"
 #include "test/xoroshiro.h"
 
+#include <algorithm>
 #include <iostream>
 #include <snmalloc/snmalloc.h>
 #include <thread>