From e1789af3378c83f78695ca828ea6d0315860cc11 Mon Sep 17 00:00:00 2001
From: Ben Wagner <bungeman@google.com>
Date: Wed, 25 Jul 2018 15:20:25 -0400
Subject: Don't double check in SkArenaAlloc.

Currently many range checks are being forced when they aren't needed.

Change-Id: I5ad6933a15fa063e76045757c7523f17900e4c1a
Reviewed-on: https://skia-review.googlesource.com/142816
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
---
 include/private/SkArenaAlloc.h | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

(limited to 'include')

diff --git a/include/private/SkArenaAlloc.h b/include/private/SkArenaAlloc.h
index 1915f8f9be..f39ebee208 100644
--- a/include/private/SkArenaAlloc.h
+++ b/include/private/SkArenaAlloc.h
@@ -8,6 +8,8 @@
 #ifndef SkArenaAlloc_DEFINED
 #define SkArenaAlloc_DEFINED
 
+#include "../private/SkTFitsIn.h"
+
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
@@ -98,6 +100,7 @@ public:
 
     template <typename T>
     T* makeArrayDefault(size_t count) {
+        AssertRelease(SkTFitsIn<uint32_t>(count));
         uint32_t safeCount = ToU32(count);
         T* array = (T*)this->commonArrayAlloc<T>(safeCount);
 
@@ -110,6 +113,7 @@ public:
 
     template <typename T>
     T* makeArray(size_t count) {
+        AssertRelease(SkTFitsIn<uint32_t>(count));
         uint32_t safeCount = ToU32(count);
         T* array = (T*)this->commonArrayAlloc<T>(safeCount);
 
@@ -123,6 +127,7 @@ public:
 
     // Only use makeBytesAlignedTo if none of the typed variants are impractical to use.
     void* makeBytesAlignedTo(size_t size, size_t align) {
+        AssertRelease(SkTFitsIn<uint32_t>(size));
         auto objStart = this->allocObject(ToU32(size), ToU32(align));
         fCursor = objStart + size;
         return objStart;
@@ -134,9 +139,7 @@ public:
 private:
     static void AssertRelease(bool cond) { if (!cond) { ::abort(); } }
     static uint32_t ToU32(size_t v) {
-#if SIZE_MAX > 0xffffffff
-        AssertRelease(v <= 0xffffffff);
-#endif
+        assert(SkTFitsIn<uint32_t>(v));
         return (uint32_t)v;
     }
 
-- 
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