From ec8d72a567b8c8bddd3d31a96d3b992946c40b4d Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Sun, 23 Aug 2020 14:40:39 -0400
Subject: microprofile: Don't memset through std::atomic types

Two of the members of the MicroProfileThreadLog contains two std::atomic
instances. Given these aren't trivially-copyable types, we shouldn't be
memsetting the structure, given implementation details can contain other
members within it.

To avoid potential undefined behavior on platforms, we can use aggregate
initialization to zero out the members while still having well-defined
behavior.

While we're at it we can also silence some sign conversion warnings.
---
 externals/microprofile/microprofile.h | 57 +++++++++++++++++++++++------------
 1 file changed, 38 insertions(+), 19 deletions(-)

(limited to 'externals/microprofile/microprofile.h')

diff --git a/externals/microprofile/microprofile.h b/externals/microprofile/microprofile.h
index 0c0d0a4d3..6dae65a66 100644
--- a/externals/microprofile/microprofile.h
+++ b/externals/microprofile/microprofile.h
@@ -152,9 +152,11 @@ typedef uint16_t MicroProfileGroupId;
 
 #include <stdint.h>
 #include <string.h>
-#include <thread>
-#include <mutex>
+#include <algorithm>
+#include <array>
 #include <atomic>
+#include <mutex>
+#include <thread>
 
 #ifndef MICROPROFILE_API
 #define MICROPROFILE_API
@@ -605,28 +607,45 @@ struct MicroProfileFrameState
 
 struct MicroProfileThreadLog
 {
-    MicroProfileLogEntry    Log[MICROPROFILE_BUFFER_SIZE];
+    std::array<MicroProfileLogEntry, MICROPROFILE_BUFFER_SIZE> Log{};
 
-    std::atomic<uint32_t>   nPut;
-    std::atomic<uint32_t>   nGet;
-    uint32_t                nActive;
-    uint32_t                nGpu;
-    ThreadIdType            nThreadId;
+    std::atomic<uint32_t>   nPut{0};
+    std::atomic<uint32_t>   nGet{0};
+    uint32_t                nActive = 0;
+    uint32_t                nGpu = 0;
+    ThreadIdType            nThreadId{};
 
-    uint32_t                nStack[MICROPROFILE_STACK_MAX];
-    int64_t                 nChildTickStack[MICROPROFILE_STACK_MAX];
-    uint32_t                nStackPos;
+    std::array<uint32_t, MICROPROFILE_STACK_MAX> nStack{};
+    std::array<int64_t, MICROPROFILE_STACK_MAX>  nChildTickStack{};
+    uint32_t                                     nStackPos = 0;
 
 
-    uint8_t                 nGroupStackPos[MICROPROFILE_MAX_GROUPS];
-    int64_t                 nGroupTicks[MICROPROFILE_MAX_GROUPS];
-    int64_t                 nAggregateGroupTicks[MICROPROFILE_MAX_GROUPS];
+    std::array<uint8_t, MICROPROFILE_MAX_GROUPS> nGroupStackPos{};
+    std::array<int64_t, MICROPROFILE_MAX_GROUPS> nGroupTicks{};
+    std::array<int64_t, MICROPROFILE_MAX_GROUPS> nAggregateGroupTicks{};
     enum
     {
         THREAD_MAX_LEN = 64,
     };
-    char                    ThreadName[64];
-    int                     nFreeListNext;
+    char                    ThreadName[64]{};
+    int                     nFreeListNext = 0;
+
+    void Reset() {
+        Log.fill({});
+        nPut = 0;
+        nGet = 0;
+        nActive = 0;
+        nGpu = 0;
+        nThreadId = {};
+        nStack.fill(0);
+        nChildTickStack.fill(0);
+        nStackPos = 0;
+        nGroupStackPos.fill(0);
+        nGroupTicks.fill(0);
+        nAggregateGroupTicks.fill(0);
+        std::fill(std::begin(ThreadName), std::end(ThreadName), '\0');
+        nFreeListNext = 0;
+    }
 };
 
 #if MICROPROFILE_GPU_TIMERS_D3D11
@@ -1151,6 +1170,7 @@ MicroProfileThreadLog* MicroProfileCreateThreadLog(const char* pName)
         MP_ASSERT(pLog->nPut.load() == 0);
         MP_ASSERT(pLog->nGet.load() == 0);
         S.nFreeListHead = S.Pool[S.nFreeListHead]->nFreeListNext;
+        pLog->Reset();
     }
     else
     {
@@ -1158,7 +1178,6 @@ MicroProfileThreadLog* MicroProfileCreateThreadLog(const char* pName)
         S.nMemUsage += sizeof(MicroProfileThreadLog);
         S.Pool[S.nNumLogs++] = pLog;
     }
-    memset(pLog, 0, sizeof(*pLog));
     int len = (int)strlen(pName);
     int maxlen = sizeof(pLog->ThreadName)-1;
     len = len < maxlen ? len : maxlen;
@@ -1206,8 +1225,8 @@ void MicroProfileOnThreadExit()
         {
             S.Frames[i].nLogStart[nLogIndex] = 0;
         }
-        memset(pLog->nGroupStackPos, 0, sizeof(pLog->nGroupStackPos));
-        memset(pLog->nGroupTicks, 0, sizeof(pLog->nGroupTicks));
+        pLog->nGroupStackPos.fill(0);
+        pLog->nGroupTicks.fill(0);
     }
 }
 
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