From eac23cead252d39a59b35072d443e45a8f81b01f Mon Sep 17 00:00:00 2001
From: joshuakr <jkriegshauser@gmail.com>
Date: Fri, 9 Apr 2021 15:33:01 -0700
Subject: [PATCH] PR feedback

---
 client/TracyProfiler.cpp |  7 +++----
 common/TracySocket.cpp   |  5 +++--
 common/TracySystem.cpp   | 33 +++++++++++++++++++++++++++++++++
 common/TracySystem.hpp   |  2 ++
 4 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/client/TracyProfiler.cpp b/client/TracyProfiler.cpp
index af49c97e..41bdce71 100644
--- a/client/TracyProfiler.cpp
+++ b/client/TracyProfiler.cpp
@@ -270,8 +270,7 @@ static int64_t SetupHwTimer()
     CpuId( regs, 0x80000007 );
     if( !( regs[3] & ( 1 << 8 ) ) )
     {
-        char buffer[32];
-        const char* noCheck = GetEnvVar( "TRACY_NO_INVARIANT_CHECK", buffer, sizeof(buffer) / sizeof(buffer[0]) );
+        const char* noCheck = GetEnvVar( "TRACY_NO_INVARIANT_CHECK" );
         if( !noCheck || noCheck[0] != '1' )
         {
 #if defined _WIN32 || defined __CYGWIN__
@@ -1264,14 +1263,14 @@ Profiler::Profiler()
 
     char buffer[32];
 #ifndef TRACY_NO_EXIT
-    const char* noExitEnv = GetEnvVar( "TRACY_NO_EXIT", buffer, sizeof(buffer) / sizeof(buffer[0]) );
+    const char* noExitEnv = GetEnvVar( "TRACY_NO_EXIT" );
     if( noExitEnv && noExitEnv[0] == '1' )
     {
         m_noExit = true;
     }
 #endif
 
-    const char* userPort = GetEnvVar( "TRACY_PORT", buffer, sizeof(buffer) / sizeof(buffer[0]) );
+    const char* userPort = GetEnvVar( "TRACY_PORT" );
     if( userPort )
     {
         m_userPort = atoi( userPort );
diff --git a/common/TracySocket.cpp b/common/TracySocket.cpp
index f16569b0..1be7f051 100644
--- a/common/TracySocket.cpp
+++ b/common/TracySocket.cpp
@@ -8,6 +8,7 @@
 
 #include "TracyAlloc.hpp"
 #include "TracySocket.hpp"
+#include "TracySystem.hpp"
 
 #ifdef _WIN32
 #  ifndef NOMINMAX
@@ -454,7 +455,7 @@ static int addrinfo_and_socket_for_family( uint16_t port, int ai_family, struct
     hints.ai_family = ai_family;
     hints.ai_socktype = SOCK_STREAM;
 #ifndef TRACY_ONLY_LOCALHOST
-    const char* onlyLocalhost = getenv( "TRACY_ONLY_LOCALHOST" );
+    const char* onlyLocalhost = GetEnvVar( "TRACY_ONLY_LOCALHOST" );
     if( !onlyLocalhost || onlyLocalhost[0] != '1' )
     {
         hints.ai_flags = AI_PASSIVE;
@@ -475,7 +476,7 @@ bool ListenSocket::Listen( uint16_t port, int backlog )
     struct addrinfo* res = nullptr;
 
 #if !defined TRACY_ONLY_IPV4 && !defined TRACY_ONLY_LOCALHOST
-    const char* onlyIPv4 = getenv( "TRACY_ONLY_IPV4" );
+    const char* onlyIPv4 = GetEnvVar( "TRACY_ONLY_IPV4" );
     if( !onlyIPv4 || onlyIPv4[0] != '1' )
     {
         m_sock = addrinfo_and_socket_for_family( port, AF_INET6, &res );
diff --git a/common/TracySystem.cpp b/common/TracySystem.cpp
index 18b39dac..c893c92c 100644
--- a/common/TracySystem.cpp
+++ b/common/TracySystem.cpp
@@ -11,6 +11,7 @@
 #endif
 #if defined _WIN32 || defined __CYGWIN__
 #  include <windows.h>
+#  include <malloc.h>
 #else
 #  include <pthread.h>
 #  include <string.h>
@@ -236,6 +237,38 @@ TRACY_API const char* GetThreadName( uint64_t id )
     return buf;
 }
 
+TRACY_API const char* GetEnvVar( const char* name )
+{
+#if defined _WIN32 || defined __CYGWIN__
+    // unfortunately getenv() on Windows is just fundamentally broken.  It caches the entire
+    // environment block once on startup, then never refreshes it again.  If any environment
+    // strings are added or modified after startup of the CRT, those changes will not be
+    // seen by getenv().  This removes the possibility of an app using this SDK from
+    // programmatically setting any of the behaviour controlling envvars here.
+    //
+    // To work around this, we'll instead go directly to the Win32 environment strings APIs
+    // to get the current value.
+    static char buffer[1024];
+    DWORD const kBufferSize = DWORD(sizeof(buffer) / sizeof(buffer[0]));
+    DWORD count = GetEnvironmentVariableA(name, buffer, kBufferSize);
+
+    if( count == 0 )
+        return nullptr;
+
+    if( count >= kBufferSize )
+    {
+        char* buf = reinterpret_cast<char*>(_alloca(count + 1));
+        count = GetEnvironmentVariableA(name, buf, count + 1);
+        memcpy(buffer, buf, kBufferSize);
+        buffer[kBufferSize - 1] = 0;
+    }
+
+    return buffer;
+#else
+    return getenv(name);
+#endif
+}
+
 }
 
 #ifdef __cplusplus
diff --git a/common/TracySystem.hpp b/common/TracySystem.hpp
index 2f539c2e..a032e606 100644
--- a/common/TracySystem.hpp
+++ b/common/TracySystem.hpp
@@ -25,6 +25,8 @@ static inline uint64_t GetThreadHandle()
 TRACY_API void SetThreadName( const char* name );
 TRACY_API const char* GetThreadName( uint64_t id );
 
+TRACY_API const char* GetEnvVar(const char* name);
+
 }
 
 #endif