fix: cross platform build

2 files changed, 62 insertions, 20 deletions

diff --git a/src/core/log.cpp b/src/core/log.cpp
new file mode 100644
index 0000000..f7285f3
--- /dev/null
+++ b/src/core/log.cpp
@@ -0,0 +1,59 @@
+#include "core/log.h"
+
+// there is no standard way to ask whether a stream is a terminal
+#ifdef HSDBG_WINDOWS
+    #define WIN32_LEAN_AND_MEAN
+    #define NOMINMAX
+    #include <windows.h>
+
+    #include <io.h>
+#else
+    #include <unistd.h>
+#endif
+
+namespace Hsdbg::Log::Detail
+{
+    namespace
+    {
+        constexpr int STDOUT_DESCRIPTOR = 1;
+        constexpr int STDERR_DESCRIPTOR = 2;
+
+#ifdef HSDBG_WINDOWS
+        // a windows console prints escapes literally until it is asked to
+        // interpret them, so a console that refuses gets the plain format
+        auto probe(bool to_stderr) -> bool
+        {
+            if (_isatty(to_stderr ? STDERR_DESCRIPTOR : STDOUT_DESCRIPTOR) == 0)
+                return false;
+
+            const HANDLE console = GetStdHandle(to_stderr ? STD_ERROR_HANDLE : STD_OUTPUT_HANDLE);
+
+            if (console == nullptr || console == INVALID_HANDLE_VALUE)
+                return false;
+
+            DWORD mode = 0;
+
+            if (GetConsoleMode(console, &mode) == 0)
+                return false;
+
+            if ((mode & ENABLE_VIRTUAL_TERMINAL_PROCESSING) != 0)
+                return true;
+
+            return SetConsoleMode(console, mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING) != 0;
+        }
+#else
+        auto probe(bool to_stderr) -> bool
+        {
+            return isatty(to_stderr ? STDERR_DESCRIPTOR : STDOUT_DESCRIPTOR) != 0;
+        }
+#endif
+    }
+
+    auto is_terminal(bool to_stderr) -> bool
+    {
+        static const bool out = probe(false);
+        static const bool err = probe(true);
+
+        return to_stderr ? err : out;
+    }
+}
diff --git a/src/core/log.h b/src/core/log.h
index a66a61e..7caf93f 100644
--- a/src/core/log.h
+++ b/src/core/log.h
@@ -8,13 +8,6 @@
 #include <string_view>
 #include <utility>
 
-// there is no standard way to ask whether a stream is a terminal
-#ifdef HSDBG_WINDOWS
-    #include <io.h>
-#else
-    #include <unistd.h>
-#endif
-
 namespace Hsdbg::Log
 {
     enum class Level : uint8_t
@@ -66,19 +59,9 @@ namespace Hsdbg::Log
             return "";
         }
 
-        inline auto is_terminal(bool to_stderr) -> bool
-        {
-            constexpr int STDOUT_DESCRIPTOR = 1;
-            constexpr int STDERR_DESCRIPTOR = 2;
-
-            const int descriptor = to_stderr ? STDERR_DESCRIPTOR : STDOUT_DESCRIPTOR;
-
-#ifdef HSDBG_WINDOWS
-            return _isatty(descriptor) != 0;
-#else
-            return isatty(descriptor) != 0;
-#endif
-        }
+        // true only when the stream is a terminal that understands ansi escapes,
+        // which needs platform calls, so it lives in log.cpp
+        auto is_terminal(bool to_stderr) -> bool;
 
         inline auto write(Level level, std::string_view message) -> void
         {