[UCRT] No __declspec(spectre(nomitigation)) for GCC/Clang

tkreuzer · tkreuzer · commit 47e3f49e5266 · 2025-01-16T14:18:53.000+02:00
diff --git a/sdk/lib/ucrt/inc/corecrt_internal_stdio_output.h b/sdk/lib/ucrt/inc/corecrt_internal_stdio_output.h
@@ -576,7 +576,10 @@ class spectre_mitigated_lookup_table
 
     // Instead of using an lfence mitigation, we can fill the table to a power of two,
     // then bitwise-and all values used to index into the array.
-    __declspec(spectre(nomitigation)) T const& operator[](size_t const index) const
+    #if defined(_MSC_VER) && !defined(__clang__)
+    __declspec(spectre(nomitigation))
+    #endif
+    T const& operator[](size_t const index) const
     {
         return m_array[index & mask];
     }

Original file line number	Diff line number	Diff line change
`@@ -576,7 +576,10 @@ class spectre_mitigated_lookup_table`
`576`	`576`
`577`	`577`	`// Instead of using an lfence mitigation, we can fill the table to a power of two,`
`578`	`578`	`// then bitwise-and all values used to index into the array.`
`579`		`- __declspec(spectre(nomitigation)) T const& operator[](size_t const index) const`
	`579`	`+ #if defined(_MSC_VER) && !defined(__clang__)`
	`580`	`+ __declspec(spectre(nomitigation))`
	`581`	`+ #endif`
	`582`	`+ T const& operator[](size_t const index) const`
`580`	`583`	`{`
`581`	`584`	`return m_array[index & mask];`
`582`	`585`	`}`