[Qemu-devel] [PATCH] linux-user: Avoid compilation error with --disable-guest-base

[Laurent Vivier <laurent@vivier.eu>]

When guest base is disabled, RESERVED_VA is 0, and
(__guest < RESERVED_VA) is always false as __guest is unsigned.

With -Werror=type-limits, this triggers an error:

    include/exec/cpu_ldst.h:60:31: error: comparison of unsigned expression < 0 is always false [-Werror=type-limits]
         (!RESERVED_VA || (__guest < RESERVED_VA)); \

This patch removes this comparison when guest base is disabled.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 include/exec/cpu_ldst.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h
index 1239c60..f278126 100644
--- a/include/exec/cpu_ldst.h
+++ b/include/exec/cpu_ldst.h
@@ -54,11 +54,16 @@
 #if HOST_LONG_BITS <= TARGET_VIRT_ADDR_SPACE_BITS
 #define h2g_valid(x) 1
 #else
+#if defined(CONFIG_USE_GUEST_BASE)
 #define h2g_valid(x) ({ \
     unsigned long __guest = (unsigned long)(x) - GUEST_BASE; \
     (__guest < (1ul << TARGET_VIRT_ADDR_SPACE_BITS)) && \
     (!RESERVED_VA || (__guest < RESERVED_VA)); \
 })
+#else
+#define h2g_valid(x) \
+    ((unsigned long)(x) < (1ul << TARGET_VIRT_ADDR_SPACE_BITS))
+#endif
 #endif
 
 #define h2g_nocheck(x) ({ \
-- 
2.4.3