Rename target_phys_addr_t to hwaddr

[mirror_qemu.git] / HACKING

diff --git a/HACKING b/HACKING
index 5b4ae10654185a9c0d34d97b142266feb7411334..89a6b3ad444436732c2bae557f6e37ca5b01782a 100644 (file)
--- a/HACKING
+++ b/HACKING
@@ -32,7 +32,7 @@ mandatory for VMState fields.
 
 Don't use Linux kernel internal types like u32, __u32 or __le32.
 
-Use target_phys_addr_t for guest physical addresses except pcibus_t
+Use hwaddr for guest physical addresses except pcibus_t
 for PCI addresses.  In addition, ram_addr_t is a QEMU internal address
 space that maps guest RAM physical addresses into an intermediate
 address space that can map to host virtual address spaces.  Generally
@@ -77,11 +77,13 @@ avoided.
 
 Use of the malloc/free/realloc/calloc/valloc/memalign/posix_memalign
 APIs is not allowed in the QEMU codebase. Instead of these routines,
-use the replacement g_malloc/g_malloc0/g_realloc/g_free or
-qemu_vmalloc/qemu_memalign/qemu_vfree APIs.
+use the GLib memory allocation routines g_malloc/g_malloc0/g_new/
+g_new0/g_realloc/g_free or QEMU's qemu_vmalloc/qemu_memalign/qemu_vfree
+APIs.
 
-Please note that NULL check for the qemu_malloc result is redundant and
-that g_malloc() call with zero size is not allowed.
+Please note that g_malloc will exit on allocation failure, so there
+is no need to test for failure (as you would have to with malloc).
+Calling g_malloc with a zero size is valid and will return NULL.
 
 Memory allocated by qemu_vmalloc or qemu_memalign must be freed with
 qemu_vfree, since breaking this will cause problems on Win32 and user
@@ -89,10 +91,11 @@ emulators.
 
 4. String manipulation
 
-Do not use the strncpy function.  According to the man page, it does
-*not* guarantee a NULL-terminated buffer, which makes it extremely dangerous
-to use.  Instead, use functionally equivalent function:
-void pstrcpy(char *buf, int buf_size, const char *str)
+Do not use the strncpy function.  As mentioned in the man page, it does *not*
+guarantee a NULL-terminated buffer, which makes it extremely dangerous to use.
+It also zeros trailing destination bytes out to the specified length.  Instead,
+use this similar function when possible, but note its different signature:
+void pstrcpy(char *dest, int dest_buf_size, const char *src)
 
 Don't use strcat because it can't check for buffer overflows, but:
 char *pstrcat(char *buf, int buf_size, const char *s)