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authorEric Blake <eblake@redhat.com>2017-12-01 17:24:32 -0600
committerPaolo Bonzini <pbonzini@redhat.com>2018-01-16 14:54:52 +0100
commit2562755ee78983930d0662fa4d3bc5e2ac166350 (patch)
tree0dd521d04be12d99cabc73ca928c862eabc0c348 /hw/misc
parent241187c11818e5223c4bdfac79f28fdf63731733 (diff)
downloadfocaccia-qemu-2562755ee78983930d0662fa4d3bc5e2ac166350.tar.gz
focaccia-qemu-2562755ee78983930d0662fa4d3bc5e2ac166350.zip
maint: Fix macros with broken 'do/while(0); ' usage
The point of writing a macro embedded in a 'do { ... } while (0)'
loop (particularly if the macro has multiple statements or would
otherwise end with an 'if' statement) is so that the macro can be
used as a drop-in statement with the caller supplying the
trailing ';'.  Although our coding style frowns on brace-less 'if':
  if (cond)
    statement;
  else
    something else;
that is the classic case where failure to use do/while(0) wrapping
would cause the 'else' to pair with any embedded 'if' in the macro
rather than the intended outer 'if'.  But conversely, if the macro
includes an embedded ';', then the same brace-less coding style
would now have two statements, making the 'else' a syntax error
rather than pairing with the outer 'if'.  Thus, even though our
coding style with required braces is not impacted, ending a macro
with ';' makes our code harder to port to projects that use
brace-less styles.

The change should have no semantic impact.  I was not able to
fully compile-test all of the changes (as some of them are
examples of the ugly bit-rotting debug print statements that are
completely elided by default, and I didn't want to recompile
with the necessary -D witnesses - cleaning those up is left as a
bite-sized task for another day); I did, however, audit that for
all files touched, all callers of the changed macros DID supply
a trailing ';' at the callsite, and did not appear to be used
as part of a brace-less conditional.

Found mechanically via: $ git grep -B1 'while (0);' | grep -A1 \\\\

Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20171201232433.25193-7-eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw/misc')
-rw-r--r--hw/misc/auxbus.c2
-rw-r--r--hw/misc/macio/mac_dbdma.c4
-rw-r--r--hw/misc/mmio_interface.c2
-rw-r--r--hw/misc/stm32f2xx_syscfg.c2
-rw-r--r--hw/misc/zynq_slcr.c2
5 files changed, 6 insertions, 6 deletions
diff --git a/hw/misc/auxbus.c b/hw/misc/auxbus.c
index 1182745044..b4cacd664b 100644
--- a/hw/misc/auxbus.c
+++ b/hw/misc/auxbus.c
@@ -40,7 +40,7 @@
     if (DEBUG_AUX) {                                                           \
         qemu_log("aux: " fmt , ## __VA_ARGS__);                                \
     }                                                                          \
-} while (0);
+} while (0)
 
 #define TYPE_AUXTOI2C "aux-to-i2c-bridge"
 #define AUXTOI2C(obj) OBJECT_CHECK(AUXTOI2CState, (obj), TYPE_AUXTOI2C)
diff --git a/hw/misc/macio/mac_dbdma.c b/hw/misc/macio/mac_dbdma.c
index 0eddf2e700..1b2a69b3ef 100644
--- a/hw/misc/macio/mac_dbdma.c
+++ b/hw/misc/macio/mac_dbdma.c
@@ -52,7 +52,7 @@
     if (DEBUG_DBDMA) { \
         printf("DBDMA: " fmt , ## __VA_ARGS__); \
     } \
-} while (0);
+} while (0)
 
 #define DBDMA_DPRINTFCH(ch, fmt, ...) do { \
     if (DEBUG_DBDMA) { \
@@ -60,7 +60,7 @@
             printf("DBDMA[%02x]: " fmt , (ch)->channel, ## __VA_ARGS__); \
         } \
     } \
-} while (0);
+} while (0)
 
 /*
  */
diff --git a/hw/misc/mmio_interface.c b/hw/misc/mmio_interface.c
index 894e9801cb..3b0e2039a3 100644
--- a/hw/misc/mmio_interface.c
+++ b/hw/misc/mmio_interface.c
@@ -39,7 +39,7 @@ static uint64_t mmio_interface_counter;
     if (DEBUG_MMIO_INTERFACE) {                                                \
         qemu_log("mmio_interface: 0x%" PRIX64 ": " fmt, s->id, ## __VA_ARGS__);\
     }                                                                          \
-} while (0);
+} while (0)
 
 static void mmio_interface_init(Object *obj)
 {
diff --git a/hw/misc/stm32f2xx_syscfg.c b/hw/misc/stm32f2xx_syscfg.c
index 7c45833d09..7f10195862 100644
--- a/hw/misc/stm32f2xx_syscfg.c
+++ b/hw/misc/stm32f2xx_syscfg.c
@@ -34,7 +34,7 @@
     if (STM_SYSCFG_ERR_DEBUG >= lvl) { \
         qemu_log("%s: " fmt, __func__, ## args); \
     } \
-} while (0);
+} while (0)
 
 #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
 
diff --git a/hw/misc/zynq_slcr.c b/hw/misc/zynq_slcr.c
index 44304d48be..d6bdd027ef 100644
--- a/hw/misc/zynq_slcr.c
+++ b/hw/misc/zynq_slcr.c
@@ -30,7 +30,7 @@
             fprintf(stderr,  ": %s: ", __func__); \
             fprintf(stderr, ## __VA_ARGS__); \
         } \
-    } while (0);
+    } while (0)
 
 #define XILINX_LOCK_KEY 0x767b
 #define XILINX_UNLOCK_KEY 0xdf0d