diff --git a/elf.h b/elf.h
index 1bba022..861f1d3 100644
--- a/elf.h
+++ b/elf.h
@@ -1123,6 +1123,7 @@
   Elf64_Word n_type;	/* Content type */
 } Elf64_Nhdr;
 
+#ifdef ELF_CLASS
 #if ELF_CLASS == ELFCLASS32
 
 #define elfhdr		elf32_hdr
@@ -1165,5 +1166,7 @@
 # endif
 #endif
 
+#endif /* ELF_CLASS */
+
 
 #endif /* _QEMU_ELF_H */
diff --git a/exec.c b/exec.c
index 3f686d8..5e30689 100644
--- a/exec.c
+++ b/exec.c
@@ -2259,7 +2259,7 @@
 #endif
 #ifdef TARGET_SPARC
     do_unassigned_access(addr, 0, 0, 0);
-#elif TARGET_CRIS
+#elif defined(TARGET_CRIS)
     do_unassigned_access(addr, 0, 0, 0);
 #endif
     return 0;
@@ -2272,7 +2272,7 @@
 #endif
 #ifdef TARGET_SPARC
     do_unassigned_access(addr, 1, 0, 0);
-#elif TARGET_CRIS
+#elif defined(TARGET_CRIS)
     do_unassigned_access(addr, 1, 0, 0);
 #endif
 }
diff --git a/hw/omap1.c b/hw/omap1.c
index 5854500..101d36b 100644
--- a/hw/omap1.c
+++ b/hw/omap1.c
@@ -3478,7 +3478,7 @@
 
     switch (offset) {
     case 0x00:	/* SECONDS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC SEC_REG <-- %02x\n", value);
 #endif
         s->ti -= s->current_tm.tm_sec;
@@ -3486,7 +3486,7 @@
         return;
 
     case 0x04:	/* MINUTES_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC MIN_REG <-- %02x\n", value);
 #endif
         s->ti -= s->current_tm.tm_min * 60;
@@ -3494,7 +3494,7 @@
         return;
 
     case 0x08:	/* HOURS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC HRS_REG <-- %02x\n", value);
 #endif
         s->ti -= s->current_tm.tm_hour * 3600;
@@ -3506,7 +3506,7 @@
         return;
 
     case 0x0c:	/* DAYS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC DAY_REG <-- %02x\n", value);
 #endif
         s->ti -= s->current_tm.tm_mday * 86400;
@@ -3514,7 +3514,7 @@
         return;
 
     case 0x10:	/* MONTHS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC MTH_REG <-- %02x\n", value);
 #endif
         memcpy(&new_tm, &s->current_tm, sizeof(new_tm));
@@ -3533,7 +3533,7 @@
         return;
 
     case 0x14:	/* YEARS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC YRS_REG <-- %02x\n", value);
 #endif
         memcpy(&new_tm, &s->current_tm, sizeof(new_tm));
@@ -3555,7 +3555,7 @@
         return;	/* Ignored */
 
     case 0x20:	/* ALARM_SECONDS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("ALM SEC_REG <-- %02x\n", value);
 #endif
         s->alarm_tm.tm_sec = omap_rtc_bin(value);
@@ -3563,7 +3563,7 @@
         return;
 
     case 0x24:	/* ALARM_MINUTES_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("ALM MIN_REG <-- %02x\n", value);
 #endif
         s->alarm_tm.tm_min = omap_rtc_bin(value);
@@ -3571,7 +3571,7 @@
         return;
 
     case 0x28:	/* ALARM_HOURS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("ALM HRS_REG <-- %02x\n", value);
 #endif
         if (s->pm_am)
@@ -3584,7 +3584,7 @@
         return;
 
     case 0x2c:	/* ALARM_DAYS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("ALM DAY_REG <-- %02x\n", value);
 #endif
         s->alarm_tm.tm_mday = omap_rtc_bin(value);
@@ -3592,7 +3592,7 @@
         return;
 
     case 0x30:	/* ALARM_MONTHS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("ALM MON_REG <-- %02x\n", value);
 #endif
         s->alarm_tm.tm_mon = omap_rtc_bin(value);
@@ -3600,7 +3600,7 @@
         return;
 
     case 0x34:	/* ALARM_YEARS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("ALM YRS_REG <-- %02x\n", value);
 #endif
         s->alarm_tm.tm_year = omap_rtc_bin(value);
@@ -3608,7 +3608,7 @@
         return;
 
     case 0x40:	/* RTC_CTRL_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC CONTROL <-- %02x\n", value);
 #endif
         s->pm_am = (value >> 3) & 1;
@@ -3620,7 +3620,7 @@
         return;
 
     case 0x44:	/* RTC_STATUS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC STATUSL <-- %02x\n", value);
 #endif
         s->status &= ~((value & 0xc0) ^ 0x80);
@@ -3628,14 +3628,14 @@
         return;
 
     case 0x48:	/* RTC_INTERRUPTS_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC INTRS <-- %02x\n", value);
 #endif
         s->interrupts = value;
         return;
 
     case 0x4c:	/* RTC_COMP_LSB_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC COMPLSB <-- %02x\n", value);
 #endif
         s->comp_reg &= 0xff00;
@@ -3643,7 +3643,7 @@
         return;
 
     case 0x50:	/* RTC_COMP_MSB_REG */
-#if ALMDEBUG
+#ifdef ALMDEBUG
         printf("RTC COMPMSB <-- %02x\n", value);
 #endif
         s->comp_reg &= 0x00ff;
diff --git a/hw/pc.c b/hw/pc.c
index 213ead8..435c7d4 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -76,7 +76,7 @@
     /* Note: when using kqemu, it is more logical to return the host TSC
        because kqemu does not trap the RDTSC instruction for
        performance reasons */
-#if USE_KQEMU
+#ifdef USE_KQEMU
     if (env->kqemu_enabled) {
         return cpu_get_real_ticks();
     } else
diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index 6aec2ff..cae8788 100644
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -3356,7 +3356,7 @@
     return next_time;
 }
 
-#if RTL8139_ONBOARD_TIMER
+#ifdef RTL8139_ONBOARD_TIMER
 static void rtl8139_timer(void *opaque)
 {
     RTL8139State *s = opaque;
@@ -3456,7 +3456,7 @@
 
     register_savevm("rtl8139", -1, 3, rtl8139_save, rtl8139_load, s);
 
-#if RTL8139_ONBOARD_TIMER
+#ifdef RTL8139_ONBOARD_TIMER
     s->timer = qemu_new_timer(vm_clock, rtl8139_timer, s);
 
     qemu_mod_timer(s->timer,
diff --git a/hw/usb-net.c b/hw/usb-net.c
index 27dea10..63edfd5 100644
--- a/hw/usb-net.c
+++ b/hw/usb-net.c
@@ -1069,7 +1069,7 @@
     case ClassInterfaceOutRequest | USB_CDC_SEND_ENCAPSULATED_COMMAND:
         if (!s->rndis || value || index != 0)
             goto fail;
-#if TRAFFIC_DEBUG
+#ifdef TRAFFIC_DEBUG
         {
             unsigned int i;
             fprintf(stderr, "SEND_ENCAPSULATED_COMMAND:");
@@ -1092,7 +1092,7 @@
             data[0] = 0;
             ret = 1;
         }
-#if TRAFFIC_DEBUG
+#ifdef TRAFFIC_DEBUG
         {
             unsigned int i;
             fprintf(stderr, "GET_ENCAPSULATED_RESPONSE:");
@@ -1219,7 +1219,7 @@
     if (!s->rndis_resp.tqh_first)
         ret = USB_RET_NAK;
 
-#if DEBUG
+#ifdef TRAFFIC_DEBUG
     fprintf(stderr, "usbnet: interrupt poll len %u return %d", p->len, ret);
     {
         int i;
@@ -1260,7 +1260,7 @@
         s->in_ptr = s->in_len = 0;
     }
 
-#if TRAFFIC_DEBUG
+#ifdef TRAFFIC_DEBUG
     fprintf(stderr, "usbnet: data in len %u return %d", p->len, ret);
     {
         int i;
@@ -1285,7 +1285,7 @@
             (struct rndis_packet_msg_type *) s->out_buf;
     uint32_t len;
 
-#if TRAFFIC_DEBUG
+#ifdef TRAFFIC_DEBUG
     fprintf(stderr, "usbnet: data out len %u\n", p->len);
     {
         int i;
diff --git a/hw/usb-ohci.c b/hw/usb-ohci.c
index 68995b0..afd5506 100644
--- a/hw/usb-ohci.c
+++ b/hw/usb-ohci.c
@@ -1598,7 +1598,7 @@
     int i;
 
     if (usb_frame_time == 0) {
-#if OHCI_TIME_WARP
+#ifdef OHCI_TIME_WARP
         usb_frame_time = ticks_per_sec;
         usb_bit_time = muldiv64(1, ticks_per_sec, USB_HZ/1000);
 #else
diff --git a/linux-user/arm/nwfpe/fpa11.c b/linux-user/arm/nwfpe/fpa11.c
index 626a87a..beed968 100644
--- a/linux-user/arm/nwfpe/fpa11.c
+++ b/linux-user/arm/nwfpe/fpa11.c
@@ -54,7 +54,7 @@
   fpa11->fpsr = FP_EMULATOR | BIT_AC;
 
   /* FPCR: set SB, AB and DA bits, clear all others */
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
   fpa11->fpcr = MASK_RESET;
 #endif
 }
@@ -64,7 +64,7 @@
     int rounding_mode;
    FPA11 *fpa11 = GET_FPA11();
 
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
    fpa11->fpcr &= ~MASK_ROUNDING_MODE;
 #endif
    switch (opcode & MASK_ROUNDING_MODE)
@@ -72,28 +72,28 @@
       default:
       case ROUND_TO_NEAREST:
          rounding_mode = float_round_nearest_even;
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_TO_NEAREST;
 #endif
       break;
 
       case ROUND_TO_PLUS_INFINITY:
          rounding_mode = float_round_up;
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_TO_PLUS_INFINITY;
 #endif
       break;
 
       case ROUND_TO_MINUS_INFINITY:
          rounding_mode = float_round_down;
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_TO_MINUS_INFINITY;
 #endif
       break;
 
       case ROUND_TO_ZERO:
          rounding_mode = float_round_to_zero;
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_TO_ZERO;
 #endif
       break;
@@ -105,28 +105,28 @@
 {
     int rounding_precision;
    FPA11 *fpa11 = GET_FPA11();
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
    fpa11->fpcr &= ~MASK_ROUNDING_PRECISION;
 #endif
    switch (opcode & MASK_ROUNDING_PRECISION)
    {
       case ROUND_SINGLE:
          rounding_precision = 32;
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_SINGLE;
 #endif
       break;
 
       case ROUND_DOUBLE:
          rounding_precision = 64;
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_DOUBLE;
 #endif
       break;
 
       case ROUND_EXTENDED:
          rounding_precision = 80;
-#if MAINTAIN_FPCR
+#ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_EXTENDED;
 #endif
       break;
diff --git a/linux-user/main.c b/linux-user/main.c
index cca696c..2a30519 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -282,7 +282,7 @@
     p[1] = tswap32(e2);
 }
 
-#if TARGET_X86_64
+#ifdef TARGET_X86_64
 uint64_t idt_table[512];
 
 static void set_gate64(void *ptr, unsigned int type, unsigned int dpl,
diff --git a/mips-dis.c b/mips-dis.c
index 867ecf2..5b0b247 100644
--- a/mips-dis.c
+++ b/mips-dis.c
@@ -3302,7 +3302,7 @@
 #endif
 
   /* Set ISA, architecture, and cp0 register names as best we can.  */
-#if ! SYMTAB_AVAILABLE && 0
+#if !defined(SYMTAB_AVAILABLE) && 0
   /* This is running out on a target machine, not in a host tool.
      FIXME: Where does mips_target_info come from?  */
   target_processor = mips_target_info.processor;
diff --git a/slirp/ip_icmp.c b/slirp/ip_icmp.c
index d1da0a2..53566c1 100644
--- a/slirp/ip_icmp.c
+++ b/slirp/ip_icmp.c
@@ -228,7 +228,7 @@
   /* check msrc */
   if(!msrc) goto end_error;
   ip = mtod(msrc, struct ip *);
-#if DEBUG
+#ifdef DEBUG
   { char bufa[20], bufb[20];
     strcpy(bufa, inet_ntoa(ip->ip_src));
     strcpy(bufb, inet_ntoa(ip->ip_dst));
@@ -285,7 +285,7 @@
   HTONS(icp->icmp_ip.ip_id);
   HTONS(icp->icmp_ip.ip_off);
 
-#if DEBUG
+#ifdef DEBUG
   if(message) {           /* DEBUG : append message to ICMP packet */
     int message_len;
     char *cpnt;
diff --git a/slirp/slirp.h b/slirp/slirp.h
index 9ee240b..d49be12 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -103,7 +103,7 @@
 # include <sys/time.h>
 # include <time.h>
 #else
-# if HAVE_SYS_TIME_H
+# ifdef HAVE_SYS_TIME_H
 #  include <sys/time.h>
 # else
 #  include <time.h>
diff --git a/target-i386/op_helper.c b/target-i386/op_helper.c
index 0b5fdc0..32cdf2a 100644
--- a/target-i386/op_helper.c
+++ b/target-i386/op_helper.c
@@ -1217,7 +1217,7 @@
         }
     }
     if (env->cr[0] & CR0_PE_MASK) {
-#if TARGET_X86_64
+#ifdef TARGET_X86_64
         if (env->hflags & HF_LMA_MASK) {
             do_interrupt64(intno, is_int, error_code, next_eip, is_hw);
         } else
diff --git a/vnc.c b/vnc.c
index 2fe1e51..3c029f5 100644
--- a/vnc.c
+++ b/vnc.c
@@ -35,14 +35,14 @@
 #include "keymaps.c"
 #include "d3des.h"
 
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 #include <gnutls/gnutls.h>
 #include <gnutls/x509.h>
 #endif /* CONFIG_VNC_TLS */
 
 // #define _VNC_DEBUG 1
 
-#if _VNC_DEBUG
+#ifdef _VNC_DEBUG
 #define VNC_DEBUG(fmt, ...) do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
 
 #if CONFIG_VNC_TLS && _VNC_DEBUG >= 2
@@ -93,7 +93,7 @@
     VNC_AUTH_VENCRYPT = 19
 };
 
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 enum {
     VNC_WIREMODE_CLEAR,
     VNC_WIREMODE_TLS,
@@ -141,7 +141,7 @@
     char *display;
     char *password;
     int auth;
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
     int subauth;
     int x509verify;
 
@@ -152,7 +152,7 @@
 #endif
     char challenge[VNC_AUTH_CHALLENGE_SIZE];
 
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
     int wiremode;
     gnutls_session_t tls_session;
 #endif
@@ -662,7 +662,7 @@
 	buffer_reset(&vs->input);
 	buffer_reset(&vs->output);
 	vs->need_update = 0;
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 	if (vs->tls_session) {
 	    gnutls_deinit(vs->tls_session);
 	    vs->tls_session = NULL;
@@ -684,7 +684,7 @@
     long ret;
     VncState *vs = opaque;
 
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
     if (vs->tls_session) {
 	ret = gnutls_write(vs->tls_session, vs->output.buffer, vs->output.offset);
 	if (ret < 0) {
@@ -722,7 +722,7 @@
 
     buffer_reserve(&vs->input, 4096);
 
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
     if (vs->tls_session) {
 	ret = gnutls_read(vs->tls_session, buffer_end(&vs->input), 4096);
 	if (ret < 0) {
@@ -829,7 +829,7 @@
 	    (data[offset + 2] << 8) | data[offset + 3]);
 }
 
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 static ssize_t vnc_tls_push(gnutls_transport_ptr_t transport,
                             const void *data,
                             size_t len) {
@@ -1439,7 +1439,7 @@
 }
 
 
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 #define DH_BITS 1024
 static gnutls_dh_params_t dh_params;
 
@@ -1877,7 +1877,7 @@
            VNC_DEBUG("Start VNC auth\n");
            return start_auth_vnc(vs);
 
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
        case VNC_AUTH_VENCRYPT:
            VNC_DEBUG("Accept VeNCrypt auth\n");;
            return start_auth_vencrypt(vs);
@@ -2030,7 +2030,7 @@
     vnc_dpy_resize(vs->ds, 640, 400);
 }
 
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 static int vnc_set_x509_credential(VncState *vs,
 				   const char *certdir,
 				   const char *filename,
@@ -2107,7 +2107,7 @@
 	buffer_reset(&vs->input);
 	buffer_reset(&vs->output);
 	vs->need_update = 0;
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 	if (vs->tls_session) {
 	    gnutls_deinit(vs->tls_session);
 	    vs->tls_session = NULL;
@@ -2116,7 +2116,7 @@
 #endif /* CONFIG_VNC_TLS */
     }
     vs->auth = VNC_AUTH_INVALID;
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
     vs->subauth = VNC_AUTH_INVALID;
     vs->x509verify = 0;
 #endif
@@ -2152,7 +2152,7 @@
     const char *options;
     int password = 0;
     int reverse = 0;
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
     int tls = 0, x509 = 0;
 #endif
 
@@ -2170,7 +2170,7 @@
 	    password = 1; /* Require password auth */
 	} else if (strncmp(options, "reverse", 7) == 0) {
 	    reverse = 1;
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 	} else if (strncmp(options, "tls", 3) == 0) {
 	    tls = 1; /* Require TLS */
 	} else if (strncmp(options, "x509", 4) == 0) {
@@ -2208,7 +2208,7 @@
     }
 
     if (password) {
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 	if (tls) {
 	    vs->auth = VNC_AUTH_VENCRYPT;
 	    if (x509) {
@@ -2222,12 +2222,12 @@
 #endif
 	    VNC_DEBUG("Initializing VNC server with password auth\n");
 	    vs->auth = VNC_AUTH_VNC;
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 	    vs->subauth = VNC_AUTH_INVALID;
 	}
 #endif
     } else {
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 	if (tls) {
 	    vs->auth = VNC_AUTH_VENCRYPT;
 	    if (x509) {
@@ -2241,7 +2241,7 @@
 #endif
 	    VNC_DEBUG("Initializing VNC server with no auth\n");
 	    vs->auth = VNC_AUTH_NONE;
-#if CONFIG_VNC_TLS
+#ifdef CONFIG_VNC_TLS
 	    vs->subauth = VNC_AUTH_INVALID;
 	}
 #endif