macro do/while (0) cleanup
Subsystems (3)
v2 cover macro do/while (0) cleanup
Noticed this by chance in the tests/ directory, so I broadened it to a grep of the entire code base. I suspect^wKNOW many of the bad macros were the victims of copy-and-paste from some other bad location (particularly given how many bit-rotten debug print macros were involved).
https://wiki.qemu.org/BiteSizedTasks#Bitrot_prevention is still left for someone else, for another day.
In v2:
- add review tags
- audit that the maint patch has no semantic change (all callers were indeed supplying ';' at the macro call-sites)
- improved commit messages
- more patches for some additional cleanups
- tighten the checkpatch rule to also flag 'while (false);'
Eric Blake (7):
net: Drop unusual use of do { } while (0);
mips: Tweak location of ';' in macros
chardev: Use goto/label instead of do/break/while(0)
chardev: Clean up previous patch indentation
tests: Avoid 'do/while(false);' in vhost-user-bridge
maint: Fix macros with broken 'do/while(0);' usage
checkpatch: Enforce proper do/while (0) style
tests/acpi-utils.h | 8 ++--- ui/sdl_zoom_template.h | 8 ++--- audio/paaudio.c | 4 +-- chardev/char-serial.c | 75 ++++++++++++++++++++++++---------------------- hw/adc/stm32f2xx_adc.c | 2 +- hw/block/m25p80.c | 2 +- hw/char/cadence_uart.c | 2 +- hw/char/stm32f2xx_usart.c | 2 +- hw/display/cg3.c | 2 +- hw/display/dpcd.c | 2 +- hw/display/xlnx_dp.c | 2 +- hw/dma/pl330.c | 2 +- hw/dma/xlnx-zynq-devcfg.c | 2 +- hw/dma/xlnx_dpdma.c | 2 +- hw/i2c/i2c-ddc.c | 2 +- hw/misc/auxbus.c | 2 +- hw/misc/macio/mac_dbdma.c | 4 +-- hw/misc/mmio_interface.c | 2 +- hw/misc/stm32f2xx_syscfg.c | 2 +- hw/misc/zynq_slcr.c | 2 +- hw/net/cadence_gem.c | 2 +- hw/net/pcnet.c | 20 ++++++------- hw/ssi/mss-spi.c | 2 +- hw/ssi/stm32f2xx_spi.c | 2 +- hw/ssi/xilinx_spi.c | 2 +- hw/ssi/xilinx_spips.c | 2 +- hw/timer/a9gtimer.c | 2 +- hw/timer/cadence_ttc.c | 2 +- hw/timer/mss-timer.c | 2 +- hw/timer/stm32f2xx_timer.c | 2 +- hw/tpm/tpm_passthrough.c | 2 +- hw/tpm/tpm_tis.c | 2 +- migration/rdma.c | 2 +- target/arm/translate-a64.c | 2 +- target/mips/msa_helper.c | 34 +++++++++++---------- target/s390x/kvm.c | 2 +- tests/tcg/test-mmap.c | 2 +- tests/vhost-user-bridge.c | 6 ++-- scripts/checkpatch.pl | 5 ++++ 39 files changed, 119 insertions(+), 105 deletions(-)
Signature · 1 line
2.14.3
PATCH v2 1/7 net: Drop unusual use of do { } while (0);
For a couple of macros in pcnet.c, we have to provide a new scope to avoid compiler warnings about declarations in the middle of a switch statement that aren't in a sub-scope. But use of 'do { ... } while (0);' merely to provide that new scope is arcane overkill, compared to just using '{ ... }'.
--- hw/net/pcnet.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-)
hw/net/pcnet.c +10 -10
@@ -455,32 +455,32 @@ static inline void pcnet_rmd_store(PCNetState *s, struct pcnet_RMD *rmd,#define CHECK_RMD (ADDR ,RES ) do { \ switch (BCR_SWSTYLE(s)) { \ case 0x00: \ - do { \ + { \ uint16_t rda[4]; \ s->phys_mem_read(s->dma_opaque, (ADDR), \ (void *)&rda[0], sizeof(rda), 0); \ (RES) |= (rda[2] & 0xf000)!=0xf000; \ (RES) |= (rda[3] & 0xf000)!=0x0000; \ - } while (0); \ + } \ break; \ case 0x01: \ case 0x02: \ - do { \ + { \ uint32_t rda[4]; \ s->phys_mem_read(s->dma_opaque, (ADDR), \ (void *)&rda[0], sizeof(rda), 0); \ (RES) |= (rda[1] & 0x0000f000L)!=0x0000f000L; \ (RES) |= (rda[2] & 0x0000f000L)!=0x00000000L; \ - } while (0); \ + } \ break; \ case 0x03: \ - do { \ + { \ uint32_t rda[4]; \ s->phys_mem_read(s->dma_opaque, (ADDR), \ (void *)&rda[0], sizeof(rda), 0); \ (RES) |= (rda[0] & 0x0000f000L)!=0x00000000L; \ (RES) |= (rda[1] & 0x0000f000L)!=0x0000f000L; \ - } while (0); \ + } \ break; \ } \ } while (0)
@@ -488,22 +488,22 @@ static inline void pcnet_rmd_store(PCNetState *s, struct pcnet_RMD *rmd,#define CHECK_TMD (ADDR ,RES ) do { \ switch (BCR_SWSTYLE(s)) { \ case 0x00: \ - do { \ + { \ uint16_t xda[4]; \ s->phys_mem_read(s->dma_opaque, (ADDR), \ (void *)&xda[0], sizeof(xda), 0); \ (RES) |= (xda[2] & 0xf000)!=0xf000; \ - } while (0); \ + } \ break; \ case 0x01: \ case 0x02: \ case 0x03: \ - do { \ + { \ uint32_t xda[4]; \ s->phys_mem_read(s->dma_opaque, (ADDR), \ (void *)&xda[0], sizeof(xda), 0); \ (RES) |= (xda[1] & 0x0000f000L)!=0x0000f000L; \ - } while (0); \ + } \ break; \ } \ } while (0)
Signature · 1 line
2.14.3
PATCH v2 2/7 mips: Tweak location of ';' in macros
In reply to Eric BlakeIt is more typical to provide the ';' by the caller of a macro than to embed it in the macro itself; this is because syntax highlight engines can get confused if a macro is called without a semicolon before the closing '}'.
--- target/mips/msa_helper.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-)
target/mips/msa_helper.c +18 -16
@@ -682,13 +682,13 @@ static inline int64_t msa_mod_u_df(uint32_t df, int64_t arg1, int64_t arg2)do { \ e =SIGNED_EVEN (a, df); \ o =SIGNED_ODD (a, df); \ - }while (0 ); + } while (0)#define UNSIGNED_EXTRACT (e, o, a, df) \ do { \ e = UNSIGNED_EVEN(a, df); \ o = UNSIGNED_ODD(a, df); \ - } while (0); + } while (0)static inline int64_t msa_dotp_s_df (uint32_t df,int64_t arg1,int64_t arg2) {
@@ -1120,9 +1120,11 @@ void helper_msa_splat_df(CPUMIPSState *env, uint32_t df, uint32_t wd,#define MSA_LOOP_COND_D MSA_LOOP_COND(DF_DOUBLE)#define MSA_LOOP (DF ) \ + do { \ for (i = 0; i < (MSA_LOOP_COND_ ## DF) ; i++) { \ - MSA_DO_ ## DF \ - } + MSA_DO_ ## DF; \ + } \ + } while (0)#define MSA_FN_DF (FUNC ) \ void helper_msa_##FUNC(CPUMIPSState *env, uint32_t df, uint32_t wd, \
@@ -1135,17 +1137,17 @@ void helper_msa_##FUNC(CPUMIPSState *env, uint32_t df, uint32_t wd, \uint32_t i; \switch (df) { \case DF_BYTE : \ -MSA_LOOP_B \ +MSA_LOOP_B ; \break ; \case DF_HALF : \ -MSA_LOOP_H \ +MSA_LOOP_H ; \break ; \case DF_WORD : \ -MSA_LOOP_W \ +MSA_LOOP_W ; \break ; \case DF_DOUBLE : \ -MSA_LOOP_D \ - break; \ +MSA_LOOP_D ; \ +break ; \default : \assert (0 ); \ } \
@@ -1168,7 +1170,7 @@ void helper_msa_##FUNC(CPUMIPSState *env, uint32_t df, uint32_t wd, \ do { \ R##DF(pwx, i) = pwt->DF[2*i]; \ L##DF(pwx, i) = pws->DF[2*i]; \ - } while (0); + } while (0) MSA_FN_DF(pckev_df) #undef MSA_DO
@@ -1176,7 +1178,7 @@ MSA_FN_DF(pckev_df) do { \ R##DF(pwx, i) = pwt->DF[2*i+1]; \ L##DF(pwx, i) = pws->DF[2*i+1]; \ - } while (0); + } while (0) MSA_FN_DF(pckod_df) #undef MSA_DO
@@ -1184,7 +1186,7 @@ MSA_FN_DF(pckod_df) do { \ pwx->DF[2*i] = L##DF(pwt, i); \ pwx->DF[2*i+1] = L##DF(pws, i); \ - } while (0); + } while (0) MSA_FN_DF(ilvl_df) #undef MSA_DO
@@ -1192,7 +1194,7 @@ MSA_FN_DF(ilvl_df) do { \ pwx->DF[2*i] = R##DF(pwt, i); \ pwx->DF[2*i+1] = R##DF(pws, i); \ - } while (0); + } while (0) MSA_FN_DF(ilvr_df) #undef MSA_DO
@@ -1200,7 +1202,7 @@ MSA_FN_DF(ilvr_df)do { \ pwx->DF[2 *i] = pwt->DF[2 *i]; \ pwx->DF[2 *i+1 ] = pws->DF[2 *i]; \ - }while (0 ); + } while (0)MSA_FN_DF (ilvev_df) #undef MSA_DO
@@ -1208,7 +1210,7 @@ MSA_FN_DF(ilvev_df)do { \ pwx->DF[2 *i] = pwt->DF[2 *i+1 ]; \ pwx->DF[2 *i+1 ] = pws->DF[2 *i+1 ]; \ - }while (0 ); + } while (0) MSA_FN_DF(ilvod_df)#undef MSA_DO#undef MSA_LOOP_COND
@@ -1222,7 +1224,7 @@ MSA_FN_DF(ilvod_df)uint32_t k = (pwd->DF[i] &0x3f ) % (2 * n); \ pwx->DF[i] = \ (pwd->DF[i] &0xc0 ) ?0 : k < n ? pwt->DF[k] : pws->DF[k - n]; \ - }while (0 ); + }while (0 ) MSA_FN_DF(vshf_df)#undef MSA_DO#undef MSA_LOOP_COND
Signature · 1 line
2.14.3
PATCH v2 3/7 chardev: Use goto/label instead of do/break/while(0)
In reply to Eric BlakeUse of a do/while(0) control flow in order to permit an early break is an unusual paradigm, and triggers a false positive with a planned future syntax check against 'while (0);'. Rewrite the code to use a goto instead. This patch temporarily keeps an extra level of indentation to highlight the change; the next patch cleans it up.
--- chardev/char-serial.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
chardev/char-serial.c +10 -3
@@ -64,9 +64,14 @@ static void tty_serial_init(int fd, int speed,#endif tcgetattr (fd, &tty); -#define check_speed (val) if (speed <= val) { spd = B##val; break; } +#define check_speed (val) \ + if (speed <= val) { \ + spd = B##val; \ + goto done; \ + } + speed = speed *10 /11 ; - do { + {check_speed (50 );check_speed (75 );check_speed (110 );
@@ -125,8 +130,10 @@ static void tty_serial_init(int fd, int speed,check_speed (4000000 );#endif spd =B115200 ; - }while (0 ); + } +#undef check_speed + done:cfsetispeed (&tty, spd);cfsetospeed (&tty, spd);
Signature · 1 line
2.14.3
Re: [Qemu-devel] [PATCH v2 3/7] chardev: Use goto/label instead of do/break/while(0)
Quoted 8 lines · Eric Blake
Use of a do/while(0) control flow in order to permit an early break is an unusual paradigm, and triggers a false positive with a planned future syntax check against 'while (0);'. Rewrite the code to use a goto instead. This patch temporarily keeps an extra level of indentation to highlight the change; the next patch cleans it up.
Signed-off-by Eric Blake <[email protected]>---
Quoted 40 lines
chardev/char-serial.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)chardev/char-serial.c +10
-4@@ -64,9 +64,14 @@ static void tty_serial_init(int fd, int speed,#endif tcgetattr (fd, &tty); -#define check_speed (val) if (speed <= val) { spd = B##val; break; } +#define check_speed (val) \ + if (speed <= val) { \ + spd = B##val; \ + goto done; \ + } + speed = speed *10 /11 ; - do { + {check_speed (50 );check_speed (75 );check_speed (110 );@@ -125,8 +130,10 @@ static void tty_serial_init(int fd, int speed,check_speed (4000000 );#endif spd =B115200 ; - }while (0 ); + } +#undef check_speed + done:cfsetispeed (&tty, spd);cfsetospeed (&tty, spd); --2.14.3
Signature · 1 line
Marc-André Lureau
PATCH v2 4/7 chardev: Clean up previous patch indentation
In reply to Eric BlakeThe previous patch left in an extra scope layer for ease of review; time to remove it. No semantic change.
--- chardev/char-serial.c | 66 +++++++++++++++++++++++++-------------------------- 1 file changed, 32 insertions(+), 34 deletions(-)
chardev/char-serial.c +32 -34
@@ -71,66 +71,64 @@ static void tty_serial_init(int fd, int speed, } speed = speed *10 /11 ; - { -check_speed (50 ); -check_speed (75 ); -check_speed (110 ); -check_speed (134 ); -check_speed (150 ); -check_speed (200 ); -check_speed (300 ); -check_speed (600 ); -check_speed (1200 ); -check_speed (1800 ); -check_speed (2400 ); -check_speed (4800 ); -check_speed (9600 ); -check_speed (19200 ); -check_speed (38400 ); -/* Non-Posix values follow. They may be unsupported on some systems. */ -check_speed (57600 ); -check_speed (115200 ); +check_speed (50 ); +check_speed (75 ); +check_speed (110 ); +check_speed (134 ); +check_speed (150 ); +check_speed (200 ); +check_speed (300 ); +check_speed (600 ); +check_speed (1200 ); +check_speed (1800 ); +check_speed (2400 ); +check_speed (4800 ); +check_speed (9600 ); +check_speed (19200 ); +check_speed (38400 ); +/* Non-Posix values follow. They may be unsupported on some systems. */ +check_speed (57600 ); +check_speed (115200 );#ifdef B230400 -check_speed (230400 ); +check_speed (230400 );#endif #ifdef B460800 -check_speed (460800 ); +check_speed (460800 );#endif #ifdef B500000 -check_speed (500000 ); +check_speed (500000 );#endif #ifdef B576000 -check_speed (576000 ); +check_speed (576000 );#endif #ifdef B921600 -check_speed (921600 ); +check_speed (921600 );#endif #ifdef B1000000 -check_speed (1000000 ); +check_speed (1000000 );#endif #ifdef B1152000 -check_speed (1152000 ); +check_speed (1152000 );#endif #ifdef B1500000 -check_speed (1500000 ); +check_speed (1500000 );#endif #ifdef B2000000 -check_speed (2000000 ); +check_speed (2000000 );#endif #ifdef B2500000 -check_speed (2500000 ); +check_speed (2500000 );#endif #ifdef B3000000 -check_speed (3000000 ); +check_speed (3000000 );#endif #ifdef B3500000 -check_speed (3500000 ); +check_speed (3500000 );#endif #ifdef B4000000 -check_speed (4000000 ); +check_speed (4000000 );#endif - spd =B115200 ; - } + spd =B115200 ;#undef check_speed done:
Signature · 1 line
2.14.3
Re: [Qemu-devel] [PATCH v2 4/7] chardev: Clean up previous patch indentation
Quoted 5 lines · Eric Blake
The previous patch left in an extra scope layer for ease of review; time to remove it. No semantic change.
Signed-off-by Eric Blake <[email protected]>
---
Quoted 110 lines
chardev/char-serial.c | 66 +++++++++++++++++++++++++-------------------------- 1 file changed, 32 insertions(+), 34 deletions(-)chardev/char-serial.c +32
-35@@ -71,66 +71,64 @@ static void tty_serial_init(int fd, int speed, } speed = speed *10 /11 ; - { -check_speed (50 ); -check_speed (75 ); -check_speed (110 ); -check_speed (134 ); -check_speed (150 ); -check_speed (200 ); -check_speed (300 ); -check_speed (600 ); -check_speed (1200 ); -check_speed (1800 ); -check_speed (2400 ); -check_speed (4800 ); -check_speed (9600 ); -check_speed (19200 ); -check_speed (38400 ); -/* Non-Posix values follow. They may be unsupported on some systems. */ -check_speed (57600 ); -check_speed (115200 ); +check_speed (50 ); +check_speed (75 ); +check_speed (110 ); +check_speed (134 ); +check_speed (150 ); +check_speed (200 ); +check_speed (300 ); +check_speed (600 ); +check_speed (1200 ); +check_speed (1800 ); +check_speed (2400 ); +check_speed (4800 ); +check_speed (9600 ); +check_speed (19200 ); +check_speed (38400 ); +/* Non-Posix values follow. They may be unsupported on some systems. */ +check_speed (57600 ); +check_speed (115200 );#ifdef B230400 -check_speed (230400 ); +check_speed (230400 );#endif #ifdef B460800 -check_speed (460800 ); +check_speed (460800 );#endif #ifdef B500000 -check_speed (500000 ); +check_speed (500000 );#endif #ifdef B576000 -check_speed (576000 ); +check_speed (576000 );#endif #ifdef B921600 -check_speed (921600 ); +check_speed (921600 );#endif #ifdef B1000000 -check_speed (1000000 ); +check_speed (1000000 );#endif #ifdef B1152000 -check_speed (1152000 ); +check_speed (1152000 );#endif #ifdef B1500000 -check_speed (1500000 ); +check_speed (1500000 );#endif #ifdef B2000000 -check_speed (2000000 ); +check_speed (2000000 );#endif #ifdef B2500000 -check_speed (2500000 ); +check_speed (2500000 );#endif #ifdef B3000000 -check_speed (3000000 ); +check_speed (3000000 );#endif #ifdef B3500000 -check_speed (3500000 ); +check_speed (3500000 );#endif #ifdef B4000000 -check_speed (4000000 ); +check_speed (4000000 );#endif - spd =B115200 ; - } + spd =B115200 ;#undef check_speed done: --2.14.3
Signature · 1 line
Marc-André Lureau
PATCH v2 5/7 tests: Avoid 'do/while(false); ' in vhost-user-bridge
In reply to Eric BlakeUse of a do/while(0) loop as a way to allow break statements in the middle of execute-once code is unusual. More typical is the use of goto for early exits, with a label at the end of the execute-once code, rather than nesting code in a scope; however, the comment at the end of the existing code makes this alternative a bit unpractical.
So, to avoid false positives from a future syntax check about 'while (false);', and to keep the loop form (in case someone ever does add DONTWAIT support, where they can just as easily manipulate the initial loop condition or add an if around the final 'break'), I opted to use the form of a while(1) loop (the break as an early exit is more idiomatic there), coupled with a final break preserving the original comment.
--- tests/vhost-user-bridge.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
tests/vhost-user-bridge.c +4 -2
@@ -283,7 +283,7 @@ vubr_backend_recv_cb(int sock, void *ctx)return ; } - do { +while (1 ) {struct iovec *sg;ssize_t ret, total =0 ;unsigned int num;
@@ -343,7 +343,9 @@ vubr_backend_recv_cb(int sock, void *ctx)free (elem); elem =NULL ; - }while (false);/* could loop if DONTWAIT worked? */ + +break ;/* could loop if DONTWAIT worked? */ + }if (mhdr_cnt) { mhdr.num_buffers = i;
Signature · 1 line
2.14.3
PATCH v2 6/7 maint: Fix macros with broken 'do/while(0); ' usage
In reply to Eric BlakeThe 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 \\\\
--- tests/acpi-utils.h | 8 ++++---- ui/sdl_zoom_template.h | 8 ++++---- audio/paaudio.c | 4 ++-- hw/adc/stm32f2xx_adc.c | 2 +- hw/block/m25p80.c | 2 +- hw/char/cadence_uart.c | 2 +- hw/char/stm32f2xx_usart.c | 2 +- hw/display/cg3.c | 2 +- hw/display/dpcd.c | 2 +- hw/display/xlnx_dp.c | 2 +- hw/dma/pl330.c | 2 +- hw/dma/xlnx-zynq-devcfg.c | 2 +- hw/dma/xlnx_dpdma.c | 2 +- hw/i2c/i2c-ddc.c | 2 +- hw/misc/auxbus.c | 2 +- hw/misc/macio/mac_dbdma.c | 4 ++-- hw/misc/mmio_interface.c | 2 +- hw/misc/stm32f2xx_syscfg.c | 2 +- hw/misc/zynq_slcr.c | 2 +- hw/net/cadence_gem.c | 2 +- hw/ssi/mss-spi.c | 2 +- hw/ssi/stm32f2xx_spi.c | 2 +- hw/ssi/xilinx_spi.c | 2 +- hw/ssi/xilinx_spips.c | 2 +- hw/timer/a9gtimer.c | 2 +- hw/timer/cadence_ttc.c | 2 +- hw/timer/mss-timer.c | 2 +- hw/timer/stm32f2xx_timer.c | 2 +- hw/tpm/tpm_passthrough.c | 2 +- hw/tpm/tpm_tis.c | 2 +- migration/rdma.c | 2 +- target/arm/translate-a64.c | 2 +- target/s390x/kvm.c | 2 +- tests/tcg/test-mmap.c | 2 +- 34 files changed, 42 insertions(+), 42 deletions(-)
tests/acpi-utils.h +4 -4
@@ -32,7 +32,7 @@ typedef struct {do { \memread (addr, &field,sizeof (field)); \ addr +=sizeof (field); \ - }while (0 ); + } while (0)#define ACPI_READ_ARRAY_PTR (arr, length, addr) \ do { \
@@ -40,7 +40,7 @@ typedef struct {for (idx =0 ; idx < length; ++idx) { \ACPI_READ_FIELD (arr[idx], addr); \ } \ - }while (0 ); + } while (0)#define ACPI_READ_ARRAY (arr, addr) \ ACPI_READ_ARRAY_PTR(arr, sizeof(arr) / sizeof(arr[0]), addr)
@@ -56,7 +56,7 @@ typedef struct {ACPI_READ_FIELD ((table)->oem_revision, addr); \ACPI_READ_ARRAY ((table)->asl_compiler_id, addr); \ACPI_READ_FIELD ((table)->asl_compiler_revision, addr); \ - }while (0 ); + } while (0)#define ACPI_ASSERT_CMP (actual, expected) do { \ char ACPI_ASSERT_CMP_str[5] = {}; \
@@ -77,7 +77,7 @@ typedef struct {ACPI_READ_FIELD ((field).bit_offset, addr); \ACPI_READ_FIELD ((field).access_width, addr); \ACPI_READ_FIELD ((field).address, addr); \ - }while (0 ); + }while (0 ) uint8_t acpi_calc_checksum(const uint8_t *data, int len);
ui/sdl_zoom_template.h +4 -4
@@ -34,22 +34,22 @@#define setRed (r, pcolor) do { \ *pcolor = ((*pcolor) & (~(dpf->Rmask))) + \ (((r) & (dpf->Rmask >> dpf->Rshift)) << dpf->Rshift); \ -} while (0); +} while (0)#define setGreen (g, pcolor) do { \ *pcolor = ((*pcolor) & (~(dpf->Gmask))) + \ (((g) & (dpf->Gmask >> dpf->Gshift)) << dpf->Gshift); \ -} while (0); +} while (0)#define setBlue (b, pcolor) do { \ *pcolor = ((*pcolor) & (~(dpf->Bmask))) + \ (((b) & (dpf->Bmask >> dpf->Bshift)) << dpf->Bshift); \ -} while (0); +} while (0)#define setAlpha (a, pcolor) do { \ *pcolor = ((*pcolor) & (~(dpf->Amask))) + \ (((a) & (dpf->Amask >> dpf->Ashift)) << dpf->Ashift); \ -} while (0); +} while (0)static void glue (sdl_zoom_rgb ,BPP )(SDL_Surface *src,SDL_Surface *dst,int smooth,SDL_Rect *dst_rect)
audio/paaudio.c +2 -2
@@ -89,7 +89,7 @@ static inline int PA_STREAM_IS_GOOD(pa_stream_state_t x) } \ goto label; \ } \ - }while (0 ); + } while (0)#define CHECK_DEAD_GOTO (c, stream, rerror, label) \ do { \
@@ -107,7 +107,7 @@ static inline int PA_STREAM_IS_GOOD(pa_stream_state_t x) } \ goto label; \ } \ - }while (0 ); + }while (0 ) static int qpa_simple_read (PAVoiceIn *p, void *data, size_t length, int *rerror) {
hw/adc/stm32f2xx_adc.c +1 -1
@@ -37,7 +37,7 @@if (STM_ADC_ERR_DEBUG >= lvl) { \ qemu_log("%s: " fmt, __func__, ## args); \ } \ -}while (0 ); +}while (0 ) #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
hw/block/m25p80.c +1 -1
@@ -40,7 +40,7 @@fprintf (stderr,": %s: " , __func__); \ fprintf(stderr, ## __VA_ARGS__); \ } \ -}while (0 ); +}while (0 )/* Fields for FlashPartInfo->flags */
hw/char/cadence_uart.c +1 -1
@@ -33,7 +33,7 @@#define DB_PRINT (...) do { \ fprintf(stderr, ": %s: ", __func__); \ fprintf(stderr, ## __VA_ARGS__); \ - } while (0); + } while (0)#else #define DB_PRINT (...)#endif
hw/char/stm32f2xx_usart.c +1 -1
@@ -34,7 +34,7 @@if (STM_USART_ERR_DEBUG >= lvl) { \ qemu_log("%s: " fmt, __func__, ## args); \ } \ -}while (0 ); +}while (0 ) #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
hw/display/cg3.c +1 -1
@@ -63,7 +63,7 @@if (DEBUG_CG3 ) { \ printf("CG3: " fmt , ## __VA_ARGS__); \ } \ -}while (0 ); +} while (0)#define TYPE_CG3 "cgthree"#define CG3 (obj) OBJECT_CHECK(CG3State, (obj), TYPE_CG3)
hw/display/dpcd.c +1 -1
@@ -39,7 +39,7 @@if (DEBUG_DPCD ) { \ qemu_log("dpcd: " fmt, ## __VA_ARGS__); \ } \ -}while (0 ); +} while (0)#define DPCD_READABLE_AREA 0x600
hw/display/xlnx_dp.c +1 -1
@@ -34,7 +34,7 @@if (DEBUG_DP ) { \ qemu_log("xlnx_dp: " fmt , ## __VA_ARGS__); \ } \ -}while (0 ); +}while (0 )/* * Register offset for DP.
hw/dma/pl330.c +1 -1
@@ -29,7 +29,7 @@if (PL330_ERR_DEBUG >= lvl) {\ fprintf(stderr, "PL330: %s:" fmt, __func__, ## args);\ } \ -}while (0 ); +}while (0 ) #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
hw/dma/xlnx-zynq-devcfg.c +1 -1
@@ -43,7 +43,7 @@if (XLNX_ZYNQ_DEVCFG_ERR_DEBUG ) { \ qemu_log("%s: " fmt, __func__, ## args); \ } \ -}while (0 ); +}while (0 ) REG32(CTRL, 0x00)FIELD (CTRL ,FORCE_RST ,31 ,1 )/* Not supported, wr ignored */
hw/dma/xlnx_dpdma.c +1 -1
@@ -34,7 +34,7 @@if (DEBUG_DPDMA ) { \ qemu_log("xlnx_dpdma: " fmt , ## __VA_ARGS__); \ } \ -}while (0 ); +}while (0 )/* * Registers offset for DPDMA.
hw/i2c/i2c-ddc.c +1 -1
@@ -30,7 +30,7 @@if (DEBUG_I2CDDC ) { \ qemu_log("i2c-ddc: " fmt , ## __VA_ARGS__); \ } \ -}while (0 ); +}while (0 )/* Structure defining a monitor's characteristics in a * readable format: this should be passed to build_edid_blob()
hw/misc/auxbus.c +1 -1
@@ -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)
hw/misc/macio/mac_dbdma.c +2 -2
@@ -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 )/* */
hw/misc/mmio_interface.c +1 -1
@@ -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) {
hw/misc/stm32f2xx_syscfg.c +1 -1
@@ -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)
hw/misc/zynq_slcr.c +1 -1
@@ -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
hw/net/cadence_gem.c +1 -1
@@ -34,7 +34,7 @@#define DB_PRINT (...) do { \ fprintf(stderr, ": %s: ", __func__); \ fprintf(stderr, ## __VA_ARGS__); \ - } while (0); + } while (0)#else #define DB_PRINT (...)#endif
hw/ssi/mss-spi.c +1 -1
@@ -35,7 +35,7 @@if (MSS_SPI_ERR_DEBUG >= lvl) { \ qemu_log("%s: " fmt "\n", __func__, ## args); \ } \ -}while (0 ); +}while (0 ) #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
hw/ssi/stm32f2xx_spi.c +1 -1
@@ -35,7 +35,7 @@if (STM_SPI_ERR_DEBUG >= lvl) { \ qemu_log("%s: " fmt, __func__, ## args); \ } \ -}while (0 ); +}while (0 ) #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
hw/ssi/xilinx_spi.c +1 -1
@@ -36,7 +36,7 @@#define DB_PRINT (...) do { \ fprintf(stderr, ": %s: ", __func__); \ fprintf(stderr, ## __VA_ARGS__); \ - } while (0); + } while (0)#else #define DB_PRINT (...)#endif
hw/ssi/xilinx_spips.c +1 -1
@@ -43,7 +43,7 @@fprintf (stderr,": %s: " , __func__); \ fprintf(stderr, ## __VA_ARGS__); \ } \ -}while (0 ); +}while (0 )/* config register */ #define R_CONFIG (0x00 / 4)
hw/timer/a9gtimer.c +1 -1
@@ -37,7 +37,7 @@fprintf (stderr,": %s: " , __func__); \ fprintf(stderr, ## __VA_ARGS__); \ } \ -}while (0 ); +} while (0)#define DB_PRINT (...) DB_PRINT_L(0, ## __VA_ARGS__)
hw/timer/cadence_ttc.c +1 -1
@@ -24,7 +24,7 @@#define DB_PRINT (...) do { \ fprintf(stderr, ": %s: ", __func__); \ fprintf(stderr, ## __VA_ARGS__); \ - } while (0); + } while (0)#else #define DB_PRINT (...)#endif
hw/timer/mss-timer.c +1 -1
@@ -36,7 +36,7 @@if (MSS_TIMER_ERR_DEBUG >= lvl) { \ qemu_log("%s: " fmt "\n", __func__, ## args); \ } \ -}while (0 ); +}while (0 ) #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
hw/timer/stm32f2xx_timer.c +1 -1
@@ -34,7 +34,7 @@if (STM_TIMER_ERR_DEBUG >= lvl) { \ qemu_log("%s: " fmt, __func__, ## args); \ } \ -}while (0 ); +}while (0 ) #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
hw/tpm/tpm_passthrough.c +1 -1
@@ -39,7 +39,7 @@if (DEBUG_TPM ) { \ fprintf(stderr, fmt, ## __VA_ARGS__); \ } \ -}while (0 ); +} while (0)#define TYPE_TPM_PASSTHROUGH "tpm-passthrough"#define TPM_PASSTHROUGH (obj) \
hw/tpm/tpm_tis.c +1 -1
@@ -105,7 +105,7 @@ struct TPMState {if (DEBUG_TIS ) { \ printf(fmt, ## __VA_ARGS__); \ } \ -}while (0 ); +}while (0 ) /* tis registers */#define TPM_TIS_REG_ACCESS 0x00
migration/rdma.c +1 -1
@@ -88,7 +88,7 @@ static uint32_t known_capabilities = RDMA_CAPABILITY_PIN_ALL; } \return rdma->error_state; \ } \ - }while (0 ); + }while (0 )/* * A work request ID is 64-bits and we split up these bits
target/arm/translate-a64.c +1 -1
@@ -400,7 +400,7 @@ static void unallocated_encoding(DisasContext *s)"at pc=%016" PRIx64"\n" , \ __FILE__, __LINE__, insn, s->pc - 4); \unallocated_encoding (s); \ - }while (0 ); + }while (0 ) static void init_tmp_a64_array(DisasContext *s) {
target/s390x/kvm.c +1 -1
@@ -58,7 +58,7 @@if (DEBUG_KVM ) { \ fprintf(stderr, fmt, ## __VA_ARGS__); \ } \ -}while (0 ); +} while (0)#define kvm_vm_check_mem_attr (s, attr) \ kvm_vm_check_attr(s, KVM_S390_VM_MEM_CTRL, attr)
tests/tcg/test-mmap.c +1 -1
@@ -39,7 +39,7 @@ do \fprintf (stderr,"FAILED at %s:%d\n" , __FILE__, __LINE__); \exit (EXIT_FAILURE ); \ } \ -}while (0 ); +}while (0 ) unsigned char *dummybuf;static unsigned int pagesize;
Signature · 1 line
2.14.3
Re: [Qemu-arm] [PATCH v2 6/7] maint: Fix macros with broken 'do/while(0); ' usage
Quoted 29 lines · Eric Blake
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.
Quoted 6 lines
Found mechanically via: $ git grep -B1 'while (0);' | grep -A1 \\\\
Signed-off-by Eric Blake <[email protected]>Acked-by Cornelia Huck <[email protected]>Reviewed-by Michael S. Tsirkin <[email protected]>
PATCH v2 7/7 checkpatch: Enforce proper do/while (0) style
In reply to Eric BlakeUse of a loop construct for code that is not intended to repeat does not make much idiomatic sense, except in one place: it is a common usage in macros in order to wrap arbitrary code with single-statement semantics. But when used in a macro, it is more typical for the caller to supply the trailing ';' when calling the macro.
Although qemu coding style frowns on bare:
if (cond)
statement1;
else
statement2;where extra semicolons actually cause syntax errors, we still want our macro styles to be easily copied to other projects. Thus, declare it an error if we encounter any form of 'while (0)' with a semicolon in the same line.
--- scripts/checkpatch.pl | 5 +++++ 1 file changed, 5 insertions(+)
scripts/checkpatch.pl +5 -0
@@ -1622,6 +1622,11 @@ sub process { } } +# 'do ... while (0/false)' only makes sense in macros, without trailing ';' + if ($line =~ /while\s*\((0|false)\);/) { + ERROR("suspicious ; after while (0)\n" . $herecurr); + } + # Check relative indent for conditionals and blocks. if ($line =~ /\b(?:(?:if|while|for)\s*\(|do\b)/ && $line !~ /^.\s*#/ && $line !~ /\}\s*while\s*/) { my ($s, $c) = ($stat, $cond);
Signature · 1 line
2.14.3
ping
Quoted 67 lines · Eric Blake
Noticed this by chance in the tests/ directory, so I broadened it to a grep of the entire code base. I suspect^wKNOW many of the bad macros were the victims of copy-and-paste from some other bad location (particularly given how many bit-rotten debug print macros were involved).
https://wiki.qemu.org/BiteSizedTasks#Bitrot_prevention is still left for someone else, for another day.
In v2:
- add review tags
- audit that the maint patch has no semantic change (all callers were indeed supplying ';' at the macro call-sites)
- improved commit messages
- more patches for some additional cleanups
- tighten the checkpatch rule to also flag 'while (false);'Eric Blake (7):
net: Drop unusual use of do { } while (0);
mips: Tweak location of ';' in macros
chardev: Use goto/label instead of do/break/while(0)
chardev: Clean up previous patch indentation
tests: Avoid 'do/while(false);' in vhost-user-bridge
maint: Fix macros with broken 'do/while(0);' usage
checkpatch: Enforce proper do/while (0) styletests/acpi-utils.h | 8 ++--- ui/sdl_zoom_template.h | 8 ++--- audio/paaudio.c | 4 +-- chardev/char-serial.c | 75 ++++++++++++++++++++++++---------------------- hw/adc/stm32f2xx_adc.c | 2 +- hw/block/m25p80.c | 2 +- hw/char/cadence_uart.c | 2 +- hw/char/stm32f2xx_usart.c | 2 +- hw/display/cg3.c | 2 +- hw/display/dpcd.c | 2 +- hw/display/xlnx_dp.c | 2 +- hw/dma/pl330.c | 2 +- hw/dma/xlnx-zynq-devcfg.c | 2 +- hw/dma/xlnx_dpdma.c | 2 +- hw/i2c/i2c-ddc.c | 2 +- hw/misc/auxbus.c | 2 +- hw/misc/macio/mac_dbdma.c | 4 +-- hw/misc/mmio_interface.c | 2 +- hw/misc/stm32f2xx_syscfg.c | 2 +- hw/misc/zynq_slcr.c | 2 +- hw/net/cadence_gem.c | 2 +- hw/net/pcnet.c | 20 ++++++------- hw/ssi/mss-spi.c | 2 +- hw/ssi/stm32f2xx_spi.c | 2 +- hw/ssi/xilinx_spi.c | 2 +- hw/ssi/xilinx_spips.c | 2 +- hw/timer/a9gtimer.c | 2 +- hw/timer/cadence_ttc.c | 2 +- hw/timer/mss-timer.c | 2 +- hw/timer/stm32f2xx_timer.c | 2 +- hw/tpm/tpm_passthrough.c | 2 +- hw/tpm/tpm_tis.c | 2 +- migration/rdma.c | 2 +- target/arm/translate-a64.c | 2 +- target/mips/msa_helper.c | 34 +++++++++++---------- target/s390x/kvm.c | 2 +- tests/tcg/test-mmap.c | 2 +- tests/vhost-user-bridge.c | 6 ++-- scripts/checkpatch.pl | 5 ++++ 39 files changed, 119 insertions(+), 105 deletions(-)
Signature · 3 lines
Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
Paolo Bonzini
AppliedQuoted 1 line · Eric Blake
ping
Hmm, the actual posting of the patches wasn't CCed to qemu-trivial.
Queued now, thanks.
Paolo
Quoted 69 lines · Eric Blake
Quoted 67 lines
Noticed this by chance in the tests/ directory, so I broadened it to a grep of the entire code base. I suspect^wKNOW many of the bad macros were the victims of copy-and-paste from some other bad location (particularly given how many bit-rotten debug print macros were involved).
https://wiki.qemu.org/BiteSizedTasks#Bitrot_prevention is still left for someone else, for another day.
In v2:
- add review tags
- audit that the maint patch has no semantic change (all callers were indeed supplying ';' at the macro call-sites)
- improved commit messages
- more patches for some additional cleanups
- tighten the checkpatch rule to also flag 'while (false);'Eric Blake (7):
net: Drop unusual use of do { } while (0);
mips: Tweak location of ';' in macros
chardev: Use goto/label instead of do/break/while(0)
chardev: Clean up previous patch indentation
tests: Avoid 'do/while(false);' in vhost-user-bridge
maint: Fix macros with broken 'do/while(0);' usage
checkpatch: Enforce proper do/while (0) styletests/acpi-utils.h | 8 ++--- ui/sdl_zoom_template.h | 8 ++--- audio/paaudio.c | 4 +-- chardev/char-serial.c | 75 ++++++++++++++++++++++++---------------------- hw/adc/stm32f2xx_adc.c | 2 +- hw/block/m25p80.c | 2 +- hw/char/cadence_uart.c | 2 +- hw/char/stm32f2xx_usart.c | 2 +- hw/display/cg3.c | 2 +- hw/display/dpcd.c | 2 +- hw/display/xlnx_dp.c | 2 +- hw/dma/pl330.c | 2 +- hw/dma/xlnx-zynq-devcfg.c | 2 +- hw/dma/xlnx_dpdma.c | 2 +- hw/i2c/i2c-ddc.c | 2 +- hw/misc/auxbus.c | 2 +- hw/misc/macio/mac_dbdma.c | 4 +-- hw/misc/mmio_interface.c | 2 +- hw/misc/stm32f2xx_syscfg.c | 2 +- hw/misc/zynq_slcr.c | 2 +- hw/net/cadence_gem.c | 2 +- hw/net/pcnet.c | 20 ++++++------- hw/ssi/mss-spi.c | 2 +- hw/ssi/stm32f2xx_spi.c | 2 +- hw/ssi/xilinx_spi.c | 2 +- hw/ssi/xilinx_spips.c | 2 +- hw/timer/a9gtimer.c | 2 +- hw/timer/cadence_ttc.c | 2 +- hw/timer/mss-timer.c | 2 +- hw/timer/stm32f2xx_timer.c | 2 +- hw/tpm/tpm_passthrough.c | 2 +- hw/tpm/tpm_tis.c | 2 +- migration/rdma.c | 2 +- target/arm/translate-a64.c | 2 +- target/mips/msa_helper.c | 34 +++++++++++---------- target/s390x/kvm.c | 2 +- tests/tcg/test-mmap.c | 2 +- tests/vhost-user-bridge.c | 6 ++-- scripts/checkpatch.pl | 5 ++++ 39 files changed, 119 insertions(+), 105 deletions(-)