On Sat, Oct 17, 2020 at 9:10 AM trix@redhat.com wrote:
From: Tom Rix trix@redhat.com
This is a upcoming change to clean up a new warning treewide. I am wondering if the change could be one mega patch (see below) or normal patch per file about 100 patches or somewhere half way by collecting early acks.
clang has a number of useful, new warnings see https://clang.llvm.org/docs/DiagnosticsReference.html
This change cleans up -Wunreachable-code-break https://clang.llvm.org/docs/DiagnosticsReference.html#wunreachable-code-brea... for 266 of 485 warnings in this week's linux-next, allyesconfig on x86_64.
The method of fixing was to look for warnings where the preceding statement was a simple statement and by inspection made the subsequent break unneeded. In order of frequency these look like
return and break
switch (c->x86_vendor) { case X86_VENDOR_INTEL: intel_p5_mcheck_init(c); return 1;
break;goto and break
default: operation = 0; /* make gcc happy */ goto fail_response;
break;break and break case COLOR_SPACE_SRGB: /* by pass */ REG_SET(OUTPUT_CSC_CONTROL, 0, OUTPUT_CSC_GRPH_MODE, 0); break;
break;The exception to the simple statement, is a switch case with a block and the end of block is a return
struct obj_buffer *buff = r->ptr; return scnprintf(str, PRIV_STR_SIZE, "size=%u\naddr=0x%X\n", buff->size, buff->addr); }
break;Not considered obvious and excluded, breaks after multi level switches complicated if-else if-else blocks panic() or similar calls
And there is an odd addition of a 'fallthrough' in drivers/tty/nozomi.c
[..]
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c index 5a7c80053c62..2f250874b1a4 100644 --- a/drivers/nvdimm/claim.c +++ b/drivers/nvdimm/claim.c @@ -200,11 +200,10 @@ ssize_t nd_namespace_store(struct device *dev, } break; default: len = -EBUSY; goto out_attach;
break; }
Acked-by: Dan Williams dan.j.williams@intel.com