perf: Enable more compiler warnings

Related to a shadowed variable bug fix Valdis Kletnieks noticed
that perf does not get built with -Wshadow, which could have
helped us avoid the bug.

So enable -Wshadow and also enable the following warnings on
perf builds, in addition to the already enabled -Wall -Wextra
-std=gnu99 warnings:

 -Wcast-align
 -Wformat=2
 -Wshadow
 -Winit-self
 -Wpacked
 -Wredundant-decls
 -Wstack-protector
 -Wstrict-aliasing=3
 -Wswitch-default
 -Wswitch-enum
 -Wno-system-headers
 -Wundef
 -Wvolatile-register-var
 -Wwrite-strings
 -Wbad-function-cast
 -Wmissing-declarations
 -Wmissing-prototypes
 -Wnested-externs
 -Wold-style-definition
 -Wstrict-prototypes
 -Wdeclaration-after-statement

And change/fix the perf code to build cleanly under GCC 4.3.2.

The list of warnings enablement is rather arbitrary: it's based
on my (quick) reading of the GCC manpages and trying them on
perf.

I categorized the warnings based on individually enabling them
and looking whether they trigger something in the perf build.
If i liked those warnings (i.e. if they trigger for something
that arguably could be improved) i enabled the warning.

If the warnings seemed to come from language laywers spamming
the build with tons of nuisance warnings i generally kept them
off. Most of the sign conversion related warnings were in
this category. (A second patch enabling some of the sign
warnings might be welcome - sign bugs can be nasty.)

I also kept warnings that seem to make sense from their manpage
description and which produced no actual warnings on our code
base. These warnings might still be turned off if they end up
being a nuisance.

I also left out a few warnings that are not supported in older
compilers.

[ Note that these changes might break the build on older
  compilers i did not test, or on non-x86 architectures that
  produce different warnings, so more testing would be welcome. ]

Reported-by: Valdis.Kletnieks@vt.edu
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 22 insertions, 0 deletions

diff --git a/tools/perf/util/parse-options.c b/tools/perf/util/parse-options.c
index 1bf67190c820..6d8af48c925e 100644
--- a/tools/perf/util/parse-options.c
+++ b/tools/perf/util/parse-options.c
@@ -53,6 +53,12 @@ static int get_value(struct parse_opt_ctx_t *p,
 		case OPTION_SET_INT:
 		case OPTION_SET_PTR:
 			return opterror(opt, "takes no value", flags);
+		case OPTION_END:
+		case OPTION_ARGUMENT:
+		case OPTION_GROUP:
+		case OPTION_STRING:
+		case OPTION_INTEGER:
+		case OPTION_LONG:
 		default:
 			break;
 		}
@@ -130,6 +136,9 @@ static int get_value(struct parse_opt_ctx_t *p,
 			return opterror(opt, "expects a numerical value", flags);
 		return 0;
 
+	case OPTION_END:
+	case OPTION_ARGUMENT:
+	case OPTION_GROUP:
 	default:
 		die("should not happen, someone must be hit on the forehead");
 	}
@@ -296,6 +305,8 @@ int parse_options_step(struct parse_opt_ctx_t *ctx,
 				return parse_options_usage(usagestr, options);
 			case -2:
 				goto unknown;
+			default:
+				break;
 			}
 			if (ctx->opt)
 				check_typos(arg + 1, options);
@@ -314,6 +325,8 @@ int parse_options_step(struct parse_opt_ctx_t *ctx,
 					ctx->argv[0] = strdup(ctx->opt - 1);
 					*(char *)ctx->argv[0] = '-';
 					goto unknown;
+				default:
+					break;
 				}
 			}
 			continue;
@@ -336,6 +349,8 @@ int parse_options_step(struct parse_opt_ctx_t *ctx,
 			return parse_options_usage(usagestr, options);
 		case -2:
 			goto unknown;
+		default:
+			break;
 		}
 		continue;
 unknown:
@@ -456,6 +471,13 @@ int usage_with_options_internal(const char * const *usagestr,
 			}
 			break;
 		default: /* OPTION_{BIT,BOOLEAN,SET_INT,SET_PTR} */
+		case OPTION_END:
+		case OPTION_GROUP:
+		case OPTION_BIT:
+		case OPTION_BOOLEAN:
+		case OPTION_SET_INT:
+		case OPTION_SET_PTR:
+		case OPTION_LONG:
 			break;
 		}