4 files changed, 37 insertions, 4 deletions
diff --git a/cgcc b/cgcc
index a28b140e..7611dc9f 100755
--- a/cgcc
+++ b/cgcc
@@ -103,7 +103,7 @@ sub check_only_option {
     my ($arg) = @_;
     return 1 if $arg =~ /^-W(no-?)?(address-space|bitwise|cast-to-as|cast-truncate|context|decl|default-bitfield-sign|designated-init|do-while|enum-mismatch|init-cstring|memcpy-max-count|non-pointer-null|old-initializer|one-bit-signed-bitfield|override-init-all|paren-string|ptr-subtraction-blows|return-void|sizeof-bool|sparse-all|sparse-error|transparent-union|typesign|undef|unknown-attribute)$/;
     return 1 if $arg =~ /^-v(no-?)?(entry|dead)$/;
-    return 1 if $arg =~ /^-f(dump-ir|memcpy-max-count)(=\S*)?$/;
+    return 1 if $arg =~ /^-f(dump-ir|memcpy-max-count|diagnostic-prefix)(=\S*)?$/;
     return 1 if $arg =~ /^-f(mem2reg|optim)(-enable|-disable|=last)?$/;
     return 0;
 }
diff --git a/lib.c b/lib.c
index d549c554..1c8ead84 100644
--- a/lib.c
+++ b/lib.c
@@ -62,6 +62,7 @@ int gcc_patchlevel = __GNUC_PATCHLEVEL__;
 
 const char *base_filename;
 
+static const char *diag_prefix = "";
 static const char *gcc_base_dir = GCC_BASE;
 static const char *multiarch_dir = MULTIARCH_TRIPLET;
 
@@ -133,8 +134,8 @@ static void do_warn(const char *type, struct position pos, const char * fmt, va_
 	name = stream_name(pos.stream);
 		
 	fflush(stdout);
-	fprintf(stderr, "%s:%d:%d: %s%s\n",
-		name, pos.line, pos.pos, type, buffer);
+	fprintf(stderr, "%s:%d:%d: %s%s%s\n",
+		name, pos.line, pos.pos, diag_prefix, type, buffer);
 }
 
 unsigned int fmax_warnings = 100;
@@ -237,7 +238,7 @@ void die(const char *fmt, ...)
 	vsnprintf(buffer, sizeof(buffer), fmt, args);
 	va_end(args);
 
-	fprintf(stderr, "%s\n", buffer);
+	fprintf(stderr, "%s%s\n", diag_prefix, buffer);
 	exit(1);
 }
 
@@ -899,6 +900,20 @@ static int handle_fpasses(const char *arg, const char *opt, const struct flag *f
 	return 0;
 }
 
+static int handle_fdiagnostic_prefix(const char *arg, const char *opt, const struct flag *flag, int options)
+{
+	switch (*opt) {
+	case '\0':
+		diag_prefix = "sparse: ";
+		return 1;
+	case '=':
+		diag_prefix = xasprintf("%s: ", opt+1);
+		return 1;
+	default:
+		return 0;
+	}
+}
+
 static int handle_fdump_ir(const char *arg, const char *opt, const struct flag *flag, int options)
 {
 	static const struct mask_map dump_ir_options[] = {
@@ -925,6 +940,7 @@ static int handle_fmax_warnings(const char *arg, const char *opt, const struct f
 }
 
 static struct flag fflags[] = {
+	{ "diagnostic-prefix",	NULL,	handle_fdiagnostic_prefix },
 	{ "dump-ir",		NULL,	handle_fdump_ir },
 	{ "max-warnings=",	NULL,	handle_fmax_warnings },
 	{ "mem-report",		&fmem_report },
diff --git a/sparse.1 b/sparse.1
index a1946c86..806fb0cf 100644
--- a/sparse.1
+++ b/sparse.1
@@ -390,6 +390,12 @@ Report some statistics about memory allocation used by the tool.
 .
 .SH OTHER OPTIONS
 .TP
+.B \-fdiagnostic-prefix[=PREFIX]
+Prefix all diagnostics by the given PREFIX, followed by ": ".
+If no one is given "sparse" is used.
+The default is to not use a prefix at all.
+.
+.TP
 .B \-fmemcpy-max-count=COUNT
 Set the limit for the warnings given by \fB-Wmemcpy-max-count\fR.
 A COUNT of 'unlimited' or '0' will effectively disable the warning.
diff --git a/validation/fdiag-prefix.c b/validation/fdiag-prefix.c
new file mode 100644
index 00000000..71160d45
--- /dev/null
+++ b/validation/fdiag-prefix.c
@@ -0,0 +1,11 @@
+int a.
+
+/*
+ * check-name: fdiag-prefix
+ * check-command: sparse -fdiagnostic-prefix=prefix $file
+ *
+ * check-error-start
+fdiag-prefix.c:1:6: prefix: error: Expected ; at end of declaration
+fdiag-prefix.c:1:6: prefix: error: got .
+ * check-error-end
+ */