color-lcms: wrap cmsHPROFILE type

cmsHPROFILE is a typedef of void *.

This means you can change the type of pointer variable to or from
cmsHPROFILE, and the compiler will not see any difference. The compiler
is happy to implicitly cast any pointer type to cmsHPROFILE and back.

In order to bring some type safety for future refactorings that will be
doing such type changes, introduce a wrapper struct. The wrapper being
an actual unique type will not allow implicit casting.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

3 files changed, 62 insertions, 43 deletions

diff --git a/libweston/color-lcms/color-lcms.h b/libweston/color-lcms/color-lcms.h
index eb1c3b83..5c9a960a 100644
--- a/libweston/color-lcms/color-lcms.h
+++ b/libweston/color-lcms/color-lcms.h
@@ -35,6 +35,25 @@
 #include "shared/helpers.h"
 #include "shared/os-compatibility.h"
 
+/*
+ * Because cmsHPROFILE is a typedef of void*, it happily and implicitly
+ * casts to and from any pointer at all. In order to bring some type
+ * safety, wrap it.
+ */
+struct lcmsProfilePtr {
+	cmsHPROFILE p;
+};
+
+/* Cast an array of lcmsProfilePtr into array of cmsHPROFILE */
+static inline cmsHPROFILE *
+from_lcmsProfilePtr_array(struct lcmsProfilePtr *arr)
+{
+	static_assert(sizeof(struct lcmsProfilePtr) == sizeof(cmsHPROFILE),
+		      "arrays of cmsHPROFILE wrapper are castable");
+
+	return &arr[0].p;
+}
+
 struct weston_color_manager_lcms {
 	struct weston_color_manager base;
 	struct weston_log_scope *profiles_scope;
@@ -88,7 +107,7 @@ struct cmlcms_color_profile {
 	/* struct weston_color_manager_lcms::color_profile_list */
 	struct wl_list link;
 
-	cmsHPROFILE profile;
+	struct lcmsProfilePtr profile;
 	struct cmlcms_md5_sum md5sum;
 
 	/* Only for profiles created from an ICC file. */
diff --git a/libweston/color-lcms/color-profile.c b/libweston/color-lcms/color-profile.c
index 2624d17d..e7efc4d2 100644
--- a/libweston/color-lcms/color-profile.c
+++ b/libweston/color-lcms/color-profile.c
@@ -56,14 +56,14 @@ xyz_dot_prod(const struct xyz_arr_flt a, const struct xyz_arr_flt b)
  */
 static bool
 build_eotf_from_clut_profile(cmsContext lcms_ctx,
-			     cmsHPROFILE profile,
+			     struct lcmsProfilePtr profile,
 			     cmsToneCurve *output_eotf[3],
 			     int num_points)
 {
 	int ch, point;
 	float *curve_array[3];
 	float *red = NULL;
-	cmsHPROFILE xyz_profile = NULL;
+	struct lcmsProfilePtr xyz_profile = { NULL };
 	cmsHTRANSFORM transform_rgb_to_xyz = NULL;
 	bool ret = false;
 	const float div = num_points - 1;
@@ -76,12 +76,12 @@ build_eotf_from_clut_profile(cmsContext lcms_ctx,
 	curve_array[1] = red + num_points;
 	curve_array[2] = red + 2 * num_points;
 
-	xyz_profile = cmsCreateXYZProfileTHR(lcms_ctx);
-	if (!xyz_profile)
+	xyz_profile.p = cmsCreateXYZProfileTHR(lcms_ctx);
+	if (!xyz_profile.p)
 		goto release;
 
-	transform_rgb_to_xyz = cmsCreateTransformTHR(lcms_ctx, profile,
-						     TYPE_RGB_FLT, xyz_profile,
+	transform_rgb_to_xyz = cmsCreateTransformTHR(lcms_ctx, profile.p,
+						     TYPE_RGB_FLT, xyz_profile.p,
 						     TYPE_XYZ_FLT,
 						     INTENT_ABSOLUTE_COLORIMETRIC,
 						     0);
@@ -136,8 +136,8 @@ build_eotf_from_clut_profile(cmsContext lcms_ctx,
 release:
 	if (transform_rgb_to_xyz)
 		cmsDeleteTransform(transform_rgb_to_xyz);
-	if (xyz_profile)
-		cmsCloseProfile(xyz_profile);
+	if (xyz_profile.p)
+		cmsCloseProfile(xyz_profile.p);
 	free(red);
 	if (ret == false)
 		cmsFreeToneCurveTriple(output_eotf);
@@ -185,7 +185,7 @@ error:
 static bool
 ensure_output_profile_extract_icc(struct cmlcms_output_profile_extract *extract,
 				  cmsContext lcms_ctx,
-				  cmsHPROFILE hProfile,
+				  struct lcmsProfilePtr hProfile,
 				  unsigned int num_points,
 				  const char **err_msg)
 {
@@ -196,7 +196,7 @@ ensure_output_profile_extract_icc(struct cmlcms_output_profile_extract *extract,
 			cmsSigRedTRCTag, cmsSigGreenTRCTag, cmsSigBlueTRCTag
 	};
 
-	if (cmsIsMatrixShaper(hProfile)) {
+	if (cmsIsMatrixShaper(hProfile.p)) {
 		/**
 		 * Matrix-shaper profiles contain TRC and MatrixColumn tags.
 		 * Assumes that AToB or DToB tags do not exist or are
@@ -204,7 +204,7 @@ ensure_output_profile_extract_icc(struct cmlcms_output_profile_extract *extract,
 		 * We can take the TRC curves straight as EOTF.
 		 */
 		for (i = 0 ; i < 3; i++) {
-			curve = cmsReadTag(hProfile, tags[i]);
+			curve = cmsReadTag(hProfile.p, tags[i]);
 			if (!curve) {
 				*err_msg = "TRC tag missing from matrix-shaper ICC profile";
 				goto fail;
@@ -235,7 +235,7 @@ ensure_output_profile_extract_icc(struct cmlcms_output_profile_extract *extract,
 		}
 		extract->output_inv_eotf_vcgt[i] = curve;
 	}
-	vcgt_curves = cmsReadTag(hProfile, cmsSigVcgtTag);
+	vcgt_curves = cmsReadTag(hProfile.p, cmsSigVcgtTag);
 	if (vcgt_curves && vcgt_curves[0] && vcgt_curves[1] && vcgt_curves[2]) {
 		for (i = 0; i < 3; i++) {
 			curve = lcmsJoinToneCurve(lcms_ctx,
@@ -286,11 +286,11 @@ ensure_output_profile_extract(struct cmlcms_color_profile *cprof,
 
 /* FIXME: sync with spec! */
 static bool
-validate_icc_profile(cmsHPROFILE profile, char **errmsg)
+validate_icc_profile(struct lcmsProfilePtr profile, char **errmsg)
 {
-	cmsColorSpaceSignature cs = cmsGetColorSpace(profile);
+	cmsColorSpaceSignature cs = cmsGetColorSpace(profile.p);
 	uint32_t nr_channels = cmsChannelsOf(cs);
-	uint8_t version = cmsGetEncodedICCversion(profile) >> 24;
+	uint8_t version = cmsGetEncodedICCversion(profile.p) >> 24;
 
 	if (version != 2 && version != 4) {
 		str_printf(errmsg,
@@ -306,7 +306,7 @@ validate_icc_profile(cmsHPROFILE profile, char **errmsg)
 		return false;
 	}
 
-	if (cmsGetDeviceClass(profile) != cmsSigDisplayClass) {
+	if (cmsGetDeviceClass(profile.p) != cmsSigDisplayClass) {
 		str_printf(errmsg, "ICC profile is required to be of Display device class, but it is not.");
 		return false;
 	}
@@ -342,7 +342,7 @@ cmlcms_color_profile_print(const struct cmlcms_color_profile *cprof)
 
 static struct cmlcms_color_profile *
 cmlcms_color_profile_create(struct weston_color_manager_lcms *cm,
-			    cmsHPROFILE profile,
+			    struct lcmsProfilePtr profile,
 			    char *desc,
 			    char **errmsg)
 {
@@ -356,7 +356,7 @@ cmlcms_color_profile_create(struct weston_color_manager_lcms *cm,
 	weston_color_profile_init(&cprof->base, &cm->base);
 	cprof->base.description = desc;
 	cprof->profile = profile;
-	cmsGetHeaderProfileID(profile, cprof->md5sum.bytes);
+	cmsGetHeaderProfileID(profile.p, cprof->md5sum.bytes);
 	wl_list_insert(&cm->color_profile_list, &cprof->link);
 
 	weston_log_scope_printf(cm->profiles_scope,
@@ -378,7 +378,7 @@ cmlcms_color_profile_destroy(struct cmlcms_color_profile *cprof)
 	cmsFreeToneCurveTriple(cprof->extract.vcgt);
 	cmsFreeToneCurveTriple(cprof->extract.eotf);
 	cmsFreeToneCurveTriple(cprof->extract.output_inv_eotf_vcgt);
-	cmsCloseProfile(cprof->profile);
+	cmsCloseProfile(cprof->profile.p);
 
 	/* Only profiles created from ICC files have these. */
 	if (cprof->prof_rofile)
@@ -411,7 +411,7 @@ unref_cprof(struct cmlcms_color_profile *cprof)
 }
 
 static char *
-make_icc_file_description(cmsHPROFILE profile,
+make_icc_file_description(struct lcmsProfilePtr profile,
 			  const struct cmlcms_md5_sum *md5sum,
 			  const char *name_part)
 {
@@ -424,7 +424,7 @@ make_icc_file_description(cmsHPROFILE profile,
 			 "%02x", md5sum->bytes[i]);
 	}
 
-	str_printf(&desc, "ICCv%.1f %s %s", cmsGetProfileVersion(profile),
+	str_printf(&desc, "ICCv%.1f %s %s", cmsGetProfileVersion(profile.p),
 		   name_part, md5sum_str);
 
 	return desc;
@@ -437,22 +437,22 @@ make_icc_file_description(cmsHPROFILE profile,
 bool
 cmlcms_create_stock_profile(struct weston_color_manager_lcms *cm)
 {
-	cmsHPROFILE profile;
+	struct lcmsProfilePtr profile;
 	struct cmlcms_md5_sum md5sum;
 	char *desc = NULL;
 	const char *err_msg = NULL;
 
-	profile = cmsCreate_sRGBProfileTHR(cm->lcms_ctx);
-	if (!profile) {
+	profile.p = cmsCreate_sRGBProfileTHR(cm->lcms_ctx);
+	if (!profile.p) {
 		weston_log("color-lcms: error: cmsCreate_sRGBProfileTHR failed\n");
 		return false;
 	}
-	if (!cmsMD5computeID(profile)) {
+	if (!cmsMD5computeID(profile.p)) {
 		weston_log("Failed to compute MD5 for ICC profile\n");
 		goto err_close;
 	}
 
-	cmsGetHeaderProfileID(profile, md5sum.bytes);
+	cmsGetHeaderProfileID(profile.p, md5sum.bytes);
 	desc = make_icc_file_description(profile, &md5sum, "sRGB stock");
 	if (!desc)
 		goto err_close;
@@ -472,7 +472,7 @@ err_close:
 		weston_log("%s\n", err_msg);
 
 	free(desc);
-	cmsCloseProfile(profile);
+	cmsCloseProfile(profile.p);
 	return false;
 }
 
@@ -496,7 +496,7 @@ cmlcms_get_color_profile_from_icc(struct weston_color_manager *cm_base,
 				  char **errmsg)
 {
 	struct weston_color_manager_lcms *cm = to_cmlcms(cm_base);
-	cmsHPROFILE profile;
+	struct lcmsProfilePtr profile;
 	struct cmlcms_md5_sum md5sum;
 	struct cmlcms_color_profile *cprof = NULL;
 	char *desc = NULL;
@@ -510,8 +510,8 @@ cmlcms_get_color_profile_from_icc(struct weston_color_manager *cm_base,
 		return false;
 	}
 
-	profile = cmsOpenProfileFromMemTHR(cm->lcms_ctx, icc_data, icc_len);
-	if (!profile) {
+	profile.p = cmsOpenProfileFromMemTHR(cm->lcms_ctx, icc_data, icc_len);
+	if (!profile.p) {
 		str_printf(errmsg, "ICC data not understood.");
 		return false;
 	}
@@ -519,16 +519,16 @@ cmlcms_get_color_profile_from_icc(struct weston_color_manager *cm_base,
 	if (!validate_icc_profile(profile, errmsg))
 		goto err_close;
 
-	if (!cmsMD5computeID(profile)) {
+	if (!cmsMD5computeID(profile.p)) {
 		str_printf(errmsg, "Failed to compute MD5 for ICC profile.");
 		goto err_close;
 	}
 
-	cmsGetHeaderProfileID(profile, md5sum.bytes);
+	cmsGetHeaderProfileID(profile.p, md5sum.bytes);
 	cprof = cmlcms_find_color_profile_by_md5(cm, &md5sum);
 	if (cprof) {
 		*cprof_out = weston_color_profile_ref(&cprof->base);
-		cmsCloseProfile(profile);
+		cmsCloseProfile(profile.p);
 		return true;
 	}
 
@@ -551,7 +551,7 @@ err_close:
 	if (cprof)
 		cmlcms_color_profile_destroy(cprof);
 	free(desc);
-	cmsCloseProfile(profile);
+	cmsCloseProfile(profile.p);
 	return false;
 }
 
diff --git a/libweston/color-lcms/color-transform.c b/libweston/color-lcms/color-transform.c
index 3d06a92d..fb3ff6a6 100644
--- a/libweston/color-lcms/color-transform.c
+++ b/libweston/color-lcms/color-transform.c
@@ -863,17 +863,17 @@ lcms_xform_error_logger(cmsContext context_id,
 		   text);
 }
 
-static cmsHPROFILE
+static struct lcmsProfilePtr
 profile_from_rgb_curves(cmsContext ctx, cmsToneCurve *const curveset[3])
 {
-	cmsHPROFILE p;
+	struct lcmsProfilePtr p;
 	int i;
 
 	for (i = 0; i < 3; i++)
 		assert(curveset[i]);
 
-	p = cmsCreateLinearizationDeviceLinkTHR(ctx, cmsSigRgbData, curveset);
-	abort_oom_if_null(p);
+	p.p = cmsCreateLinearizationDeviceLinkTHR(ctx, cmsSigRgbData, curveset);
+	abort_oom_if_null(p.p);
 
 	return p;
 }
@@ -883,9 +883,9 @@ xform_realize_chain(struct cmlcms_color_transform *xform)
 {
 	struct weston_color_manager_lcms *cm = to_cmlcms(xform->base.cm);
 	struct cmlcms_color_profile *output_profile = xform->search_key.output_profile;
-	cmsHPROFILE chain[5];
+	struct lcmsProfilePtr chain[5];
 	unsigned chain_len = 0;
-	cmsHPROFILE extra = NULL;
+	struct lcmsProfilePtr extra = { NULL };
 	cmsUInt32Number dwFlags;
 
 	chain[chain_len++] = xform->search_key.input_profile->profile;
@@ -926,13 +926,13 @@ xform_realize_chain(struct cmlcms_color_transform *xform)
 	/* transform_factory() is invoked by this call. */
 	dwFlags = xform->search_key.render_intent->bps ? cmsFLAGS_BLACKPOINTCOMPENSATION : 0;
 	xform->cmap_3dlut = cmsCreateMultiprofileTransformTHR(xform->lcms_ctx,
-							      chain,
+							      from_lcmsProfilePtr_array(chain),
 							      chain_len,
 							      TYPE_RGB_FLT,
 							      TYPE_RGB_FLT,
 							      xform->search_key.render_intent->lcms_intent,
 							      dwFlags);
-	cmsCloseProfile(extra);
+	cmsCloseProfile(extra.p);
 
 	if (!xform->cmap_3dlut)
 		goto failed;