Add support for YAML encoded output

YAML encoded DT is useful for validation of DTs using binding schemas.

The YAML encoding is an intermediate format used for validation and
is therefore subject to change as needed. The YAML output is dependent
on DTS input with type information preserved.

Signed-off-by: Grant Likely <grant.likely@arm.com>
[robh: make YAML support optional, build fixes, Travis CI test,
 preserve type information in paths and phandles]
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

9 files changed, 307 insertions, 2 deletions

diff --git a/.travis.yml b/.travis.yml
index ecdef0d..114932a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,7 @@ matrix:
             - swig
             - python-dev
             - valgrind
+            - libyaml-0-2
         coverity_scan:
           project:
             name: dtc
@@ -26,7 +27,7 @@ matrix:
         - make check && make checkm
 
     # Check it builds properly without optional packages:
-    #     python, valgrind
+    #     python, valgrind, libyaml
     - script:
         - make
         - make check
diff --git a/Documentation/manual.txt b/Documentation/manual.txt
index 6898caa..db32dd7 100644
--- a/Documentation/manual.txt
+++ b/Documentation/manual.txt
@@ -78,6 +78,9 @@ The currently supported Output Formats are:
         then simply be added to your Makefile.  Additionally, the
         assembly file exports some symbols that can be used.
 
+     - "yaml": DT encoded in YAML format. This representation is an
+       intermediate format used for validation tools.
+
 
 3) Command Line
 
diff --git a/Makefile b/Makefile
index c4bfae6..7a472b7 100644
--- a/Makefile
+++ b/Makefile
@@ -46,6 +46,13 @@ else
 	CFLAGS += $(shell $(PKG_CONFIG) --cflags valgrind)
 endif
 
+NO_YAML := $(shell $(PKG_CONFIG) --exists yaml-0.1; echo $$?)
+ifeq ($(NO_YAML),1)
+	CFLAGS += -DNO_YAML
+else
+	LDLIBS += $(shell $(PKG_CONFIG) --libs yaml-0.1)
+endif
+
 ifeq ($(HOSTOS),darwin)
 SHAREDLIB_EXT     = dylib
 SHAREDLIB_CFLAGS  = -fPIC
@@ -329,7 +336,7 @@ clean: libfdt_clean pylibfdt_clean tests_clean
 #
 %: %.o
 	@$(VECHO) LD $@
-	$(LINK.c) -o $@ $^
+	$(LINK.c) -o $@ $^ $(LDLIBS)
 
 %.o: %.c
 	@$(VECHO) CC $@
diff --git a/Makefile.dtc b/Makefile.dtc
index bece49b..d437563 100644
--- a/Makefile.dtc
+++ b/Makefile.dtc
@@ -14,5 +14,9 @@ DTC_SRCS = \
 	treesource.c \
 	util.c
 
+ifneq ($(NO_YAML),1)
+DTC_SRCS += yamltree.c
+endif
+
 DTC_GEN_SRCS = dtc-lexer.lex.c dtc-parser.tab.c
 DTC_OBJS = $(DTC_SRCS:%.c=%.o) $(DTC_GEN_SRCS:%.c=%.o)
diff --git a/dtc.c b/dtc.c
index c36994e..64134aa 100644
--- a/dtc.c
+++ b/dtc.c
@@ -95,6 +95,9 @@ static const char * const usage_opts_help[] = {
 	"\n\tOutput formats are:\n"
 	 "\t\tdts - device tree source text\n"
 	 "\t\tdtb - device tree blob\n"
+#ifndef NO_YAML
+	 "\t\tyaml - device tree encoded as YAML\n"
+#endif
 	 "\t\tasm - assembler source",
 	"\n\tBlob version to produce, defaults to "stringify(DEFAULT_FDT_VERSION)" (for dtb and asm output)",
 	"\n\tOutput dependency file",
@@ -128,6 +131,8 @@ static const char *guess_type_by_name(const char *fname, const char *fallback)
 		return fallback;
 	if (!strcasecmp(s, ".dts"))
 		return "dts";
+	if (!strcasecmp(s, ".yaml"))
+		return "yaml";
 	if (!strcasecmp(s, ".dtb"))
 		return "dtb";
 	return fallback;
@@ -350,6 +355,12 @@ int main(int argc, char *argv[])
 
 	if (streq(outform, "dts")) {
 		dt_to_source(outf, dti);
+#ifndef NO_YAML
+	} else if (streq(outform, "yaml")) {
+		if (!streq(inform, "dts"))
+			die("YAML output format requires dts input format\n");
+		dt_to_yaml(outf, dti);
+#endif
 	} else if (streq(outform, "dtb")) {
 		dt_to_blob(outf, dti, outversion);
 	} else if (streq(outform, "asm")) {
diff --git a/dtc.h b/dtc.h
index bb769d2..cbe5415 100644
--- a/dtc.h
+++ b/dtc.h
@@ -299,6 +299,10 @@ struct dt_info *dt_from_blob(const char *fname);
 void dt_to_source(FILE *f, struct dt_info *dti);
 struct dt_info *dt_from_source(const char *f);
 
+/* YAML source */
+
+void dt_to_yaml(FILE *f, struct dt_info *dti);
+
 /* FS trees */
 
 struct dt_info *dt_from_fs(const char *dirname);
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index bbdc5c8..adc4dae 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -568,6 +568,14 @@ dtc_tests () {
         run_wrap_test cmp $tree $tree.test.dts
     done
 
+    # Check -Oyaml output
+    if pkg-config --exists yaml-0.1; then
+            for tree in type-preservation; do
+                run_dtc_test -I dts -O yaml -o $tree.test.dt.yaml $tree.dts
+                run_wrap_test cmp $tree.dt.yaml $tree.test.dt.yaml
+            done
+    fi
+
     # Check version conversions
     for tree in test_tree1.dtb ; do
 	 for aver in 1 2 3 16 17; do
diff --git a/tests/type-preservation.dt.yaml b/tests/type-preservation.dt.yaml
new file mode 100644
index 0000000..ee8cfde
--- /dev/null
+++ b/tests/type-preservation.dt.yaml
@@ -0,0 +1,20 @@
+---
+- '#address-cells': [[0x1]]
+  '#size-cells': [[0x0]]
+  subnode@1:
+    compatible: ["subnode1"]
+    reg: [[0x1]]
+    int-array: [[0x0, 0x1], [0x2, 0x3]]
+    int8: [!u8 [0x56]]
+    int8-array: [!u8 [0x0, 0x12, 0x34, 0x56]]
+    int16: [!u16 [0x3210]]
+    int16-array: [!u16 [0x1234, 0x5678, 0x90ab, 0xcdef]]
+    int16-matrix: [!u16 [0x1234, 0x5678], [0x90ab, 0xcdef]]
+    int64: [!u64 [0x200000000]]
+    int64-array: [!u64 [0x100000000, 0x0]]
+    a-string-with-nulls: ["foo\0bar", "baz"]
+    subsubnode:
+      compatible: ["subsubnode1", "subsubnode"]
+      subsubsubnode:
+        compatible: ["subsubsubnode1", [0x1234], "subsubsubnode"]
+...
diff --git a/yamltree.c b/yamltree.c
new file mode 100644
index 0000000..a00285a
--- /dev/null
+++ b/yamltree.c
@@ -0,0 +1,247 @@
+/*
+ * (C) Copyright Linaro, Ltd. 2018
+ * (C) Copyright Arm Holdings.  2017
+ * (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation.  2005.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+ *                                                                   USA
+ */
+
+#include <stdlib.h>
+#include <yaml.h>
+#include "dtc.h"
+#include "srcpos.h"
+
+char *yaml_error_name[] = {
+	[YAML_NO_ERROR] = "no error",
+	[YAML_MEMORY_ERROR] = "memory error",
+	[YAML_READER_ERROR] = "reader error",
+	[YAML_SCANNER_ERROR] = "scanner error",
+	[YAML_PARSER_ERROR] = "parser error",
+	[YAML_COMPOSER_ERROR] = "composer error",
+	[YAML_WRITER_ERROR] = "writer error",
+	[YAML_EMITTER_ERROR] = "emitter error",
+};
+
+#define yaml_emitter_emit_or_die(emitter, event) (			\
+{									\
+	if (!yaml_emitter_emit(emitter, event))				\
+		die("yaml '%s': %s in %s, line %i\n",			\
+		    yaml_error_name[(emitter)->error], 			\
+		    (emitter)->problem, __func__, __LINE__);		\
+})
+
+static void yaml_propval_int(yaml_emitter_t *emitter, struct marker *markers, char *data, int len, int width)
+{
+	yaml_event_t event;
+	void *tag;
+	int off, start_offset = markers->offset;
+
+	switch(width) {
+		case 1: tag = "!u8"; break;
+		case 2: tag = "!u16"; break;
+		case 4: tag = "!u32"; break;
+		case 8: tag = "!u64"; break;
+		default:
+			die("Invalid width %i", width);
+	}
+	assert(len % width == 0);
+
+	yaml_sequence_start_event_initialize(&event, NULL,
+		(yaml_char_t *)tag, width == 4, YAML_FLOW_SEQUENCE_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+
+	for (off = 0; off < len; off += width) {
+		char buf[32];
+		struct marker *m;
+		bool is_phandle = false;
+
+		switch(width) {
+		case 1:
+			sprintf(buf, "0x%"PRIx8, *(uint8_t*)(data + off));
+			break;
+		case 2:
+			sprintf(buf, "0x%"PRIx16, fdt16_to_cpu(*(fdt16_t*)(data + off)));
+			break;
+		case 4:
+			sprintf(buf, "0x%"PRIx32, fdt32_to_cpu(*(fdt32_t*)(data + off)));
+			m = markers;
+			is_phandle = false;
+			for_each_marker_of_type(m, REF_PHANDLE) {
+				if (m->offset == (start_offset + off)) {
+					is_phandle = true;
+					break;
+				}
+			}
+			break;
+		case 8:
+			sprintf(buf, "0x%"PRIx64, fdt64_to_cpu(*(fdt64_t*)(data + off)));
+			break;
+		}
+
+		if (is_phandle)
+			yaml_scalar_event_initialize(&event, NULL,
+				(yaml_char_t*)"!phandle", (yaml_char_t *)buf,
+				strlen(buf), 0, 0, YAML_PLAIN_SCALAR_STYLE);
+		else
+			yaml_scalar_event_initialize(&event, NULL,
+				(yaml_char_t*)YAML_INT_TAG, (yaml_char_t *)buf,
+				strlen(buf), 1, 1, YAML_PLAIN_SCALAR_STYLE);
+		yaml_emitter_emit_or_die(emitter, &event);
+	}
+
+	yaml_sequence_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(emitter, &event);
+}
+
+static void yaml_propval_string(yaml_emitter_t *emitter, char *str, int len)
+{
+	yaml_event_t event;
+	int i;
+
+	assert(str[len-1] == '\0');
+
+	/* Make sure the entire string is in the lower 7-bit ascii range */
+	for (i = 0; i < len; i++)
+		assert(isascii(str[i]));
+
+	yaml_scalar_event_initialize(&event, NULL,
+		(yaml_char_t *)YAML_STR_TAG, (yaml_char_t*)str,
+		len-1, 0, 1, YAML_DOUBLE_QUOTED_SCALAR_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+}
+
+static void yaml_propval(yaml_emitter_t *emitter, struct property *prop)
+{
+	yaml_event_t event;
+	int len = prop->val.len;
+	struct marker *m = prop->val.markers;
+
+	/* Emit the property name */
+	yaml_scalar_event_initialize(&event, NULL,
+		(yaml_char_t *)YAML_STR_TAG, (yaml_char_t*)prop->name,
+		strlen(prop->name), 1, 1, YAML_PLAIN_SCALAR_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+
+	/* Boolean properties are easiest to deal with. Length is zero, so just emit 'true' */
+	if (len == 0) {
+		yaml_scalar_event_initialize(&event, NULL,
+			(yaml_char_t *)YAML_BOOL_TAG,
+			(yaml_char_t*)"true",
+			strlen("true"), 1, 0, YAML_PLAIN_SCALAR_STYLE);
+		yaml_emitter_emit_or_die(emitter, &event);
+		return;
+	}
+
+	if (!m)
+		die("No markers present in property '%s' value\n", prop->name);
+
+	yaml_sequence_start_event_initialize(&event, NULL,
+		(yaml_char_t *)YAML_SEQ_TAG, 1, YAML_FLOW_SEQUENCE_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+
+	for_each_marker(m) {
+		int chunk_len;
+		char *data = &prop->val.val[m->offset];
+
+		if (m->type < TYPE_UINT8)
+			continue;
+
+		chunk_len = type_marker_length(m) ? : len;
+		assert(chunk_len > 0);
+		len -= chunk_len;
+
+		switch(m->type) {
+		case TYPE_UINT16:
+			yaml_propval_int(emitter, m, data, chunk_len, 2);
+			break;
+		case TYPE_UINT32:
+			yaml_propval_int(emitter, m, data, chunk_len, 4);
+			break;
+		case TYPE_UINT64:
+			yaml_propval_int(emitter, m, data, chunk_len, 8);
+			break;
+		case TYPE_STRING:
+			yaml_propval_string(emitter, data, chunk_len);
+			break;
+		default:
+			yaml_propval_int(emitter, m, data, chunk_len, 1);
+			break;
+		}
+	}
+
+	yaml_sequence_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(emitter, &event);
+}
+
+
+static void yaml_tree(struct node *tree, yaml_emitter_t *emitter)
+{
+	struct property *prop;
+	struct node *child;
+	yaml_event_t event;
+
+	if (tree->deleted)
+		return;
+
+	yaml_mapping_start_event_initialize(&event, NULL,
+		(yaml_char_t *)YAML_MAP_TAG, 1, YAML_ANY_MAPPING_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+
+	for_each_property(tree, prop)
+		yaml_propval(emitter, prop);
+
+	/* Loop over all the children, emitting them into the map */
+	for_each_child(tree, child) {
+		yaml_scalar_event_initialize(&event, NULL,
+			(yaml_char_t *)YAML_STR_TAG, (yaml_char_t*)child->name,
+			strlen(child->name), 1, 0, YAML_PLAIN_SCALAR_STYLE);
+		yaml_emitter_emit_or_die(emitter, &event);
+		yaml_tree(child, emitter);
+	}
+
+	yaml_mapping_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(emitter, &event);
+}
+
+void dt_to_yaml(FILE *f, struct dt_info *dti)
+{
+	yaml_emitter_t emitter;
+	yaml_event_t event;
+
+	yaml_emitter_initialize(&emitter);
+	yaml_emitter_set_output_file(&emitter, f);
+	yaml_stream_start_event_initialize(&event, YAML_UTF8_ENCODING);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_document_start_event_initialize(&event, NULL, NULL, NULL, 0);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_sequence_start_event_initialize(&event, NULL, (yaml_char_t *)YAML_SEQ_TAG, 1, YAML_ANY_SEQUENCE_STYLE);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_tree(dti->dt, &emitter);
+
+	yaml_sequence_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_document_end_event_initialize(&event, 0);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_stream_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_emitter_delete(&emitter);
+}