Rename SkFontConfigParser_android SkFontMgr_android_parser.

There are a number of files with 'FontConfig' in their names which
just have to do with font configuration, but nothing to do with
the FontConfig project or even with each other. This clarifies
that these files deal with parsing for the Android font manager.

Review URL: https://codereview.chromium.org/1200103008

1 files changed, 796 insertions, 0 deletions

diff --git a/src/ports/SkFontMgr_android_parser.cpp b/src/ports/SkFontMgr_android_parser.cpp
new file mode 100644
index 0000000000..5ca6d4fcc5
--- /dev/null
+++ b/src/ports/SkFontMgr_android_parser.cpp
@@ -0,0 +1,796 @@
+/*
+ * Copyright 2011 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkFontMgr_android_parser.h"
+#include "SkStream.h"
+#include "SkTDArray.h"
+#include "SkTSearch.h"
+#include "SkTypeface.h"
+
+#include <expat.h>
+#include <dirent.h>
+
+#include <stdlib.h>
+
+#define LMP_SYSTEM_FONTS_FILE "/system/etc/fonts.xml"
+#define OLD_SYSTEM_FONTS_FILE "/system/etc/system_fonts.xml"
+#define FALLBACK_FONTS_FILE "/system/etc/fallback_fonts.xml"
+#define VENDOR_FONTS_FILE "/vendor/etc/fallback_fonts.xml"
+
+#define LOCALE_FALLBACK_FONTS_SYSTEM_DIR "/system/etc"
+#define LOCALE_FALLBACK_FONTS_VENDOR_DIR "/vendor/etc"
+#define LOCALE_FALLBACK_FONTS_PREFIX "fallback_fonts-"
+#define LOCALE_FALLBACK_FONTS_SUFFIX ".xml"
+
+#ifndef SK_FONT_FILE_PREFIX
+#    define SK_FONT_FILE_PREFIX "/fonts/"
+#endif
+
+/**
+ * This file contains TWO 'familyset' handlers:
+ * One for JB and earlier which works with
+ *   /system/etc/system_fonts.xml
+ *   /system/etc/fallback_fonts.xml
+ *   /vendor/etc/fallback_fonts.xml
+ *   /system/etc/fallback_fonts-XX.xml
+ *   /vendor/etc/fallback_fonts-XX.xml
+ * and the other for LMP and later which works with
+ *   /system/etc/fonts.xml
+ *
+ * If the 'familyset' 'version' attribute is 21 or higher the LMP parser is used, otherwise the JB.
+ */
+
+struct FamilyData;
+
+struct TagHandler {
+    /** Called at the start tag.
+     *  Called immediately after the parent tag retuns this handler from a call to 'tag'.
+     *  Allows setting up for handling the tag content and processing attributes.
+     *  If NULL, will not be called.
+     */
+    void (*start)(FamilyData* data, const char* tag, const char** attributes);
+
+    /** Called at the end tag.
+     *  Allows post-processing of any accumulated information.
+     *  This will be the last call made in relation to the current tag.
+     *  If NULL, will not be called.
+     */
+    void (*end)(FamilyData* data, const char* tag);
+
+    /** Called when a nested tag is encountered.
+     *  This is responsible for determining how to handle the tag.
+     *  If the tag is not recognized, return NULL to skip the tag.
+     *  If NULL, all nested tags will be skipped.
+     */
+    const TagHandler* (*tag)(FamilyData* data, const char* tag, const char** attributes);
+
+    /** The character handler for this tag.
+     *  This is only active for character data contained directly in this tag (not sub-tags).
+     *  The first parameter will be castable to a FamilyData*.
+     *  If NULL, any character data in this tag will be ignored.
+     */
+    XML_CharacterDataHandler chars;
+};
+
+/** Represents the current parsing state. */
+struct FamilyData {
+    FamilyData(XML_Parser parser, SkTDArray<FontFamily*>& families,
+               const SkString& basePath, bool isFallback, const char* filename,
+               const TagHandler* topLevelHandler)
+        : fParser(parser)
+        , fFamilies(families)
+        , fCurrentFamily(NULL)
+        , fCurrentFontInfo(NULL)
+        , fVersion(0)
+        , fBasePath(basePath)
+        , fIsFallback(isFallback)
+        , fFilename(filename)
+        , fDepth(1)
+        , fSkip(0)
+        , fHandler(&topLevelHandler, 1)
+    { };
+
+    XML_Parser fParser;                       // The expat parser doing the work, owned by caller
+    SkTDArray<FontFamily*>& fFamilies;        // The array to append families, owned by caller
+    SkAutoTDelete<FontFamily> fCurrentFamily; // The family being created, owned by this
+    FontFileInfo* fCurrentFontInfo;           // The fontInfo being created, owned by fCurrentFamily
+    int fVersion;                             // The version of the file parsed.
+    const SkString& fBasePath;                // The current base path.
+    const bool fIsFallback;                   // Indicates the file being parsed is a fallback file
+    const char* fFilename;                    // The name of the file currently being parsed.
+
+    int fDepth;                               // The current element depth of the parse.
+    int fSkip;                                // The depth to stop skipping, 0 if not skipping.
+    SkTDArray<const TagHandler*> fHandler;    // The stack of current tag handlers.
+};
+
+static bool memeq(const char* s1, const char* s2, size_t n1, size_t n2) {
+    return n1 == n2 && 0 == memcmp(s1, s2, n1);
+}
+#define MEMEQ(c, s, n) memeq(c, s, sizeof(c) - 1, n)
+
+#define ATTS_NON_NULL(a, i) (a[i] != NULL && a[i+1] != NULL)
+
+#define SK_FONTMGR_ANDROID_PARSER_PREFIX "[SkFontMgr Android Parser] "
+
+#define SK_FONTCONFIGPARSER_WARNING(message, ...) SkDebugf( \
+    SK_FONTMGR_ANDROID_PARSER_PREFIX "%s:%d:%d: warning: " message "\n", \
+    self->fFilename, \
+    XML_GetCurrentLineNumber(self->fParser), \
+    XML_GetCurrentColumnNumber(self->fParser), \
+    ##__VA_ARGS__);
+
+static bool is_whitespace(char c) {
+    return c == ' ' || c == '\n'|| c == '\r' || c == '\t';
+}
+
+static void trim_string(SkString* s) {
+    char* str = s->writable_str();
+    const char* start = str;  // start is inclusive
+    const char* end = start + s->size();  // end is exclusive
+    while (is_whitespace(*start)) { ++start; }
+    if (start != end) {
+        --end;  // make end inclusive
+        while (is_whitespace(*end)) { --end; }
+        ++end;  // make end exclusive
+    }
+    size_t len = end - start;
+    memmove(str, start, len);
+    s->resize(len);
+}
+
+namespace lmpParser {
+
+static const TagHandler axisHandler = {
+    /*start*/[](FamilyData* self, const char* tag, const char** attributes) {
+        FontFileInfo& file = *self->fCurrentFontInfo;
+        FontFileInfo::Axis& axis = file.fAxes.push_back();
+        for (size_t i = 0; ATTS_NON_NULL(attributes, i); i += 2) {
+            const char* name = attributes[i];
+            const char* value = attributes[i+1];
+            size_t nameLen = strlen(name);
+            if (MEMEQ("tag", name, nameLen)) {
+                size_t valueLen = strlen(value);
+                if (valueLen == 4) {
+                    SkFourByteTag tag = SkSetFourByteTag(value[0], value[1], value[2], value[3]);
+                    for (int j = 0; j < file.fAxes.count() - 1; ++j) {
+                        if (file.fAxes[j].fTag == tag) {
+                            SK_FONTCONFIGPARSER_WARNING("'%c%c%c%c' axis specified more than once",
+                                                        (tag >> 24) & 0xFF,
+                                                        (tag >> 16) & 0xFF,
+                                                        (tag >>  8) & 0xFF,
+                                                        (tag      ) & 0xFF);
+                        }
+                    }
+                    axis.fTag = SkSetFourByteTag(value[0], value[1], value[2], value[3]);
+                } else {
+                    SK_FONTCONFIGPARSER_WARNING("'%s' is an invalid axis tag", value);
+                }
+            } else if (MEMEQ("stylevalue", name, nameLen)) {
+                if (!parse_fixed<16>(value, &axis.fValue)) {
+                    SK_FONTCONFIGPARSER_WARNING("'%s' is an invalid axis stylevalue", value);
+                }
+            }
+        }
+    },
+    /*end*/NULL,
+    /*tag*/NULL,
+    /*chars*/NULL,
+};
+
+static const TagHandler fontHandler = {
+    /*start*/[](FamilyData* self, const char* tag, const char** attributes) {
+        // 'weight' (non-negative integer) [default 0]
+        // 'style' ("normal", "italic") [default "auto"]
+        // 'index' (non-negative integer) [default 0]
+        // The character data should be a filename.
+        FontFileInfo& file = self->fCurrentFamily->fFonts.push_back();
+        self->fCurrentFontInfo = &file;
+        for (size_t i = 0; ATTS_NON_NULL(attributes, i); i += 2) {
+            const char* name = attributes[i];
+            const char* value = attributes[i+1];
+            size_t nameLen = strlen(name);
+            if (MEMEQ("weight", name, nameLen)) {
+                if (!parse_non_negative_integer(value, &file.fWeight)) {
+                    SK_FONTCONFIGPARSER_WARNING("'%s' is an invalid weight", value);
+                }
+            } else if (MEMEQ("style", name, nameLen)) {
+                size_t valueLen = strlen(value);
+                if (MEMEQ("normal", value, valueLen)) {
+                    file.fStyle = FontFileInfo::Style::kNormal;
+                } else if (MEMEQ("italic", value, valueLen)) {
+                    file.fStyle = FontFileInfo::Style::kItalic;
+                }
+            } else if (MEMEQ("index", name, nameLen)) {
+                if (!parse_non_negative_integer(value, &file.fIndex)) {
+                    SK_FONTCONFIGPARSER_WARNING("'%s' is an invalid index", value);
+                }
+            }
+        }
+    },
+    /*end*/[](FamilyData* self, const char* tag) {
+        trim_string(&self->fCurrentFontInfo->fFileName);
+    },
+    /*tag*/[](FamilyData* self, const char* tag, const char** attributes) -> const TagHandler* {
+        size_t len = strlen(tag);
+        if (MEMEQ("axis", tag, len)) {
+            return &axisHandler;
+        }
+        return NULL;
+    },
+    /*chars*/[](void* data, const char* s, int len) {
+        FamilyData* self = static_cast<FamilyData*>(data);
+        self->fCurrentFontInfo->fFileName.append(s, len);
+    }
+};
+
+static const TagHandler familyHandler = {
+    /*start*/[](FamilyData* self, const char* tag, const char** attributes) {
+        // 'name' (string) [optional]
+        // 'lang' (string) [default ""]
+        // 'variant' ("elegant", "compact") [default "default"]
+        // If there is no name, this is a fallback only font.
+        FontFamily* family = new FontFamily(self->fBasePath, true);
+        self->fCurrentFamily.reset(family);
+        for (size_t i = 0; ATTS_NON_NULL(attributes, i); i += 2) {
+            const char* name = attributes[i];
+            const char* value = attributes[i+1];
+            size_t nameLen = strlen(name);
+            size_t valueLen = strlen(value);
+            if (MEMEQ("name", name, nameLen)) {
+                SkAutoAsciiToLC tolc(value);
+                family->fNames.push_back().set(tolc.lc());
+                family->fIsFallbackFont = false;
+            } else if (MEMEQ("lang", name, nameLen)) {
+                family->fLanguage = SkLanguage(value, valueLen);
+            } else if (MEMEQ("variant", name, nameLen)) {
+                if (MEMEQ("elegant", value, valueLen)) {
+                    family->fVariant = kElegant_FontVariant;
+                } else if (MEMEQ("compact", value, valueLen)) {
+                    family->fVariant = kCompact_FontVariant;
+                }
+            }
+        }
+    },
+    /*end*/[](FamilyData* self, const char* tag) {
+        *self->fFamilies.append() = self->fCurrentFamily.detach();
+    },
+    /*tag*/[](FamilyData* self, const char* tag, const char** attributes) -> const TagHandler* {
+        size_t len = strlen(tag);
+        if (MEMEQ("font", tag, len)) {
+            return &fontHandler;
+        }
+        return NULL;
+    },
+    /*chars*/NULL,
+};
+
+static FontFamily* find_family(FamilyData* self, const SkString& familyName) {
+    for (int i = 0; i < self->fFamilies.count(); i++) {
+        FontFamily* candidate = self->fFamilies[i];
+        for (int j = 0; j < candidate->fNames.count(); j++) {
+            if (candidate->fNames[j] == familyName) {
+                return candidate;
+            }
+        }
+    }
+    return NULL;
+}
+
+static const TagHandler aliasHandler = {
+    /*start*/[](FamilyData* self, const char* tag, const char** attributes) {
+        // 'name' (string) introduces a new family name.
+        // 'to' (string) specifies which (previous) family to alias
+        // 'weight' (non-negative integer) [optional]
+        // If it *does not* have a weight, 'name' is an alias for the entire 'to' family.
+        // If it *does* have a weight, 'name' is a new family consisting of
+        // the font(s) with 'weight' from the 'to' family.
+
+        SkString aliasName;
+        SkString to;
+        int weight = 0;
+        for (size_t i = 0; ATTS_NON_NULL(attributes, i); i += 2) {
+            const char* name = attributes[i];
+            const char* value = attributes[i+1];
+            size_t nameLen = strlen(name);
+            if (MEMEQ("name", name, nameLen)) {
+                SkAutoAsciiToLC tolc(value);
+                aliasName.set(tolc.lc());
+            } else if (MEMEQ("to", name, nameLen)) {
+                to.set(value);
+            } else if (MEMEQ("weight", name, nameLen)) {
+                if (!parse_non_negative_integer(value, &weight)) {
+                    SK_FONTCONFIGPARSER_WARNING("'%s' is an invalid weight", value);
+                }
+            }
+        }
+
+        // Assumes that the named family is already declared
+        FontFamily* targetFamily = find_family(self, to);
+        if (!targetFamily) {
+            SK_FONTCONFIGPARSER_WARNING("'%s' alias target not found", to.c_str());
+            return;
+        }
+
+        if (weight) {
+            FontFamily* family = new FontFamily(targetFamily->fBasePath, self->fIsFallback);
+            family->fNames.push_back().set(aliasName);
+
+            for (int i = 0; i < targetFamily->fFonts.count(); i++) {
+                if (targetFamily->fFonts[i].fWeight == weight) {
+                    family->fFonts.push_back(targetFamily->fFonts[i]);
+                }
+            }
+            *self->fFamilies.append() = family;
+        } else {
+            targetFamily->fNames.push_back().set(aliasName);
+        }
+    },
+    /*end*/NULL,
+    /*tag*/NULL,
+    /*chars*/NULL,
+};
+
+static const TagHandler familySetHandler = {
+    /*start*/[](FamilyData* self, const char* tag, const char** attributes) { },
+    /*end*/NULL,
+    /*tag*/[](FamilyData* self, const char* tag, const char** attributes) -> const TagHandler* {
+        size_t len = strlen(tag);
+        if (MEMEQ("family", tag, len)) {
+            return &familyHandler;
+        } else if (MEMEQ("alias", tag, len)) {
+            return &aliasHandler;
+        }
+        return NULL;
+    },
+    /*chars*/NULL,
+};
+
+} // lmpParser
+
+namespace jbParser {
+
+static const TagHandler fileHandler = {
+    /*start*/[](FamilyData* self, const char* tag, const char** attributes) {
+        // 'variant' ("elegant", "compact") [default "default"]
+        // 'lang' (string) [default ""]
+        // 'index' (non-negative integer) [default 0]
+        // The character data should be a filename.
+        FontFamily& currentFamily = *self->fCurrentFamily.get();
+        FontFileInfo& newFileInfo = currentFamily.fFonts.push_back();
+        if (attributes) {
+            for (size_t i = 0; ATTS_NON_NULL(attributes, i); i += 2) {
+                const char* name = attributes[i];
+                const char* value = attributes[i+1];
+                size_t nameLen = strlen(name);
+                size_t valueLen = strlen(value);
+                if (MEMEQ("variant", name, nameLen)) {
+                    const FontVariant prevVariant = currentFamily.fVariant;
+                    if (MEMEQ("elegant", value, valueLen)) {
+                        currentFamily.fVariant = kElegant_FontVariant;
+                    } else if (MEMEQ("compact", value, valueLen)) {
+                        currentFamily.fVariant = kCompact_FontVariant;
+                    }
+                    if (currentFamily.fFonts.count() > 1 && currentFamily.fVariant != prevVariant) {
+                        SK_FONTCONFIGPARSER_WARNING("'%s' unexpected variant found\n"
+                            "Note: Every font file within a family must have identical variants.",
+                            value);
+                    }
+
+                } else if (MEMEQ("lang", name, nameLen)) {
+                    SkLanguage prevLang = currentFamily.fLanguage;
+                    currentFamily.fLanguage = SkLanguage(value, valueLen);
+                    if (currentFamily.fFonts.count() > 1 && currentFamily.fLanguage != prevLang) {
+                        SK_FONTCONFIGPARSER_WARNING("'%s' unexpected language found\n"
+                            "Note: Every font file within a family must have identical languages.",
+                            value);
+                    }
+
+                } else if (MEMEQ("index", name, nameLen)) {
+                    if (!parse_non_negative_integer(value, &newFileInfo.fIndex)) {
+                        SK_FONTCONFIGPARSER_WARNING("'%s' is an invalid index", value);
+                    }
+                }
+            }
+        }
+        self->fCurrentFontInfo = &newFileInfo;
+    },
+    /*end*/NULL,
+    /*tag*/NULL,
+    /*chars*/[](void* data, const char* s, int len) {
+        FamilyData* self = static_cast<FamilyData*>(data);
+        self->fCurrentFontInfo->fFileName.append(s, len);
+    }
+};
+
+static const TagHandler fileSetHandler = {
+    /*start*/NULL,
+    /*end*/NULL,
+    /*tag*/[](FamilyData* self, const char* tag, const char** attributes) -> const TagHandler* {
+        size_t len = strlen(tag);
+        if (MEMEQ("file", tag, len)) {
+            return &fileHandler;
+        }
+        return NULL;
+    },
+    /*chars*/NULL,
+};
+
+static const TagHandler nameHandler = {
+    /*start*/[](FamilyData* self, const char* tag, const char** attributes) {
+        // The character data should be a name for the font.
+        self->fCurrentFamily->fNames.push_back();
+    },
+    /*end*/NULL,
+    /*tag*/NULL,
+    /*chars*/[](void* data, const char* s, int len) {
+        FamilyData* self = static_cast<FamilyData*>(data);
+        SkAutoAsciiToLC tolc(s, len);
+        self->fCurrentFamily->fNames.back().append(tolc.lc(), len);
+    }
+};
+
+static const TagHandler nameSetHandler = {
+    /*start*/NULL,
+    /*end*/NULL,
+    /*tag*/[](FamilyData* self, const char* tag, const char** attributes) -> const TagHandler* {
+        size_t len = strlen(tag);
+        if (MEMEQ("name", tag, len)) {
+            return &nameHandler;
+        }
+        return NULL;
+    },
+    /*chars*/NULL,
+};
+
+static const TagHandler familyHandler = {
+    /*start*/[](FamilyData* self, const char* tag, const char** attributes) {
+        self->fCurrentFamily.reset(new FontFamily(self->fBasePath, self->fIsFallback));
+        // 'order' (non-negative integer) [default -1]
+        for (size_t i = 0; ATTS_NON_NULL(attributes, i); i += 2) {
+            const char* value = attributes[i+1];
+            parse_non_negative_integer(value, &self->fCurrentFamily->fOrder);
+        }
+    },
+    /*end*/[](FamilyData* self, const char* tag) {
+        *self->fFamilies.append() = self->fCurrentFamily.detach();
+    },
+    /*tag*/[](FamilyData* self, const char* tag, const char** attributes) -> const TagHandler* {
+        size_t len = strlen(tag);
+        if (MEMEQ("nameset", tag, len)) {
+            return &nameSetHandler;
+        } else if (MEMEQ("fileset", tag, len)) {
+            return &fileSetHandler;
+        }
+        return NULL;
+    },
+    /*chars*/NULL,
+};
+
+static const TagHandler familySetHandler = {
+    /*start*/NULL,
+    /*end*/NULL,
+    /*tag*/[](FamilyData* self, const char* tag, const char** attributes) -> const TagHandler* {
+        size_t len = strlen(tag);
+        if (MEMEQ("family", tag, len)) {
+            return &familyHandler;
+        }
+        return NULL;
+    },
+    /*chars*/NULL,
+};
+
+} // namespace jbParser
+
+static const TagHandler topLevelHandler = {
+    /*start*/NULL,
+    /*end*/NULL,
+    /*tag*/[](FamilyData* self, const char* tag, const char** attributes) -> const TagHandler* {
+        size_t len = strlen(tag);
+        if (MEMEQ("familyset", tag, len)) {
+            // 'version' (non-negative integer) [default 0]
+            for (size_t i = 0; ATTS_NON_NULL(attributes, i); i += 2) {
+                const char* name = attributes[i];
+                size_t nameLen = strlen(name);
+                if (MEMEQ("version", name, nameLen)) {
+                    const char* value = attributes[i+1];
+                    if (parse_non_negative_integer(value, &self->fVersion)) {
+                        if (self->fVersion >= 21) {
+                            return &lmpParser::familySetHandler;
+                        }
+                    }
+                }
+            }
+            return &jbParser::familySetHandler;
+        }
+        return NULL;
+    },
+    /*chars*/NULL,
+};
+
+static void XMLCALL start_element_handler(void *data, const char *tag, const char **attributes) {
+    FamilyData* self = static_cast<FamilyData*>(data);
+
+    if (!self->fSkip) {
+        const TagHandler* parent = self->fHandler.top();
+        const TagHandler* child = parent->tag ? parent->tag(self, tag, attributes) : NULL;
+        if (child) {
+            if (child->start) {
+                child->start(self, tag, attributes);
+            }
+            self->fHandler.push(child);
+            XML_SetCharacterDataHandler(self->fParser, child->chars);
+        } else {
+            SK_FONTCONFIGPARSER_WARNING("'%s' tag not recognized, skipping", tag);
+            XML_SetCharacterDataHandler(self->fParser, NULL);
+            self->fSkip = self->fDepth;
+        }
+    }
+
+    ++self->fDepth;
+}
+
+static void XMLCALL end_element_handler(void* data, const char* tag) {
+    FamilyData* self = static_cast<FamilyData*>(data);
+    --self->fDepth;
+
+    if (!self->fSkip) {
+        const TagHandler* child = self->fHandler.top();
+        if (child->end) {
+            child->end(self, tag);
+        }
+        self->fHandler.pop();
+        const TagHandler* parent = self->fHandler.top();
+        XML_SetCharacterDataHandler(self->fParser, parent->chars);
+    }
+
+    if (self->fSkip == self->fDepth) {
+        self->fSkip = 0;
+        const TagHandler* parent = self->fHandler.top();
+        XML_SetCharacterDataHandler(self->fParser, parent->chars);
+    }
+}
+
+static void XMLCALL xml_entity_decl_handler(void *data,
+                                            const XML_Char *entityName,
+                                            int is_parameter_entity,
+                                            const XML_Char *value,
+                                            int value_length,
+                                            const XML_Char *base,
+                                            const XML_Char *systemId,
+                                            const XML_Char *publicId,
+                                            const XML_Char *notationName)
+{
+    FamilyData* self = static_cast<FamilyData*>(data);
+    SK_FONTCONFIGPARSER_WARNING("'%s' entity declaration found, stopping processing", entityName);
+    XML_StopParser(self->fParser, XML_FALSE);
+}
+
+static const XML_Memory_Handling_Suite sk_XML_alloc = {
+    sk_malloc_throw,
+    sk_realloc_throw,
+    sk_free
+};
+
+template<typename T> struct remove_ptr {typedef T type;};
+template<typename T> struct remove_ptr<T*> {typedef T type;};
+
+/**
+ * This function parses the given filename and stores the results in the given
+ * families array. Returns the version of the file, negative if the file does not exist.
+ */
+static int parse_config_file(const char* filename, SkTDArray<FontFamily*>& families,
+                             const SkString& basePath, bool isFallback)
+{
+    SkFILEStream file(filename);
+
+    // Some of the files we attempt to parse (in particular, /vendor/etc/fallback_fonts.xml)
+    // are optional - failure here is okay because one of these optional files may not exist.
+    if (!file.isValid()) {
+        SkDebugf(SK_FONTMGR_ANDROID_PARSER_PREFIX "'%s' could not be opened\n", filename);
+        return -1;
+    }
+
+    SkAutoTCallVProc<remove_ptr<XML_Parser>::type, XML_ParserFree> parser(
+        XML_ParserCreate_MM(NULL, &sk_XML_alloc, NULL));
+    if (!parser) {
+        SkDebugf(SK_FONTMGR_ANDROID_PARSER_PREFIX "could not create XML parser\n");
+        return -1;
+    }
+
+    FamilyData self(parser, families, basePath, isFallback, filename, &topLevelHandler);
+    XML_SetUserData(parser, &self);
+
+    // Disable entity processing, to inhibit internal entity expansion. See expat CVE-2013-0340
+    XML_SetEntityDeclHandler(parser, xml_entity_decl_handler);
+
+    // Start parsing oldschool; switch these in flight if we detect a newer version of the file.
+    XML_SetElementHandler(parser, start_element_handler, end_element_handler);
+
+    // One would assume it would be faster to have a buffer on the stack and call XML_Parse.
+    // But XML_Parse will call XML_GetBuffer anyway and memmove the passed buffer into it.
+    // (Unless XML_CONTEXT_BYTES is undefined, but all users define it.)
+    // In debug, buffer a small odd number of bytes to detect slicing in XML_CharacterDataHandler.
+    static const int bufferSize = 512 SkDEBUGCODE( - 507);
+    bool done = false;
+    while (!done) {
+        void* buffer = XML_GetBuffer(parser, bufferSize);
+        if (!buffer) {
+            SkDebugf(SK_FONTMGR_ANDROID_PARSER_PREFIX "could not buffer enough to continue\n");
+            return -1;
+        }
+        size_t len = file.read(buffer, bufferSize);
+        done = file.isAtEnd();
+        XML_Status status = XML_ParseBuffer(parser, len, done);
+        if (XML_STATUS_ERROR == status) {
+            XML_Error error = XML_GetErrorCode(parser);
+            int line = XML_GetCurrentLineNumber(parser);
+            int column = XML_GetCurrentColumnNumber(parser);
+            const XML_LChar* errorString = XML_ErrorString(error);
+            SkDebugf(SK_FONTMGR_ANDROID_PARSER_PREFIX "%s:%d:%d error %d: %s.\n",
+                     filename, line, column, error, errorString);
+            return -1;
+        }
+    }
+    return self.fVersion;
+}
+
+/** Returns the version of the system font file actually found, negative if none. */
+static int append_system_font_families(SkTDArray<FontFamily*>& fontFamilies,
+                                       const SkString& basePath)
+{
+    int initialCount = fontFamilies.count();
+    int version = parse_config_file(LMP_SYSTEM_FONTS_FILE, fontFamilies, basePath, false);
+    if (version < 0 || fontFamilies.count() == initialCount) {
+        version = parse_config_file(OLD_SYSTEM_FONTS_FILE, fontFamilies, basePath, false);
+    }
+    return version;
+}
+
+/**
+ * In some versions of Android prior to Android 4.2 (JellyBean MR1 at API
+ * Level 17) the fallback fonts for certain locales were encoded in their own
+ * XML files with a suffix that identified the locale.  We search the provided
+ * directory for those files,add all of their entries to the fallback chain, and
+ * include the locale as part of each entry.
+ */
+static void append_fallback_font_families_for_locale(SkTDArray<FontFamily*>& fallbackFonts,
+                                                     const char* dir,
+                                                     const SkString& basePath)
+{
+#if defined(SK_BUILD_FOR_ANDROID_FRAMEWORK)
+    // The framework is beyond Android 4.2 and can therefore skip this function
+    return;
+#endif
+
+    SkAutoTCallIProc<DIR, closedir> fontDirectory(opendir(dir));
+    if (NULL == fontDirectory) {
+        return;
+    }
+
+    for (struct dirent* dirEntry; (dirEntry = readdir(fontDirectory));) {
+        // The size of the prefix and suffix.
+        static const size_t fixedLen = sizeof(LOCALE_FALLBACK_FONTS_PREFIX) - 1
+                                     + sizeof(LOCALE_FALLBACK_FONTS_SUFFIX) - 1;
+
+        // The size of the prefix, suffix, and a minimum valid language code
+        static const size_t minSize = fixedLen + 2;
+
+        SkString fileName(dirEntry->d_name);
+        if (fileName.size() < minSize ||
+            !fileName.startsWith(LOCALE_FALLBACK_FONTS_PREFIX) ||
+            !fileName.endsWith(LOCALE_FALLBACK_FONTS_SUFFIX))
+        {
+            continue;
+        }
+
+        SkString locale(fileName.c_str() + sizeof(LOCALE_FALLBACK_FONTS_PREFIX) - 1,
+                        fileName.size() - fixedLen);
+
+        SkString absoluteFilename;
+        absoluteFilename.printf("%s/%s", dir, fileName.c_str());
+
+        SkTDArray<FontFamily*> langSpecificFonts;
+        parse_config_file(absoluteFilename.c_str(), langSpecificFonts, basePath, true);
+
+        for (int i = 0; i < langSpecificFonts.count(); ++i) {
+            FontFamily* family = langSpecificFonts[i];
+            family->fLanguage = SkLanguage(locale);
+            *fallbackFonts.append() = family;
+        }
+    }
+}
+
+static void append_system_fallback_font_families(SkTDArray<FontFamily*>& fallbackFonts,
+                                                 const SkString& basePath)
+{
+    parse_config_file(FALLBACK_FONTS_FILE, fallbackFonts, basePath, true);
+    append_fallback_font_families_for_locale(fallbackFonts,
+                                             LOCALE_FALLBACK_FONTS_SYSTEM_DIR,
+                                             basePath);
+}
+
+static void mixin_vendor_fallback_font_families(SkTDArray<FontFamily*>& fallbackFonts,
+                                                const SkString& basePath)
+{
+    SkTDArray<FontFamily*> vendorFonts;
+    parse_config_file(VENDOR_FONTS_FILE, vendorFonts, basePath, true);
+    append_fallback_font_families_for_locale(vendorFonts,
+                                             LOCALE_FALLBACK_FONTS_VENDOR_DIR,
+                                             basePath);
+
+    // This loop inserts the vendor fallback fonts in the correct order in the
+    // overall fallbacks list.
+    int currentOrder = -1;
+    for (int i = 0; i < vendorFonts.count(); ++i) {
+        FontFamily* family = vendorFonts[i];
+        int order = family->fOrder;
+        if (order < 0) {
+            if (currentOrder < 0) {
+                // Default case - just add it to the end of the fallback list
+                *fallbackFonts.append() = family;
+            } else {
+                // no order specified on this font, but we're incrementing the order
+                // based on an earlier order insertion request
+                *fallbackFonts.insert(currentOrder++) = family;
+            }
+        } else {
+            // Add the font into the fallback list in the specified order. Set
+            // currentOrder for correct placement of other fonts in the vendor list.
+            *fallbackFonts.insert(order) = family;
+            currentOrder = order + 1;
+        }
+    }
+}
+
+void SkFontMgr_Android_Parser::GetSystemFontFamilies(SkTDArray<FontFamily*>& fontFamilies) {
+    // Version 21 of the system font configuration does not need any fallback configuration files.
+    SkString basePath(getenv("ANDROID_ROOT"));
+    basePath.append(SK_FONT_FILE_PREFIX, sizeof(SK_FONT_FILE_PREFIX) - 1);
+
+    if (append_system_font_families(fontFamilies, basePath) >= 21) {
+        return;
+    }
+
+    // Append all the fallback fonts to system fonts
+    SkTDArray<FontFamily*> fallbackFonts;
+    append_system_fallback_font_families(fallbackFonts, basePath);
+    mixin_vendor_fallback_font_families(fallbackFonts, basePath);
+    fontFamilies.append(fallbackFonts.count(), fallbackFonts.begin());
+}
+
+void SkFontMgr_Android_Parser::GetCustomFontFamilies(SkTDArray<FontFamily*>& fontFamilies,
+                                                     const SkString& basePath,
+                                                     const char* fontsXml,
+                                                     const char* fallbackFontsXml,
+                                                     const char* langFallbackFontsDir)
+{
+    if (fontsXml) {
+        parse_config_file(fontsXml, fontFamilies, basePath, false);
+    }
+    if (fallbackFontsXml) {
+        parse_config_file(fallbackFontsXml, fontFamilies, basePath, true);
+    }
+    if (langFallbackFontsDir) {
+        append_fallback_font_families_for_locale(fontFamilies,
+                                                 langFallbackFontsDir,
+                                                 basePath);
+    }
+}
+
+SkLanguage SkLanguage::getParent() const {
+    SkASSERT(!fTag.isEmpty());
+    const char* tag = fTag.c_str();
+
+    // strip off the rightmost "-.*"
+    const char* parentTagEnd = strrchr(tag, '-');
+    if (parentTagEnd == NULL) {
+        return SkLanguage();
+    }
+    size_t parentTagLen = parentTagEnd - tag;
+    return SkLanguage(tag, parentTagLen);
+}