Switch to the new SkSL lexer.

This completely replaces flex with a new in-house lexical analyzer generator,
which we have done for performance and memory usage reasons. Flex requires us
to copy strings every time we need the text of a token, whereas this new lexer
allows us to handle strings as a (non-null-terminated) pointer and length
everywhere, eliminating most string copies.

Bug: skia:
Change-Id: I2add26efc9e20cb699520e82abcf713af3968aca
Reviewed-on: https://skia-review.googlesource.com/39780
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

1 files changed, 238 insertions, 0 deletions

diff --git a/src/sksl/SkSLLexer.h b/src/sksl/SkSLLexer.h
new file mode 100644
index 0000000000..246be22b9e
--- /dev/null
+++ b/src/sksl/SkSLLexer.h
@@ -0,0 +1,238 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+/*****************************************************************************************
+ ******************** This file was generated by sksllex. Do not edit. *******************
+ *****************************************************************************************/
+#ifndef SKSL_Lexer
+#define SKSL_Lexer
+#include <cstddef>
+#include <cstdint>
+namespace SkSL {
+
+struct Token {
+    enum Kind {
+#undef END_OF_FILE
+        END_OF_FILE,
+#undef FLOAT_LITERAL
+        FLOAT_LITERAL,
+#undef INT_LITERAL
+        INT_LITERAL,
+#undef TRUE_LITERAL
+        TRUE_LITERAL,
+#undef FALSE_LITERAL
+        FALSE_LITERAL,
+#undef IF
+        IF,
+#undef STATIC_IF
+        STATIC_IF,
+#undef ELSE
+        ELSE,
+#undef FOR
+        FOR,
+#undef WHILE
+        WHILE,
+#undef DO
+        DO,
+#undef SWITCH
+        SWITCH,
+#undef STATIC_SWITCH
+        STATIC_SWITCH,
+#undef CASE
+        CASE,
+#undef DEFAULT
+        DEFAULT,
+#undef BREAK
+        BREAK,
+#undef CONTINUE
+        CONTINUE,
+#undef DISCARD
+        DISCARD,
+#undef RETURN
+        RETURN,
+#undef IN
+        IN,
+#undef OUT
+        OUT,
+#undef INOUT
+        INOUT,
+#undef UNIFORM
+        UNIFORM,
+#undef CONST
+        CONST,
+#undef LOWP
+        LOWP,
+#undef MEDIUMP
+        MEDIUMP,
+#undef HIGHP
+        HIGHP,
+#undef FLAT
+        FLAT,
+#undef NOPERSPECTIVE
+        NOPERSPECTIVE,
+#undef READONLY
+        READONLY,
+#undef WRITEONLY
+        WRITEONLY,
+#undef COHERENT
+        COHERENT,
+#undef VOLATILE
+        VOLATILE,
+#undef RESTRICT
+        RESTRICT,
+#undef BUFFER
+        BUFFER,
+#undef HASSIDEEFFECTS
+        HASSIDEEFFECTS,
+#undef STRUCT
+        STRUCT,
+#undef LAYOUT
+        LAYOUT,
+#undef PRECISION
+        PRECISION,
+#undef IDENTIFIER
+        IDENTIFIER,
+#undef DIRECTIVE
+        DIRECTIVE,
+#undef SECTION
+        SECTION,
+#undef LPAREN
+        LPAREN,
+#undef RPAREN
+        RPAREN,
+#undef LBRACE
+        LBRACE,
+#undef RBRACE
+        RBRACE,
+#undef LBRACKET
+        LBRACKET,
+#undef RBRACKET
+        RBRACKET,
+#undef DOT
+        DOT,
+#undef COMMA
+        COMMA,
+#undef PLUSPLUS
+        PLUSPLUS,
+#undef MINUSMINUS
+        MINUSMINUS,
+#undef PLUS
+        PLUS,
+#undef MINUS
+        MINUS,
+#undef STAR
+        STAR,
+#undef SLASH
+        SLASH,
+#undef PERCENT
+        PERCENT,
+#undef SHL
+        SHL,
+#undef SHR
+        SHR,
+#undef BITWISEOR
+        BITWISEOR,
+#undef BITWISEXOR
+        BITWISEXOR,
+#undef BITWISEAND
+        BITWISEAND,
+#undef BITWISENOT
+        BITWISENOT,
+#undef LOGICALOR
+        LOGICALOR,
+#undef LOGICALXOR
+        LOGICALXOR,
+#undef LOGICALAND
+        LOGICALAND,
+#undef LOGICALNOT
+        LOGICALNOT,
+#undef QUESTION
+        QUESTION,
+#undef COLON
+        COLON,
+#undef EQ
+        EQ,
+#undef EQEQ
+        EQEQ,
+#undef NEQ
+        NEQ,
+#undef GT
+        GT,
+#undef LT
+        LT,
+#undef GTEQ
+        GTEQ,
+#undef LTEQ
+        LTEQ,
+#undef PLUSEQ
+        PLUSEQ,
+#undef MINUSEQ
+        MINUSEQ,
+#undef STAREQ
+        STAREQ,
+#undef SLASHEQ
+        SLASHEQ,
+#undef PERCENTEQ
+        PERCENTEQ,
+#undef SHLEQ
+        SHLEQ,
+#undef SHREQ
+        SHREQ,
+#undef BITWISEOREQ
+        BITWISEOREQ,
+#undef BITWISEXOREQ
+        BITWISEXOREQ,
+#undef BITWISEANDEQ
+        BITWISEANDEQ,
+#undef LOGICALOREQ
+        LOGICALOREQ,
+#undef LOGICALXOREQ
+        LOGICALXOREQ,
+#undef LOGICALANDEQ
+        LOGICALANDEQ,
+#undef SEMICOLON
+        SEMICOLON,
+#undef ARROW
+        ARROW,
+#undef COLONCOLON
+        COLONCOLON,
+#undef WHITESPACE
+        WHITESPACE,
+#undef LINE_COMMENT
+        LINE_COMMENT,
+#undef BLOCK_COMMENT
+        BLOCK_COMMENT,
+#undef INVALID
+        INVALID,
+    };
+
+    Token() : fKind(Kind::INVALID), fOffset(-1), fLength(-1) {}
+
+    Token(Kind kind, int offset, int length) : fKind(kind), fOffset(offset), fLength(length) {}
+
+    Kind fKind;
+    int fOffset;
+    int fLength;
+};
+
+class Lexer {
+public:
+    void start(const char* text, size_t length) {
+        fText = text;
+        fLength = length;
+        fOffset = 0;
+    }
+
+    Token next();
+
+private:
+    const char* fText;
+    int fLength;
+    int fOffset;
+};
+
+}  // namespace
+#endif