Revert "Switch to the new SkSL lexer."

This reverts commit c576e93d174f3106e072a2f506bca3990b541265.

Reason for revert: ASAN failures

Original change's description:
> 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>

TBR=bsalomon@google.com,ethannicholas@google.com

Change-Id: If27b750a5f696d06a6bcffed12fe9f0598e084a6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/44881
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

38 files changed, 97 insertions, 101 deletions

diff --git a/src/sksl/ast/SkSLASTBinaryExpression.h b/src/sksl/ast/SkSLASTBinaryExpression.h
index c2f7b749a5..9a24970262 100644
--- a/src/sksl/ast/SkSLASTBinaryExpression.h
+++ b/src/sksl/ast/SkSLASTBinaryExpression.h
@@ -9,8 +9,7 @@
 #define SKSL_ASTBINARYEXPRESSION
 
 #include "SkSLASTExpression.h"
-#include "../SkSLCompiler.h"
-#include "../SkSLLexer.h"
+#include "../SkSLToken.h"
 
 namespace SkSL {
 
@@ -20,13 +19,13 @@ namespace SkSL {
 struct ASTBinaryExpression : public ASTExpression {
     ASTBinaryExpression(std::unique_ptr<ASTExpression> left, Token op,
                         std::unique_ptr<ASTExpression> right)
-    : INHERITED(op.fOffset, kBinary_Kind)
+    : INHERITED(op.fPosition, kBinary_Kind)
     , fLeft(std::move(left))
     , fOperator(op.fKind)
     , fRight(std::move(right)) {}
 
     String description() const override {
-        return "(" + fLeft->description() + " " + Compiler::OperatorName(fOperator) + " " +
+        return "(" + fLeft->description() + " " + Token::OperatorName(fOperator) + " " +
                fRight->description() + ")";
     }
 
diff --git a/src/sksl/ast/SkSLASTBlock.h b/src/sksl/ast/SkSLASTBlock.h
index df01f62a15..37c0e81a95 100644
--- a/src/sksl/ast/SkSLASTBlock.h
+++ b/src/sksl/ast/SkSLASTBlock.h
@@ -16,8 +16,8 @@ namespace SkSL {
  * Represents a curly-braced block of statements.
  */
 struct ASTBlock : public ASTStatement {
-    ASTBlock(int offset, std::vector<std::unique_ptr<ASTStatement>> statements)
-    : INHERITED(offset, kBlock_Kind)
+    ASTBlock(Position position, std::vector<std::unique_ptr<ASTStatement>> statements)
+    : INHERITED(position, kBlock_Kind)
     , fStatements(std::move(statements)) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTBoolLiteral.h b/src/sksl/ast/SkSLASTBoolLiteral.h
index 6782d36e7e..48e916eed5 100644
--- a/src/sksl/ast/SkSLASTBoolLiteral.h
+++ b/src/sksl/ast/SkSLASTBoolLiteral.h
@@ -16,8 +16,8 @@ namespace SkSL {
  * Represents "true" or "false".
  */
 struct ASTBoolLiteral : public ASTExpression {
-    ASTBoolLiteral(int offset, bool value)
-    : INHERITED(offset, kBool_Kind)
+    ASTBoolLiteral(Position position, bool value)
+    : INHERITED(position, kBool_Kind)
     , fValue(value) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTBreakStatement.h b/src/sksl/ast/SkSLASTBreakStatement.h
index 2937dae447..079ee76d20 100644
--- a/src/sksl/ast/SkSLASTBreakStatement.h
+++ b/src/sksl/ast/SkSLASTBreakStatement.h
@@ -16,8 +16,8 @@ namespace SkSL {
  * A 'break' statement.
  */
 struct ASTBreakStatement : public ASTStatement {
-    ASTBreakStatement(int offset)
-    : INHERITED(offset, kBreak_Kind) {}
+    ASTBreakStatement(Position position)
+    : INHERITED(position, kBreak_Kind) {}
 
     String description() const override {
         return String("break;");
diff --git a/src/sksl/ast/SkSLASTCallSuffix.h b/src/sksl/ast/SkSLASTCallSuffix.h
index 316a0ae7cc..3ba3f0e60f 100644
--- a/src/sksl/ast/SkSLASTCallSuffix.h
+++ b/src/sksl/ast/SkSLASTCallSuffix.h
@@ -17,8 +17,8 @@ namespace SkSL {
  * A parenthesized list of arguments following an expression, indicating a function call.
  */
 struct ASTCallSuffix : public ASTSuffix {
-    ASTCallSuffix(int offset, std::vector<std::unique_ptr<ASTExpression>> arguments)
-    : INHERITED(offset, ASTSuffix::kCall_Kind)
+    ASTCallSuffix(Position position, std::vector<std::unique_ptr<ASTExpression>> arguments)
+    : INHERITED(position, ASTSuffix::kCall_Kind)
     , fArguments(std::move(arguments)) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTContinueStatement.h b/src/sksl/ast/SkSLASTContinueStatement.h
index 30b2dae4ec..fdfce8598d 100644
--- a/src/sksl/ast/SkSLASTContinueStatement.h
+++ b/src/sksl/ast/SkSLASTContinueStatement.h
@@ -16,8 +16,8 @@ namespace SkSL {
  * A 'continue' statement.
  */
 struct ASTContinueStatement : public ASTStatement {
-    ASTContinueStatement(int offset)
-    : INHERITED(offset, kContinue_Kind) {}
+    ASTContinueStatement(Position position)
+    : INHERITED(position, kContinue_Kind) {}
 
     String description() const override {
         return String("continue;");
diff --git a/src/sksl/ast/SkSLASTDeclaration.h b/src/sksl/ast/SkSLASTDeclaration.h
index 53aa65f6f2..873c6b2208 100644
--- a/src/sksl/ast/SkSLASTDeclaration.h
+++ b/src/sksl/ast/SkSLASTDeclaration.h
@@ -26,8 +26,8 @@ struct ASTDeclaration : public ASTPositionNode {
         kSection_Kind
     };
 
-    ASTDeclaration(int offset, Kind kind)
-    : INHERITED(offset)
+    ASTDeclaration(Position position, Kind kind)
+    : INHERITED(position)
     , fKind(kind) {}
 
     Kind fKind;
diff --git a/src/sksl/ast/SkSLASTDiscardStatement.h b/src/sksl/ast/SkSLASTDiscardStatement.h
index 083c3f82d7..dcf6b15e64 100644
--- a/src/sksl/ast/SkSLASTDiscardStatement.h
+++ b/src/sksl/ast/SkSLASTDiscardStatement.h
@@ -16,8 +16,8 @@ namespace SkSL {
  * A 'discard' statement.
  */
 struct ASTDiscardStatement : public ASTStatement {
-    ASTDiscardStatement(int offset)
-    : INHERITED(offset, kDiscard_Kind) {}
+    ASTDiscardStatement(Position position)
+    : INHERITED(position, kDiscard_Kind) {}
 
     String description() const override {
         return String("discard;");
diff --git a/src/sksl/ast/SkSLASTDoStatement.h b/src/sksl/ast/SkSLASTDoStatement.h
index 36324e3685..fc97d9e142 100644
--- a/src/sksl/ast/SkSLASTDoStatement.h
+++ b/src/sksl/ast/SkSLASTDoStatement.h
@@ -16,9 +16,9 @@ namespace SkSL {
  * A 'do' loop.
  */
 struct ASTDoStatement : public ASTStatement {
-    ASTDoStatement(int offset, std::unique_ptr<ASTStatement> statement,
+    ASTDoStatement(Position position, std::unique_ptr<ASTStatement> statement,
                    std::unique_ptr<ASTExpression> test)
-    : INHERITED(offset, kDo_Kind)
+    : INHERITED(position, kDo_Kind)
     , fStatement(std::move(statement))
     , fTest(std::move(test)) {}
 
diff --git a/src/sksl/ast/SkSLASTExpression.h b/src/sksl/ast/SkSLASTExpression.h
index 0d8ddc781f..11815aef84 100644
--- a/src/sksl/ast/SkSLASTExpression.h
+++ b/src/sksl/ast/SkSLASTExpression.h
@@ -27,8 +27,8 @@ struct ASTExpression : public ASTPositionNode {
         kTernary_Kind
     };
 
-    ASTExpression(int offset, Kind kind)
-    : INHERITED(offset)
+    ASTExpression(Position position, Kind kind)
+    : INHERITED(position)
     , fKind(kind) {}
 
     const Kind fKind;
diff --git a/src/sksl/ast/SkSLASTExpressionStatement.h b/src/sksl/ast/SkSLASTExpressionStatement.h
index 14f087f57c..398a16a23a 100644
--- a/src/sksl/ast/SkSLASTExpressionStatement.h
+++ b/src/sksl/ast/SkSLASTExpressionStatement.h
@@ -17,7 +17,7 @@ namespace SkSL {
  */
 struct ASTExpressionStatement : public ASTStatement {
     ASTExpressionStatement(std::unique_ptr<ASTExpression> expression)
-    : INHERITED(expression->fOffset, kExpression_Kind)
+    : INHERITED(expression->fPosition, kExpression_Kind)
     , fExpression(std::move(expression)) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTExtension.h b/src/sksl/ast/SkSLASTExtension.h
index c394b1d4d0..a6fde0694c 100644
--- a/src/sksl/ast/SkSLASTExtension.h
+++ b/src/sksl/ast/SkSLASTExtension.h
@@ -16,8 +16,8 @@ namespace SkSL {
  * An extension declaration.
  */
 struct ASTExtension : public ASTDeclaration {
-    ASTExtension(int offset, String name)
-    : INHERITED(offset, kExtension_Kind)
+    ASTExtension(Position position, String name)
+    : INHERITED(position, kExtension_Kind)
     , fName(std::move(name)) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTFieldSuffix.h b/src/sksl/ast/SkSLASTFieldSuffix.h
index b29ddf3bda..bde1e4aec5 100644
--- a/src/sksl/ast/SkSLASTFieldSuffix.h
+++ b/src/sksl/ast/SkSLASTFieldSuffix.h
@@ -17,15 +17,15 @@ namespace SkSL {
  * actually vector swizzle (which looks the same to the parser).
  */
 struct ASTFieldSuffix : public ASTSuffix {
-    ASTFieldSuffix(int offset, StringFragment field)
-    : INHERITED(offset, ASTSuffix::kField_Kind)
-    , fField(field) {}
+    ASTFieldSuffix(Position position, String field)
+    : INHERITED(position, ASTSuffix::kField_Kind)
+    , fField(std::move(field)) {}
 
     String description() const override {
         return "." + fField;
     }
 
-    StringFragment fField;
+    String fField;
 
     typedef ASTSuffix INHERITED;
 };
diff --git a/src/sksl/ast/SkSLASTFloatLiteral.h b/src/sksl/ast/SkSLASTFloatLiteral.h
index 6e63b4e4ca..15fe836049 100644
--- a/src/sksl/ast/SkSLASTFloatLiteral.h
+++ b/src/sksl/ast/SkSLASTFloatLiteral.h
@@ -16,8 +16,8 @@ namespace SkSL {
  * A literal floating point number.
  */
 struct ASTFloatLiteral : public ASTExpression {
-    ASTFloatLiteral(int offset, double value)
-    : INHERITED(offset, kFloat_Kind)
+    ASTFloatLiteral(Position position, double value)
+    : INHERITED(position, kFloat_Kind)
     , fValue(value) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTForStatement.h b/src/sksl/ast/SkSLASTForStatement.h
index 713f9522f7..326713eb62 100644
--- a/src/sksl/ast/SkSLASTForStatement.h
+++ b/src/sksl/ast/SkSLASTForStatement.h
@@ -16,10 +16,10 @@ namespace SkSL {
  * A 'for' loop.
  */
 struct ASTForStatement : public ASTStatement {
-    ASTForStatement(int offset, std::unique_ptr<ASTStatement> initializer,
+    ASTForStatement(Position position, std::unique_ptr<ASTStatement> initializer,
                    std::unique_ptr<ASTExpression> test, std::unique_ptr<ASTExpression> next,
                    std::unique_ptr<ASTStatement> statement)
-    : INHERITED(offset, kFor_Kind)
+    : INHERITED(position, kFor_Kind)
     , fInitializer(std::move(initializer))
     , fTest(std::move(test))
     , fNext(std::move(next))
diff --git a/src/sksl/ast/SkSLASTFunction.h b/src/sksl/ast/SkSLASTFunction.h
index 4fa2482d8b..36d8a3af9f 100644
--- a/src/sksl/ast/SkSLASTFunction.h
+++ b/src/sksl/ast/SkSLASTFunction.h
@@ -19,13 +19,13 @@ namespace SkSL {
  * A function declaration or definition. The fBody field will be null for declarations.
  */
 struct ASTFunction : public ASTDeclaration {
-    ASTFunction(int offset, Modifiers modifiers,  std::unique_ptr<ASTType> returnType,
-                StringFragment name, std::vector<std::unique_ptr<ASTParameter>> parameters,
+    ASTFunction(Position position, Modifiers modifiers,  std::unique_ptr<ASTType> returnType,
+                String name, std::vector<std::unique_ptr<ASTParameter>> parameters,
                 std::unique_ptr<ASTBlock> body)
-    : INHERITED(offset, kFunction_Kind)
+    : INHERITED(position, kFunction_Kind)
     , fModifiers(modifiers)
     , fReturnType(std::move(returnType))
-    , fName(name)
+    , fName(std::move(name))
     , fParameters(std::move(parameters))
     , fBody(std::move(body)) {}
 
@@ -47,7 +47,7 @@ struct ASTFunction : public ASTDeclaration {
 
     const Modifiers fModifiers;
     const std::unique_ptr<ASTType> fReturnType;
-    const StringFragment fName;
+    const String fName;
     const std::vector<std::unique_ptr<ASTParameter>> fParameters;
     const std::unique_ptr<ASTBlock> fBody;
 
diff --git a/src/sksl/ast/SkSLASTIdentifier.h b/src/sksl/ast/SkSLASTIdentifier.h
index a84370ec3f..016123cf8c 100644
--- a/src/sksl/ast/SkSLASTIdentifier.h
+++ b/src/sksl/ast/SkSLASTIdentifier.h
@@ -16,15 +16,15 @@ namespace SkSL {
  * An identifier in an expression context.
  */
 struct ASTIdentifier : public ASTExpression {
-    ASTIdentifier(int offset, StringFragment text)
-    : INHERITED(offset, kIdentifier_Kind)
-    , fText(text) {}
+    ASTIdentifier(Position position, String text)
+    : INHERITED(position, kIdentifier_Kind)
+    , fText(std::move(text)) {}
 
     String description() const override {
-        return String(fText);
+        return fText;
     }
 
-    const StringFragment fText;
+    const String fText;
 
     typedef ASTExpression INHERITED;
 };
diff --git a/src/sksl/ast/SkSLASTIfStatement.h b/src/sksl/ast/SkSLASTIfStatement.h
index 85b1239e0b..2752b2b750 100644
--- a/src/sksl/ast/SkSLASTIfStatement.h
+++ b/src/sksl/ast/SkSLASTIfStatement.h
@@ -16,9 +16,9 @@ namespace SkSL {
  * An 'if' statement.
  */
 struct ASTIfStatement : public ASTStatement {
-    ASTIfStatement(int offset, bool isStatic, std::unique_ptr<ASTExpression> test,
+    ASTIfStatement(Position position, bool isStatic, std::unique_ptr<ASTExpression> test,
                    std::unique_ptr<ASTStatement> ifTrue, std::unique_ptr<ASTStatement> ifFalse)
-    : INHERITED(offset, kIf_Kind)
+    : INHERITED(position, kIf_Kind)
     , fIsStatic(isStatic)
     , fTest(std::move(test))
     , fIfTrue(std::move(ifTrue))
diff --git a/src/sksl/ast/SkSLASTIndexSuffix.h b/src/sksl/ast/SkSLASTIndexSuffix.h
index cb19e549ef..31142e3685 100644
--- a/src/sksl/ast/SkSLASTIndexSuffix.h
+++ b/src/sksl/ast/SkSLASTIndexSuffix.h
@@ -18,12 +18,12 @@ namespace SkSL {
  * 'float[](5, 6)' are represented with a null fExpression.
  */
 struct ASTIndexSuffix : public ASTSuffix {
-    ASTIndexSuffix(int offset)
-    : INHERITED(offset, ASTSuffix::kIndex_Kind)
+    ASTIndexSuffix(Position position)
+    : INHERITED(position, ASTSuffix::kIndex_Kind)
     , fExpression(nullptr) {}
 
     ASTIndexSuffix(std::unique_ptr<ASTExpression> expression)
-    : INHERITED(expression ? expression->fOffset : -1, ASTSuffix::kIndex_Kind)
+    : INHERITED(expression ? expression->fPosition : Position(), ASTSuffix::kIndex_Kind)
     , fExpression(std::move(expression)) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTIntLiteral.h b/src/sksl/ast/SkSLASTIntLiteral.h
index 927537b250..fe04347fd8 100644
--- a/src/sksl/ast/SkSLASTIntLiteral.h
+++ b/src/sksl/ast/SkSLASTIntLiteral.h
@@ -17,8 +17,8 @@ namespace SkSL {
  * appear as a unary minus being applied to an integer literal.
  */
 struct ASTIntLiteral : public ASTExpression {
-    ASTIntLiteral(int offset, uint64_t value)
-    : INHERITED(offset, kInt_Kind)
+    ASTIntLiteral(Position position, uint64_t value)
+    : INHERITED(position, kInt_Kind)
     , fValue(value) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTInterfaceBlock.h b/src/sksl/ast/SkSLASTInterfaceBlock.h
index d445ae0398..f111f73e18 100644
--- a/src/sksl/ast/SkSLASTInterfaceBlock.h
+++ b/src/sksl/ast/SkSLASTInterfaceBlock.h
@@ -23,17 +23,17 @@ namespace SkSL {
  */
 struct ASTInterfaceBlock : public ASTDeclaration {
     // valueName is empty when it was not present in the source
-    ASTInterfaceBlock(int offset,
+    ASTInterfaceBlock(Position position,
                       Modifiers modifiers,
-                      StringFragment typeName,
+                      String typeName,
                       std::vector<std::unique_ptr<ASTVarDeclarations>> declarations,
-                      StringFragment instanceName,
+                      String instanceName,
                       std::vector<std::unique_ptr<ASTExpression>> sizes)
-    : INHERITED(offset, kInterfaceBlock_Kind)
+    : INHERITED(position, kInterfaceBlock_Kind)
     , fModifiers(modifiers)
-    , fTypeName(typeName)
+    , fTypeName(std::move(typeName))
     , fDeclarations(std::move(declarations))
-    , fInstanceName(instanceName)
+    , fInstanceName(std::move(instanceName))
     , fSizes(std::move(sizes)) {}
 
     String description() const override {
@@ -42,7 +42,7 @@ struct ASTInterfaceBlock : public ASTDeclaration {
             result += fDeclarations[i]->description() + "\n";
         }
         result += "}";
-        if (fInstanceName.fLength) {
+        if (fInstanceName.size()) {
             result += " " + fInstanceName;
             for (const auto& size : fSizes) {
                 result += "[";
@@ -56,9 +56,9 @@ struct ASTInterfaceBlock : public ASTDeclaration {
     }
 
     const Modifiers fModifiers;
-    const StringFragment fTypeName;
+    const String fTypeName;
     const std::vector<std::unique_ptr<ASTVarDeclarations>> fDeclarations;
-    const StringFragment fInstanceName;
+    const String fInstanceName;
     const std::vector<std::unique_ptr<ASTExpression>> fSizes;
 
     typedef ASTDeclaration INHERITED;
diff --git a/src/sksl/ast/SkSLASTModifiersDeclaration.h b/src/sksl/ast/SkSLASTModifiersDeclaration.h
index 5269cd54d4..ba07f168b2 100644
--- a/src/sksl/ast/SkSLASTModifiersDeclaration.h
+++ b/src/sksl/ast/SkSLASTModifiersDeclaration.h
@@ -20,7 +20,7 @@ namespace SkSL {
  */
 struct ASTModifiersDeclaration : public ASTDeclaration {
     ASTModifiersDeclaration(Modifiers modifiers)
-    : INHERITED(-1, kModifiers_Kind)
+    : INHERITED(Position(), kModifiers_Kind)
     , fModifiers(modifiers) {}
 
     String description() const {
diff --git a/src/sksl/ast/SkSLASTParameter.h b/src/sksl/ast/SkSLASTParameter.h
index 965e374540..01227c637e 100644
--- a/src/sksl/ast/SkSLASTParameter.h
+++ b/src/sksl/ast/SkSLASTParameter.h
@@ -20,12 +20,12 @@ namespace SkSL {
 struct ASTParameter : public ASTPositionNode {
     // 'sizes' is a list of the array sizes appearing on a parameter, in source order.
     // e.g. int x[3][1] would have sizes [3, 1].
-    ASTParameter(int offset, Modifiers modifiers, std::unique_ptr<ASTType> type,
-                 StringFragment name, std::vector<int> sizes)
-    : INHERITED(offset)
+    ASTParameter(Position position, Modifiers modifiers, std::unique_ptr<ASTType> type,
+                 String name, std::vector<int> sizes)
+    : INHERITED(position)
     , fModifiers(modifiers)
     , fType(std::move(type))
-    , fName(name)
+    , fName(std::move(name))
     , fSizes(std::move(sizes)) {}
 
     String description() const override {
@@ -38,7 +38,7 @@ struct ASTParameter : public ASTPositionNode {
 
     const Modifiers fModifiers;
     const std::unique_ptr<ASTType> fType;
-    const StringFragment fName;
+    const String fName;
     const std::vector<int> fSizes;
 
     typedef ASTPositionNode INHERITED;
diff --git a/src/sksl/ast/SkSLASTPositionNode.h b/src/sksl/ast/SkSLASTPositionNode.h
index b8f22a765b..cc435c486c 100644
--- a/src/sksl/ast/SkSLASTPositionNode.h
+++ b/src/sksl/ast/SkSLASTPositionNode.h
@@ -17,12 +17,10 @@ namespace SkSL {
  * An AST node with an associated position in the source.
  */
 struct ASTPositionNode : public ASTNode {
-    ASTPositionNode(int offset)
-    : fOffset(offset) {}
+    ASTPositionNode(Position position)
+    : fPosition(position) {}
 
-    // character offset of this element within the program being compiled, for error reporting
-    // purposes
-    const int fOffset;
+    const Position fPosition;
 };
 
 } // namespace
diff --git a/src/sksl/ast/SkSLASTPrecision.h b/src/sksl/ast/SkSLASTPrecision.h
index 0b81ca3887..4b50ed3979 100644
--- a/src/sksl/ast/SkSLASTPrecision.h
+++ b/src/sksl/ast/SkSLASTPrecision.h
@@ -18,8 +18,8 @@ namespace SkSL {
  */
 struct ASTPrecision : public ASTDeclaration {
     // FIXME handle the type
-    ASTPrecision(int offset, Modifiers::Flag precision)
-    : INHERITED(offset, kPrecision_Kind)
+    ASTPrecision(Position position, Modifiers::Flag precision)
+    : INHERITED(position, kPrecision_Kind)
     , fPrecision(precision) {}
 
     String description() const {
diff --git a/src/sksl/ast/SkSLASTPrefixExpression.h b/src/sksl/ast/SkSLASTPrefixExpression.h
index 0403a2f172..08e50f7bf1 100644
--- a/src/sksl/ast/SkSLASTPrefixExpression.h
+++ b/src/sksl/ast/SkSLASTPrefixExpression.h
@@ -9,8 +9,7 @@
 #define SKSL_ASTPREFIXEXPRESSION
 
 #include "SkSLASTExpression.h"
-#include "../SkSLCompiler.h"
-#include "../SkSLLexer.h"
+#include "../SkSLToken.h"
 
 namespace SkSL {
 
@@ -19,12 +18,12 @@ namespace SkSL {
  */
 struct ASTPrefixExpression : public ASTExpression {
     ASTPrefixExpression(Token op, std::unique_ptr<ASTExpression> operand)
-    : INHERITED(op.fOffset, kPrefix_Kind)
+    : INHERITED(op.fPosition, kPrefix_Kind)
     , fOperator(op.fKind)
     , fOperand(std::move(operand)) {}
 
     String description() const override {
-        return Compiler::OperatorName(fOperator) + fOperand->description();
+        return Token::OperatorName(fOperator) + fOperand->description();
     }
 
     const Token::Kind fOperator;
diff --git a/src/sksl/ast/SkSLASTReturnStatement.h b/src/sksl/ast/SkSLASTReturnStatement.h
index 489658a78b..6762eb3f90 100644
--- a/src/sksl/ast/SkSLASTReturnStatement.h
+++ b/src/sksl/ast/SkSLASTReturnStatement.h
@@ -17,8 +17,8 @@ namespace SkSL {
  */
 struct ASTReturnStatement : public ASTStatement {
     // expression may be null
-    ASTReturnStatement(int offset, std::unique_ptr<ASTExpression> expression)
-    : INHERITED(offset, kReturn_Kind)
+    ASTReturnStatement(Position position, std::unique_ptr<ASTExpression> expression)
+    : INHERITED(position, kReturn_Kind)
     , fExpression(std::move(expression)) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTSection.h b/src/sksl/ast/SkSLASTSection.h
index 6c1f8eefa2..d0887e20fe 100644
--- a/src/sksl/ast/SkSLASTSection.h
+++ b/src/sksl/ast/SkSLASTSection.h
@@ -16,8 +16,8 @@ namespace SkSL {
  * A section declaration (e.g. @body { body code here })..
  */
 struct ASTSection : public ASTDeclaration {
-    ASTSection(int offset, String name, String arg, String text)
-    : INHERITED(offset, kSection_Kind)
+    ASTSection(Position position, String name, String arg, String text)
+    : INHERITED(position, kSection_Kind)
     , fName(std::move(name))
     , fArgument(std::move(arg))
     , fText(std::move(text)) {}
diff --git a/src/sksl/ast/SkSLASTStatement.h b/src/sksl/ast/SkSLASTStatement.h
index c22a2fbb0a..1989a1fce6 100644
--- a/src/sksl/ast/SkSLASTStatement.h
+++ b/src/sksl/ast/SkSLASTStatement.h
@@ -33,8 +33,8 @@ struct ASTStatement : public ASTPositionNode {
         kDiscard_Kind
     };
 
-    ASTStatement(int offset, Kind kind)
-    : INHERITED(offset)
+    ASTStatement(Position position, Kind kind)
+    : INHERITED(position)
     , fKind(kind) {}
 
     Kind fKind;
diff --git a/src/sksl/ast/SkSLASTSuffix.h b/src/sksl/ast/SkSLASTSuffix.h
index 898855c478..f06c6fd362 100644
--- a/src/sksl/ast/SkSLASTSuffix.h
+++ b/src/sksl/ast/SkSLASTSuffix.h
@@ -26,8 +26,8 @@ struct ASTSuffix : public ASTPositionNode {
         kPostDecrement_Kind
     };
 
-    ASTSuffix(int offset, Kind kind)
-    : INHERITED(offset)
+    ASTSuffix(Position position, Kind kind)
+    : INHERITED(position)
     , fKind(kind) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTSuffixExpression.h b/src/sksl/ast/SkSLASTSuffixExpression.h
index 31cddb29d1..2cff9a865f 100644
--- a/src/sksl/ast/SkSLASTSuffixExpression.h
+++ b/src/sksl/ast/SkSLASTSuffixExpression.h
@@ -18,7 +18,7 @@ namespace SkSL {
  */
 struct ASTSuffixExpression : public ASTExpression {
     ASTSuffixExpression(std::unique_ptr<ASTExpression> base, std::unique_ptr<ASTSuffix> suffix)
-    : INHERITED(base->fOffset, kSuffix_Kind)
+    : INHERITED(base->fPosition, kSuffix_Kind)
     , fBase(std::move(base))
     , fSuffix(std::move(suffix)) {}
 
diff --git a/src/sksl/ast/SkSLASTSwitchCase.h b/src/sksl/ast/SkSLASTSwitchCase.h
index 221e2128ed..405013a6a7 100644
--- a/src/sksl/ast/SkSLASTSwitchCase.h
+++ b/src/sksl/ast/SkSLASTSwitchCase.h
@@ -17,9 +17,9 @@ namespace SkSL {
  */
 struct ASTSwitchCase : public ASTStatement {
     // a null value means "default:"
-    ASTSwitchCase(int offset, std::unique_ptr<ASTExpression> value,
+    ASTSwitchCase(Position position, std::unique_ptr<ASTExpression> value,
                   std::vector<std::unique_ptr<ASTStatement>> statements)
-    : INHERITED(offset, kSwitch_Kind)
+    : INHERITED(position, kSwitch_Kind)
     , fValue(std::move(value))
     , fStatements(std::move(statements)) {}
 
diff --git a/src/sksl/ast/SkSLASTSwitchStatement.h b/src/sksl/ast/SkSLASTSwitchStatement.h
index 3bee0a4728..ecd0a6755d 100644
--- a/src/sksl/ast/SkSLASTSwitchStatement.h
+++ b/src/sksl/ast/SkSLASTSwitchStatement.h
@@ -17,9 +17,9 @@ namespace SkSL {
  * A 'switch' statement.
  */
 struct ASTSwitchStatement : public ASTStatement {
-    ASTSwitchStatement(int offset, bool isStatic, std::unique_ptr<ASTExpression> value,
+    ASTSwitchStatement(Position position, bool isStatic, std::unique_ptr<ASTExpression> value,
                        std::vector<std::unique_ptr<ASTSwitchCase>> cases)
-    : INHERITED(offset, kSwitch_Kind)
+    : INHERITED(position, kSwitch_Kind)
     , fIsStatic(isStatic)
     , fValue(std::move(value))
     , fCases(std::move(cases)) {}
diff --git a/src/sksl/ast/SkSLASTTernaryExpression.h b/src/sksl/ast/SkSLASTTernaryExpression.h
index 35795e9f12..07c92975e0 100644
--- a/src/sksl/ast/SkSLASTTernaryExpression.h
+++ b/src/sksl/ast/SkSLASTTernaryExpression.h
@@ -19,7 +19,7 @@ struct ASTTernaryExpression : public ASTExpression {
     ASTTernaryExpression(std::unique_ptr<ASTExpression> test,
                          std::unique_ptr<ASTExpression> ifTrue,
                          std::unique_ptr<ASTExpression> ifFalse)
-    : INHERITED(test->fOffset, kTernary_Kind)
+    : INHERITED(test->fPosition, kTernary_Kind)
     , fTest(std::move(test))
     , fIfTrue(std::move(ifTrue))
     , fIfFalse(std::move(ifFalse)) {}
diff --git a/src/sksl/ast/SkSLASTType.h b/src/sksl/ast/SkSLASTType.h
index 44fd95bdc7..57a8025b7b 100644
--- a/src/sksl/ast/SkSLASTType.h
+++ b/src/sksl/ast/SkSLASTType.h
@@ -21,9 +21,9 @@ struct ASTType : public ASTPositionNode {
         kStruct_Kind
     };
 
-    ASTType(int offset, StringFragment name, Kind kind, std::vector<int> sizes)
-    : INHERITED(offset)
-    , fName(name)
+    ASTType(Position position, String name, Kind kind, std::vector<int> sizes)
+    : INHERITED(position)
+    , fName(std::move(name))
     , fKind(kind)
     , fSizes(std::move(sizes)) {}
 
@@ -31,7 +31,7 @@ struct ASTType : public ASTPositionNode {
         return fName;
     }
 
-    const StringFragment fName;
+    const String fName;
 
     const Kind fKind;
 
diff --git a/src/sksl/ast/SkSLASTVarDeclaration.h b/src/sksl/ast/SkSLASTVarDeclaration.h
index 38c9104865..2dcb9787ea 100644
--- a/src/sksl/ast/SkSLASTVarDeclaration.h
+++ b/src/sksl/ast/SkSLASTVarDeclaration.h
@@ -22,7 +22,7 @@ namespace SkSL {
  * instances.
  */
 struct ASTVarDeclaration {
-    ASTVarDeclaration(StringFragment name,
+    ASTVarDeclaration(const String name,
                       std::vector<std::unique_ptr<ASTExpression>> sizes,
                       std::unique_ptr<ASTExpression> value)
     : fName(name)
@@ -30,7 +30,7 @@ struct ASTVarDeclaration {
     , fValue(std::move(value)) {}
 
     String description() const {
-        String result(fName);
+        String result = fName;
         for (const auto& size : fSizes) {
             if (size) {
                 result += "[" + size->description() + "]";
@@ -44,7 +44,7 @@ struct ASTVarDeclaration {
         return result;
     }
 
-    StringFragment fName;
+    String fName;
 
     // array sizes, if any. e.g. 'foo[3][]' has sizes [3, null]
     std::vector<std::unique_ptr<ASTExpression>> fSizes;
@@ -60,7 +60,7 @@ struct ASTVarDeclarations : public ASTDeclaration {
     ASTVarDeclarations(Modifiers modifiers,
                        std::unique_ptr<ASTType> type,
                        std::vector<ASTVarDeclaration> vars)
-    : INHERITED(type->fOffset, kVar_Kind)
+    : INHERITED(type->fPosition, kVar_Kind)
     , fModifiers(modifiers)
     , fType(std::move(type))
     , fVars(std::move(vars)) {}
diff --git a/src/sksl/ast/SkSLASTVarDeclarationStatement.h b/src/sksl/ast/SkSLASTVarDeclarationStatement.h
index 8ec5bf6789..c3a4069ba0 100644
--- a/src/sksl/ast/SkSLASTVarDeclarationStatement.h
+++ b/src/sksl/ast/SkSLASTVarDeclarationStatement.h
@@ -18,7 +18,7 @@ namespace SkSL {
  */
 struct ASTVarDeclarationStatement : public ASTStatement {
     ASTVarDeclarationStatement(std::unique_ptr<ASTVarDeclarations> decl)
-    : INHERITED(decl->fOffset, kVarDeclaration_Kind)
+    : INHERITED(decl->fPosition, kVarDeclaration_Kind)
     , fDeclarations(std::move(decl)) {}
 
     String description() const override {
diff --git a/src/sksl/ast/SkSLASTWhileStatement.h b/src/sksl/ast/SkSLASTWhileStatement.h
index c0da0afb7d..e63c50293a 100644
--- a/src/sksl/ast/SkSLASTWhileStatement.h
+++ b/src/sksl/ast/SkSLASTWhileStatement.h
@@ -16,9 +16,9 @@ namespace SkSL {
  * A 'while' statement.
  */
 struct ASTWhileStatement : public ASTStatement {
-    ASTWhileStatement(int offset, std::unique_ptr<ASTExpression> test,
+    ASTWhileStatement(Position position, std::unique_ptr<ASTExpression> test,
                       std::unique_ptr<ASTStatement> statement)
-    : INHERITED(offset, kWhile_Kind)
+    : INHERITED(position, kWhile_Kind)
     , fTest(std::move(test))
     , fStatement(std::move(statement)) {}