Add support for parsing LSL from an in-memory buffer

fuzz/fuzz.cc

@@ -26,7 +26,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
 
   Tailslide::ScopedScriptParser parser(nullptr);
   try {
-    auto *script = parser.parseLSL(file);
+    auto *script = parser.parseLSLFile(file);
     if (script) {
       script->collectSymbols();
       script->determineTypes();

libtailslide/lslmini.hh

@@ -44,6 +44,7 @@ struct ScriptContext {
   // any nodes created while this is false will be considered synthetic by default
   bool parsing = false;
   Tailslide::TailslideLType glloc {0};
+  void *scanner = nullptr;
 };
 
 struct Vector3 {

libtailslide/passes/desugaring.cc

@@ -4,7 +4,7 @@
 namespace Tailslide {
 
 // any time an int appears in a binary expression with these it must be promoted
-std::vector<LSLIType> SIBLINGS_CAUSING_INT_PROMOTION = {
+static const std::vector<LSLIType> SIBLINGS_CAUSING_INT_PROMOTION = {
     LST_FLOATINGPOINT,
     LST_VECTOR,
     LST_QUATERNION,

libtailslide/tailslide.cc

@@ -4,8 +4,8 @@
 #include "lslmini.tab.hh"
 
 int tailslide_lex_init_extra(Tailslide::ScriptContext *, void **);
-
 void tailslide_set_in(FILE *, void *);
+void *tailslide__scan_bytes ( const char *bytes, int len, void *);
 
 int tailslide_lex_destroy(void *);
 
@@ -31,43 +31,54 @@ class FileCloser {
     FILE *_mFile;
 };
 
-LSLScript *ScopedScriptParser::parseLSL(const std::string &filename) {
+LSLScript *ScopedScriptParser::parseLSLFile(const std::string &filename) {
   // can only be used to parse a single script.
   assert(!script);
   FILE *yyin = fopen(filename.c_str(), "rb");
   if (yyin == nullptr) {
     throw "couldn't open file";
   }
   FileCloser closer(yyin);
-  auto result = parseLSL(yyin);
-  return result;
+  return parseLSLFile(yyin);
+}
+
+LSLScript *ScopedScriptParser::parseLSLFile(FILE *yyin) {
+  initScanner();
+  // set input file
+  tailslide_set_in(yyin, context.scanner);
+  parseInternal();
+  return script;
+}
+
+LSLScript *ScopedScriptParser::parseLSLBytes(const char *buf, int buf_len) {
+  initScanner();
+  // set input file
+  tailslide__scan_bytes(buf, buf_len, context.scanner);
+  parseInternal();
+  return script;
 }
 
-LSLScript *ScopedScriptParser::parseLSL(FILE *yyin) {
+void ScopedScriptParser::initScanner() {
   assert(!script);
-  void *scanner;
   // ScopedScriptParser owns the allocator and context instance because we can't
   // reasonably re-use Allocator instances with our current model of having
   // it magically pass along the current script context.
   allocator.setContext(&context);
 
   // initialize flex
-  tailslide_lex_init_extra(&context, &scanner);
-
-  // set input file
-  tailslide_set_in(yyin, scanner);
+  tailslide_lex_init_extra(&context, &context.scanner);
+}
 
+void ScopedScriptParser::parseInternal() {
   // parse
   context.parsing = true;
-  tailslide_parse(scanner);
+  tailslide_parse(context.scanner);
   context.parsing = false;
 
   // clean up flex
-  tailslide_lex_destroy(scanner);
+  tailslide_lex_destroy(context.scanner);
   ast_sane = context.ast_sane;
   script = context.script;
-
-  return script;
 }
 
 }

libtailslide/tailslide.hh

@@ -22,8 +22,13 @@ struct ScopedScriptParser {
     ScriptContext context;
     LSLSymbolTableManager table_manager;
 
-    LSLScript *parseLSL(FILE *yyin);
-    LSLScript *parseLSL(const std::string &filename);
+    LSLScript *parseLSLFile(FILE *yyin);
+    LSLScript *parseLSLFile(const std::string &filename);
+    LSLScript *parseLSLBytes(const char *buf, int buf_len);
+
+  protected:
+    void initScanner();
+    void parseInternal();
 };
 
 }

tailslide_cli/main.cc

@@ -146,7 +146,7 @@ int main(int argc, char **argv) {
   if (check_assertions)
     logger->setCheckAssertions(true);
 
-  auto script = parser.parseLSL(yyin);
+  auto script = parser.parseLSLFile(yyin);
   if (yyin != nullptr)
     fclose(yyin);
 

tests/conformance.cc

@@ -302,4 +302,13 @@ TEST_CASE("jump_kinds.lsl") {
   checkTreeDumpOutput("jump_kinds.lsl", OptimizationOptions{});
 }
 
+static const char *SIMPLE_SCRIPT_BYTES = "default{state_entry(){}}";
+
+TEST_CASE("Parse script buffer") {
+  ParserRef parser(new ScopedScriptParser(nullptr));
+  auto script = parser->parseLSLBytes(SIMPLE_SCRIPT_BYTES, (int)strlen(SIMPLE_SCRIPT_BYTES));
+  CHECK_NE(nullptr, script);
+  CHECK_EQ(0, parser->logger.getErrors());
+}
+
 TEST_SUITE_END();

tests/testutils.cc

@@ -14,7 +14,7 @@ ParserRef runConformance(const char *name, bool allow_syntax_errors)
   ParserRef parser(new ScopedScriptParser(nullptr));
   Logger *logger = &parser->logger;
   logger->setCheckAssertions(true);
-  parser->parseLSL(path);
+  parser->parseLSLFile(path);
   LSLScript *script = parser->script;
 
   if (script == nullptr)