Optimize C __builtin_strlen for literals

Author: totalspectrum

Changelog.txt

@@ -3,7 +3,8 @@ Version 6.1.6
 - Implemented flush() for FATFS files (thanks to Ada)
 - Improved some error messages
 - In C++ output, treat unknown types in prints as generic
-- Optimized a few BASIC string expressions 
+- Optimized a few BASIC string expressions
+- Optimized calculating length of string literals
 - Revised BASIC use of + operator on strings
 
 Version 6.1.5

ast.c

@@ -1013,7 +1013,7 @@ static void doASTDump(AST *ast, int indent)
             case K_ASC:
                 opString = "asc";
                 break;
-            case K_LEN:
+            case K_STRLEN:
                 opString = "strlen";
                 break;
             case K_POWER:

frontends/basic/basic.y

@@ -1642,7 +1642,7 @@ unary_op:
   | BAS_ASC
     { $$ = AstOperator(K_ASC, NULL, NULL); }
   | BAS_LEN
-    { $$ = AstOperator(K_LEN, NULL, NULL); }
+    { $$ = AstOperator(K_STRLEN, NULL, NULL); }
   | BAS_SQRT
     { $$ = AstOperator(K_SQRT, NULL, NULL); }
 ;

frontends/c/cgram.y

@@ -1062,6 +1062,8 @@ ConstructDefaultValue(AST *decl, AST *val)
 %token C_BUILTIN_SETJMP   "__builtin_setjmp"
 %token C_BUILTIN_LONGJMP  "__builtin_longjmp"
 
+%token C_BUILTIN_STRLEN   "__builtin_strlen"
+
 %token C_EOF "end of file"
 
 %start translation_unit
@@ -1254,6 +1256,10 @@ postfix_expression
             {
                 $$ = NewAST(AST_THROW, $5, $3);
             }
+        | C_BUILTIN_STRLEN '(' assignment_expression ')'
+            {
+                $$ = AstOperator(K_STRLEN, NULL, $3);
+            }
 	| postfix_expression '[' expression ']'
             { $$ = NewAST(AST_ARRAYREF, $1, $3); }
 	| postfix_expression '(' ')'

frontends/common.c

@@ -253,7 +253,6 @@ Aliases basicalias[] = {
     { "getus", "_getus" },
     { "getsec", "_getsec" },
     { "kill", "_remove" },
-    { "len", "__builtin_strlen" },
     { "lpeek", "__lpeek" },
     { "lpoke", "__lpoke" },
     { "mount", "_mount" },

frontends/lexer.c

@@ -2405,6 +2405,7 @@ struct reservedword c_keywords[] = {
     { "__builtin_propeller_rev", C_BUILTIN_REV },
     { "__builtin_setjmp", C_BUILTIN_SETJMP },
     { "__builtin_sqrt", C_BUILTIN_SQRT },
+    { "__builtin_strlen", C_BUILTIN_STRLEN },
     { "__builtin_va_arg", C_BUILTIN_VA_ARG },
     { "__builtin_va_start", C_BUILTIN_VA_START },
     { "case", C_CASE },

frontends/types.c

@@ -1128,7 +1128,7 @@ AST *CoerceOperatorTypes(AST *ast, AST *lefttype, AST *righttype)
             }
         }
         return ast_type_long;
-    case K_LEN:
+    case K_STRLEN:
         if (!CompatibleTypes(righttype, ast_type_string)) {
             if (curfunc && IsBasicLang(curfunc->language)) {
                 ERROR(ast, "expected string argument to LEN");

optokens.h

@@ -42,8 +42,8 @@ enum OpToken {
     K_GTU,
     K_GEU,
 
-    K_ASC,  /* BASIC ASC operator */
-    K_LEN,  /* BASIC LEN operator */
+    K_ASC,     /* BASIC ASC operator */
+    K_STRLEN,  /* BASIC LEN operator */
 
     K_LIMITMIN_UNS,
     K_LIMITMAX_UNS,