src/bz/scripting/script.c

   1 #include <bz/scripting/script_internal.h>
   2
   3 #include <bz/memory/allocator.h>
   4 #include <bz/resources/resource.h>
   5 //#include <bz/scripting/bindings_internal.h>
   6 //#include <bz/scripting/environment_internal.h>
   7 #include <bz/types/identifier_internal.h>
   8 #include <sun/compiler/compiler.h>
   9 #include <string.h>
  10
  11 #define kMaxIncludeDepth 8
  12
  13 struct BZScriptReadContext {
  14         size_t currentHandleIdx;
  15         BZResourceID handles[kMaxIncludeDepth];
  16         bool handlePreprocessor;
  17         bool pastFirstCharacter;
  18 };
  19 typedef struct BZScriptReadContext BZScriptReadContext;
  20
  21 static size_t readSource(char *out, size_t outSize, void *userParam) {
  22         BZScriptReadContext *context = userParam;
  23
  24         BZResourceID currentHandle = context->handles[context->currentHandleIdx];
  25         size_t readStartPosition = bzResourcesTell(currentHandle);
  26
  27 process:
  28         if (context->handlePreprocessor) {
  29                 // Extract the current line...
  30
  31                 size_t preprocessorLength = 0;
  32                 while (bzResourcesReadBytes(currentHandle, out, 1) > 0) {
  33                         if (*out == '\n') {
  34                                 break;
  35                         }
  36                         preprocessorLength += 1;
  37                 }
  38
  39                 char *preprocessorInstruction = alloca(preprocessorLength + 1);
  40                 preprocessorInstruction[preprocessorLength] = '\0';
  41                 bzResourcesSeek(currentHandle, readStartPosition);
  42                 bzResourcesReadBytes(currentHandle, preprocessorInstruction, preprocessorLength);
  43
  44                 if (strncmp(preprocessorInstruction, "#include ", 9) == 0) {
  45                         context->currentHandleIdx++;
  46                         bzAssert(context->currentHandleIdx < kMaxIncludeDepth);
  47                         preprocessorInstruction += 9;
  48                         context->handles[context->currentHandleIdx] = bzResourcesOpenResource("script", "assets/scripts/%s", preprocessorInstruction);
  49                         bzAssertMessage(context->handles[context->currentHandleIdx] != NULL, "Invalid include '%s'", preprocessorInstruction);
  50                 }
  51         }
  52
  53         size_t readSize = 0;
  54         while (readSize == 0) {
  55                 currentHandle = context->handles[context->currentHandleIdx];
  56                 readStartPosition = bzResourcesTell(currentHandle);
  57                 readSize = bzResourcesReadBytes(currentHandle, out, outSize);
  58
  59                 if (readSize == 0) {
  60                         if (context->currentHandleIdx > 0) {
  61                                 bzResourcesCloseResource(currentHandle);
  62                                 --context->currentHandleIdx;
  63                         } else {
  64                                 // 0th level is closed in main code
  65                                 break;
  66                         }
  67                 }
  68         }
  69
  70         for (size_t i = 0; i < readSize; ++i) {
  71                 switch (out[i]) {
  72                         case '#':
  73                                 if (context->pastFirstCharacter == false) {
  74                                         // need to handle preprocessor, set flag and return only the read characters
  75                                         bzResourcesSeek(currentHandle, readStartPosition + i);
  76                                         context->handlePreprocessor = true;
  77
  78                                         if (i > 0) {
  79                                                 return i; // don't return the '#' character
  80                                         } else {
  81                                                 goto process; // I know this is horrible, don't @ me.
  82                                         }
  83                                 }
  84                                 break;
  85
  86                         case '\n':
  87                                 context->pastFirstCharacter = false;
  88                                 break;
  89
  90                         case ' ':
  91                         case '\t':
  92                                 // These still count as 'first character' techically...
  93                                 break;
  94
  95                         default:
  96                                 context->pastFirstCharacter = true;
  97                                 break;
  98                 }
  99         }
 100
 101         return readSize;
 102 }
 103
 104 static void *sourceMalloc(void *memory, size_t size) {
 105         return alloca(size);
 106 }
 107
 108 SVMModule *bzScriptingLoadScriptModule(BZMemoryArenaID arena, const char *identifierFmt, ...) {
 109         bzMakeIdentifier(identifier, identifierFmt);
 110
 111         BZScriptReadContext context = {
 112                 .handles = { bzResourcesOpenResource("script", "assets/scripts/%s.sun", identifier), },
 113                 .currentHandleIdx = 0,
 114                 .handlePreprocessor = false,
 115                 .pastFirstCharacter = false,
 116         };
 117         bzAssertMessage(context.handles[0] != NULL, "Invalid script '%s'", identifier);
 118
 119         SLCCompileConfiguration config = {
 120                 .sourceReadCallback = readSource,
 121                 .sourceUserParam = &context,
 122                 .realloc = sourceMalloc, // fixme
 123                 .free = NULL, // fixme
 124         };
 125
 126         SVMModule *module = slcCompileSource(&config);
 127         bzResourcesCloseResource(context.handles[0]);
 128
 129         if (module == NULL) {
 130                 bzError("Could not load script %s", identifier);
 131         }
 132
 133         return module;
 134 }