convert input parsing to pluggable specs

CMakeLists.txt

@@ -19,6 +19,7 @@ add_executable(forth
     src/fh_error.c
     src/fh_see.c
     src/fh_parse.c
+    src/fh_input.c
 )
 
 target_include_directories(forth PRIVATE include)

include/fh_config.h

@@ -34,4 +34,6 @@
 #define MAGICADDR_UNRESOLVED       0xFFFFFBADULL
 #define MAGICADDR_ENDCASE_UNRESOLVED 0xFFFC5BADULL
 
+#define FH_PROMPT_STR "> "
+
 #endif //FORTH_FH_CONFIG_H

include/fh_input.h

@@ -0,0 +1,46 @@
+/**
+ * TODO file description
+ *
+ * Created on 2021/11/21.
+ */
+
+#ifndef FORTH_FH_INPUT_H
+#define FORTH_FH_INPUT_H
+
+struct fh_thread_s;
+struct fh_input_spec_s;
+
+/** Refill the input buffer, returns false on failure / EOF */
+typedef bool (*fh_input_refill_t)(struct fh_thread_s *fh, struct fh_input_spec_s *spec);
+/** Spec free func */
+typedef void (*fh_input_free_t)(void *spec);
+
+struct fh_input_spec_s {
+  struct fh_input_spec_s *previous;
+  fh_input_refill_t refill_input_buffer;
+  fh_input_free_t free_self;
+  uint32_t linenum;
+
+  // saved values, filled when pushing
+  char saved_buffer[INPUT_BUFFER_SIZE];
+  uint32_t saved_inputptr;
+  uint32_t saved_inputlen;
+};
+
+/**
+ * Push current input spec and state, replace with new one
+ */
+void fh_push_input(struct fh_thread_s *fh, struct fh_input_spec_s *newinput);
+
+/**
+ * Discard current input spec, restore previous.
+ * fh->input will be NULL if this was the topmost one
+ */
+void fh_pop_input(struct fh_thread_s *fh);
+
+struct fh_input_spec_s *fh_create_input_from_filename(char *path);
+struct fh_input_spec_s *fh_create_input_from_filestruct(FILE *f);
+struct fh_input_spec_s *fh_create_input_from_string(char *str, size_t len);
+void fh_input_teardown(struct fh_thread_s *fh);
+
+#endif //FORTH_FH_INPUT_H

include/fh_runtime.h

@@ -217,6 +217,9 @@ struct fh_thread_s {
   uint32_t parse_if_level;
 
   bool executing_compiled;
+
+  /** Input spec */
+  struct fh_input_spec_s *input;
 };
 
 enum fh_error fh_loop_nest(struct fh_thread_s *fh, uint32_t indexvalue);
@@ -265,7 +268,9 @@ enum fh_error fh_find_word(struct fh_thread_s *fh, const char *name, size_t word
 
 enum fh_error fh_init(struct fh_thread_s *fh);
 
-enum fh_error fh_process_line(struct fh_thread_s *fh, const char *linebuf, size_t len);
+//enum fh_error fh_process_line(struct fh_thread_s *fh, const char *linebuf, size_t len);
+
+enum fh_error fh_runtime_start(struct fh_thread_s *fh, struct fh_input_spec_s *input);
 
 static inline uint32_t word_addr(struct fh_thread_s *fh, const struct fh_word_s *w)
 {

include/forth.h

@@ -14,6 +14,7 @@
 #include "fh_config.h"
 #include "fh_error.h"
 #include "fh_globals.h"
+#include "fh_input.h"
 #include "fh_runtime.h"
 #include "fh_print.h"
 

include/forth_internal.h

@@ -23,6 +23,7 @@
 #include "fh_helpers.h"
 #include "fh_globals.h"
 #include "fh_print.h"
+#include "fh_input.h"
 #include "fh_runtime.h"
 #include "fh_mem.h"
 #include "fh_stack.h"

src/fh_input.c

@@ -0,0 +1,191 @@
+#include "forth_internal.h"
+
+void fh_push_input(struct fh_thread_s *fh, struct fh_input_spec_s *newinput)
+{
+  if (newinput == NULL) {
+    LOGE("push input with NULL");
+    return;
+  }
+
+  struct fh_input_spec_s *oldinput = fh->input;
+  if (NULL == oldinput) {
+    // no previous input spec, just use the new one
+    fh->input = newinput;
+    return;
+  }
+
+  fh->input = NULL;
+
+  memcpy(&oldinput->saved_buffer[0], &fh->heap[INPUTBUF_ADDR], INPUT_BUFFER_SIZE);
+  oldinput->saved_inputlen = fh->inputlen;
+  oldinput->saved_inputptr = fh->inputptr;
+  newinput->previous = oldinput;
+
+  fh->input = newinput;
+}
+
+void fh_pop_input(struct fh_thread_s *fh)
+{
+  struct fh_input_spec_s *discarded = fh->input;
+  fh->input = NULL;
+
+  struct fh_input_spec_s *restored = discarded->previous;
+  if (!restored) {
+    return;
+  }
+  fh->input = restored; // this can be NULL, that must be checked by caller.
+
+  memcpy(&fh->heap[INPUTBUF_ADDR], &restored->saved_buffer[0], INPUT_BUFFER_SIZE);
+  fh->inputlen = restored->saved_inputlen;
+  fh->inputptr = restored->saved_inputptr;
+
+  if (discarded->free_self) {
+    discarded->free_self(discarded);
+  }
+}
+
+struct file_input_spec {
+  struct fh_input_spec_s spec;
+  FILE *file;
+};
+
+struct string_input_spec {
+  struct fh_input_spec_s spec;
+  char *str;
+  size_t len;
+  size_t readpos;
+};
+
+static inline uint8_t *inputbuf_at(struct fh_thread_s *fh, size_t pos)
+{
+  return &fh->heap[INPUTBUF_ADDR + pos];
+}
+
+void fh_input_memmove_leftovers(struct fh_thread_s *fh)
+{
+  if (fh->inputptr < fh->inputlen) {
+    // something is left
+    uint32_t remains = fh->inputlen - fh->inputptr;
+    if (remains > 0) {
+      LOG("Refill, reuse %d bytes left in buffer", remains);
+      memmove(inputbuf_at(fh, 0), inputbuf_at(fh, fh->inputptr), remains);
+      fh->inputptr = 0;
+      fh->inputlen = remains;
+    } else {
+      LOG("Refill, nothing reused (1)");
+      fh->inputptr = 0;
+      fh->inputlen = 0;
+    }
+  } else {
+    LOG("Refill, nothing reused (2)");
+    fh->inputptr = 0;
+    fh->inputlen = 0;
+  }
+}
+
+static bool file_refill(struct fh_thread_s *fh, struct fh_input_spec_s *spec)
+{
+  struct file_input_spec *fis = (struct file_input_spec *) spec;
+  fh_input_memmove_leftovers(fh);
+  uint32_t space_left = INPUT_BUFFER_SIZE - fh->inputlen;
+  char *wp = (char *) inputbuf_at(fh, fh->inputptr);
+  LOG("spec %p, fgets %d", spec, space_left);
+  if (fgets(wp, (int) space_left, fis->file)) {
+    spec->linenum++;
+    fh->inputlen = strnlen(wp, INPUT_BUFFER_SIZE);
+    return true;
+  } else {
+    return fh->inputptr > fh->inputlen; // return false only if there is nothing left
+  }
+}
+
+static bool str_refill(struct fh_thread_s *fh, struct fh_input_spec_s *spec)
+{
+  struct string_input_spec *fis = (struct string_input_spec *) spec;
+  fh_input_memmove_leftovers(fh);
+  uint32_t space_left = INPUTBUF_ADDR - fh->inputlen;
+  char *wp = (char *) inputbuf_at(fh, fh->inputptr);
+
+  uint32_t chars_remaining_in_string = fis->len - fis->readpos;
+  if (chars_remaining_in_string > 0) {
+    if (chars_remaining_in_string < space_left) {
+      space_left = chars_remaining_in_string;
+    }
+
+    memcpy(wp, &fis->str[fis->readpos], space_left);
+    return true;
+  } else {
+    return false;
+  }
+}
+
+static void free_filespec(void *p)
+{
+  struct file_input_spec *spec = (struct file_input_spec *) p;
+  if (spec->file != stdin) {
+    fclose(spec->file);
+    spec->file = NULL;
+  }
+  free(spec);
+}
+
+struct fh_input_spec_s *fh_create_input_from_filestruct(FILE *f)
+{
+  struct file_input_spec *spec = calloc(sizeof(struct file_input_spec), 1);
+  if (!spec) {
+    return NULL;
+  }
+
+  spec->spec.free_self = free;
+  spec->spec.refill_input_buffer = file_refill;
+  spec->file = f;
+  return (struct fh_input_spec_s*) spec;
+}
+
+struct fh_input_spec_s *fh_create_input_from_filename(char *path)
+{
+  struct file_input_spec *spec = calloc(sizeof(struct file_input_spec), 1);
+  if (!spec) {
+    return NULL;
+  }
+
+  FILE *f = fopen(path, "r");
+  if (!f) {
+    free(spec);
+    return NULL;
+  }
+
+  spec->spec.free_self = free_filespec;
+  spec->spec.refill_input_buffer = file_refill;
+  spec->file = f;
+  return (struct fh_input_spec_s*) spec;
+}
+
+struct fh_input_spec_s *fh_create_input_from_string(char *str, size_t len)
+{
+  struct string_input_spec *spec = calloc(sizeof(struct string_input_spec), 1);
+  if (!spec) {
+    return NULL;
+  }
+
+  spec->spec.free_self = free;
+  spec->spec.refill_input_buffer = str_refill;
+  spec->str = str;
+  spec->readpos = 0;
+  spec->len = len;
+  return (struct fh_input_spec_s*) spec;
+}
+
+void fh_input_teardown(struct fh_thread_s *fh)
+{
+  struct fh_input_spec_s *s = fh->input;
+  if (!s) return;
+
+  while (s) {
+    struct fh_input_spec_s *prev = s->previous;
+    if (s->free_self) {
+      s->free_self(s);
+    }
+    s = prev;
+  }
+}

src/fh_parse.c

@@ -221,8 +221,72 @@ enum fh_error fh_input_read_quotedstring(struct fh_thread_s *fh, bool escaped, c
   return FH_ERR_SYNTAX;
 }
 
+enum fh_error fh_process_line(struct fh_thread_s *fh);
+
+enum fh_error fh_runtime_start(struct fh_thread_s *fh, struct fh_input_spec_s *input)
+{
+  enum fh_error rv;
+  fh_push_input(fh, input);
+
+  if (fh_globals.interactive) {
+    FHPRINT("%s", FH_PROMPT_STR);
+  }
+
+  while (1) {
+    LOG("Refill input buffer");
+    if (fh->input->refill_input_buffer(fh, fh->input)) {
+      // discard spaces at the end
+      while (isspace(fh->heap[INPUTBUF_ADDR + fh->inputlen - 1]) && fh->inputlen > 0) {
+        fh->heap[INPUTBUF_ADDR + fh->inputlen - 1] = 0;
+        fh->inputlen--;
+      }
+
+      if (fh->inputlen == 0) {
+        continue;
+      }
+
+      rv = fh_process_line(fh);
+
+      if (rv == FH_OK) {
+        if (fh_globals.interactive || fh_globals.echo) {
+          FHPRINT_SVC(" ok\n");
+        }
+      } else {
+        LOGE("ERROR %s on line %d", fherr_name(rv), fh->input->linenum);
+        if (!fh_globals.interactive) {
+          if (fh_globals.rescue) {
+            fh_globals.interactive = 1;
+            fh_input_teardown(fh);
+            fh_push_input(fh, fh_create_input_from_filestruct(stdin));
+          } else {
+            return 1;
+          }
+        }
+        /* reset state */
+        fh_setstate(fh, FH_STATE_INTERPRET, FH_SUBSTATE_NONE);
+        // reset stack pointers
+        fh->data_stack_top = 0;
+        fh->return_stack_top = 0;
+      }
+
+      if (fh_globals.interactive) {
+        FHPRINT("%s", FH_PROMPT_STR);
+      }
+
+    } else {
+      LOG("Pop input");
+      fh_pop_input(fh);
+      if (!fh->input) {
+        // we are done.
+        break;
+      }
+    }
+  }
+  return FH_OK;
+}
+
 /** Process a line read from input */
-enum fh_error fh_process_line(struct fh_thread_s *fh, const char *linebuf, size_t len)
+enum fh_error fh_process_line(struct fh_thread_s *fh)
 {
   enum fh_error rv;
 
@@ -230,12 +294,12 @@ enum fh_error fh_process_line(struct fh_thread_s *fh, const char *linebuf, size_
 #define ReadPos (fh->inputptr)
 #define ReadLen (fh->inputlen)
 
-  fh_fill_input_buffer(fh, linebuf, len);
+  //fh_fill_input_buffer(fh, linebuf, len);
 
   char c;
 
   if (fh_globals.echo && !fh_globals.interactive) {
-    LOGI("%s", linebuf);
+    LOGI("%.*s", ReadLen, ReadPtr);
   }
 
   while (ReadPos < ReadLen && fh->state != FH_STATE_SHUTDOWN) {

src/main.c

@@ -63,53 +63,7 @@ int main(int argc, char *argv[])
     return 1;
   }
 
-  const char *prompt = "> ";
-
-  /* process input line by line */
-  int linecnt = 0;
-  char linebuf[MAXLINE];
-  if (fh_globals.interactive) {
-    FHPRINT("%s", prompt);
-  }
-  while (fh.state != FH_STATE_SHUTDOWN && fgets(linebuf, MAXLINE, infile)) {
-    linecnt++;
-
-    // trim
-    size_t end = strlen(linebuf) - 1;
-    while (isspace(linebuf[end])) {
-      linebuf[end] = 0;
-    }
-
-    if (!linebuf[0]) {
-      continue;
-    }
-
-    rv = fh_process_line(&fh, linebuf, strlen(linebuf));
-    if (rv == FH_OK) {
-      if (fh_globals.interactive || fh_globals.echo) {
-        FHPRINT_SVC(" ok\n");
-      }
-    } else {
-      LOGE("ERROR %s on line %d", fherr_name(rv), linecnt);
-      if (!fh_globals.interactive) {
-        if (fh_globals.rescue) {
-          fh_globals.interactive = 1;
-          infile = stdin;
-        } else {
-          return 1;
-        }
-      }
-      /* reset state */
-      fh_setstate(&fh, FH_STATE_INTERPRET, FH_SUBSTATE_NONE);
-      // reset stack pointers
-      fh.data_stack_top = 0;
-      fh.return_stack_top = 0;
-    }
-
-    if (fh_globals.interactive) {
-      FHPRINT("%s", prompt);
-    }
-  }
+  fh_runtime_start(&fh, fh_create_input_from_filestruct(infile));
 
   // Show resource usage
   LOG("\nResources used: DS %dW, RS %dW, memory %dB\n",