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-rw-r--r--source/pdf/pdf-lex.c553
1 files changed, 553 insertions, 0 deletions
diff --git a/source/pdf/pdf-lex.c b/source/pdf/pdf-lex.c
new file mode 100644
index 00000000..a8bf9f4b
--- /dev/null
+++ b/source/pdf/pdf-lex.c
@@ -0,0 +1,553 @@
+#include "mupdf/pdf.h"
+
+#define IS_NUMBER \
+ '+':case'-':case'.':case'0':case'1':case'2':case'3':\
+ case'4':case'5':case'6':case'7':case'8':case'9'
+#define IS_WHITE \
+ '\000':case'\011':case'\012':case'\014':case'\015':case'\040'
+#define IS_HEX \
+ '0':case'1':case'2':case'3':case'4':case'5':case'6':\
+ case'7':case'8':case'9':case'A':case'B':case'C':\
+ case'D':case'E':case'F':case'a':case'b':case'c':\
+ case'd':case'e':case'f'
+#define IS_DELIM \
+ '(':case')':case'<':case'>':case'[':case']':case'{':\
+ case'}':case'/':case'%'
+
+#define RANGE_0_9 \
+ '0':case'1':case'2':case'3':case'4':case'5':\
+ case'6':case'7':case'8':case'9'
+#define RANGE_a_f \
+ 'a':case'b':case'c':case'd':case'e':case'f'
+#define RANGE_A_F \
+ 'A':case'B':case'C':case'D':case'E':case'F'
+
+static inline int iswhite(int ch)
+{
+ return
+ ch == '\000' ||
+ ch == '\011' ||
+ ch == '\012' ||
+ ch == '\014' ||
+ ch == '\015' ||
+ ch == '\040';
+}
+
+static inline int unhex(int ch)
+{
+ if (ch >= '0' && ch <= '9') return ch - '0';
+ if (ch >= 'A' && ch <= 'F') return ch - 'A' + 0xA;
+ if (ch >= 'a' && ch <= 'f') return ch - 'a' + 0xA;
+ return 0;
+}
+
+static void
+lex_white(fz_stream *f)
+{
+ int c;
+ do {
+ c = fz_read_byte(f);
+ } while ((c <= 32) && (iswhite(c)));
+ if (c != EOF)
+ fz_unread_byte(f);
+}
+
+static void
+lex_comment(fz_stream *f)
+{
+ int c;
+ do {
+ c = fz_read_byte(f);
+ } while ((c != '\012') && (c != '\015') && (c != EOF));
+}
+
+static int
+lex_number(fz_stream *f, pdf_lexbuf *buf, int c)
+{
+ int neg = 0;
+ int i = 0;
+ int n;
+ int d;
+ float v;
+
+ /* Initially we might have +, -, . or a digit */
+ switch (c)
+ {
+ case '.':
+ goto loop_after_dot;
+ case '-':
+ neg = 1;
+ break;
+ case '+':
+ break;
+ default: /* Must be a digit */
+ i = c - '0';
+ break;
+ }
+
+ while (1)
+ {
+ c = fz_read_byte(f);
+ switch (c)
+ {
+ case '.':
+ goto loop_after_dot;
+ case RANGE_0_9:
+ i = 10*i + c - '0';
+ /* FIXME: Need overflow check here; do we care? */
+ break;
+ default:
+ fz_unread_byte(f);
+ /* Fallthrough */
+ case EOF:
+ if (neg)
+ i = -i;
+ buf->i = i;
+ return PDF_TOK_INT;
+ }
+ }
+
+ /* In here, we've seen a dot, so can accept just digits */
+loop_after_dot:
+ n = 0;
+ d = 1;
+ while (1)
+ {
+ c = fz_read_byte(f);
+ switch (c)
+ {
+ case RANGE_0_9:
+ if (d >= INT_MAX/10)
+ goto underflow;
+ n = n*10 + (c - '0');
+ d *= 10;
+ break;
+ default:
+ fz_unread_byte(f);
+ /* Fallthrough */
+ case EOF:
+ v = (float)i + ((float)n / (float)d);
+ if (neg)
+ v = -v;
+ buf->f = v;
+ return PDF_TOK_REAL;
+ }
+ }
+
+underflow:
+ /* Ignore any digits after here, because they are too small */
+ while (1)
+ {
+ c = fz_read_byte(f);
+ switch (c)
+ {
+ case RANGE_0_9:
+ break;
+ default:
+ fz_unread_byte(f);
+ /* Fallthrough */
+ case EOF:
+ v = (float)i + ((float)n / (float)d);
+ if (neg)
+ v = -v;
+ buf->f = v;
+ return PDF_TOK_REAL;
+ }
+ }
+}
+
+static void
+lex_name(fz_stream *f, pdf_lexbuf *buf)
+{
+ char *s = buf->scratch;
+ int n = buf->size;
+
+ while (n > 1)
+ {
+ int c = fz_read_byte(f);
+ switch (c)
+ {
+ case IS_WHITE:
+ case IS_DELIM:
+ fz_unread_byte(f);
+ goto end;
+ case EOF:
+ goto end;
+ case '#':
+ {
+ int d;
+ c = fz_read_byte(f);
+ switch (c)
+ {
+ case RANGE_0_9:
+ d = (c - '0') << 4;
+ break;
+ case RANGE_a_f:
+ d = (c - 'a' + 10) << 4;
+ break;
+ case RANGE_A_F:
+ d = (c - 'A' + 10) << 4;
+ break;
+ default:
+ fz_unread_byte(f);
+ /* fallthrough */
+ case EOF:
+ goto end;
+ }
+ c = fz_read_byte(f);
+ switch (c)
+ {
+ case RANGE_0_9:
+ c -= '0';
+ break;
+ case RANGE_a_f:
+ c -= 'a' - 10;
+ break;
+ case RANGE_A_F:
+ c -= 'A' - 10;
+ break;
+ default:
+ fz_unread_byte(f);
+ /* fallthrough */
+ case EOF:
+ *s++ = d;
+ n--;
+ goto end;
+ }
+ *s++ = d + c;
+ n--;
+ break;
+ }
+ default:
+ *s++ = c;
+ n--;
+ break;
+ }
+ }
+end:
+ *s = '\0';
+ buf->len = s - buf->scratch;
+}
+
+static int
+lex_string(fz_stream *f, pdf_lexbuf *lb)
+{
+ char *s = lb->scratch;
+ char *e = s + lb->size;
+ int bal = 1;
+ int oct;
+ int c;
+
+ while (1)
+ {
+ if (s == e)
+ {
+ s += pdf_lexbuf_grow(lb);
+ e = lb->scratch + lb->size;
+ }
+ c = fz_read_byte(f);
+ switch (c)
+ {
+ case EOF:
+ goto end;
+ case '(':
+ bal++;
+ *s++ = c;
+ break;
+ case ')':
+ bal --;
+ if (bal == 0)
+ goto end;
+ *s++ = c;
+ break;
+ case '\\':
+ c = fz_read_byte(f);
+ switch (c)
+ {
+ case EOF:
+ goto end;
+ case 'n':
+ *s++ = '\n';
+ break;
+ case 'r':
+ *s++ = '\r';
+ break;
+ case 't':
+ *s++ = '\t';
+ break;
+ case 'b':
+ *s++ = '\b';
+ break;
+ case 'f':
+ *s++ = '\f';
+ break;
+ case '(':
+ *s++ = '(';
+ break;
+ case ')':
+ *s++ = ')';
+ break;
+ case '\\':
+ *s++ = '\\';
+ break;
+ case RANGE_0_9:
+ oct = c - '0';
+ c = fz_read_byte(f);
+ if (c >= '0' && c <= '9')
+ {
+ oct = oct * 8 + (c - '0');
+ c = fz_read_byte(f);
+ if (c >= '0' && c <= '9')
+ oct = oct * 8 + (c - '0');
+ else if (c != EOF)
+ fz_unread_byte(f);
+ }
+ else if (c != EOF)
+ fz_unread_byte(f);
+ *s++ = oct;
+ break;
+ case '\n':
+ break;
+ case '\r':
+ c = fz_read_byte(f);
+ if ((c != '\n') && (c != EOF))
+ fz_unread_byte(f);
+ break;
+ default:
+ *s++ = c;
+ }
+ break;
+ default:
+ *s++ = c;
+ break;
+ }
+ }
+end:
+ lb->len = s - lb->scratch;
+ return PDF_TOK_STRING;
+}
+
+static int
+lex_hex_string(fz_stream *f, pdf_lexbuf *lb)
+{
+ char *s = lb->scratch;
+ char *e = s + lb->size;
+ int a = 0, x = 0;
+ int c;
+
+ while (1)
+ {
+ if (s == e)
+ {
+ s += pdf_lexbuf_grow(lb);
+ e = lb->scratch + lb->size;
+ }
+ c = fz_read_byte(f);
+ switch (c)
+ {
+ case IS_WHITE:
+ break;
+ case IS_HEX:
+ if (x)
+ {
+ *s++ = a * 16 + unhex(c);
+ x = !x;
+ }
+ else
+ {
+ a = unhex(c);
+ x = !x;
+ }
+ break;
+ case '>':
+ case EOF:
+ goto end;
+ default:
+ fz_warn(f->ctx, "ignoring invalid character in hex string");
+ }
+ }
+end:
+ lb->len = s - lb->scratch;
+ return PDF_TOK_STRING;
+}
+
+static pdf_token
+pdf_token_from_keyword(char *key)
+{
+ switch (*key)
+ {
+ case 'R':
+ if (!strcmp(key, "R")) return PDF_TOK_R;
+ break;
+ case 't':
+ if (!strcmp(key, "true")) return PDF_TOK_TRUE;
+ if (!strcmp(key, "trailer")) return PDF_TOK_TRAILER;
+ break;
+ case 'f':
+ if (!strcmp(key, "false")) return PDF_TOK_FALSE;
+ break;
+ case 'n':
+ if (!strcmp(key, "null")) return PDF_TOK_NULL;
+ break;
+ case 'o':
+ if (!strcmp(key, "obj")) return PDF_TOK_OBJ;
+ break;
+ case 'e':
+ if (!strcmp(key, "endobj")) return PDF_TOK_ENDOBJ;
+ if (!strcmp(key, "endstream")) return PDF_TOK_ENDSTREAM;
+ break;
+ case 's':
+ if (!strcmp(key, "stream")) return PDF_TOK_STREAM;
+ if (!strcmp(key, "startxref")) return PDF_TOK_STARTXREF;
+ break;
+ case 'x':
+ if (!strcmp(key, "xref")) return PDF_TOK_XREF;
+ break;
+ default:
+ break;
+ }
+
+ return PDF_TOK_KEYWORD;
+}
+
+void pdf_lexbuf_init(fz_context *ctx, pdf_lexbuf *lb, int size)
+{
+ lb->size = lb->base_size = size;
+ lb->len = 0;
+ lb->ctx = ctx;
+ lb->scratch = &lb->buffer[0];
+}
+
+void pdf_lexbuf_fin(pdf_lexbuf *lb)
+{
+ if (lb && lb->size != lb->base_size)
+ fz_free(lb->ctx, lb->scratch);
+}
+
+ptrdiff_t pdf_lexbuf_grow(pdf_lexbuf *lb)
+{
+ char *old = lb->scratch;
+ int newsize = lb->size * 2;
+ if (lb->size == lb->base_size)
+ {
+ lb->scratch = fz_malloc(lb->ctx, newsize);
+ memcpy(lb->scratch, lb->buffer, lb->size);
+ }
+ else
+ {
+ lb->scratch = fz_resize_array(lb->ctx, lb->scratch, newsize, 1);
+ }
+ lb->size = newsize;
+ return lb->scratch - old;
+}
+
+pdf_token
+pdf_lex(fz_stream *f, pdf_lexbuf *buf)
+{
+ while (1)
+ {
+ int c = fz_read_byte(f);
+ switch (c)
+ {
+ case EOF:
+ return PDF_TOK_EOF;
+ case IS_WHITE:
+ lex_white(f);
+ break;
+ case '%':
+ lex_comment(f);
+ break;
+ case '/':
+ lex_name(f, buf);
+ return PDF_TOK_NAME;
+ case '(':
+ return lex_string(f, buf);
+ case ')':
+ fz_warn(f->ctx, "lexical error (unexpected ')')");
+ continue;
+ case '<':
+ c = fz_read_byte(f);
+ if (c == '<')
+ {
+ return PDF_TOK_OPEN_DICT;
+ }
+ else
+ {
+ fz_unread_byte(f);
+ return lex_hex_string(f, buf);
+ }
+ case '>':
+ c = fz_read_byte(f);
+ if (c == '>')
+ {
+ return PDF_TOK_CLOSE_DICT;
+ }
+ fz_warn(f->ctx, "lexical error (unexpected '>')");
+ fz_unread_byte(f);
+ continue;
+ case '[':
+ return PDF_TOK_OPEN_ARRAY;
+ case ']':
+ return PDF_TOK_CLOSE_ARRAY;
+ case '{':
+ return PDF_TOK_OPEN_BRACE;
+ case '}':
+ return PDF_TOK_CLOSE_BRACE;
+ case IS_NUMBER:
+ return lex_number(f, buf, c);
+ default: /* isregular: !isdelim && !iswhite && c != EOF */
+ fz_unread_byte(f);
+ lex_name(f, buf);
+ return pdf_token_from_keyword(buf->scratch);
+ }
+ }
+}
+
+void pdf_print_token(fz_context *ctx, fz_buffer *fzbuf, int tok, pdf_lexbuf *buf)
+{
+ switch (tok)
+ {
+ case PDF_TOK_NAME:
+ fz_buffer_printf(ctx, fzbuf, "/%s", buf->scratch);
+ break;
+ case PDF_TOK_STRING:
+ if (buf->len >= buf->size)
+ pdf_lexbuf_grow(buf);
+ buf->scratch[buf->len] = 0;
+ fz_buffer_cat_pdf_string(ctx, fzbuf, buf->scratch);
+ break;
+ case PDF_TOK_OPEN_DICT:
+ fz_buffer_printf(ctx, fzbuf, "<<");
+ break;
+ case PDF_TOK_CLOSE_DICT:
+ fz_buffer_printf(ctx, fzbuf, ">>");
+ break;
+ case PDF_TOK_OPEN_ARRAY:
+ fz_buffer_printf(ctx, fzbuf, "[");
+ break;
+ case PDF_TOK_CLOSE_ARRAY:
+ fz_buffer_printf(ctx, fzbuf, "]");
+ break;
+ case PDF_TOK_OPEN_BRACE:
+ fz_buffer_printf(ctx, fzbuf, "{");
+ break;
+ case PDF_TOK_CLOSE_BRACE:
+ fz_buffer_printf(ctx, fzbuf, "}");
+ break;
+ case PDF_TOK_INT:
+ fz_buffer_printf(ctx, fzbuf, "%d", buf->i);
+ break;
+ case PDF_TOK_REAL:
+ {
+ char sbuf[256];
+ sprintf(sbuf, "%g", buf->f);
+ if (strchr(sbuf, 'e')) /* bad news! */
+ sprintf(sbuf, fabsf(buf->f) > 1 ? "%1.1f" : "%1.8f", buf->f);
+ fz_buffer_printf(ctx, fzbuf, "%s", sbuf);
+ }
+ break;
+ default:
+ fz_buffer_printf(ctx, fzbuf, "%s", buf->scratch);
+ break;
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-29 00:04:12 +0000