1 files changed, 143 insertions, 0 deletions
diff --git a/asm/evalstr.c b/asm/evalstr.c
new file mode 100644
index 00000000..5183f4e5
--- /dev/null
+++ b/asm/evalstr.c
@@ -0,0 +1,143 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2018 The NASM Authors - All Rights Reserved
+ *   See the file AUTHORS included with the NASM distribution for
+ *   the specific copyright holders.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following
+ *   conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *
+ *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Wrapper routine for evaluation
+ *
+ * Useful in directives etc. where we have a string and want a number
+ * or possibly a relocatable expression.
+ */
+
+#include "compiler.h"
+#include "nasm.h"
+#include "stdscan.h"
+#include "eval.h"
+#include "evalstr.h"
+
+/*
+ * Evaluate a simple value from a string. A segment and/or WRT MAY be
+ * permitted, but if NULL is passed into the respective pointers, then
+ * that is an error.
+ */
+static int stdscan_save(void *pvt, struct tokenval *tv)
+{
+    char **strptr = pvt;
+
+    *strptr = stdscan_get();
+    return stdscan(NULL, tv);
+}
+
+int64_t evaluate_str(char **str, bool crit, int32_t *segment, int32_t *wrt)
+{
+    struct tokenval tokval;
+    expr *e;
+    int32_t seg;
+
+    stdscan_reset();
+    stdscan_set(*str);
+
+    tokval.t_type = TOKEN_INVALID;
+    e = evaluate(stdscan_save, str, &tokval, NULL, crit, NULL);
+    *str = nasm_skip_spaces(*str);
+
+    if (segment)
+        *segment = NO_SEG;
+
+    if (is_unknown(e) && !crit)
+        return 0;
+
+    if (!is_reloc(e)) {
+        nasm_nonfatal("invalid expression");
+        return 0;
+    }
+
+    seg = reloc_seg(e);
+    if (*segment) {
+        *segment = seg;
+    } else if (seg != NO_SEG) {
+        nasm_nonfatal("expression cannot contain a segment reference");
+    }
+
+    seg = reloc_wrt(e);
+    if (*wrt) {
+        *wrt = seg;
+    } else if (seg != NO_SEG) {
+        nasm_nonfatal("expression cannot contain WRT");
+    }
+
+    return reloc_value(e);
+}
+
+/*
+ * Evaluate a size expression: a pure integer, but size specifiers like
+ * BYTE are treated like integer constants.
+ */
+static int stdscan_save_size(void *pvt, struct tokenval *tv)
+{
+    char **strptr = pvt;
+    int t;
+
+    *strptr = stdscan_get();
+    t = stdscan(NULL, tv);
+
+    if (t == TOKEN_SIZE) {
+        /* Treat size specifiers as integer constants */
+        tv->t_type = t = TOKEN_NUM;
+        tv->t_integer = tv->t_inttwo; /* Contains the size equivalent */
+    }
+
+    return t;
+}
+
+int64_t evaluate_size(char **str, bool crit)
+{
+    struct tokenval tokval;
+    expr *e;
+
+    stdscan_reset();
+    stdscan_set(*str);
+
+    tokval.t_type = TOKEN_INVALID;
+    e = evaluate(stdscan_save_size, str, &tokval, NULL, crit, NULL);
+    *str = nasm_skip_spaces(*str);
+
+    if (is_unknown(e) && !crit)
+        return 0;
+
+    if (!is_reloc(e) || reloc_seg(e) != NO_SEG || reloc_wrt(e) != NO_SEG) {
+        nasm_nonfatal("invalid size expression");
+        return 0;
+    }
+
+    return reloc_value(e);
+}