stage3/constant_folding.cc
changeset 596 4efb11e44065
parent 592 99a284cec1f2
child 600 f5d4e9f91513
--- a/stage3/constant_folding.cc	Thu Jun 14 17:50:37 2012 +0100
+++ b/stage3/constant_folding.cc	Fri Jun 15 19:54:33 2012 +0100
@@ -121,6 +121,13 @@
 #include <math.h> /* required for pow function, and HUGE_VAL, HUGE_VALF, HUGE_VALL */
 #include <stdlib.h> /* required for malloc() */
 
+
+#include <string.h>  /* required for strlen() */
+// #include <stdlib.h>  /* required for atoi() */
+#include <errno.h>   /* required for errno */
+
+
+
 #define __STDC_LIMIT_MACROS /* required for UINT64_MAX, INT64_MAX, INT64_MIN, ... */
 #include <stdint.h>         /* required for UINT64_MAX, INT64_MAX, INT64_MIN, ... */
 
@@ -217,6 +224,156 @@
 
 
 
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***            convert string to numerical value                    ***/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+
+
+
+  /* To allow the compiler to be portable, we cannot assume that int64_t is mapped onto long long int,
+   * so we cannot call strtoll() and strtoull() in extract_int64() and extract_uint64().
+   *
+   * So, we create our own strtouint64() and strtoint64() functions.
+   * (We actually call them matiec_strtoint64() so they will not clash with any function
+   *  that may be added to the standard library in the future).
+   * We actually create several of each, and let the compiler choose which is the correct one,
+   * by having it resolve the call to the overloaded function. For the C++ compiler to be able
+   * to resolve this ambiguity, we need to add a dummy parameter to each function!
+   *
+   * TODO: support platforms in which int64_t is mapped onto int !! Is this really needed?
+   */
+static  int64_t matiec_strtoint64 (         long      int *dummy, const char *nptr, char **endptr, int base) {return strtol  (nptr, endptr, base);}
+static  int64_t matiec_strtoint64 (         long long int *dummy, const char *nptr, char **endptr, int base) {return strtoll (nptr, endptr, base);}
+  
+static uint64_t matiec_strtouint64(unsigned long      int *dummy, const char *nptr, char **endptr, int base) {return strtoul (nptr, endptr, base);}
+static uint64_t matiec_strtouint64(unsigned long long int *dummy, const char *nptr, char **endptr, int base) {return strtoull(nptr, endptr, base);}
+
+
+/* extract the value of an integer from an integer_c object !! */
+/* NOTE: it must ignore underscores! */
+int64_t extract_int64_value(symbol_c *sym, bool *overflow) {
+  std::string str = "";
+  integer_c *integer;
+  char *endptr;
+  int64_t ret;
+
+  if ((integer = dynamic_cast<integer_c *>(sym)) == NULL) ERROR;
+  for(unsigned int i = 0; i < strlen(integer->value); i++)
+    if (integer->value[i] != '_')  str += integer->value[i];
+
+  errno = 0; // since strtoXX() may legally return 0, we must set errno to 0 to detect errors correctly!
+  ret = matiec_strtoint64((int64_t *)NULL, str.c_str(), &endptr, 10);
+  if (overflow != NULL)
+    *overflow = (errno == ERANGE);
+  if ((errno != 0) && (errno != ERANGE))
+    ERROR;
+
+  return ret;
+}
+
+uint64_t extract_uint64_value(symbol_c *sym, bool *overflow) {
+  std::string str = "";
+  integer_c *integer;
+  neg_integer_c * neg_integer;
+  char *endptr;
+  uint64_t ret;
+  
+  if ((integer = dynamic_cast<integer_c *>(sym)) == NULL) ERROR;
+  for(unsigned int i = 0; i < strlen(integer->value); i++)
+    if (integer->value[i] != '_')  str += integer->value[i];
+
+  errno = 0; // since strtoXX() may legally return 0, we must set errno to 0 to detect errors correctly!
+  ret = matiec_strtouint64((uint64_t *)NULL, str.c_str(), &endptr, 10);
+  if (overflow != NULL)
+    *overflow = (errno == ERANGE);
+  if ((errno != 0) && (errno != ERANGE))
+    ERROR;
+
+  return ret;
+}
+
+
+
+/* extract the value of an hex integer from an hex_integer_c object !! */
+/* NOTE: it must ignore underscores! */
+uint64_t extract_hex_value(symbol_c *sym) {
+  std::string str = "";
+  char *endptr;
+  hex_integer_c * hex_integer;
+  uint64_t ret;
+
+  if ((hex_integer = dynamic_cast<hex_integer_c *>(sym)) == NULL) ERROR;
+  for(unsigned int i = 3; i < strlen(hex_integer->value); i++)
+    if (hex_integer->value[i] != '_') str += hex_integer->value[i];
+    
+  errno = 0; // since strtoXX() may legally return 0, we must set errno to 0 to detect errors correctly!
+  ret = strtoull(str.c_str(), &endptr, 16);
+  if (errno != 0) ERROR;
+
+  return ret;
+}
+
+
+/* extract the value of a real from an real_c object !! */
+/* NOTE: it must ignore underscores! */
+/* From iec_bison.yy
+ *  real:
+ *   real_token		{$$ = new real_c($1, locloc(@$));}
+ * | fixed_point_token	{$$ = new real_c($1, locloc(@$));}
+ *
+ * From iec_flex.ll
+ * {real}			{yylval.ID=strdup(yytext); return real_token;}
+ * {fixed_point}		{yylval.ID=strdup(yytext); return fixed_point_token;}
+ *
+ * real		{integer}\.{integer}{exponent}
+ * fixed_point		{integer}\.{integer}
+ * exponent        [Ee]([+-]?){integer}
+ * integer         {digit}((_?{digit})*)
+ */
+real64_t extract_real_value(symbol_c *sym, bool *overflow) {
+  std::string str = "";
+  real_c * real_sym;
+  real64_t ret;
+
+  if ((real_sym = dynamic_cast<real_c *>(sym)) == NULL) ERROR;
+  for(unsigned int i = 0; i < strlen(real_sym->value); i++)
+    if (real_sym->value[i] != '_') str += real_sym->value[i];
+    
+  errno = 0; // since strtoXX() may legally return 0, we must set errno to 0 to detect errors correctly!
+  #if    (real64_t  == float)
+    ret = strtof(str.c_str(), NULL);
+  #elif  (real64_t  == double)
+    ret = strtod(str.c_str(), NULL);
+  #elif  (real64_t  == long_double)
+    ret = strtold(str.c_str(), NULL);
+  #else 
+    #error Could not determine which data type is being used for real64_t (defined in absyntax.hh). Aborting!
+  #endif
+  if (overflow != NULL)
+    *overflow = (errno == ERANGE);
+  if ((errno != 0) && (errno != ERANGE)) 
+    ERROR;
+
+  return ret;
+}
+
+
+
+
+
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***        Functions to check for overflow situation                ***/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+
+
 /* NOTE:
  *   Most of the conditions to detect overflows on signed and unsigned integer operations were adapted from
  *   https://www.securecoding.cert.org/confluence/display/seccode/INT32-C.+Ensure+that+operations+on+signed+integers+do+not+result+in+overflow?showComments=false
@@ -383,7 +540,13 @@
 
 
 
-
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***        The constant_folding_c                                   ***/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/