Merge pull request #852 from larsclausen/vvp-string-vpi

vvp: Handle null-bytes in a conistent way when reading through VPI

ivtest/gold/br_gh827.gold

@@ -0,0 +1,4 @@
+Const Positive yes
+Const Negative  NO
+Var Positive yes
+Var Negative  NO

ivtest/gold/macro_with_args.gold

@@ -1,4 +1,4 @@
 first..last first,last last..first
-(a)..(c) (a,b,c) (c)..(a)
+(a )..(c ) (a,b,c) (c )..(a )
 sumsqr(3,4)  = 25
 sumsqr(5,12) = 169

ivtest/ivltests/br_gh827.v

@@ -0,0 +1,9 @@
+module test;
+   reg expected = 1;
+   initial begin
+      $display("Const Positive %s", 1 ? "yes" : "NO");
+      $display("Const Negative %s", !1 ? "yes" : "NO");
+      $display("Var Positive %s", expected ? "yes" : "NO");
+      $display("Var Negative %s", !expected ? "yes" : "NO");
+   end
+endmodule

ivtest/ivltests/string13.v

@@ -0,0 +1,58 @@
+// Check that null-bytes are handled consistently between string literals,
+// number literals and signals of all kinds, especially when formatting as a
+// string.
+
+module test;
+
+  reg failed = 1'b0;
+
+  `define check(val, exp) \
+    if (val != exp) begin \
+      $display("FAILED(%0d): Expected '%0s', got '%0s'.", `__LINE__, exp, val); \
+      failed = 1'b1; \
+    end
+
+  reg [255:0] s;
+  reg [31:0] x;
+  reg [31:0] y[1:0];
+  wire [31:0] z;
+  wire [31:0] w;
+
+  assign z = "\000a\000b";
+  assign w = 32'h00610062;
+
+  initial begin
+    $sformat(s, ":%x:%0x:%s:%0s:", "\000a\000b", "\000a\000b", "\000a\000b", "\000a\000b");
+    `check(s, ":00610062:610062: a b:a b:")
+    $sformat(s, ":%x:%0x:%s:%0s:", 32'h00610062, 32'h00610062, 32'h00610062, 32'h00610062);
+    `check(s, ":00610062:610062: a b:a b:")
+
+    x = "\000a\000b";
+    $sformat(s, ":%x:%0x:%s:%0s:", x, x, x, x);
+    `check(s, ":00610062:610062: a b:a b:")
+
+    x = 32'h00610062;
+    $sformat(s, ":%x:%0x:%s:%0s:", x, x, x, x);
+    `check(s, ":00610062:610062: a b:a b:")
+
+    y[0] = "\000a\000b";
+    $sformat(s, ":%x:%0x:%s:%0s:", y[0], y[0], y[0], y[0]);
+    `check(s, ":00610062:610062: a b:a b:")
+
+    y[1] = 32'h00610062;
+    $sformat(s, ":%x:%0x:%s:%0s:", y[1], y[1], y[1], y[1]);
+    `check(s, ":00610062:610062: a b:a b:")
+
+    $sformat(s, ":%x:%0x:%s:%0s:", z, z, z, z);
+    `check(s, ":00610062:610062: a b:a b:")
+
+    $sformat(s, ":%x:%0x:%s:%0s:", w, w, w, w);
+    `check(s, ":00610062:610062: a b:a b:")
+
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule

ivtest/ivltests/string14.v

@@ -0,0 +1,38 @@
+// Check that the empty string "" is equivalent to 8'h00
+
+module test;
+
+  reg failed = 1'b0;
+
+  `define check(val, exp) \
+    if (val != exp) begin \
+      $display("FAILED(%0d): Expected '%0s', got '%0s'.", `__LINE__, exp, val); \
+      failed = 1'b1; \
+    end
+
+  reg [47:0] s;
+  reg [7:0] x;
+  wire [7:0] y;
+
+  assign y = "";
+
+  initial begin
+    `check("", 8'h00);
+    `check($bits(""), 8);
+
+    $sformat(s, ":%s:%0s:", "", "");
+    `check(s, ": ::");
+
+    x = 8'h00;
+    $sformat(s, ":%s:%0s:", x, x);
+    `check(s, ": ::");
+
+    $sformat(s, ":%s:%0s:", y, y);
+    `check(s, ": ::");
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule

ivtest/regress-vlg.list

@@ -355,6 +355,7 @@ br_gh782e		normal			ivltests
 br_gh782f		normal			ivltests
 br_gh788		normal,-gno-io-range-error,-Wno-anachronisms	ivltests gold=br_gh788.gold
 br_gh793		normal			ivltests
+br_gh827		normal			ivltests gold=br_gh827.gold
 br_ml20150315		normal			ivltests gold=br_ml_20150315.gold
 br_ml20150321		CE			ivltests
 br_mw20171108		normal			ivltests
@@ -1646,6 +1647,8 @@ string9			normal			ivltests gold=string9.gold
 string10		normal			ivltests gold=string10.gold
 string11		normal			ivltests gold=string11.gold
 string12		normal			ivltests
+string13		normal			ivltests
+string14		normal			ivltests
 supply1			normal			ivltests
 supply2			normal			ivltests
 switch_primitives	normal			ivltests gold=switch_primitives.gold

tgt-vlog95/misc.c

@@ -512,8 +512,6 @@ static void emit_number_as_string(ivl_net_const_t net_const)
 		  val |= (bits[idx-bit] == '1') ?  1 << (7-bit) : 0x00;
 	    }
 
-	      /* Skip any NULL bytes. */
-	    if (val == 0) continue;
 	      /* Print some values that can be escaped. */
 	    if (val == '"') fprintf(vlog_out, "\\\"");
 	    else if (val == '\\') fprintf(vlog_out, "\\\\");

tgt-vlog95/numbers.c

@@ -346,13 +346,9 @@ static void remove_two_chars(char* str)
 void emit_string(const char* string)
 {
       char *buffer = strdup(string);
-      char *bptr = buffer;
       char *cptr;
       fprintf(vlog_out, "\"");
-	/* Prune any leading escaped NULL bytes. */
-      while ((bptr[0] == '\\') && (bptr[1] == '0') &&
-             (bptr[2] == '0') && (bptr[3] == '0')) bptr += 4;
-      for (cptr = bptr; *cptr; cptr += 1) {
+      for (cptr = buffer; *cptr; cptr += 1) {
 	    if (*cptr == '\\') {
 		    /* Replace any \011 with \t */
 		  if ((cptr[1] == '0') && (cptr[2] == '1') &&
@@ -381,7 +377,7 @@ void emit_string(const char* string)
 		  } else cptr += 3;
 	    }
       }
-      if (*bptr) fprintf(vlog_out, "%s", bptr);
+      if (*buffer) fprintf(vlog_out, "%s", buffer);
       free(buffer);
       fprintf(vlog_out, "\"");
 }

vvp/vpi_const.cc

@@ -93,7 +93,7 @@ int __vpiStringConst::vpi_get(int code)
 {
       switch (code) {
           case vpiSize:
-	    return strlen(value_)*8;
+	    return value_len_ * 8;
 
           case vpiSigned:
 	      return 0;
@@ -121,7 +121,7 @@ void __vpiStringConst::vpi_get_value(p_vpi_value vp)
 {
       unsigned uint_value;
       p_vpi_vecval vecp;
-      unsigned size = strlen(value_);
+      unsigned size = value_len_;
       char*rbuf = 0;
       char*cp;
 
@@ -131,9 +131,22 @@ void __vpiStringConst::vpi_get_value(p_vpi_value vp)
 	    vp->format = vpiStringVal;
 	    // fallthrough
 	  case vpiStringVal:
+	    cp = value_;
 	    rbuf = (char *) need_result_buf(size + 1, RBUF_VAL);
-	    strcpy(rbuf, value_);
 	    vp->value.str = rbuf;
+
+	    for (unsigned int i = 0; i < size; i++) {
+		  // Ignore leading null-bytes and replace other null-bytes with space.
+		  // The LRM is not entirely clear on how null bytes should be handled.
+		  // This is the implementation chosen for iverilog.
+		  if (*cp)
+			*rbuf++ = *cp;
+		  else if (rbuf != vp->value.str)
+			*rbuf++ = ' ';
+
+		  cp++;
+	    }
+	    *rbuf = '\0';
 	    break;
 
           case vpiDecStrVal:

vvp/vpi_priv.cc

@@ -635,6 +635,8 @@ static void vec4_get_value_string(const vvp_vector4_t&word_val, unsigned width,
 
 	    if (char_val != 0)
 		  *cp++ = char_val;
+	    else if (cp != rbuf)
+		  *cp++ = ' ';
       }
 
       for (unsigned idx = 0 ;  idx < nchar ;  idx += 1) {
@@ -645,8 +647,13 @@ static void vec4_get_value_string(const vvp_vector4_t&word_val, unsigned width,
 		  if (val == BIT4_1)
 			char_val |= 1 << bdx;
 	    }
+	    // Ignore leading null-bytes and replace other null-bytes with space.
+	    // The LRM is not entirely clear on how null bytes should be handled.
+	    // This is the implementation chosen for iverilog.
 	    if (char_val != 0)
 		  *cp++ = char_val;
+	    else if (cp != rbuf)
+		  *cp++ = ' ';
       }
 
       *cp = 0;