Fix missing leading zeros in %0d, bug367

Changes

@@ -11,6 +11,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 ***  Support $fopen and I/O with integer instead of `verilator_file_descriptor.
 
+**** Fix $display missing leading zeros in %0d, bug367.  [Alex Solomatnikov]
+
 **** Use 'vluint64_t' for SystemC instead of (same sized) 'uint64' for MSVC++.
 
 * Verilator 3.813 2011/06/28

include/verilated.cpp

@@ -284,12 +284,14 @@ void _vl_vsformat(string& output, const char* formatp, va_list ap) {
     // Note also assumes variables < 64 are not wide, this assumption is
     // sometimes not true in low-level routines written here in verilated.cpp
     static VL_THREAD char tmp[VL_VALUE_STRING_MAX_WIDTH];
+    const char* pctp = NULL;  // Most recent %##.##g format
     bool inPct = false;
     bool widthSet = false;
     int width = 0;
     const char* pos = formatp;
     for (; *pos; ++pos) {
 	if (!inPct && pos[0]=='%') {
+	    pctp = pos;
 	    inPct = true;
 	    widthSet = false;
 	    width = 0;
@@ -311,6 +313,9 @@ void _vl_vsformat(string& output, const char* formatp, va_list ap) {
 		widthSet = true;
 		width = width*10 + (fmt - '0');
 		break;
+	    case '.':
+		inPct = true;  // Get more digits
+		break;
 	    case '%':
 		output += '%';
 		break;
@@ -357,14 +362,26 @@ void _vl_vsformat(string& output, const char* formatp, va_list ap) {
 		case 'd': { // Signed decimal
 		    int digits=sprintf(tmp,"%" VL_PRI64 "d",(vlsint64_t)(VL_EXTENDS_QQ(lbits,lbits,ld)));
 		    int needmore = width-digits;
-		    if (needmore>0) output.append(needmore,' '); // Pre-pad spaces
+		    if (needmore>0) {
+			if (pctp && pctp[0] && pctp[1]=='0') { //%0
+			    output.append(needmore,'0'); // Pre-pad zero
+			} else {
+			    output.append(needmore,' '); // Pre-pad spaces
+			}
+		    }
 		    output += tmp;
 		    break;
 		}
 		case 'u': { // Unsigned decimal
 		    int digits=sprintf(tmp,"%" VL_PRI64 "u",ld);
 		    int needmore = width-digits;
-		    if (needmore>0) output.append(needmore,' '); // Pre-pad spaces
+		    if (needmore>0) {
+			if (pctp && pctp[0] && pctp[1]=='0') { //%0
+			    output.append(needmore,'0'); // Pre-pad zero
+			} else {
+			    output.append(needmore,' '); // Pre-pad spaces
+			}
+		    }
 		    output += tmp;
 		    break;
 		}

src/V3Number.cpp

@@ -472,7 +472,11 @@ string V3Number::displayed(const string& vformat) const {
 	    str = cvtToStr(toUQuad());
 	}
 	int intfmtsize = atoi(fmtsize.c_str());
-	while ((int)(str.length()) < intfmtsize) str = " "+str;
+	bool zeropad = fmtsize.length()>0 && fmtsize[0]=='0';
+	while ((int)(str.length()) < intfmtsize) {
+	    if (zeropad) str = "0"+str;
+	    else str = " "+str;
+	}
 	return str;
     }
     default:

test_regress/t/t_display.pl

@@ -19,8 +19,9 @@ execute (
 [0] In top.v.sub2
 [0] In top.v.sub2.subblock2
 [0] Back \ Quote "
-[0] %X=0c %D=12 %0X=c %0O=14 %B=001100
+[0] %X=0c %0X=c %0O=14 %B=001100
-[0] %x=0c %d=12 %0x=c %0o=14 %b=001100
+[0] %x=0c %0x=c %0o=14 %b=001100
+[0] %D=12 %d=12 %01d=12 %06d=000012 %6d=    12
 [0] %x=00abbbbcccc %0x=abbbbcccc %o=00527356746314 %b=00000101010111011101110111100110011001100
 [0] %x=00abc1234567812345678 %0x=abc1234567812345678 %o=012570110642547402215053170 %b=000001010101111000001001000110100010101100111100000010010001101000101011001111000
 

test_regress/t/t_display.v

@@ -22,9 +22,11 @@ module t;
       $display("[%0t] Back \\ Quote \"", $time);  // Old bug when \" last on the line.
 
       // Display formatting
-      $display("[%0t] %%X=%X %%D=%D %%0X=%0X %%0O=%0O %%B=%B", $time,
+      $display("[%0t] %%X=%X %%0X=%0X %%0O=%0O %%B=%B", $time,
-	       quad[5:0], quad[5:0], quad[5:0], quad[5:0], quad[5:0]);
+	       quad[5:0], quad[5:0], quad[5:0], quad[5:0]);
-      $display("[%0t] %%x=%x %%d=%d %%0x=%0x %%0o=%0o %%b=%b", $time,
+      $display("[%0t] %%x=%x %%0x=%0x %%0o=%0o %%b=%b", $time,
+	       quad[5:0], quad[5:0], quad[5:0], quad[5:0]);
+      $display("[%0t] %%D=%D %%d=%d %%01d=%01d %%06d=%06d %%6d=%6d", $time,
 	       quad[5:0], quad[5:0], quad[5:0], quad[5:0], quad[5:0]);
       $display("[%0t] %%x=%x %%0x=%0x %%o=%o %%b=%b", $time,
 	       quad, quad, quad, quad);

test_regress/t/t_display_noopt.pl

@@ -22,8 +22,9 @@ execute (
 [0] In top.v.sub2
 [0] In top.v.sub2.subblock2
 [0] Back \ Quote "
-[0] %X=0c %D=12 %0X=c %0O=14 %B=001100
+[0] %X=0c %0X=c %0O=14 %B=001100
-[0] %x=0c %d=12 %0x=c %0o=14 %b=001100
+[0] %x=0c %0x=c %0o=14 %b=001100
+[0] %D=12 %d=12 %01d=12 %06d=000012 %6d=    12
 [0] %x=00abbbbcccc %0x=abbbbcccc %o=00527356746314 %b=00000101010111011101110111100110011001100
 [0] %x=00abc1234567812345678 %0x=abc1234567812345678 %o=012570110642547402215053170 %b=000001010101111000001001000110100010101100111100000010010001101000101011001111000