Support $fseek, $ftell, $frewind, bug1496.

Changes

@@ -4,6 +4,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 * Verilator 4.019 devel
 
+***   Support $fseek, $ftell, $frewind, bug1496. [Howard Su]
+
 ****  Fix make test with no VERILATOR_ROOT, bug1494. [Ahmed El-Mahmoudy]
 
 

docs/CONTRIBUTORS

@@ -6,6 +6,7 @@ Please see the Verilator manual for additional contributors.
 
 Alex Chadwick
 Gianfranco Costamagna
+Howard Su
 Jeremy Bennett
 John Coiner
 Kanad Kanhere

src/V3AstNodes.h

@@ -2876,6 +2876,86 @@ public:
     void countp(AstNode* nodep) { setNOp4p(nodep); }
 };
 
+class AstFRewind : public AstNodeMath {
+    // Parents: stmtlist
+    // Children: file which must be a varref
+public:
+    AstFRewind(FileLine* fileline, AstNode* filep)
+        : AstNodeMath(fileline) {
+        setNOp2p(filep);
+    }
+    ASTNODE_NODE_FUNCS(FRewind)
+    virtual string verilogKwd() const { return "$frewind"; }
+    virtual string emitVerilog() { V3ERROR_NA; return ""; }
+    virtual string emitC() { V3ERROR_NA; return ""; }
+    virtual bool isGateOptimizable() const { return false; }
+    virtual bool isPredictOptimizable() const { return false; }
+    virtual bool isPure() const { return false; }
+    virtual bool isOutputter() const { return true; }
+    virtual bool isUnlikely() const { return true; }
+    virtual bool cleanOut() { return false; }
+    virtual V3Hash sameHash() const { return V3Hash(); }
+    virtual bool same(const AstNode* samep) const { return true; }
+    AstNode* filep() const { return op2p(); }
+    void filep(AstNodeVarRef* nodep) { setNOp2p(nodep); }
+};
+
+class AstFTell : public AstNodeMath {
+    // Parents: stmtlist
+    // Children: file which must be a varref
+public:
+    AstFTell(FileLine* fileline, AstNode* filep)
+        : AstNodeMath(fileline) {
+        setNOp2p(filep);
+    }
+    ASTNODE_NODE_FUNCS(FTell)
+    virtual string verilogKwd() const { return "$ftell"; }
+    virtual string emitVerilog() { V3ERROR_NA; return ""; }
+    virtual string emitC() { V3ERROR_NA; return ""; }
+    virtual bool isGateOptimizable() const { return false; }
+    virtual bool isPredictOptimizable() const { return false; }
+    virtual bool isPure() const { return false; }
+    virtual bool isOutputter() const { return true; }
+    virtual bool isUnlikely() const { return true; }
+    virtual bool cleanOut() { return false; }
+    virtual V3Hash sameHash() const { return V3Hash(); }
+    virtual bool same(const AstNode* samep) const { return true; }
+    AstNode* filep() const { return op2p(); }
+    void filep(AstNodeVarRef* nodep) { setNOp2p(nodep); }
+};
+
+class AstFSeek : public AstNodeMath {
+    // Parents: expr
+    // Children: file which must be a varref
+    // Children: offset
+    // Children: operation
+public:
+    AstFSeek(FileLine* fileline, AstNode* filep,
+             AstNode* offset, AstNode* operation)
+        : AstNodeMath(fileline) {
+        setOp2p(filep);
+        setNOp3p(offset);
+        setNOp4p(operation);
+    }
+    ASTNODE_NODE_FUNCS(FSeek)
+    virtual string verilogKwd() const { return "$fseek"; }
+    virtual string emitVerilog() { V3ERROR_NA; return ""; }
+    virtual string emitC() { V3ERROR_NA; return ""; }
+    virtual bool isGateOptimizable() const { return false; }
+    virtual bool isPredictOptimizable() const { return false; }
+    virtual bool isPure() const { return false; }  // SPECIAL: has 'visual' ordering
+    virtual bool isOutputter() const { return true; }  // SPECIAL: makes output
+    virtual bool cleanOut() { return false; }
+    virtual V3Hash sameHash() const { return V3Hash(); }
+    virtual bool same(const AstNode* samep) const { return true; }
+    AstNode* filep() const { return op2p(); }
+    void filep(AstNode* nodep) { setOp2p(nodep); }
+    AstNode* offset() const { return op3p(); }
+    void offset(AstNode* nodep) { setNOp3p(nodep); }
+    AstNode* operation() const { return op4p(); }
+    void operation(AstNode* nodep) { setNOp4p(nodep); }
+};
+
 class AstFScanF : public AstNodeMath {
     // Parents: expr
     // Children: file which must be a varref

src/V3EmitC.cpp

@@ -395,6 +395,25 @@ public:
             puts(")); }\n");
         }
     }
+    virtual void visit(AstFSeek* nodep) {
+        puts("(fseek(VL_CVT_I_FP(");
+        iterateAndNextNull(nodep->filep());
+        puts("),");
+        iterateAndNextNull(nodep->offset());
+        puts(",");
+        iterateAndNextNull(nodep->operation());
+        puts(")==-1?-1:0)");
+    }
+    virtual void visit(AstFTell* nodep) {
+        puts("ftell(VL_CVT_I_FP(");
+        iterateAndNextNull(nodep->filep());
+        puts("))");
+    }
+    virtual void visit(AstFRewind* nodep) {
+        puts("(fseek(VL_CVT_I_FP(");
+        iterateAndNextNull(nodep->filep());
+        puts("), 0, 0)==-1?-1:0)");
+    }
     virtual void visit(AstFRead* nodep) {
         puts("VL_FREAD_I(");
         puts(cvtToStr(nodep->memp()->widthMin()));  // Need real storage width

src/V3Width.cpp

@@ -2342,6 +2342,20 @@ private:
             iterateCheckFileDesc(nodep, nodep->filep(), BOTH);
         }
     }
+    virtual void visit(AstFRewind* nodep) {
+        iterateCheckFileDesc(nodep, nodep->filep(), BOTH);
+        nodep->dtypeSetLogicUnsized(32, 1, AstNumeric::SIGNED);  // Spec says integer return
+    }
+    virtual void visit(AstFTell* nodep) {
+        iterateCheckFileDesc(nodep, nodep->filep(), BOTH);
+        nodep->dtypeSetLogicUnsized(32, 1, AstNumeric::SIGNED);  // Spec says integer return
+    }
+    virtual void visit(AstFSeek* nodep) {
+        iterateCheckFileDesc(nodep, nodep->filep(), BOTH);
+        iterateCheckSigned32(nodep, "$fseek offset", nodep->offset(), BOTH);
+        iterateCheckSigned32(nodep, "$fseek operation", nodep->operation(), BOTH);
+        nodep->dtypeSetLogicUnsized(32, 1, AstNumeric::SIGNED);  // Spec says integer return
+    }
     virtual void visit(AstFGetC* nodep) {
         if (m_vup->prelim()) {
             iterateCheckFileDesc(nodep, nodep->filep(), BOTH);

src/verilog.l

@@ -179,6 +179,9 @@ vnum    {vnum1}|{vnum2}|{vnum3}|{vnum4}|{vnum5}
   "$fopen"              { FL; return yD_FOPEN; }
   "$fread"              { FL; return yD_FREAD; }
   "$fscanf"             { FL; return yD_FSCANF; }
+  "$fseek"              { FL; return yD_FSEEK; }
+  "$ftell"              { FL; return yD_FTELL; }
+  "$frewind"            { FL; return yD_FREWIND; }
   "$fullskew"           { FL; return yaTIMINGSPEC; }
   "$fwrite"             { FL; return yD_FWRITE; }
   "$hold"               { FL; return yaTIMINGSPEC; }

src/verilog.y

@@ -517,7 +517,10 @@ class AstSenTree;
 %token<fl>		yD_FLOOR	"$floor"
 %token<fl>		yD_FOPEN	"$fopen"
 %token<fl>		yD_FREAD	"$fread"
+%token<fl>		yD_FREWIND	"$frewind"
 %token<fl>		yD_FSCANF	"$fscanf"
+%token<fl>		yD_FSEEK	"$fseek"
+%token<fl>		yD_FTELL	"$ftell"
 %token<fl>		yD_FWRITE	"$fwrite"
 %token<fl>		yD_HIGH		"$high"
 %token<fl>		yD_HYPOT	"$hypot"
@@ -2907,8 +2910,11 @@ system_f_call_or_t<nodep>:	// IEEE: part of system_tf_call (can be task or func)
 	|	yD_FREAD '(' idClassSel ',' expr ')'	{ $$ = new AstFRead($1,$3,$5,NULL,NULL); }
 	|	yD_FREAD '(' idClassSel ',' expr ',' expr ')'	{ $$ = new AstFRead($1,$3,$5,$7,NULL); }
 	|	yD_FREAD '(' idClassSel ',' expr ',' expr ',' expr ')'	{ $$ = new AstFRead($1,$3,$5,$7,$9); }
+	|	yD_FREWIND '(' idClassSel ')'		{ $$ = new AstFRewind($1, $3); }
 	|	yD_FLOOR '(' expr ')'			{ $$ = new AstFloorD($1,$3); }
 	|	yD_FSCANF '(' expr ',' str commaVRDListE ')'	{ $$ = new AstFScanF($1,*$5,$3,$6); }
+	|	yD_FSEEK '(' idClassSel ',' expr ',' expr ')'	{ $$ = new AstFSeek($1,$3,$5,$7); }
+	|	yD_FTELL '(' idClassSel ')'		{ $$ = new AstFTell($1, $3); }
 	|	yD_HIGH '(' exprOrDataType ')'		{ $$ = new AstAttrOf($1,AstAttrType::DIM_HIGH,$3,NULL); }
 	|	yD_HIGH '(' exprOrDataType ',' expr ')'	{ $$ = new AstAttrOf($1,AstAttrType::DIM_HIGH,$3,$5); }
 	|	yD_HYPOT '(' expr ',' expr ')'		{ $$ = new AstHypotD($1,$3,$5); }

test_regress/t/t_sys_file_basic.v

@@ -24,6 +24,8 @@ module t;
    reg [31:0] 	v_worda;
    reg [31:0] 	v_wordb;
 
+   integer v_length, v_off;
+
 `ifdef TEST_VERBOSE
  `define verbose 1'b1
 `else
@@ -225,6 +227,27 @@ module t;
 
 	 if ($fgetc(file) != "\n") $stop;
 
+
+	v_length = $ftell(file);
+	$frewind(file);
+	v_off = $ftell(file);
+	if (v_off != 0) $stop;
+	$fseek(file, 10, 0);
+	v_off = $ftell(file);
+	if (v_off != 10) $stop;
+	$fseek(file, 1, 1);
+	v_off = $ftell(file);
+	if (v_off != 11) $stop;
+	$fseek(file, -1, 1);
+	v_off = $ftell(file);
+	if (v_off != 10) $stop;
+	$fseek(file, v_length, 0);
+	v_off = $ftell(file);
+	if (v_off != v_length) $stop;
+	if ($fseek(file, 0, 2) != 0) $stop;
+	v_off = $ftell(file);
+	if (v_off < v_length) $stop;
+
 	 $fclose(file);
       end