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Use width context for stream concat checks

This commit is contained in:
JAEUK LEE 2026-07-08 19:01:51 +09:00
parent c440c46bd0
commit 7655ccf400
3 changed files with 76 additions and 45 deletions
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114
src/V3Width.cpp
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@ -109,6 +109,12 @@ std::ostream& operator<<(std::ostream& str, const Determ& rhs) {
return str << s_det[rhs];
}
enum StreamUse : uint8_t {
STREAM_USE_NONE,
STREAM_USE_ASSIGN,
STREAM_USE_CAST,
};
#define v3widthWarn(lhs, rhs, msg) \
v3warnCode(((lhs) < (rhs) ? V3ErrorCode::WIDTHTRUNC \
: (lhs) > (rhs) ? V3ErrorCode::WIDTHEXPAND \
@ -122,21 +128,27 @@ class WidthVP final {
// Parameters to pass down hierarchy with visit functions.
AstNodeDType* const m_dtypep; // Parent's data type to resolve to
const Stage m_stage; // If true, report errors
const StreamUse m_streamUse; // Whether current expression may be a stream concat
public:
WidthVP(AstNodeDType* dtypep, Stage stage)
WidthVP(AstNodeDType* dtypep, Stage stage, StreamUse streamUse = STREAM_USE_NONE)
: m_dtypep{dtypep}
, m_stage{stage} {
, m_stage{stage}
, m_streamUse{streamUse} {
// Prelim doesn't look at assignments, so shouldn't need a dtype,
// however AstPattern uses them
}
WidthVP(Determ determ, Stage stage)
WidthVP(Determ determ, Stage stage, StreamUse streamUse = STREAM_USE_NONE)
: m_dtypep{nullptr}
, m_stage{stage} {
, m_stage{stage}
, m_streamUse{streamUse} {
if (determ != SELF && stage != PRELIM)
v3fatalSrc("Context-determined width request only allowed as prelim step");
}
WidthVP* p() { return this; }
bool selfDtm() const { return m_dtypep == nullptr; }
StreamUse streamUse() const { return m_streamUse; }
bool streamUseAllowed() const { return m_streamUse != STREAM_USE_NONE; }
AstNodeDType* dtypep() const {
// Detect where overrideDType is probably the intended call
UASSERT(m_dtypep, "Width dtype request on self-determined or preliminary VUP");
@ -164,12 +176,17 @@ public:
bool final() const { return m_stage & FINAL; }
void dump(std::ostream& str) const {
if (!m_dtypep) {
str << " VUP(s=" << m_stage << ",self)";
str << " VUP(s=" << m_stage << ",self";
} else {
str << " VUP(s=" << m_stage << ",dt=" << cvtToHex(dtypep());
dtypep()->dumpSmall(str);
str << ")";
}
if (m_streamUse == STREAM_USE_ASSIGN) {
str << ",stream=assign";
} else if (m_streamUse == STREAM_USE_CAST) {
str << ",stream=cast";
}
str << ")";
}
};
std::ostream& operator<<(std::ostream& str, const WidthVP* vup) {
@ -255,6 +272,12 @@ class WidthVisitor final : public VNVisitor {
EXTEND_OFF // No extension
};
static StreamUse streamUseForDeterm(Determ determ) {
return determ == ASSIGN ? STREAM_USE_ASSIGN : STREAM_USE_NONE;
}
StreamUse currentStreamUse() const { return m_vup ? m_vup->streamUse() : STREAM_USE_NONE; }
static void packIfUnpacked(AstNodeExpr* const nodep) {
if (AstUnpackArrayDType* const unpackDTypep = VN_CAST(nodep->dtypep(), UnpackArrayDType)) {
const int elementsNum = unpackDTypep->arrayUnpackedElements();
@ -970,29 +993,18 @@ class WidthVisitor final : public VNVisitor {
}
}
bool streamImplicitUseAllowed(const AstNodeStream* nodep) const {
const AstNode* backp = nodep->backp();
while (true) {
if (VN_IS(backp, Arg) || VN_IS(backp, SFormatArg) || VN_IS(backp, CvtArrayToArray)
|| VN_IS(backp, CvtArrayToPacked) || VN_IS(backp, CvtPackedToArray)
|| VN_IS(backp, CvtPackString) || VN_IS(backp, CvtUnpackedToQueue)) {
backp = backp->backp();
} else {
break;
}
}
if (m_streamConcat) return true;
if (m_vup && m_vup->streamUseAllowed()) return true;
const AstNode* const backp = nodep->backp();
if (!backp) return true; // Error elsewhere
// IEEE allows streaming concatenations as assignment sources/targets, nested inside
// another stream, or after an explicit cast. Other expression operands require a cast.
return VN_IS(backp, NodeAssign) //
|| VN_IS(backp, Var) //
|| VN_IS(backp, MemberDType) //
|| VN_IS(backp, Pin) //
|| VN_IS(backp, NodeFTaskRef) //
|| VN_IS(backp, NodeStream) //
|| VN_IS(backp, Cast) //
|| VN_IS(backp, CastSize) //
|| VN_IS(backp, CastWrap);
if (const AstNodeAssign* const assignp = VN_CAST(backp, NodeAssign)) {
return assignp->lhsp() == nodep || assignp->rhsp() == nodep;
}
// Explicit cast nodes are legal contexts for the stream operand.
return VN_IS(backp, Cast) || VN_IS(backp, CastSize) || VN_IS(backp, CastWrap);
}
void visit(AstNodeStream* nodep) override {
VL_RESTORER(m_streamConcat);
@ -2102,31 +2114,31 @@ class WidthVisitor final : public VNVisitor {
void visit(AstCvtPackString* nodep) override {
if (nodep->didWidthAndSet()) return;
// Opaque returns, so arbitrary
userIterateAndNext(nodep->lhsp(), WidthVP{SELF, BOTH}.p());
userIterateAndNext(nodep->lhsp(), WidthVP{SELF, BOTH, currentStreamUse()}.p());
// Type set in constructor
}
void visit(AstCvtPackedToArray* nodep) override {
if (nodep->didWidthAndSet()) return;
// Opaque returns, so arbitrary
userIterateAndNext(nodep->fromp(), WidthVP{SELF, BOTH}.p());
userIterateAndNext(nodep->fromp(), WidthVP{SELF, BOTH, currentStreamUse()}.p());
// Type set in constructor
}
void visit(AstCvtArrayToArray* nodep) override {
if (nodep->didWidthAndSet()) return;
// Opaque returns, so arbitrary
userIterateAndNext(nodep->fromp(), WidthVP{SELF, BOTH}.p());
userIterateAndNext(nodep->fromp(), WidthVP{SELF, BOTH, currentStreamUse()}.p());
// Type set in constructor
}
void visit(AstCvtArrayToPacked* nodep) override {
if (nodep->didWidthAndSet()) return;
// Opaque returns, so arbitrary
userIterateAndNext(nodep->fromp(), WidthVP{SELF, BOTH}.p());
userIterateAndNext(nodep->fromp(), WidthVP{SELF, BOTH, currentStreamUse()}.p());
// Type set in constructor
}
void visit(AstCvtUnpackedToQueue* nodep) override {
if (nodep->didWidthAndSet()) return;
// Opaque returns, so arbitrary
userIterateAndNext(nodep->fromp(), WidthVP{SELF, BOTH}.p());
userIterateAndNext(nodep->fromp(), WidthVP{SELF, BOTH, currentStreamUse()}.p());
// Type set in constructor
}
void visit(AstTimeImport* nodep) override {
@ -2846,7 +2858,7 @@ class WidthVisitor final : public VNVisitor {
if (m_vup->final()) {
UINFOTREE(9, nodep, "", "CastFPit");
iterateCheck(nodep, "value", nodep->fromp(), SELF, FINAL, nodep->fromp()->dtypep(),
EXTEND_EXP, false);
EXTEND_EXP, false, STREAM_USE_CAST);
UINFOTREE(9, nodep, "", "CastFin");
AstNodeExpr* const underp = nodep->fromp()->unlinkFrBack();
underp->dtypeFrom(nodep);
@ -7544,7 +7556,7 @@ class WidthVisitor final : public VNVisitor {
// Output args: at return caller = callee, reverse direction.
checkClassAssign(nodep, "Function Argument", pinp, portDTypep,
portp->direction() == VDirection::OUTPUT);
userIterate(pinp, WidthVP{portDTypep, FINAL}.p());
userIterate(pinp, WidthVP{portDTypep, FINAL, STREAM_USE_ASSIGN}.p());
} else {
iterateCheckAssign(nodep, "Function Argument", pinp, FINAL, portDTypep);
}
@ -9213,7 +9225,7 @@ class WidthVisitor final : public VNVisitor {
AstNode* iterateCheck(AstNode* parentp, const char* side, AstNode* underp, Determ determ,
Stage stage, AstNodeDType* expDTypep, ExtendRule extendRule,
bool warnOn = true) {
bool warnOn = true, StreamUse streamUse = STREAM_USE_NONE) {
// Perform data type check on underp, which is underneath parentp used for error reporting
// Returns the new underp
// Conversion to/from doubles and integers are before iterating.
@ -9221,30 +9233,37 @@ class WidthVisitor final : public VNVisitor {
UASSERT_OBJ(underp, parentp, "Node has no child");
UASSERT_OBJ(underp->dtypep(), underp,
"Node has no type"); // Perhaps forgot to do a prelim visit on it?
const StreamUse childStreamUse
= streamUse != STREAM_USE_NONE ? streamUse : streamUseForDeterm(determ);
if (VN_IS(underp, NodeDType)) { // Note the node itself, not node's data type
// Must be near top of these checks as underp->dtypep() will look normal
underp->v3error(ucfirst(parentp->prettyOperatorName())
<< " expected non-datatype " << side << " but "
<< underp->prettyNameQ() << " is a datatype.");
} else if (expDTypep == underp->dtypep()) { // Perfect
underp = userIterateSubtreeReturnEdits(underp, WidthVP{expDTypep, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
underp, WidthVP{expDTypep, FINAL, childStreamUse}.p());
} else if (expDTypep->isDouble() && underp->isDouble()) { // Also good
underp = userIterateSubtreeReturnEdits(underp, WidthVP{expDTypep, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
underp, WidthVP{expDTypep, FINAL, childStreamUse}.p());
} else if (expDTypep->isDouble() && !underp->isDouble()) {
AstNode* const oldp
= underp; // Need FINAL on children; otherwise splice would block it
spliceCvtD(VN_AS(underp, NodeExpr));
underp = userIterateSubtreeReturnEdits(oldp, WidthVP{SELF, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
oldp, WidthVP{SELF, FINAL, childStreamUse}.p());
} else if (!expDTypep->isDouble() && underp->isDouble()) {
AstNode* const oldp
= underp; // Need FINAL on children; otherwise splice would block it
spliceCvtS(VN_AS(underp, NodeExpr), true, expDTypep->width()); // Round RHS
underp = userIterateSubtreeReturnEdits(oldp, WidthVP{SELF, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
oldp, WidthVP{SELF, FINAL, childStreamUse}.p());
} else if (expDTypep->isString() && !underp->dtypep()->isString()) {
AstNode* const oldp
= underp; // Need FINAL on children; otherwise splice would block it
spliceCvtString(VN_AS(underp, NodeExpr));
underp = userIterateSubtreeReturnEdits(oldp, WidthVP{SELF, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
oldp, WidthVP{SELF, FINAL, childStreamUse}.p());
} else {
const AstBasicDType* const expBasicp = expDTypep->basicp();
const AstBasicDType* const underBasicp = underp->dtypep()->basicp();
@ -9272,7 +9291,8 @@ class WidthVisitor final : public VNVisitor {
// is e.g. an ADD, the ADD will auto-adjust to the proper data type
// or if another operation e.g. ATOI will not.
if (determ == SELF) {
underp = userIterateSubtreeReturnEdits(underp, WidthVP{SELF, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
underp, WidthVP{SELF, FINAL, childStreamUse}.p());
} else if (determ == ASSIGN) {
// IEEE: Signedness is solely determined by the RHS
// (underp), not by the LHS (expDTypep)
@ -9284,9 +9304,11 @@ class WidthVisitor final : public VNVisitor {
VSigning::fromBool(underp->isSigned()));
UINFO(9, "Assignment of opposite-signed RHS to LHS: " << parentp);
}
underp = userIterateSubtreeReturnEdits(underp, WidthVP{subDTypep, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
underp, WidthVP{subDTypep, FINAL, childStreamUse}.p());
} else {
underp = userIterateSubtreeReturnEdits(underp, WidthVP{subDTypep, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
underp, WidthVP{subDTypep, FINAL, childStreamUse}.p());
}
// Note the check uses the expected size, not the child's subDTypep as we want the
// child node's width to end up correct for the assignment (etc)
@ -9325,11 +9347,13 @@ class WidthVisitor final : public VNVisitor {
<< " interface modport on " << side << " but got "
<< underIfaceRefp->modportp()->prettyNameQ() << " modport.");
} else {
underp = userIterateSubtreeReturnEdits(underp, WidthVP{expDTypep, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
underp, WidthVP{expDTypep, FINAL, childStreamUse}.p());
}
} else {
// Hope it just works out (perhaps a cast will deal with it)
underp = userIterateSubtreeReturnEdits(underp, WidthVP{expDTypep, FINAL}.p());
underp = userIterateSubtreeReturnEdits(
underp, WidthVP{expDTypep, FINAL, childStreamUse}.p());
}
}
return underp;

5
test_regress/t/t_display_stream_bad.out
View File

@ -39,4 +39,9 @@
: ... Suggest use a cast
26 | void'($sformatf("%0d", {<<{value}}));
| ^~
%Error: t/t_display_stream_bad.v:27:27: Streaming concatenation cannot be used in an implicitly cast context (IEEE 1800-2023 11.4.17)
: ... note: In instance 't'
: ... Suggest use a cast
27 | result = passthrough({<<{value}} + 1);
| ^~
%Error: Exiting due to

2
test_regress/t/t_display_stream_bad.v
View File

@ -24,6 +24,8 @@ module t;
$display({<<{value}});
$display("%0d", {<<{value}});
void'($sformatf("%0d", {<<{value}}));
result = passthrough({<<{value}} + 1);
result = int'({<<{value}});
result = int'({<<{value}}) + 1;
end
endmodule