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For UNUSED, better by-bit warnings

This commit is contained in:
Wilson Snyder 2010-12-29 19:59:07 -05:00
parent 809e5fda8a
commit f85c1a995a
3 changed files with 50 additions and 25 deletions
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65
src/V3Undriven.cpp
View File

@ -75,15 +75,19 @@ public:
private:
// METHODS
inline bool bitNumOk(int bit) const { return (bit*FLAGS_PER_BIT < (int)m_flags.size()); }
inline bool usedFlag(int bit) { return m_flags[bit*FLAGS_PER_BIT + FLAG_USED]; }
inline bool drivenFlag(int bit) { return m_flags[bit*FLAGS_PER_BIT + FLAG_DRIVEN]; }
string bitNames(int index) {
inline bool usedFlag(int bit) { return m_usedWhole || m_flags[bit*FLAGS_PER_BIT + FLAG_USED]; }
inline bool drivenFlag(int bit) { return m_drivenWhole || m_flags[bit*FLAGS_PER_BIT + FLAG_DRIVEN]; }
enum BitNamesWhich { BN_UNUSED, BN_UNDRIVEN, BN_BOTH };
string bitNames(BitNamesWhich which) {
string bits="";
bool prev = false;
int msb = 0;
// bit==-1 loops below; we do one extra iteration so end with prev=false
for (int bit=(m_flags.size()/FLAGS_PER_BIT)-1; bit >= -1; --bit) {
if (bit>=0 && !m_flags[bit*FLAGS_PER_BIT + index]) {
if (bit>=0
&& ((which == BN_UNUSED && !usedFlag(bit) && drivenFlag(bit))
|| (which == BN_UNDRIVEN && usedFlag(bit) && !drivenFlag(bit))
|| (which == BN_BOTH && !usedFlag(bit) && !drivenFlag(bit)))) {
if (!prev) { prev=true; msb = bit; }
} else if (prev) {
AstBasicDType* bdtypep = m_varp->basicp();
@ -136,33 +140,46 @@ public:
bool allD=true;
bool anyU=m_usedWhole;
bool anyD=m_drivenWhole;
bool anyUnotD=false;
bool anyDnotU=false;
bool anynotDU=false;
for (unsigned bit=0; bit<m_flags.size()/FLAGS_PER_BIT; bit++) {
allU &= usedFlag(bit);
anyU |= usedFlag(bit);
allD &= drivenFlag(bit);
anyD |= drivenFlag(bit);
bool used = usedFlag(bit);
bool driv = drivenFlag(bit);
allU &= used;
anyU |= used;
allD &= driv;
anyD |= driv;
anyUnotD |= used && !driv;
anyDnotU |= !used && driv;
anynotDU |= !used && !driv;
}
if (allU) m_usedWhole = true;
if (allD) m_drivenWhole = true;
// Test results
if (m_usedWhole && m_drivenWhole) {
// Ignore
}
else if (!anyU && !anyD) {
nodep->v3warn(UNDRIVEN, "Signal is not driven, nor used: "<<nodep->prettyName());
}
else {
if (!m_usedWhole && !anyU) {
nodep->v3warn(UNUSED, "Signal is not used: "<<nodep->prettyName());
} else if (!m_usedWhole) {
nodep->v3warn(UNUSED, "Bits of signal are not used: "<<nodep->prettyName()
<<bitNames(FLAG_USED));
if (allU && allD) {
// It's fine
} else if (!anyD && !anyU) {
// UNDRIVEN is considered more serious - as is more likely a bug,
// thus undriven+unused bits get UNUSED warnings, as they're not as buggy.
nodep->v3warn(UNUSED, "Signal is not driven, nor used: "<<nodep->prettyName());
} else if (allD && !anyU) {
nodep->v3warn(UNUSED, "Signal is not used: "<<nodep->prettyName());
} else if (!anyD && allU) {
nodep->v3warn(UNDRIVEN, "Signal is not driven: "<<nodep->prettyName());
} else {
// Bits have different dispositions
if (anynotDU) {
nodep->v3warn(UNUSED, "Bits of signal are not driven, nor used: "<<nodep->prettyName()
<<bitNames(BN_BOTH));
}
if (!m_drivenWhole && !anyD) {
nodep->v3warn(UNDRIVEN, "Signal is not driven: "<<nodep->prettyName());
} else if (!m_drivenWhole) {
if (anyDnotU) {
nodep->v3warn(UNUSED, "Bits of signal are not used: "<<nodep->prettyName()
<<bitNames(BN_UNUSED));
}
if (anyUnotD) {
nodep->v3warn(UNDRIVEN, "Bits of signal are not driven: "<<nodep->prettyName()
<<bitNames(FLAG_DRIVEN));
<<bitNames(BN_UNDRIVEN));
}
}
}

5
test_regress/t/t_lint_unused_bad.pl
View File

@ -17,7 +17,10 @@ compile (
'%Warning-UNUSED: t/t_lint_unused_bad.v:\d+: Bits of signal are not used: assunu1\[5:1\]
%Warning-UNUSED: Use .* to disable this message.
%Warning-UNDRIVEN: t/t_lint_unused_bad.v:\d+: Bits of signal are not driven: udrb2\[14:13,11\]
%Warning-UNDRIVEN: t/t_lint_unused_bad.v:\d+: Signal is not driven, nor used: unu3
%Warning-UNUSED: t/t_lint_unused_bad.v:\d+: Signal is not driven, nor used: unu3
%Warning-UNUSED: t/t_lint_unused_bad.v:\d+: Bits of signal are not driven, nor used: mixed\[3\]
%Warning-UNUSED: t/t_lint_unused_bad.v:\d+: Bits of signal are not used: mixed\[2\]
%Warning-UNDRIVEN: t/t_lint_unused_bad.v:\d+: Bits of signal are not driven: mixed\[1\]
%Error: Exiting due to.*',
) if $Self->{v3};

5
test_regress/t/t_lint_unused_bad.v
View File

@ -34,10 +34,15 @@ module sub;
wire unu3; // Totally unused
wire [3:0] mixed; // [3] unused & undr, [2] unused, [1] undr, [0] ok
assign mixed[2] = 0;
assign mixed[0] = 0;
localparam THREE = 3;
initial begin
if (0 && assunu1[0] != 0 && udrb2 != 0) begin end
if (0 && assunub2[THREE] && assunub2[1:0]!=0) begin end
if (0 && mixed[1:0] != 0) begin end
end
endmodule