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Add lint check for bad delay locations.

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This commit is contained in:
Wilson Snyder
2020-05-06 19:25:13 -04:00
parent ee1b20e1cd
commit ca77a93214
5 changed files with 86 additions and 14 deletions
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src/V3Const.cpp
+12 -8
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@@ -102,7 +102,7 @@ private:
bool m_doShort; // Remove expressions that short circuit
bool m_doV; // Verilog, not C++ conversion
bool m_doGenerate; // Postpone width checking inside generate
bool m_hasJumpGo; // JumpGo under this while
bool m_hasJumpDelay; // JumpGo or Delay under this while
AstNodeModule* m_modp; // Current module
AstArraySel* m_selp; // Current select
AstNode* m_scopep; // Current scope
@@ -2114,11 +2114,11 @@ private:
iterateChildren(nodep);
}
virtual void visit(AstWhile* nodep) VL_OVERRIDE {
bool oldHasJumpGo = m_hasJumpGo;
m_hasJumpGo = false;
bool oldHasJumpDelay = m_hasJumpDelay;
m_hasJumpDelay = false;
{ iterateChildren(nodep); }
bool thisWhileHasJumpGo = m_hasJumpGo;
m_hasJumpGo = thisWhileHasJumpGo || oldHasJumpGo;
bool thisWhileHasJumpDelay = m_hasJumpDelay;
m_hasJumpDelay = thisWhileHasJumpDelay || oldHasJumpDelay;
if (m_doNConst) {
if (nodep->condp()->isZero()) {
UINFO(4, "WHILE(0) => nop " << nodep << endl);
@@ -2129,7 +2129,7 @@ private:
}
VL_DO_DANGLING(nodep->deleteTree(), nodep);
} else if (nodep->condp()->isNeqZero()) {
if (!thisWhileHasJumpGo) {
if (!thisWhileHasJumpDelay) {
nodep->v3warn(INFINITELOOP, "Infinite loop (condition always true)");
nodep->fileline()->modifyWarnOff(V3ErrorCode::INFINITELOOP,
true); // Complain just once
@@ -2161,9 +2161,13 @@ private:
//-----
// Jump elimination
virtual void visit(AstDelay* nodep) VL_OVERRIDE {
iterateChildren(nodep);
m_hasJumpDelay = true;
}
virtual void visit(AstJumpGo* nodep) VL_OVERRIDE {
iterateChildren(nodep);
m_hasJumpGo = true;
m_hasJumpDelay = true;
if (m_doExpensive) {
// If last statement in a jump label we have JumpLabel(...., JumpGo)
// Often caused by "return" in a Verilog function. The Go is pointless, remove.
@@ -2566,7 +2570,7 @@ public:
m_doShort = true; // Presently always done
m_doV = false;
m_doGenerate = false; // Inside generate conditionals
m_hasJumpGo = false;
m_hasJumpDelay = false;
m_warn = false;
m_wremove = true; // Overridden in visitors
m_modp = NULL;