From 27f3de54874ab86bd53a50fc3f1b390273722ec9 Mon Sep 17 00:00:00 2001
From: Clark Coleman <clc@zephyr-software.com>
Date: Tue, 25 Aug 2020 17:40:15 -0400
Subject: [PATCH] SPARK crash fixes.
---
src/base/SMPFunction.cpp | 32 ++++++++++++++++++++++++++------
1 file changed, 26 insertions(+), 6 deletions(-)
diff --git a/src/base/SMPFunction.cpp b/src/base/SMPFunction.cpp
index 15ff7959..05576858 100644
--- a/src/base/SMPFunction.cpp
+++ b/src/base/SMPFunction.cpp
@@ -12074,6 +12074,14 @@ void SMPFunction::FindGuardedLoops(void) {
SMPBasicBlock *NextBlock = (*NextBlockIter);
if (NextBlock->IsLoopHeaderBlock()) {
// The less simple case: some [straight-line code] between COND_BRANCH and loop header.
+
+ // To prevent being deceived by the case in which we fall through
+ // to the tail block, which the compiler has placed so that the tail block falls through
+ // to the loop header block, we require that the FallThroughBlock must dominate the loop
+ // header block. Simple, fast screening before concluding.
+ bool CorrectDomTreeStructure = this->DoesBlockDominateBlock((int) BlockIndex, NextBlock->GetNumber());
+ if (!CorrectDomTreeStructure)
+ continue; // move on to next block
FoundGuardedLoop = true;
LoopAddr = NextBlock->GetFirstNonMarkerAddr();
}
@@ -18125,7 +18133,7 @@ void SMPFunction::Dump(void) {
if (this->LoopCount > 0) {
SMP_msg("Block numbers by loop number:\n");
for (size_t LoopNum = 0; LoopNum < this->LoopCount; ++LoopNum) {
- SMP_msg("Loop %d : ", LoopNum);
+ SMP_msg("Loop %d : Loop Type: %d :", LoopNum, this->LoopTypesByLoopNum[LoopNum]);
for (size_t BlockNum = 0; BlockNum < (size_t)this->BlockCount; ++BlockNum) {
if (this->FuncBlocksByLoop[LoopNum].GetBit(BlockNum)) {
SMP_msg(" %zu", BlockNum);
@@ -18796,6 +18804,13 @@ void SMPFunction::PreProcessForSPARKAdaTranslation(void) {
}
}
size_t BlockNum = (size_t) CurrBlock->GetNumber();
+ vector<SMPInstr *>::const_reverse_iterator LastInstIter = CurrBlock->GetRevInstCBegin();
+ SMPInstr *LastInst = (*LastInstIter);
+ if (LastInst->IsBranchToOtherFunc()) {
+ SMP_msg("SPARK: WARNING: Bad CFG (branch outside function at %llx) \n", (uint64_t)LastInst->GetAddr());
+ this->HasStructuredCFG = false;
+ }
+
if (HasLoops && CurrBlock->HasMemoryWrite() && this->IsBlockInAnyLoop((int) BlockNum)) {
for (vector<SMPInstr *>::iterator InstIter = CurrBlock->GetFirstInst(); InstIter != CurrBlock->GetLastInst(); ++InstIter) {
SMPInstr *CurrInst = (*InstIter);
@@ -20217,7 +20232,7 @@ void SMPFunction::EmitFuncSPARKAda(void) {
#else
int FollowBlockNum = SMP_BLOCKNUM_UNINIT;
#endif
- this->EmitSPARKAdaForBlock(0, FollowBlockNum, BodyFile, false);
+ this->EmitSPARKAdaForBlock(0, FollowBlockNum, BodyFile, false, false);
SMP_fprintf(BodyFile, "\nend %s;\n\n", AdaFuncName.c_str());
STARS_SPARK_IndentCount = 1;
@@ -21636,8 +21651,10 @@ void SMPFunction::EmitSPARKAdaForBlock(int CurrBlockNum, int FollowBlockNum, FIL
bool TranslatingGuardedLoop = (this->LoopToGuardMap.find(LoopAddr) != this->LoopToGuardMap.cend());
int NextFollowBlockNum = this->LoopFollowNodes[LoopNum];
// Could end with a loop if we call abort, etc., in which case no follow block.
- // Otherwise, we should have a follow block.
- assert((SMP_BLOCKNUM_UNINIT != NextFollowBlockNum) || (!this->FuncReturnsToCaller()));
+ // Could be an infinite loop. Otherwise, we should have a follow block.
+ bool FuncMightNotReturn = ((!this->FuncReturnsToCaller()) || this->HasCallToNonReturningFunc());
+ bool LoopMightBeInfinite = (STARS_INFINITE_OR_MIDDLE_TESTING_LOOP == this->LoopTypesByLoopNum[LoopNum]);
+ assert((SMP_BLOCKNUM_UNINIT != NextFollowBlockNum) || FuncMightNotReturn || LoopMightBeInfinite);
if (LoopToProc) {
assert(TranslatingGuardedLoop || (ResumeBlockNum == NextFollowBlockNum)); // should be passed in as loop follow block number
@@ -21761,7 +21778,7 @@ void SMPFunction::EmitSPARKAdaForBlock(int CurrBlockNum, int FollowBlockNum, FIL
}
else if (FlowType == JUMP) {
// Get control flow type of the jump
- assert(1 == CurrBlock->GetNumSuccessors());
+ assert((1 == CurrBlock->GetNumSuccessors()) || LastInst->IsBranchToOtherFunc());
if (JUMP_INTO_LOOP_TEST == LastCFType) {
// Optimized top-testing loop becomes a bottom-testing loop with a jump to the loop header/loop-test
// block for the first iteration. We translate as a top-testing loop in Ada by starting with the
@@ -21834,7 +21851,10 @@ void SMPFunction::EmitSPARKAdaForBlock(int CurrBlockNum, int FollowBlockNum, FIL
ResumeBlockNum = FallThroughSucc->GetNumber();
}
else {
- assert(((FlowType == CALL) || (FlowType == HALT) || CurrBlock->IsUnreachableBlock()) && (0 == NumSuccessors));
+ // Nop at end of block could be for alignment, masking the control flow type of CALL
+ // or HALT before it.
+ assert(((FlowType == CALL) || (FlowType == HALT) || CurrBlock->IsUnreachableBlock() || LastInst->IsNop())
+ && (0 == NumSuccessors));
}
}
} // end if header block ... elsif tail block ... else ...
--
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