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-rw-r--r--lib/CodeGen/DwarfWriter.cpp77
-rw-r--r--lib/CodeGen/MachineModuleInfo.cpp3
-rw-r--r--lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp8
3 files changed, 60 insertions, 28 deletions
diff --git a/lib/CodeGen/DwarfWriter.cpp b/lib/CodeGen/DwarfWriter.cpp
index d1f195d556..1445a03922 100644
--- a/lib/CodeGen/DwarfWriter.cpp
+++ b/lib/CodeGen/DwarfWriter.cpp
@@ -3013,8 +3013,10 @@ private:
/// CallSiteEntry - Structure describing an entry in the call-site table.
struct CallSiteEntry {
+ // The 'try-range' is BeginLabel .. EndLabel.
unsigned BeginLabel; // zero indicates the start of the function.
unsigned EndLabel; // zero indicates the end of the function.
+ // The landing pad starts at PadLabel.
unsigned PadLabel; // zero indicates that there is no landing pad.
unsigned Action;
};
@@ -3113,13 +3115,21 @@ private:
SizeActions += SizeSiteActions;
}
- // Compute the call-site table. Entries must be ordered by address.
+ // Compute the call-site table. The entry for an invoke has a try-range
+ // containing the call, a non-zero landing pad and an appropriate action.
+ // The entry for an ordinary call has a try-range containing the call and
+ // zero for the landing pad and the action. Calls marked 'nounwind' have
+ // no entry and must not be contained in the try-range of any entry - they
+ // form gaps in the table. Entries must be ordered by try-range address.
SmallVector<CallSiteEntry, 64> CallSites;
RangeMapType PadMap;
+ // Invokes and nounwind calls have entries in PadMap (due to being bracketed
+ // by try-range labels when lowered). Ordinary calls do not, so appropriate
+ // try-ranges for them need be deduced.
for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
const LandingPadInfo *LandingPad = LandingPads[i];
- for (unsigned j=0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
+ for (unsigned j = 0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
unsigned BeginLabel = LandingPad->BeginLabels[j];
assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
PadRange P = { i, j };
@@ -3127,27 +3137,39 @@ private:
}
}
- bool MayThrow = false;
+ // The end label of the previous invoke or nounwind try-range.
unsigned LastLabel = 0;
+
+ // Whether there is a potentially throwing instruction (currently this means
+ // an ordinary call) between the end of the previous try-range and now.
+ bool SawPotentiallyThrowing = false;
+
+ // Whether the last callsite entry was for an invoke.
+ bool PreviousIsInvoke = false;
+
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
+
+ // Visit all instructions in order of address.
for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
I != E; ++I) {
for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
MI != E; ++MI) {
if (MI->getOpcode() != TargetInstrInfo::LABEL) {
- MayThrow |= TII->isCall(MI->getOpcode());
+ SawPotentiallyThrowing |= TII->isCall(MI->getOpcode());
continue;
}
unsigned BeginLabel = MI->getOperand(0).getImmedValue();
assert(BeginLabel && "Invalid label!");
+ // End of the previous try-range?
if (BeginLabel == LastLabel)
- MayThrow = false;
+ SawPotentiallyThrowing = false;
+ // Beginning of a new try-range?
RangeMapType::iterator L = PadMap.find(BeginLabel);
-
if (L == PadMap.end())
+ // Nope, it was just some random label.
continue;
PadRange P = L->second;
@@ -3159,36 +3181,43 @@ private:
// If some instruction between the previous try-range and this one may
// throw, create a call-site entry with no landing pad for the region
// between the try-ranges.
- if (MayThrow) {
+ if (SawPotentiallyThrowing) {
CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
CallSites.push_back(Site);
+ PreviousIsInvoke = false;
}
LastLabel = LandingPad->EndLabels[P.RangeIndex];
- CallSiteEntry Site = {BeginLabel, LastLabel,
- LandingPad->LandingPadLabel, FirstActions[P.PadIndex]};
-
- assert(Site.BeginLabel && Site.EndLabel && Site.PadLabel &&
- "Invalid landing pad!");
-
- // Try to merge with the previous call-site.
- if (CallSites.size()) {
- CallSiteEntry &Prev = CallSites[CallSites.size()-1];
- if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
- // Extend the range of the previous entry.
- Prev.EndLabel = Site.EndLabel;
- continue;
+ assert(BeginLabel && LastLabel && "Invalid landing pad!");
+
+ if (LandingPad->LandingPadLabel) {
+ // This try-range is for an invoke.
+ CallSiteEntry Site = {BeginLabel, LastLabel,
+ LandingPad->LandingPadLabel, FirstActions[P.PadIndex]};
+
+ // Try to merge with the previous call-site.
+ if (PreviousIsInvoke) {
+ CallSiteEntry &Prev = CallSites[CallSites.size()-1];
+ if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
+ // Extend the range of the previous entry.
+ Prev.EndLabel = Site.EndLabel;
+ continue;
+ }
}
- }
- // Otherwise, create a new call-site.
- CallSites.push_back(Site);
+ // Otherwise, create a new call-site.
+ CallSites.push_back(Site);
+ PreviousIsInvoke = true;
+ } else {
+ // Create a gap.
+ PreviousIsInvoke = false;
+ }
}
}
// If some instruction between the previous try-range and the end of the
// function may throw, create a call-site entry with no landing pad for the
// region following the try-range.
- if (MayThrow) {
+ if (SawPotentiallyThrowing) {
CallSiteEntry Site = {LastLabel, 0, 0, 0};
CallSites.push_back(Site);
}
diff --git a/lib/CodeGen/MachineModuleInfo.cpp b/lib/CodeGen/MachineModuleInfo.cpp
index 14253f4111..59c335e7fb 100644
--- a/lib/CodeGen/MachineModuleInfo.cpp
+++ b/lib/CodeGen/MachineModuleInfo.cpp
@@ -1747,7 +1747,7 @@ void MachineModuleInfo::TidyLandingPads() {
LandingPad.LandingPadLabel = MappedLabel(LandingPad.LandingPadLabel);
// Special case: we *should* emit LPs with null LP MBB. This indicates
- // "rethrow" case.
+ // "nounwind" case.
if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
LandingPads.erase(LandingPads.begin() + i);
continue;
@@ -1757,7 +1757,6 @@ void MachineModuleInfo::TidyLandingPads() {
unsigned BeginLabel = MappedLabel(LandingPad.BeginLabels[j]);
unsigned EndLabel = MappedLabel(LandingPad.EndLabels[j]);
-
if (!BeginLabel || !EndLabel) {
LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index bc336d2069..05a7a954d7 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -2952,7 +2952,11 @@ void SelectionDAGLowering::LowerCallTo(Instruction &I,
Args.push_back(Entry);
}
- if (ExceptionHandling && MMI && LandingPad) {
+ bool MarkTryRange = LandingPad ||
+ // C++ requires special handling of 'nounwind' calls.
+ (Attrs && Attrs->paramHasAttr(0, ParamAttr::NoUnwind));
+
+ if (MarkTryRange && ExceptionHandling && MMI) {
// Insert a label before the invoke call to mark the try range. This can be
// used to detect deletion of the invoke via the MachineModuleInfo.
BeginLabel = MMI->NextLabelID();
@@ -2969,7 +2973,7 @@ void SelectionDAGLowering::LowerCallTo(Instruction &I,
setValue(&I, Result.first);
DAG.setRoot(Result.second);
- if (ExceptionHandling && MMI && LandingPad) {
+ if (MarkTryRange && ExceptionHandling && MMI) {
// Insert a label at the end of the invoke call to mark the try range. This
// can be used to detect deletion of the invoke via the MachineModuleInfo.
EndLabel = MMI->NextLabelID();
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-06-25 16:25:45 +0000