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-rw-r--r--lib/CodeGen/DwarfWriter.cpp224
1 files changed, 147 insertions, 77 deletions
diff --git a/lib/CodeGen/DwarfWriter.cpp b/lib/CodeGen/DwarfWriter.cpp
index 232c5c4ba2..e9988743a5 100644
--- a/lib/CodeGen/DwarfWriter.cpp
+++ b/lib/CodeGen/DwarfWriter.cpp
@@ -2896,7 +2896,7 @@ private:
O << UsedDirective << EHFrameInfo.FnName << ".eh\n\n";
}
- /// EmitExceptionTable - Emit landpads and actions.
+ /// EmitExceptionTable - Emit landing pads and actions.
///
/// The general organization of the table is complex, but the basic concepts
/// are easy. First there is a header which describes the location and
@@ -2951,19 +2951,31 @@ private:
static bool isPod() { return true; }
};
- struct PadSite {
- unsigned PadIndex;
- unsigned SiteIndex;
- };
-
- typedef DenseMap<unsigned, PadSite, KeyInfo> PadMapType;
-
+ /// ActionEntry - Structure describing an entry in the actions table.
struct ActionEntry {
int ValueForTypeID; // The value to write - may not be equal to the type id.
int NextAction;
struct ActionEntry *Previous;
};
+ /// PadRange - Structure holding a try-range and the associated landing pad.
+ struct PadRange {
+ // The index of the landing pad.
+ unsigned PadIndex;
+ // The index of the begin and end labels in the landing pad's label lists.
+ unsigned RangeIndex;
+ };
+
+ typedef DenseMap<unsigned, PadRange, KeyInfo> RangeMapType;
+
+ /// CallSiteEntry - Structure describing an entry in the call-site table.
+ struct CallSiteEntry {
+ unsigned BeginLabel; // zero indicates the start of the function.
+ unsigned EndLabel; // zero indicates the end of the function.
+ unsigned PadLabel; // zero indicates that there is no landing pad.
+ unsigned Action;
+ };
+
void EmitExceptionTable() {
// Map all labels and get rid of any dead landing pads.
MMI->TidyLandingPads();
@@ -2981,13 +2993,6 @@ private:
LandingPads.push_back(&PadInfos[i]);
std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
- // Gather first action index for each landing pad site.
- SmallVector<unsigned, 64> FirstActions;
- FirstActions.reserve(PadInfos.size());
-
- // The actions table.
- SmallVector<ActionEntry, 32> Actions;
-
// Negative type ids index into FilterIds, positive type ids index into
// TypeInfos. The value written for a positive type id is just the type
// id itself. For a negative type id, however, the value written is the
@@ -3007,14 +3012,14 @@ private:
Offset -= Asm->SizeULEB128(*I);
}
- // Compute sizes for exception table.
- unsigned SizeSites = 0;
- unsigned SizeActions = 0;
+ // Compute the actions table and gather the first action index for each
+ // landing pad site.
+ SmallVector<ActionEntry, 32> Actions;
+ SmallVector<unsigned, 64> FirstActions;
+ FirstActions.reserve(LandingPads.size());
- // Look at each landing pad site to compute size. We need the size of each
- // landing pad site info and the size of the landing pad's actions.
int FirstAction = 0;
-
+ unsigned SizeActions = 0;
for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
const LandingPadInfo *LP = LandingPads[i];
const std::vector<int> &TypeIds = LP->TypeIds;
@@ -3063,14 +3068,96 @@ private:
// Compute this sites contribution to size.
SizeActions += SizeSiteActions;
- unsigned M = LP->BeginLabels.size();
- SizeSites += M*(sizeof(int32_t) + // Site start.
- sizeof(int32_t) + // Site length.
- sizeof(int32_t) + // Landing pad.
- Asm->SizeULEB128(FirstAction)); // Action.
}
-
+
+ // Compute the call-site table. Entries must be ordered by address.
+ SmallVector<CallSiteEntry, 64> CallSites;
+
+ RangeMapType PadMap;
+ 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) {
+ unsigned BeginLabel = LandingPad->BeginLabels[j];
+ assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
+ PadRange P = { i, j };
+ PadMap[BeginLabel] = P;
+ }
+ }
+
+ bool MayThrow = false;
+ unsigned LastLabel = 0;
+ const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
+ 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());
+ continue;
+ }
+
+ unsigned BeginLabel = MI->getOperand(0).getImmedValue();
+ assert(BeginLabel && "Invalid label!");
+ if (BeginLabel == LastLabel) {
+ MayThrow = false;
+ continue;
+ }
+
+ RangeMapType::iterator L = PadMap.find(BeginLabel);
+
+ if (L == PadMap.end())
+ continue;
+
+ PadRange P = L->second;
+ const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
+
+ assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
+ "Inconsistent landing pad map!");
+
+ // 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) {
+ CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
+ CallSites.push_back(Site);
+ }
+
+ 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;
+ }
+ }
+
+ // Otherwise, create a new call-site.
+ CallSites.push_back(Site);
+ }
+ }
+ // 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) {
+ CallSiteEntry Site = {LastLabel, 0, 0, 0};
+ CallSites.push_back(Site);
+ }
+
// Final tallies.
+ unsigned SizeSites = CallSites.size() * (sizeof(int32_t) + // Site start.
+ sizeof(int32_t) + // Site length.
+ sizeof(int32_t)); // Landing pad.
+ for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
+ SizeSites += Asm->SizeULEB128(CallSites[i].Action);
+
unsigned SizeTypes = TypeInfos.size() * TAI->getAddressSize();
unsigned TypeOffset = sizeof(int8_t) + // Call site format
@@ -3106,61 +3193,44 @@ private:
Asm->EmitULEB128Bytes(SizeSites);
Asm->EOL("Call-site table length");
- // Emit the landing pad site information in order of address.
- PadMapType PadMap;
+ // Emit the landing pad site information.
+ for (unsigned i = 0; i < CallSites.size(); ++i) {
+ CallSiteEntry &S = CallSites[i];
+ const char *BeginTag;
+ unsigned BeginNumber;
- 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) {
- unsigned BeginLabel = LandingPad->BeginLabels[j];
- assert(!PadMap.count(BeginLabel) && "duplicate landing pad labels!");
- PadSite P = { i, j };
- PadMap[BeginLabel] = P;
+ if (!S.BeginLabel) {
+ BeginTag = "eh_func_begin";
+ BeginNumber = SubprogramCount;
+ } else {
+ BeginTag = "label";
+ BeginNumber = S.BeginLabel;
}
- }
- 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)
- continue;
-
- unsigned BeginLabel = MI->getOperand(0).getImmedValue();
- PadMapType::iterator L = PadMap.find(BeginLabel);
-
- if (L == PadMap.end())
- continue;
-
- PadSite P = L->second;
- const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
+ EmitSectionOffset(BeginTag, "eh_func_begin", BeginNumber, SubprogramCount,
+ false, true);
+ Asm->EOL("Region start");
- assert(BeginLabel == LandingPad->BeginLabels[P.SiteIndex] &&
- "Inconsistent landing pad map!");
+ if (!S.EndLabel) {
+ EmitDifference("eh_func_end", SubprogramCount, BeginTag, BeginNumber);
+ } else {
+ EmitDifference("label", S.EndLabel, BeginTag, BeginNumber);
+ }
+ Asm->EOL("Region length");
- EmitSectionOffset("label", "eh_func_begin", BeginLabel, SubprogramCount,
+ if (!S.PadLabel) {
+ if (TAI->getAddressSize() == sizeof(int32_t))
+ Asm->EmitInt32(0);
+ else
+ Asm->EmitInt64(0);
+ } else {
+ EmitSectionOffset("label", "eh_func_begin", S.PadLabel, SubprogramCount,
false, true);
- Asm->EOL("Region start");
-
- EmitDifference("label", LandingPad->EndLabels[P.SiteIndex],
- "label", BeginLabel);
- Asm->EOL("Region length");
-
- if (LandingPad->TypeIds.empty()) {
- if (TAI->getAddressSize() == sizeof(int32_t))
- Asm->EmitInt32(0);
- else
- Asm->EmitInt64(0);
- } else {
- EmitSectionOffset("label", "eh_func_begin",
- LandingPad->LandingPadLabel, SubprogramCount,
- false, true);
- }
- Asm->EOL("Landing pad");
-
- Asm->EmitULEB128Bytes(FirstActions[P.PadIndex]);
- Asm->EOL("Action");
}
+ Asm->EOL("Landing pad");
+
+ Asm->EmitULEB128Bytes(S.Action);
+ Asm->EOL("Action");
}
// Emit the actions.
@@ -3183,7 +3253,7 @@ private:
O << Asm->getGlobalLinkName(GV);
else
O << "0";
-
+
Asm->EOL("TypeInfo");
}
@@ -3193,7 +3263,7 @@ private:
Asm->EmitULEB128Bytes(TypeID);
Asm->EOL("Filter TypeInfo index");
}
-
+
Asm->EmitAlignment(2);
}
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-05-09 15:12:44 +0000