[debuginfo][codeview] avoid using line zero artificial location for t…

include/swift/AST/IRGenOptions.h

@@ -642,6 +642,10 @@ class IRGenOptions {
   bool hasMultipleIRGenThreads() const { return !UseSingleModuleLLVMEmission && NumThreads > 1; }
   bool shouldPerformIRGenerationInParallel() const { return !UseSingleModuleLLVMEmission && NumThreads != 0; }
   bool hasMultipleIGMs() const { return hasMultipleIRGenThreads(); }
+
+  bool isDebugInfoCodeView() const {
+    return DebugInfoFormat == IRGenDebugInfoFormat::CodeView;
+  }
 };
 
 } // end namespace swift

lib/IRGen/IRGenDebugInfo.cpp

@@ -2661,12 +2661,18 @@ void IRGenDebugInfoImpl::addFailureMessageToCurrentLoc(IRBuilder &Builder,
   else {
     std::string FuncName = "Swift runtime failure: ";
     FuncName += failureMsg;
-    llvm::DIFile *File = getOrCreateFile({}, {});
+    // CodeView consumers do not correctly handle an artificially generated
+    // file, thus use the original location's file as the file for the debug
+    // function, and prevent reuse of this debug function.
+    bool useCompilerGeneratedFile = !Opts.isDebugInfoCodeView();
+    llvm::DIFile *File =
+        useCompilerGeneratedFile ? getOrCreateFile({}, {}) : TrapLoc->getFile();
     TrapSP = DBuilder.createFunction(
         File, FuncName, StringRef(), File, 0,
         DIFnTy, 0, llvm::DINode::FlagArtificial,
         llvm::DISubprogram::SPFlagDefinition, nullptr, nullptr, nullptr);
-    RuntimeErrorFnCache.insert({failureMsg, llvm::TrackingMDNodeRef(TrapSP)});
+    if (useCompilerGeneratedFile)
+      RuntimeErrorFnCache.insert({failureMsg, llvm::TrackingMDNodeRef(TrapSP)});
   }
 
   ScopeCache[TrapSc] = llvm::TrackingMDNodeRef(TrapSP);
@@ -2675,7 +2681,11 @@ void IRGenDebugInfoImpl::addFailureMessageToCurrentLoc(IRBuilder &Builder,
   assert(parentScopesAreSane(TrapSc) && "parent scope sanity check failed");
 
   // Wrap the existing TrapLoc into the failure function.
-  auto DL = llvm::DILocation::get(IGM.getLLVMContext(), 0, 0, TrapSP, TrapLoc);
+  // Line 0 is invalid in CodeView, so use the line and column from the original
+  // trap location.
+  auto DL = llvm::DILocation::get(
+      IGM.getLLVMContext(), Opts.isDebugInfoCodeView() ? TrapLoc.getLine() : 0,
+      Opts.isDebugInfoCodeView() ? TrapLoc.getCol() : 0, TrapSP, TrapLoc);
   Builder.SetCurrentDebugLocation(DL);
 }
 

lib/IRGen/IRGenFunction.cpp

@@ -445,6 +445,20 @@ Address IRGenFunction::emitAddressAtOffset(llvm::Value *base, Offset offset,
 
 llvm::CallInst *IRBuilder::CreateNonMergeableTrap(IRGenModule &IGM,
                                                   StringRef failureMsg) {
+  if (IGM.DebugInfo && IGM.getOptions().isDebugInfoCodeView()) {
+    auto TrapLoc = getCurrentDebugLocation();
+    // Line 0 is invalid in CodeView, so create a new location that uses the
+    // line and column from the inlined location of the trap, that should
+    // correspond to its original source location.
+    if (TrapLoc.getLine() == 0 && TrapLoc.getInlinedAt()) {
+      auto DL = llvm::DILocation::getDistinct(
+          IGM.getLLVMContext(), TrapLoc.getInlinedAt()->getLine(),
+          TrapLoc.getInlinedAt()->getColumn(), TrapLoc.getScope(),
+          TrapLoc.getInlinedAt());
+      SetCurrentDebugLocation(DL);
+    }
+  }
+
   if (IGM.IRGen.Opts.shouldOptimize()) {
     // Emit unique side-effecting inline asm calls in order to eliminate
     // the possibility that an LLVM optimization or code generation pass

test/DebugInfo/doubleinlines.swift

@@ -12,9 +12,13 @@ func callCondFail(arg: Builtin.Int1, msg: Builtin.RawPointer) {
 
 // CHECK: define hidden swiftcc void @"$s13DoubleInlines12callCondFail3arg3msgyBi1__BptF"{{.*}} !dbg ![[FUNC:.*]] {
 // CHECK: tail call void asm sideeffect "", "n"(i32 0) #3, !dbg ![[SCOPEONE:.*]]
+// CHECK: tail call void @llvm.trap(), !dbg ![[LOCTRAP:.*]]
+
 // CHECK: ![[FUNCSCOPEOTHER:.*]] = distinct !DISubprogram(name: "condFail",{{.*}}
-// CHECK: ![[SCOPEONE]] = !DILocation(line: 0, scope: ![[SCOPETWO:.*]], inlinedAt: ![[SCOPETHREE:.*]])
+// CHECK: ![[SCOPEONE]] = distinct !DILocation(line: 6, scope: ![[SCOPETWO:.*]], inlinedAt: ![[SCOPETHREE:.*]])
 // CHECK: ![[SCOPETHREE]] = !DILocation(line: 6, scope: ![[FUNCSCOPE:.*]])
 // CHECK: ![[FUNCSCOPE:[0-9]+]] = distinct !DILexicalBlock(scope: ![[FUNC]],
+// CHECK: ![[LOCTRAP]] = !DILocation(line: 6, scope: ![[SCOPETRAP:.*]], inlinedAt: ![[SCOPEONE]])
+// CHECK: ![[SCOPETRAP]] = distinct !DISubprogram(name: "Swift runtime failure: unknown program error"
 
 import Builtin

test/DebugInfo/linetable-codeview.swift

@@ -78,11 +78,10 @@ func foo() {
 
 // CHECK-DAG: ![[ADD]] = !DILocation(line: 6, scope:
 // CHECK-DAG: ![[DIV]] = !DILocation(line: 7, scope:
-// FIXME: The location of ``@llvm.trap`` should be in Integers.swift.gyb
-//        instead of being artificial.
-// CHECK: ![[INLINEDADD]] = !DILocation(line: 0, scope: ![[FAILURE_FUNC:[0-9]+]], inlinedAt: ![[INLINELOC:[0-9]+]]
+
+// CHECK: ![[INLINEDADD]] = !DILocation(line: 6, scope: ![[FAILURE_FUNC:[0-9]+]], inlinedAt: ![[INLINELOC:[0-9]+]]
 // CHECK-DAG: !{{.*}} = distinct !DISubprogram(name: "Swift runtime failure: arithmetic overflow", scope: {{.*}}, flags: DIFlagArtificial, spFlags: DISPFlagDefinition, {{.*}})
-// CHECK-DAG: ![[INLINELOC]] = !DILocation(line: 0, scope: !{{[0-9]+}}, inlinedAt: ![[ADD]]
+// CHECK-DAG: ![[INLINELOC]] = distinct !DILocation(line: 6, scope: !{{[0-9]+}}, inlinedAt: ![[ADD]]
 
 // NOTE: These prologue instructions are given artificial line locations for
 //       LLDB, but for CodeView they should have the location of the function