Add support for DW_TAG_thrown_type.

For Swift we would like to be able to encode the error types that a
function may throw, so the debugger can display them alongside the
function's return value when finish-ing a function.

DWARF defines DW_TAG_thrown_type (intended to be used for C++ throw()
declarations) that is a perfect fit for this purpose. This patch wires
up support for DW_TAG_thrown_type in LLVM by adding a list of thrown
types to DISubprogram.

To offset the cost of the extra pointer, there is a follow-up patch
that turns DISubprogram into a variable-length node.

rdar://problem/29481673

Differential Revision: https://reviews.llvm.org/D32559

llvm-svn: 301489

2 files changed, 81 insertions, 50 deletions

diff --git a/llvm/unittests/IR/IRBuilderTest.cpp b/llvm/unittests/IR/IRBuilderTest.cpp
index 830ae958769..5686c3b2b3a 100644
--- a/llvm/unittests/IR/IRBuilderTest.cpp
+++ b/llvm/unittests/IR/IRBuilderTest.cpp
@@ -356,6 +356,25 @@ TEST_F(IRBuilderTest, RAIIHelpersTest) {
   EXPECT_EQ(BB, Builder.GetInsertBlock());
 }
 
+TEST_F(IRBuilderTest, createFunction) {
+  IRBuilder<> Builder(BB);
+  DIBuilder DIB(*M);
+  auto File = DIB.createFile("error.swift", "/");
+  auto CU =
+      DIB.createCompileUnit(dwarf::DW_LANG_Swift, File, "swiftc", true, "", 0);
+  auto Type = DIB.createSubroutineType(DIB.getOrCreateTypeArray(None));
+  auto NoErr = DIB.createFunction(CU, "noerr", "", File, 1, Type, false, true, 1,
+                               DINode::FlagZero, true);
+  EXPECT_TRUE(!NoErr->getThrownTypes());
+  auto Int = DIB.createBasicType("Int", 64, dwarf::DW_ATE_signed);
+  auto Error = DIB.getOrCreateArray({Int});
+  auto Err =
+      DIB.createFunction(CU, "err", "", File, 1, Type, false, true, 1,
+      DINode::FlagZero, true, nullptr, nullptr, Error.get());
+  EXPECT_TRUE(Err->getThrownTypes().get() == Error.get());
+  DIB.finalize();
+}
+
 TEST_F(IRBuilderTest, DIBuilder) {
   IRBuilder<> Builder(BB);
   DIBuilder DIB(*M);
diff --git a/llvm/unittests/IR/MetadataTest.cpp b/llvm/unittests/IR/MetadataTest.cpp
index 103ba4c92dd..8dc97956d11 100644
--- a/llvm/unittests/IR/MetadataTest.cpp
+++ b/llvm/unittests/IR/MetadataTest.cpp
@@ -1512,13 +1512,14 @@ TEST_F(DISubprogramTest, get) {
   MDTuple *TemplateParams = getTuple();
   DISubprogram *Declaration = getSubprogram();
   MDTuple *Variables = getTuple();
+  MDTuple *ThrownTypes = getTuple();
   DICompileUnit *Unit = getUnit();
 
-  auto *N = DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                              Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                              ContainingType, Virtuality, VirtualIndex,
-                              ThisAdjustment, Flags, IsOptimized, Unit,
-                              TemplateParams, Declaration, Variables);
+  auto *N = DISubprogram::get(
+      Context, Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit,
+      IsDefinition, ScopeLine, ContainingType, Virtuality, VirtualIndex,
+      ThisAdjustment, Flags, IsOptimized, Unit, TemplateParams, Declaration,
+      Variables, ThrownTypes);
 
   EXPECT_EQ(dwarf::DW_TAG_subprogram, N->getTag());
   EXPECT_EQ(Scope, N->getScope());
@@ -1540,98 +1541,109 @@ TEST_F(DISubprogramTest, get) {
   EXPECT_EQ(TemplateParams, N->getTemplateParams().get());
   EXPECT_EQ(Declaration, N->getDeclaration());
   EXPECT_EQ(Variables, N->getVariables().get());
-  EXPECT_EQ(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+  EXPECT_EQ(ThrownTypes, N->getThrownTypes().get());
+  EXPECT_EQ(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
 
   EXPECT_NE(N, DISubprogram::get(
                    Context, getCompositeType(), Name, LinkageName, File, Line,
                    Type, IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(
                    Context, Scope, "other", LinkageName, File, Line, Type,
                    IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
-  EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, "other", File, Line,
-                                 Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, "other", File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(
                    Context, Scope, Name, LinkageName, getFile(), Line, Type,
                    IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(
                    Context, Scope, Name, LinkageName, File, Line + 1, Type,
                    IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
-  EXPECT_NE(N,
-            DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                              getSubroutineType(), IsLocalToUnit, IsDefinition,
-                              ScopeLine, ContainingType, Virtuality,
-                              VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                              Unit, TemplateParams, Declaration, Variables));
-  EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, !IsLocalToUnit, IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, IsLocalToUnit, !IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                                 getSubroutineType(), IsLocalToUnit,
+                                 IsDefinition, ScopeLine, ContainingType,
+                                 Virtuality, VirtualIndex, ThisAdjustment,
+                                 Flags, IsOptimized, Unit, TemplateParams,
+                                 Declaration, Variables, ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   !IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, !IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(
                    Context, Scope, Name, LinkageName, File, Line, Type,
                    IsLocalToUnit, IsDefinition, ScopeLine + 1, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
-  EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                                 getCompositeType(), Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, getCompositeType(),
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality + 1, VirtualIndex,
                                  ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                                 TemplateParams, Declaration, Variables,
+                                 ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex + 1,
                                  ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                                 TemplateParams, Declaration, Variables,
+                                 ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex,
                                  ThisAdjustment, Flags, !IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                                 TemplateParams, Declaration, Variables,
+                                 ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex,
                                  ThisAdjustment, Flags, IsOptimized, nullptr,
-                                 TemplateParams, Declaration, Variables));
-  EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 getTuple(), Declaration, Variables));
+                                 TemplateParams, Declaration, Variables,
+                                 ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, getTuple(), Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex,
                                  ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, getSubprogram(), Variables));
+                                 TemplateParams, getSubprogram(), Variables,
+                                 ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex,
                                  ThisAdjustment, Flags, IsOptimized, Unit,
                                  TemplateParams, Declaration, getTuple()));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, getTuple()));
 
   TempDISubprogram Temp = N->clone();
   EXPECT_EQ(N, MDNode::replaceWithUniqued(std::move(Temp)));