Add tests to verify behavior of .cfi_sections .debug_frame intrinsic.

There was some lacking test coverage for checking when the
.cfi_sections .debug_frame intrinsic is emitted. On x86_64,
with -fno-exceptions there is no .cfi_sections .debug_frame intrinsic
emitted because there is an unwind table attribute.

On AArch64, with -fno-exceptions, there is no unwind table attribute, so
the .cfi_sections .debug_frame intrinsic is emitted correctly.

Alternatively, with -fexceptions, both AArch64 and x86_64 emit an unwind
table and therefore do not emit a .cfi_sections .debug_frame intrinsic

All this work was done in addition to https://reviews.llvm.org/D139663
patch.

Differential Revision: https://reviews.llvm.org/D147747

clang/test/Driver/test-uwtable.cpp

@@ -0,0 +1,26 @@
+// This test is added to provide test coverage for the uwtable attribute. It
+// aims to make sure that for an X86_64 output compiled with -fexceptions or
+//  -fno-exceptions, a uwtable attribute is emitted. However, for an AArch64
+//  output with -fexceptions a uwtable attribute is emitted, but with 
+// -fno-exceptions a uwtable attribute is not emitted.
+
+// RUN: %clang -g -fexceptions --target=x86_64-apple-darwin %s -S -emit-llvm -o - | FileCheck %s --check-prefix=X86_64_UWTABLE_EXCEPTIONS
+// X86_64_UWTABLE_EXCEPTIONS: attributes #0 = { {{.*}} uwtable
+// X86_64_UWTABLE_EXCEPTIONS: !{{[0-9]+}} = !{i32 7, !"uwtable", i32 2}
+
+// RUN: %clang -g -fno-exceptions --target=x86_64-apple-darwin %s -S -emit-llvm -o - | FileCheck %s --check-prefix=X86_64_UWTABLE
+// X86_64_UWTABLE: attributes #0 = { {{.*}} uwtable
+// X86_64_UWTABLE: !{{[0-9]+}} = !{i32 7, !"uwtable", i32 2}
+
+// RUN: %clang -g -fexceptions --target=arm64-apple-darwin %s -S -emit-llvm -o - | FileCheck %s --check-prefix=ARM64_UWTABLE_EXCEPTIONS
+// ARM64_UWTABLE_EXCEPTIONS: attributes #0 = { {{.*}} uwtable
+// ARM64_UWTABLE_EXCEPTIONS: !{{[0-9]+}} = !{i32 7, !"uwtable", i32 1}
+
+// RUN: %clang -g -fno-exceptions --target=arm64-apple-darwin %s -S -emit-llvm -o - | FileCheck %s --check-prefix=ARM64_UWTABLE
+// ARM64_UWTABLE-NOT: attributes #0 = { {{.*}} uwtable
+// ARM64_UWTABLE-NOT: !{{[0-9]+}} = !{i32 7, !"uwtable", i32 2}
+// ARM64_UWTABLE: attributes #0 =
+
+int main() {
+    return 1;
+}

llvm/test/DebugInfo/AArch64/test-fexceptions-debug-frame.ll

@@ -0,0 +1,43 @@
+; This test is added to provide test coverage for the 
+; .cfi_sections .debug_frame intrinsic. It aims to make sure that for a AArch64
+; output compiled with -fexceptions, no .cfi_sections .debug_frame is emitted.
+
+; RUN: llc --filetype=asm %s -o - | FileCheck %s
+; CHECK-NOT: .cfi_sections .debug_frame
+; CHECK: .cfi_startproc
+
+
+; ModuleID = 'test.cpp'
+source_filename = "test.cpp"
+target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+target triple = "arm64-apple-macosx13.0.0"
+
+; Function Attrs: noinline norecurse nounwind optnone ssp uwtable(sync)
+define i32 @main() #0 !dbg !10 {
+  %1 = alloca i32, align 4
+  store i32 0, ptr %1, align 4
+  ret i32 1, !dbg !15
+}
+
+attributes #0 = { noinline norecurse nounwind optnone ssp uwtable(sync)}
+
+!llvm.module.flags = !{!0, !1, !2, !3, !4, !5, !6}
+!llvm.dbg.cu = !{!7}
+!llvm.ident = !{!9}
+
+!0 = !{i32 2, !"SDK Version", [2 x i32] [i32 14, i32 0]}
+!1 = !{i32 7, !"Dwarf Version", i32 4}
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!3 = !{i32 1, !"wchar_size", i32 4}
+!4 = !{i32 8, !"PIC Level", i32 2}
+!5 = !{i32 7, !"uwtable", i32 1}
+!6 = !{i32 7, !"frame-pointer", i32 1}
+!7 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !8, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None, sysroot: "/Applications/Xcode.app", sdk: "MacOSX.sdk")
+!8 = !DIFile(filename: "test.cpp", directory: "/Users/shubham/Development")
+!9 = !{!"clang"}
+!10 = distinct !DISubprogram(name: "main", scope: !8, file: !8, line: 1, type: !11, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !7, retainedNodes: !14)
+!11 = !DISubroutineType(types: !12)
+!12 = !{!13}
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!14 = !{}
+!15 = !DILocation(line: 2, column: 5, scope: !10)

llvm/test/DebugInfo/AArch64/test-fno-exceptions-debug-frame.ll

@@ -0,0 +1,40 @@
+; This test is added to provide test coverage for the 
+; .cfi_sections .debug_frame intrinsic. It aims to make sure that for a AArch64
+; output compiled with -fno-exceptions, a .cfi_sections .debug_frame is emitted.
+
+; RUN: llc --filetype=asm %s -o - | FileCheck %s
+; CHECK: .cfi_sections .debug_frame
+
+; ModuleID = 'test.cpp'
+source_filename = "test.cpp"
+target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+target triple = "arm64-apple-macosx13.0.0"
+
+; Function Attrs: noinline norecurse nounwind optnone ssp
+define i32 @main() #0 !dbg !9 {
+  %1 = alloca i32, align 4
+  store i32 0, ptr %1, align 4
+  ret i32 1, !dbg !14
+}
+
+attributes #0 = { noinline norecurse nounwind optnone ssp }
+
+!llvm.module.flags = !{!0, !1, !2, !3, !4, !5}
+!llvm.dbg.cu = !{!6}
+!llvm.ident = !{!8}
+
+!0 = !{i32 2, !"SDK Version", [2 x i32] [i32 14, i32 0]}
+!1 = !{i32 7, !"Dwarf Version", i32 4}
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!3 = !{i32 1, !"wchar_size", i32 4}
+!4 = !{i32 8, !"PIC Level", i32 2}
+!5 = !{i32 7, !"frame-pointer", i32 1}
+!6 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !7, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None, sysroot: "/Applications/Xcode.app", sdk: "MacOSX.sdk")
+!7 = !DIFile(filename: "test.cpp", directory: "/Users/shubham/Development")
+!8 = !{!"clang"}
+!9 = distinct !DISubprogram(name: "main", scope: !7, file: !7, line: 1, type: !10, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !6, retainedNodes: !13)
+!10 = !DISubroutineType(types: !11)
+!11 = !{!12}
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !{}
+!14 = !DILocation(line: 2, column: 5, scope: !9)

llvm/test/DebugInfo/X86/test-fexceptions-debug-frame.ll

@@ -0,0 +1,42 @@
+; This test is added to provide test coverage for the 
+; .cfi_sections .debug_frame intrinsic. It aims to make sure that for an X86_64
+; output compiled with -fexceptions, no .cfi_sections .debug_frame is emitted.
+
+; RUN: llc --filetype=asm %s -o - | FileCheck %s
+; CHECK-NOT: .cfi_sections .debug_frame
+; CHECK: .cfi_startproc
+
+; ModuleID = 'test.cpp'
+source_filename = "test.cpp"
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx13.0.0"
+
+; Function Attrs: noinline norecurse nounwind optnone ssp uwtable
+define i32 @main() #0 !dbg !10 {
+  %1 = alloca i32, align 4
+  store i32 0, ptr %1, align 4
+  ret i32 1, !dbg !15
+}
+
+attributes #0 = { noinline norecurse nounwind optnone ssp uwtable  }
+
+!llvm.module.flags = !{!0, !1, !2, !3, !4, !5, !6}
+!llvm.dbg.cu = !{!7}
+!llvm.ident = !{!9}
+
+!0 = !{i32 2, !"SDK Version", [2 x i32] [i32 14, i32 0]}
+!1 = !{i32 7, !"Dwarf Version", i32 4}
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!3 = !{i32 1, !"wchar_size", i32 4}
+!4 = !{i32 8, !"PIC Level", i32 2}
+!5 = !{i32 7, !"uwtable", i32 2}
+!6 = !{i32 7, !"frame-pointer", i32 2}
+!7 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !8, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None, sysroot: "/Applications/Xcode.app", sdk: "MacOSX.sdk")
+!8 = !DIFile(filename: "test.cpp", directory: "/Users/shubham/Development")
+!9 = !{!"clang"}
+!10 = distinct !DISubprogram(name: "main", scope: !8, file: !8, line: 1, type: !11, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !7, retainedNodes: !14)
+!11 = !DISubroutineType(types: !12)
+!12 = !{!13}
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!14 = !{}
+!15 = !DILocation(line: 2, column: 5, scope: !10)

llvm/test/DebugInfo/X86/test-fno-exceptions-debug-frame.ll

@@ -0,0 +1,43 @@
+; This test is added to provide test coverage for the 
+; .cfi_sections .debug_frame intrinsic. It aims to make sure that for an X86_64
+; output compiled with -fno-exceptions, no .cfi_sections .debug_frame is 
+; emitted.
+
+; RUN: llc --filetype=asm %s -o - | FileCheck %s
+; CHECK-NOT: .cfi_sections .debug_frame
+; CHECK: .cfi_startproc
+
+; ModuleID = 'test.cpp'
+source_filename = "test.cpp"
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx13.0.0"
+
+; Function Attrs: noinline norecurse nounwind optnone ssp uwtable
+define i32 @main() #0 !dbg !10 {
+  %1 = alloca i32, align 4
+  store i32 0, ptr %1, align 4
+  ret i32 1, !dbg !15
+}
+
+attributes #0 = { noinline norecurse nounwind optnone ssp uwtable }
+
+!llvm.module.flags = !{!0, !1, !2, !3, !4, !5, !6}
+!llvm.dbg.cu = !{!7}
+!llvm.ident = !{!9}
+
+!0 = !{i32 2, !"SDK Version", [2 x i32] [i32 14, i32 0]}
+!1 = !{i32 7, !"Dwarf Version", i32 4}
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!3 = !{i32 1, !"wchar_size", i32 4}
+!4 = !{i32 8, !"PIC Level", i32 2}
+!5 = !{i32 7, !"uwtable", i32 2}
+!6 = !{i32 7, !"frame-pointer", i32 2}
+!7 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !8, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None, sysroot: "/Applications/Xcode.app", sdk: "MacOSX.sdk")
+!8 = !DIFile(filename: "test.cpp", directory: "/Users/shubham/Development")
+!9 = !{!"clang"}
+!10 = distinct !DISubprogram(name: "main", scope: !8, file: !8, line: 1, type: !11, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !7, retainedNodes: !14)
+!11 = !DISubroutineType(types: !12)
+!12 = !{!13}
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!14 = !{}
+!15 = !DILocation(line: 2, column: 5, scope: !10)