1 // RUN: %clang_cc1 -emit-llvm -triple x86_64-unknown_unknown -debug-info-kind=limited -gsimple-template-names=mangled %s -o - -w -std=c++17 | FileCheck %s
2 // RUN: %clang_cc1 -emit-llvm -triple x86_64-unknown_unknown -debug-info-kind=limited -gsimple-template-names=simple %s -o - -w -std=c++17 | FileCheck --check-prefix=SIMPLE --implicit-check-not=_STN %s
3 // RUN: %clang_cc1 -emit-llvm -triple x86_64-unknown_unknown -debug-info-kind=limited %s -o - -w -std=c++17 | FileCheck --check-prefix=FULL --implicit-check-not=_STN %s
4 
5 template <typename... T>
6 void f1() {}
7 template <typename T, T V>
8 void f2() {}
9 template <typename... T>
10 struct t1 {};
11 extern int x;
12 int x;
13 struct t2 {
14   template <typename T = float>
15   operator t1<int>() { __builtin_unreachable(); }
16 };
17 template <template <typename...> class T>
18 void f3() {}
19 void f() {
20   // Basic examples of simplifiable/rebuildable names
21   f1<>();
22   // CHECK: !DISubprogram(name: "_STNf1|<>",
23   // SIMPLE: !DISubprogram(name: "f1",
24   // FULL: !DISubprogram(name: "f1<>",
25   f1<int>();
26   // CHECK: !DISubprogram(name: "_STNf1|<int>",
27   f1<void()>();
28   // CHECK: !DISubprogram(name: "_STNf1|<void ()>",
29   f2<int, 42>();
30   // CHECK: !DISubprogram(name: "_STNf2|<int, 42>",
31 
32   // Check that even though the nested name can't be rebuilt, it'll carry its
33   // full name and the outer name can be rebuilt from that.
34   f1<t1<void() noexcept>>();
35   // CHECK: !DISubprogram(name: "_STNf1|<t1<void () noexcept> >",
36 
37   // Vector array types are encoded in DWARF but the decoding in llvm-dwarfdump
38   // isn't implemented yet.
39   f1<__attribute__((__vector_size__((sizeof(int) * 2)))) int>();
40   // CHECK: !DISubprogram(name: "f1<__attribute__((__vector_size__(2 * sizeof(int)))) int>",
41 
42   // noexcept is part of function types in C++17 onwards, but not encoded in
43   // DWARF
44   f1<void() noexcept>();
45   // CHECK: !DISubprogram(name: "f1<void () noexcept>",
46 
47   // Unnamed entities (lambdas, structs/classes, enums) can't be fully rebuilt
48   // since we don't emit the column number. Also lambdas and unnamed classes are
49   // ambiguous with each other - there's no DWARF that designates a lambda as
50   // anything other than another unnamed class/struct.
51   auto A = [] {};
52   f1<decltype(A)>();
53   // CHECK: !DISubprogram(name: "f1<(lambda at {{.*}}debug-info-simple-template-names.cpp:[[# @LINE - 2]]:12)>",
54   struct {
55   } unnamed_struct;
56   f1<decltype(unnamed_struct)>();
57   // CHECK: !DISubprogram(name: "f1<(unnamed struct at {{.*}}debug-info-simple-template-names.cpp:[[# @LINE - 3]]:3)>",
58   f1<void (decltype(unnamed_struct))>();
59   // CHECK: !DISubprogram(name: "f1<void ((unnamed struct at {{.*}}debug-info-simple-template-names.cpp:[[# @LINE - 5]]:3))>",
60   enum {} unnamed_enum;
61   f1<decltype(unnamed_enum)>();
62   // CHECK: !DISubprogram(name: "f1<(unnamed enum at {{.*}}debug-info-simple-template-names.cpp:[[# @LINE - 2]]:3)>",
63 
64   // Declarations can't readily be reversed as the value in the DWARF only
65   // contains the address of the value - we'd have to do symbol lookup to find
66   // the name of that value (& rely on it not having been stripped out, etc).
67   f2<int *, &x>();
68   // CHECK: !DISubprogram(name: "f2<int *, &x>",
69 
70   // We could probably handle \/ this case, but since it's a small subset of
71   // pointer typed non-type-template parameters which can't be handled it
72   // doesn't seem high priority.
73   f2<decltype(nullptr), nullptr>();
74   // CHECK: !DISubprogram(name: "f2<std::nullptr_t, nullptr>",
75 
76   // These larger constants are encoded as data blocks which makes them a bit
77   // harder to re-render. I think they might be missing sign information, or at
78   // maybe it's just a question of doing APInt things to render such large
79   // values. Punting on this for now.
80   f2<__int128, ((__int128)9223372036854775807) * 2>();
81   // CHECK: !DISubprogram(name: "f2<__int128, (__int128)18446744073709551614>",
82 
83   t2().operator t1<int>();
84   // FIXME: This should be something like "operator t1<int><float>"
85   // CHECK: !DISubprogram(name: "operator t1<float>",
86 
87   // Function pointer non-type-template parameters currently don't get any DWARF
88   // value (GCC doesn't provide one either) and even if there was a value, if
89   // it's like variable/pointer non-type template parameters, it couldn't be
90   // rebuilt anyway (see the note above for details on that) so we don't have to
91   // worry about seeing conversion operators as parameters to other templates.
92 
93   f3<t1>();
94   // CHECK: !DISubprogram(name: "_STNf3|<t1>",
95 }
96