[clang] [clang][DebugInfo] Don't mark structured bindings as artificial (PR #100355)
Michael Buch via cfe-commits
cfe-commits at lists.llvm.org
Thu Aug 8 16:56:13 PDT 2024
https://github.com/Michael137 updated https://github.com/llvm/llvm-project/pull/100355
>From 2b1255de05856e4c79f58d3e4071384ba80a881d Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Thu, 18 Jul 2024 16:26:16 -0500
Subject: [PATCH 1/3] [clang][Sema] Don't mark VarDecls of bindings in
tuple-like decompositions as implicit
---
clang/lib/AST/DeclCXX.cpp | 1 -
clang/lib/Sema/SemaDeclCXX.cpp | 1 -
.../debug-info-structured-binding.cpp | 36 ++++++++++--
.../ASTMatchers/ASTMatchersTraversalTest.cpp | 57 +++++++++++++++++++
4 files changed, 88 insertions(+), 7 deletions(-)
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 72d68f39a97a5..2c22f42a5e0a8 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -3327,7 +3327,6 @@ VarDecl *BindingDecl::getHoldingVar() const {
return nullptr;
auto *VD = cast<VarDecl>(DRE->getDecl());
- assert(VD->isImplicit() && "holding var for binding decl not implicit");
return VD;
}
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index f24912cde275a..f4cc1fc4583aa 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -1316,7 +1316,6 @@ static bool checkTupleLikeDecomposition(Sema &S,
S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
RefVD->setTSCSpec(Src->getTSCSpec());
- RefVD->setImplicit();
if (Src->isInlineSpecified())
RefVD->setInlineSpecified();
RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
diff --git a/clang/test/CodeGenCXX/debug-info-structured-binding.cpp b/clang/test/CodeGenCXX/debug-info-structured-binding.cpp
index c88a5cdaa20e7..4a3126a36598d 100644
--- a/clang/test/CodeGenCXX/debug-info-structured-binding.cpp
+++ b/clang/test/CodeGenCXX/debug-info-structured-binding.cpp
@@ -5,20 +5,46 @@
// CHECK: #dbg_declare(ptr %{{[0-9]+}}, ![[VAR_2:[0-9]+]], !DIExpression(DW_OP_plus_uconst, 4),
// CHECK: #dbg_declare(ptr %{{[0-9]+}}, ![[VAR_3:[0-9]+]], !DIExpression(DW_OP_deref),
// CHECK: #dbg_declare(ptr %{{[0-9]+}}, ![[VAR_4:[0-9]+]], !DIExpression(DW_OP_deref, DW_OP_plus_uconst, 4),
+// CHECK: #dbg_declare(ptr %z1, ![[VAR_5:[0-9]+]], !DIExpression()
+// CHECK: #dbg_declare(ptr %z2, ![[VAR_6:[0-9]+]], !DIExpression()
// CHECK: ![[VAR_0]] = !DILocalVariable(name: "a"
-// CHECK: ![[VAR_1]] = !DILocalVariable(name: "x1"
-// CHECK: ![[VAR_2]] = !DILocalVariable(name: "y1"
-// CHECK: ![[VAR_3]] = !DILocalVariable(name: "x2"
-// CHECK: ![[VAR_4]] = !DILocalVariable(name: "y2"
+// CHECK: ![[VAR_1]] = !DILocalVariable(name: "x1", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+// CHECK: ![[VAR_2]] = !DILocalVariable(name: "y1", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+// CHECK: ![[VAR_3]] = !DILocalVariable(name: "x2", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+// CHECK: ![[VAR_4]] = !DILocalVariable(name: "y2", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+// CHECK: ![[VAR_5]] = !DILocalVariable(name: "z1", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+// CHECK: ![[VAR_6]] = !DILocalVariable(name: "z2", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
struct A {
int x;
int y;
};
+struct B {
+ int w;
+ int z;
+ template<int> int get();
+ template<> int get<0>() { return w; }
+ template<> int get<1>() { return z; }
+};
+
+namespace std {
+template<typename T> struct tuple_size {
+};
+template<>
+struct tuple_size<B> {
+ static constexpr int value = 2;
+};
+
+template<int, typename T> struct tuple_element {};
+template<> struct tuple_element<0, B> { using type = int; };
+template<> struct tuple_element<1, B> { using type = int; };
+}
+
int f() {
A a{10, 20};
auto [x1, y1] = a;
auto &[x2, y2] = a;
- return x1 + y1 + x2 + y2;
+ auto [z1, z2] = B{1, 2};
+ return x1 + y1 + x2 + y2 + z1 + z2;
}
diff --git a/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
index 47a71134d5027..06ac07cb12509 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
@@ -3163,6 +3163,63 @@ void foo()
matchesConditionally(Code, traverse(TK_IgnoreUnlessSpelledInSource, M),
true, {"-std=c++17"}));
}
+
+ Code = R"cpp(
+struct Pair
+{
+ int x, y;
+};
+
+// Note: these utilities are required to force binding to tuple like structure
+namespace std
+{
+ template <typename E>
+ struct tuple_size
+ {
+ };
+
+ template <>
+ struct tuple_size<Pair>
+ {
+ static constexpr unsigned value = 2;
+ };
+
+ template <unsigned I, class T>
+ struct tuple_element
+ {
+ using type = int;
+ };
+
+};
+
+template <unsigned I>
+int &&get(Pair &&p);
+
+void decompTuple()
+{
+ Pair p{1, 2};
+ auto [a, b] = p;
+
+ a = 3;
+}
+ )cpp";
+
+ {
+ auto M = bindingDecl(hasName("a"));
+ EXPECT_TRUE(
+ matchesConditionally(Code, traverse(TK_AsIs, M), true, {"-std=c++17"}));
+ EXPECT_TRUE(
+ matchesConditionally(Code, traverse(TK_IgnoreUnlessSpelledInSource, M),
+ true, {"-std=c++17"}));
+ }
+ {
+ auto M = varDecl(hasName("a"));
+ EXPECT_TRUE(
+ matchesConditionally(Code, traverse(TK_AsIs, M), true, {"-std=c++17"}));
+ EXPECT_TRUE(
+ matchesConditionally(Code, traverse(TK_IgnoreUnlessSpelledInSource, M),
+ true, {"-std=c++17"}));
+ }
}
TEST(Traversal, traverseNoImplicit) {
>From 05e48902a3306eec6490c492a65fe75e34603972 Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Wed, 24 Jul 2024 00:10:21 +0100
Subject: [PATCH 2/3] fixup! detect holding vars in CGDebugInfo; revert to
setting isImplicit for bindings
---
clang/lib/AST/DeclCXX.cpp | 1 +
clang/lib/CodeGen/CGDebugInfo.cpp | 41 +++++++++++--
clang/lib/Sema/SemaDeclCXX.cpp | 1 +
.../debug-info-structured-binding.cpp | 10 ++--
.../ASTMatchers/ASTMatchersTraversalTest.cpp | 57 -------------------
5 files changed, 42 insertions(+), 68 deletions(-)
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 2c22f42a5e0a8..72d68f39a97a5 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -3327,6 +3327,7 @@ VarDecl *BindingDecl::getHoldingVar() const {
return nullptr;
auto *VD = cast<VarDecl>(DRE->getDecl());
+ assert(VD->isImplicit() && "holding var for binding decl not implicit");
return VD;
}
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 3d8a715b692de..8b261df1ea8b8 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -21,6 +21,7 @@
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
+#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclFriend.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
@@ -79,6 +80,35 @@ static uint32_t getDeclAlignIfRequired(const Decl *D, const ASTContext &Ctx) {
return D->hasAttr<AlignedAttr>() ? D->getMaxAlignment() : 0;
}
+/// Returns true if \ref VD is a VarDecl that is a holding variable
+/// (aka a VarDecl retrieved using \ref BindingDecl::getHoldingVar).
+static bool IsDecomposedVarDecl(VarDecl const *VD) {
+ auto const *Init = VD->getInit();
+ if (!Init)
+ return false;
+
+ auto const *RefExpr =
+ llvm::dyn_cast_or_null<DeclRefExpr>(Init->IgnoreUnlessSpelledInSource());
+ if (!RefExpr)
+ return false;
+
+ return llvm::dyn_cast_or_null<DecompositionDecl>(RefExpr->getDecl());
+}
+
+/// Return true if \ref VD is a compiler-generated variable
+/// and should be treated as artificial for the purposes
+/// of debug-info generation.
+static bool IsArtificial(VarDecl const *VD) {
+ // Tuple-like bindings are marked as implicit despite
+ // being spelled out in source. Don't treat them as artificial
+ // variables.
+ if (IsDecomposedVarDecl(VD))
+ return false;
+
+ return VD->isImplicit() || (isa<Decl>(VD->getDeclContext()) &&
+ cast<Decl>(VD->getDeclContext())->isImplicit());
+}
+
CGDebugInfo::CGDebugInfo(CodeGenModule &CGM)
: CGM(CGM), DebugKind(CGM.getCodeGenOpts().getDebugInfo()),
DebugTypeExtRefs(CGM.getCodeGenOpts().DebugTypeExtRefs),
@@ -4753,11 +4783,10 @@ llvm::DILocalVariable *CGDebugInfo::EmitDeclare(const VarDecl *VD,
if (VD->hasAttr<NoDebugAttr>())
return nullptr;
- bool Unwritten =
- VD->isImplicit() || (isa<Decl>(VD->getDeclContext()) &&
- cast<Decl>(VD->getDeclContext())->isImplicit());
+ const bool VarIsArtificial = IsArtificial(VD);
+
llvm::DIFile *Unit = nullptr;
- if (!Unwritten)
+ if (!VarIsArtificial)
Unit = getOrCreateFile(VD->getLocation());
llvm::DIType *Ty;
uint64_t XOffset = 0;
@@ -4774,13 +4803,13 @@ llvm::DILocalVariable *CGDebugInfo::EmitDeclare(const VarDecl *VD,
// Get location information.
unsigned Line = 0;
unsigned Column = 0;
- if (!Unwritten) {
+ if (!VarIsArtificial) {
Line = getLineNumber(VD->getLocation());
Column = getColumnNumber(VD->getLocation());
}
SmallVector<uint64_t, 13> Expr;
llvm::DINode::DIFlags Flags = llvm::DINode::FlagZero;
- if (VD->isImplicit())
+ if (VarIsArtificial)
Flags |= llvm::DINode::FlagArtificial;
auto Align = getDeclAlignIfRequired(VD, CGM.getContext());
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index f4cc1fc4583aa..f24912cde275a 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -1316,6 +1316,7 @@ static bool checkTupleLikeDecomposition(Sema &S,
S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
RefVD->setTSCSpec(Src->getTSCSpec());
+ RefVD->setImplicit();
if (Src->isInlineSpecified())
RefVD->setInlineSpecified();
RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
diff --git a/clang/test/CodeGenCXX/debug-info-structured-binding.cpp b/clang/test/CodeGenCXX/debug-info-structured-binding.cpp
index 4a3126a36598d..5fbd54c16382c 100644
--- a/clang/test/CodeGenCXX/debug-info-structured-binding.cpp
+++ b/clang/test/CodeGenCXX/debug-info-structured-binding.cpp
@@ -28,18 +28,18 @@ struct B {
template<> int get<1>() { return z; }
};
+// Note: the following declarations are necessary for decomposition of tuple-like
+// structured bindings
namespace std {
template<typename T> struct tuple_size {
};
template<>
struct tuple_size<B> {
- static constexpr int value = 2;
+ static constexpr unsigned value = 2;
};
-template<int, typename T> struct tuple_element {};
-template<> struct tuple_element<0, B> { using type = int; };
-template<> struct tuple_element<1, B> { using type = int; };
-}
+template<unsigned, typename T> struct tuple_element { using type = int; };
+} // namespace std
int f() {
A a{10, 20};
diff --git a/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
index 06ac07cb12509..47a71134d5027 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
@@ -3163,63 +3163,6 @@ void foo()
matchesConditionally(Code, traverse(TK_IgnoreUnlessSpelledInSource, M),
true, {"-std=c++17"}));
}
-
- Code = R"cpp(
-struct Pair
-{
- int x, y;
-};
-
-// Note: these utilities are required to force binding to tuple like structure
-namespace std
-{
- template <typename E>
- struct tuple_size
- {
- };
-
- template <>
- struct tuple_size<Pair>
- {
- static constexpr unsigned value = 2;
- };
-
- template <unsigned I, class T>
- struct tuple_element
- {
- using type = int;
- };
-
-};
-
-template <unsigned I>
-int &&get(Pair &&p);
-
-void decompTuple()
-{
- Pair p{1, 2};
- auto [a, b] = p;
-
- a = 3;
-}
- )cpp";
-
- {
- auto M = bindingDecl(hasName("a"));
- EXPECT_TRUE(
- matchesConditionally(Code, traverse(TK_AsIs, M), true, {"-std=c++17"}));
- EXPECT_TRUE(
- matchesConditionally(Code, traverse(TK_IgnoreUnlessSpelledInSource, M),
- true, {"-std=c++17"}));
- }
- {
- auto M = varDecl(hasName("a"));
- EXPECT_TRUE(
- matchesConditionally(Code, traverse(TK_AsIs, M), true, {"-std=c++17"}));
- EXPECT_TRUE(
- matchesConditionally(Code, traverse(TK_IgnoreUnlessSpelledInSource, M),
- true, {"-std=c++17"}));
- }
}
TEST(Traversal, traverseNoImplicit) {
>From 9a830ffca04eea63c3752c24377891addd9abb64 Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Thu, 25 Jul 2024 00:18:14 +0100
Subject: [PATCH 3/3] fixup! fix comment
---
clang/lib/CodeGen/CGDebugInfo.cpp | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 8b261df1ea8b8..4c59c7b65000b 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -80,8 +80,8 @@ static uint32_t getDeclAlignIfRequired(const Decl *D, const ASTContext &Ctx) {
return D->hasAttr<AlignedAttr>() ? D->getMaxAlignment() : 0;
}
-/// Returns true if \ref VD is a VarDecl that is a holding variable
-/// (aka a VarDecl retrieved using \ref BindingDecl::getHoldingVar).
+/// Returns true if \ref VD is a a holding variable (aka a
+/// VarDecl retrieved using \ref BindingDecl::getHoldingVar).
static bool IsDecomposedVarDecl(VarDecl const *VD) {
auto const *Init = VD->getInit();
if (!Init)
@@ -95,7 +95,7 @@ static bool IsDecomposedVarDecl(VarDecl const *VD) {
return llvm::dyn_cast_or_null<DecompositionDecl>(RefExpr->getDecl());
}
-/// Return true if \ref VD is a compiler-generated variable
+/// Returns true if \ref VD is a compiler-generated variable
/// and should be treated as artificial for the purposes
/// of debug-info generation.
static bool IsArtificial(VarDecl const *VD) {
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