Merging r359809:
------------------------------------------------------------------------
r359809 | rnk | 2019-05-02 10:45:54 -0700 (Thu, 02 May 2019) | 27 lines
Use primary template parameter names for variable template debug info
Summary:
Fixes PR41677
Consider:
template <typename LHS, typename RHS> constexpr bool is_same_v = false;
template <typename T> constexpr bool is_same_v<T, T> = true;
template constexpr bool is_same_v<int, int>;
Before this change, when emitting debug info for the
`is_same_v<int, int>` global variable, clang would crash because it
would try to use the template parameter list from the partial
specialization to give parameter names to template arguments. This
doesn't work in general, since a partial specialization can have fewer
arguments than the primary template. Therefore, always use the primary
template. Hypothetically we could try to use the parameter names from
the partial specialization when possible, but it's not clear this really
helps debugging in practice.
Reviewers: JDevlieghere, aprantl, ormris, dblaikie
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D61408
------------------------------------------------------------------------
git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_80@364483 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 41f8721..ad1a915 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1817,32 +1817,24 @@
}
llvm::DINodeArray CGDebugInfo::CollectVarTemplateParams(const VarDecl *VL,
- llvm::DIFile *Unit) {
- if (auto *TS = dyn_cast<VarTemplateSpecializationDecl>(VL)) {
- auto T = TS->getSpecializedTemplateOrPartial();
- auto TA = TS->getTemplateArgs().asArray();
- // Collect parameters for a partial specialization
- if (T.is<VarTemplatePartialSpecializationDecl *>()) {
- const TemplateParameterList *TList =
- T.get<VarTemplatePartialSpecializationDecl *>()
- ->getTemplateParameters();
- return CollectTemplateParams(TList, TA, Unit);
- }
-
- // Collect parameters for an explicit specialization
- if (T.is<VarTemplateDecl *>()) {
- const TemplateParameterList *TList = T.get<VarTemplateDecl *>()
- ->getTemplateParameters();
- return CollectTemplateParams(TList, TA, Unit);
- }
- }
- return llvm::DINodeArray();
+ llvm::DIFile *Unit) {
+ // Always get the full list of parameters, not just the ones from the
+ // specialization. A partial specialization may have fewer parameters than
+ // there are arguments.
+ auto *TS = dyn_cast<VarTemplateSpecializationDecl>(VL);
+ if (!TS)
+ return llvm::DINodeArray();
+ VarTemplateDecl *T = TS->getSpecializedTemplate();
+ const TemplateParameterList *TList = T->getTemplateParameters();
+ auto TA = TS->getTemplateArgs().asArray();
+ return CollectTemplateParams(TList, TA, Unit);
}
llvm::DINodeArray CGDebugInfo::CollectCXXTemplateParams(
const ClassTemplateSpecializationDecl *TSpecial, llvm::DIFile *Unit) {
- // Always get the full list of parameters, not just the ones from
- // the specialization.
+ // Always get the full list of parameters, not just the ones from the
+ // specialization. A partial specialization may have fewer parameters than
+ // there are arguments.
TemplateParameterList *TPList =
TSpecial->getSpecializedTemplate()->getTemplateParameters();
const TemplateArgumentList &TAList = TSpecial->getTemplateArgs();
diff --git a/test/CodeGenCXX/debug-info-template-member.cpp b/test/CodeGenCXX/debug-info-template-member.cpp
index db6006c..3d5b04d 100644
--- a/test/CodeGenCXX/debug-info-template-member.cpp
+++ b/test/CodeGenCXX/debug-info-template-member.cpp
@@ -30,7 +30,7 @@
// CHECK: {{![0-9]+}} = distinct !DIGlobalVariable(
// CHECK-SAME: name: "var"
// CHECK-SAME: templateParams: {{![0-9]+}}
-// CHECK: !DITemplateTypeParameter(name: "P", type: {{![0-9]+}})
+// CHECK: !DITemplateTypeParameter(name: "T", type: {{![0-9]+}})
// CHECK: {{![0-9]+}} = distinct !DIGlobalVariable(
// CHECK-SAME: name: "varray"
// CHECK-SAME: templateParams: {{![0-9]+}}
diff --git a/test/CodeGenCXX/debug-info-var-template-partial.cpp b/test/CodeGenCXX/debug-info-var-template-partial.cpp
new file mode 100644
index 0000000..16c5f82
--- /dev/null
+++ b/test/CodeGenCXX/debug-info-var-template-partial.cpp
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -emit-llvm -triple x86_64-linux-gnu %s -o - -debug-info-kind=limited | FileCheck %s
+
+template <typename LHS, typename RHS> constexpr bool is_same_v = false;
+template <typename T> constexpr bool is_same_v<T, T> = true;
+
+template constexpr bool is_same_v<int, int>;
+static_assert(is_same_v<int, int>, "should get partial spec");
+
+// Note that the template arguments for the instantiated variable use the
+// parameter names from the primary template. The partial specialization might
+// not have enough parameters.
+
+// CHECK: distinct !DIGlobalVariable(name: "is_same_v", linkageName: "_ZL9is_same_vIiiE", {{.*}} templateParams: ![[PARAMS:[0-9]+]])
+// CHECK: ![[PARAMS]] = !{![[LHS:[0-9]+]], ![[RHS:[0-9]+]]}
+// CHECK: ![[LHS]] = !DITemplateTypeParameter(name: "LHS", type: ![[INT:[0-9]+]])
+// CHECK: ![[INT]] = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+// CHECK: ![[RHS]] = !DITemplateTypeParameter(name: "RHS", type: ![[INT]])
