[Sema][clangd] add noexcept to override functions during code completion #75937
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@llvm/pr-subscribers-clangd Author: Sirui Mu (Lancern) ChangesIf a virtual function is declared with Full diff: https://github.com/llvm/llvm-project/pull/75937.diff 2 Files Affected:
diff --git a/clang-tools-extra/clangd/test/completion-override-except-spec.test b/clang-tools-extra/clangd/test/completion-override-except-spec.test
new file mode 100644
index 00000000000000..19c7f84bc679d8
--- /dev/null
+++ b/clang-tools-extra/clangd/test/completion-override-except-spec.test
@@ -0,0 +1,69 @@
+# RUN: clangd -lit-test < %s | FileCheck %s
+# RUN: clangd -lit-test -pch-storage=memory < %s | FileCheck %s
+{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"clangd","capabilities":{},"trace":"off"}}
+---
+{"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"test:///main.cpp","languageId":"cpp","version":1,"text":"struct Base {\n virtual void virt_method() noexcept = 0;\n};\n\nstruct Derived : Base {\n virt_\n};"}}}
+---
+{"jsonrpc":"2.0","id":1,"method":"textDocument/completion","params":{"textDocument":{"uri":"test:///main.cpp"},"position":{"line":5,"character":6}}}
+# CHECK: "id": 1,
+# CHECK-NEXT: "jsonrpc": "2.0",
+# CHECK-NEXT: "result": {
+# CHECK-NEXT: "isIncomplete": false,
+# CHECK-NEXT: "items": [
+# CHECK-NEXT: {
+# CHECK-NEXT: "filterText": "virt_method() noexcept override",
+# CHECK-NEXT: "insertText": "void virt_method() noexcept override",
+# CHECK-NEXT: "insertTextFormat": 1,
+# CHECK-NEXT: "kind": 2,
+# CHECK-NEXT: "label": " void virt_method() noexcept override",
+# CHECK-NEXT: "score": {{[0-9]+.[0-9]+}},
+# CHECK-NEXT: "sortText": "{{.*}}virt_method() noexcept override",
+# CHECK-NEXT: "textEdit": {
+# CHECK-NEXT: "newText": "void virt_method() noexcept override",
+# CHECK-NEXT: "range": {
+# CHECK-NEXT: "end": {
+# CHECK-NEXT: "character": 6,
+# CHECK-NEXT: "line": 5
+# CHECK-NEXT: },
+# CHECK-NEXT: "start": {
+# CHECK-NEXT: "character": 2,
+# CHECK-NEXT: "line": 5
+# CHECK-NEXT: }
+# CHECK-NEXT: }
+# CHECK-NEXT: }
+# CHECK-NEXT: },
+---
+{"jsonrpc":"2.0","method":"textDocument/didChange","params":{"textDocument":{"uri":"test:///main.cpp","version":2},"contentChanges":[{"text":"struct Base {\n virtual void virt_method() = 0;\n};\n\nstruct Derived : Base {\n virt_\n};"}]}}
+---
+{"jsonrpc":"2.0","id":3,"method":"textDocument/completion","params":{"textDocument":{"uri":"test:///main.cpp"},"position":{"line":5,"character":6}}}
+# CHECK: "id": 3,
+# CHECK-NEXT: "jsonrpc": "2.0",
+# CHECK-NEXT: "result": {
+# CHECK-NEXT: "isIncomplete": false,
+# CHECK-NEXT: "items": [
+# CHECK-NEXT: {
+# CHECK-NEXT: "filterText": "virt_method() override",
+# CHECK-NEXT: "insertText": "void virt_method() override",
+# CHECK-NEXT: "insertTextFormat": 1,
+# CHECK-NEXT: "kind": 2,
+# CHECK-NEXT: "label": " void virt_method() override",
+# CHECK-NEXT: "score": {{[0-9]+.[0-9]+}},
+# CHECK-NEXT: "sortText": "{{.*}}virt_method() override",
+# CHECK-NEXT: "textEdit": {
+# CHECK-NEXT: "newText": "void virt_method() override",
+# CHECK-NEXT: "range": {
+# CHECK-NEXT: "end": {
+# CHECK-NEXT: "character": 6,
+# CHECK-NEXT: "line": 5
+# CHECK-NEXT: },
+# CHECK-NEXT: "start": {
+# CHECK-NEXT: "character": 2,
+# CHECK-NEXT: "line": 5
+# CHECK-NEXT: }
+# CHECK-NEXT: }
+# CHECK-NEXT: }
+# CHECK-NEXT: },
+---
+{"jsonrpc":"2.0","id":4,"method":"shutdown"}
+---
+{"jsonrpc":"2.0","method":"exit"}
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index c44be0df9b0a85..516936311a278d 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -25,6 +25,7 @@
#include "clang/AST/Type.h"
#include "clang/Basic/AttributeCommonInfo.h"
#include "clang/Basic/CharInfo.h"
+#include "clang/Basic/ExceptionSpecificationType.h"
#include "clang/Basic/OperatorKinds.h"
#include "clang/Basic/Specifiers.h"
#include "clang/Lex/HeaderSearch.h"
@@ -3292,6 +3293,25 @@ AddFunctionTypeQualsToCompletionString(CodeCompletionBuilder &Result,
Result.AddInformativeChunk(Result.getAllocator().CopyString(QualsStr));
}
+static void
+AddFunctionExceptSpecToCompletionString(CodeCompletionBuilder &Result,
+ const FunctionDecl *Function) {
+ const auto *Proto = Function->getType()->getAs<FunctionProtoType>();
+ if (!Proto)
+ return;
+
+ auto ExceptInfo = Proto->getExceptionSpecInfo();
+ switch (ExceptInfo.Type) {
+ case EST_BasicNoexcept:
+ case EST_NoexceptTrue:
+ Result.AddInformativeChunk(" noexcept");
+ break;
+
+ default:
+ break;
+ }
+}
+
/// Add the name of the given declaration
static void AddTypedNameChunk(ASTContext &Context, const PrintingPolicy &Policy,
const NamedDecl *ND,
@@ -3560,6 +3580,7 @@ CodeCompletionString *CodeCompletionResult::createCodeCompletionStringForDecl(
AddFunctionParameterChunks(PP, Policy, Function, Result);
Result.AddChunk(CodeCompletionString::CK_RightParen);
AddFunctionTypeQualsToCompletionString(Result, Function);
+ AddFunctionExceptSpecToCompletionString(Result, Function);
};
if (const auto *Function = dyn_cast<FunctionDecl>(ND)) {
@@ -3642,6 +3663,7 @@ CodeCompletionString *CodeCompletionResult::createCodeCompletionStringForDecl(
AddFunctionParameterChunks(PP, Policy, Function, Result);
Result.AddChunk(CodeCompletionString::CK_RightParen);
AddFunctionTypeQualsToCompletionString(Result, Function);
+ AddFunctionExceptSpecToCompletionString(Result, Function);
return Result.TakeString();
}
|
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@llvm/pr-subscribers-clang Author: Sirui Mu (Lancern) ChangesIf a virtual function is declared with Full diff: https://github.com/llvm/llvm-project/pull/75937.diff 2 Files Affected:
diff --git a/clang-tools-extra/clangd/test/completion-override-except-spec.test b/clang-tools-extra/clangd/test/completion-override-except-spec.test
new file mode 100644
index 00000000000000..19c7f84bc679d8
--- /dev/null
+++ b/clang-tools-extra/clangd/test/completion-override-except-spec.test
@@ -0,0 +1,69 @@
+# RUN: clangd -lit-test < %s | FileCheck %s
+# RUN: clangd -lit-test -pch-storage=memory < %s | FileCheck %s
+{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"clangd","capabilities":{},"trace":"off"}}
+---
+{"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"test:///main.cpp","languageId":"cpp","version":1,"text":"struct Base {\n virtual void virt_method() noexcept = 0;\n};\n\nstruct Derived : Base {\n virt_\n};"}}}
+---
+{"jsonrpc":"2.0","id":1,"method":"textDocument/completion","params":{"textDocument":{"uri":"test:///main.cpp"},"position":{"line":5,"character":6}}}
+# CHECK: "id": 1,
+# CHECK-NEXT: "jsonrpc": "2.0",
+# CHECK-NEXT: "result": {
+# CHECK-NEXT: "isIncomplete": false,
+# CHECK-NEXT: "items": [
+# CHECK-NEXT: {
+# CHECK-NEXT: "filterText": "virt_method() noexcept override",
+# CHECK-NEXT: "insertText": "void virt_method() noexcept override",
+# CHECK-NEXT: "insertTextFormat": 1,
+# CHECK-NEXT: "kind": 2,
+# CHECK-NEXT: "label": " void virt_method() noexcept override",
+# CHECK-NEXT: "score": {{[0-9]+.[0-9]+}},
+# CHECK-NEXT: "sortText": "{{.*}}virt_method() noexcept override",
+# CHECK-NEXT: "textEdit": {
+# CHECK-NEXT: "newText": "void virt_method() noexcept override",
+# CHECK-NEXT: "range": {
+# CHECK-NEXT: "end": {
+# CHECK-NEXT: "character": 6,
+# CHECK-NEXT: "line": 5
+# CHECK-NEXT: },
+# CHECK-NEXT: "start": {
+# CHECK-NEXT: "character": 2,
+# CHECK-NEXT: "line": 5
+# CHECK-NEXT: }
+# CHECK-NEXT: }
+# CHECK-NEXT: }
+# CHECK-NEXT: },
+---
+{"jsonrpc":"2.0","method":"textDocument/didChange","params":{"textDocument":{"uri":"test:///main.cpp","version":2},"contentChanges":[{"text":"struct Base {\n virtual void virt_method() = 0;\n};\n\nstruct Derived : Base {\n virt_\n};"}]}}
+---
+{"jsonrpc":"2.0","id":3,"method":"textDocument/completion","params":{"textDocument":{"uri":"test:///main.cpp"},"position":{"line":5,"character":6}}}
+# CHECK: "id": 3,
+# CHECK-NEXT: "jsonrpc": "2.0",
+# CHECK-NEXT: "result": {
+# CHECK-NEXT: "isIncomplete": false,
+# CHECK-NEXT: "items": [
+# CHECK-NEXT: {
+# CHECK-NEXT: "filterText": "virt_method() override",
+# CHECK-NEXT: "insertText": "void virt_method() override",
+# CHECK-NEXT: "insertTextFormat": 1,
+# CHECK-NEXT: "kind": 2,
+# CHECK-NEXT: "label": " void virt_method() override",
+# CHECK-NEXT: "score": {{[0-9]+.[0-9]+}},
+# CHECK-NEXT: "sortText": "{{.*}}virt_method() override",
+# CHECK-NEXT: "textEdit": {
+# CHECK-NEXT: "newText": "void virt_method() override",
+# CHECK-NEXT: "range": {
+# CHECK-NEXT: "end": {
+# CHECK-NEXT: "character": 6,
+# CHECK-NEXT: "line": 5
+# CHECK-NEXT: },
+# CHECK-NEXT: "start": {
+# CHECK-NEXT: "character": 2,
+# CHECK-NEXT: "line": 5
+# CHECK-NEXT: }
+# CHECK-NEXT: }
+# CHECK-NEXT: }
+# CHECK-NEXT: },
+---
+{"jsonrpc":"2.0","id":4,"method":"shutdown"}
+---
+{"jsonrpc":"2.0","method":"exit"}
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index c44be0df9b0a85..516936311a278d 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -25,6 +25,7 @@
#include "clang/AST/Type.h"
#include "clang/Basic/AttributeCommonInfo.h"
#include "clang/Basic/CharInfo.h"
+#include "clang/Basic/ExceptionSpecificationType.h"
#include "clang/Basic/OperatorKinds.h"
#include "clang/Basic/Specifiers.h"
#include "clang/Lex/HeaderSearch.h"
@@ -3292,6 +3293,25 @@ AddFunctionTypeQualsToCompletionString(CodeCompletionBuilder &Result,
Result.AddInformativeChunk(Result.getAllocator().CopyString(QualsStr));
}
+static void
+AddFunctionExceptSpecToCompletionString(CodeCompletionBuilder &Result,
+ const FunctionDecl *Function) {
+ const auto *Proto = Function->getType()->getAs<FunctionProtoType>();
+ if (!Proto)
+ return;
+
+ auto ExceptInfo = Proto->getExceptionSpecInfo();
+ switch (ExceptInfo.Type) {
+ case EST_BasicNoexcept:
+ case EST_NoexceptTrue:
+ Result.AddInformativeChunk(" noexcept");
+ break;
+
+ default:
+ break;
+ }
+}
+
/// Add the name of the given declaration
static void AddTypedNameChunk(ASTContext &Context, const PrintingPolicy &Policy,
const NamedDecl *ND,
@@ -3560,6 +3580,7 @@ CodeCompletionString *CodeCompletionResult::createCodeCompletionStringForDecl(
AddFunctionParameterChunks(PP, Policy, Function, Result);
Result.AddChunk(CodeCompletionString::CK_RightParen);
AddFunctionTypeQualsToCompletionString(Result, Function);
+ AddFunctionExceptSpecToCompletionString(Result, Function);
};
if (const auto *Function = dyn_cast<FunctionDecl>(ND)) {
@@ -3642,6 +3663,7 @@ CodeCompletionString *CodeCompletionResult::createCodeCompletionStringForDecl(
AddFunctionParameterChunks(PP, Policy, Function, Result);
Result.AddChunk(CodeCompletionString::CK_RightParen);
AddFunctionTypeQualsToCompletionString(Result, Function);
+ AddFunctionExceptSpecToCompletionString(Result, Function);
return Result.TakeString();
}
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Thanks for the patch. For the test, it would be better to write it in this format rather than using clangd. |
|
In addition to Nathan’s advice, I have a question about the commit message
I didn't see anything reflecting this condition; are you still working on this patch? Would you mind adding a WIP prefix to the title before everything is ready? Thank you! |
No, this is not a WIP. I primarily changed the Yes, I'm not explicitly testing if we're overriding a virtual function in the base. I understand the |
Thanks for your helpful review. I'll move the test to clang/test/CodeCompletion/overrides.cpp. |
The place you're patching is not only specific to "completing override functions", but handles all completion strings involving function declarations. |
|
Bonus: It appears that neither gcc nor clang implements a provision change from CWG1351,
giving errors on the following code. struct B {
virtual void h() noexcept = delete;
};
struct D: B {
void h() = delete; // Should be OK
};
int main() {
D();
} |
OK. I'll move the changes to the
Good catch. Maybe this deserves a new issue for clang Sema? |
Sounds reasonable to me. Feel free to put up a PR / issue for this if you are interested. |
Hi Younan. FYI, I have opened a new PR that addresses this problem. See #76248. |
Lancern
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Ping. Does this PR still get a chance to be merged? |
HighCommander4
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Jun 27, 2025
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Hi @Lancern, thanks for the reminder and sorry for the long delay here.
The patch looks good to me, thanks! The only thing I notice is that there area number of unrelated formatting changes; if it's not too much trouble, it would be nice to remove those.
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I have removed the unrelated formatting changes. Will land later if the CI is green. |
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/59/builds/20116 Here is the relevant piece of the build log for the reference |
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/195/builds/11073 Here is the relevant piece of the build log for the reference |
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…ion (llvm#75937) If a virtual function is declared with `noexcept`, functions that override this function in the derived classes must be declared with `noexcept` as well. This PR updates code completion in clang Sema. It adds `noexcept` specifier to override functions in the code completion result if the functions override a `noexcept` virtual function.
rlavaee
pushed a commit
to rlavaee/llvm-project
that referenced
this pull request
Jul 1, 2025
…ion (llvm#75937) If a virtual function is declared with `noexcept`, functions that override this function in the derived classes must be declared with `noexcept` as well. This PR updates code completion in clang Sema. It adds `noexcept` specifier to override functions in the code completion result if the functions override a `noexcept` virtual function.
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If a virtual function is declared with
noexcept, functions that override this function in the derived classes must be declared withnoexceptas well. This PR updates code completion in clang Sema. It addsnoexceptspecifier to override functions in the code completion result if the functions override anoexceptvirtual function.