[clang] [Sema] Add code completion for if constexpr and consteval (PR #124315)

Letu Ren via cfe-commits cfe-commits at lists.llvm.org
Sun Feb 23 09:26:13 PST 2025


https://github.com/FantasqueX updated https://github.com/llvm/llvm-project/pull/124315

>From 576dcfa4a403b95665e98f9ff225ab5353192e23 Mon Sep 17 00:00:00 2001
From: Letu Ren <fantasquex at gmail.com>
Date: Sat, 25 Jan 2025 01:23:52 +0800
Subject: [PATCH 1/7] [Sema] Add code completion for if constexpr

C++17 supports `if constexpr` statement. This patch implements this in
code completion.
---
 clang/include/clang/Sema/SemaCodeCompletion.h |  1 +
 clang/lib/Parse/ParseStmt.cpp                 |  8 ++++++++
 clang/lib/Sema/SemaCodeComplete.cpp           | 15 +++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/clang/include/clang/Sema/SemaCodeCompletion.h b/clang/include/clang/Sema/SemaCodeCompletion.h
index e931596c215d3..af44745d5d123 100644
--- a/clang/include/clang/Sema/SemaCodeCompletion.h
+++ b/clang/include/clang/Sema/SemaCodeCompletion.h
@@ -152,6 +152,7 @@ class SemaCodeCompletion : public SemaBase {
   void CodeCompleteDesignator(const QualType BaseType,
                               llvm::ArrayRef<Expr *> InitExprs,
                               const Designation &D);
+  void CodeCompleteIfConstExpr(Scope *S) const;
   void CodeCompleteAfterIf(Scope *S, bool IsBracedThen);
 
   void CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS, bool EnteringContext,
diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
index cd4504630f871..3f9900dd997ad 100644
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -1553,6 +1553,14 @@ StmtResult Parser::ParseIfStatement(SourceLocation *TrailingElseLoc) {
       IsConsteval = true;
       ConstevalLoc = ConsumeToken();
     }
+
+    if (Tok.is(tok::code_completion)) {
+      if (getLangOpts().CPlusPlus17) {
+        cutOffParsing();
+        Actions.CodeCompletion().CodeCompleteIfConstExpr(getCurScope());
+        return StmtError();
+      }
+    }
   }
   if (!IsConsteval && (NotLocation.isValid() || Tok.isNot(tok::l_paren))) {
     Diag(Tok, diag::err_expected_lparen_after) << "if";
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 80ae87e7c5725..bcc0cb18b8739 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -6749,6 +6749,21 @@ void SemaCodeCompletion::CodeCompleteInitializer(Scope *S, Decl *D) {
   CodeCompleteExpression(S, Data);
 }
 
+void SemaCodeCompletion::CodeCompleteIfConstExpr(Scope *S) const {
+  ResultBuilder Results(SemaRef, CodeCompleter->getAllocator(),
+                        CodeCompleter->getCodeCompletionTUInfo(),
+                        CodeCompletionContext::CCC_SymbolOrNewName);
+  Results.EnterNewScope();
+
+  Results.AddResult(CodeCompletionResult("constexpr"));
+
+  Results.ExitScope();
+
+  HandleCodeCompleteResults(&SemaRef, CodeCompleter,
+                            Results.getCompletionContext(), Results.data(),
+                            Results.size());
+}
+
 void SemaCodeCompletion::CodeCompleteAfterIf(Scope *S, bool IsBracedThen) {
   ResultBuilder Results(SemaRef, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(),

>From e7b7a6f2cfa4d056b643716e28e9d91ee5ab9738 Mon Sep 17 00:00:00 2001
From: Letu Ren <fantasquex at gmail.com>
Date: Mon, 3 Feb 2025 22:49:38 +0800
Subject: [PATCH 2/7] Add test for if constexpr completion

---
 clang/test/CodeCompletion/if-constexpr.cpp | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 clang/test/CodeCompletion/if-constexpr.cpp

diff --git a/clang/test/CodeCompletion/if-constexpr.cpp b/clang/test/CodeCompletion/if-constexpr.cpp
new file mode 100644
index 0000000000000..48a89b4799cbc
--- /dev/null
+++ b/clang/test/CodeCompletion/if-constexpr.cpp
@@ -0,0 +1,4 @@
+void test() {
+  if c
+  // RUN: %clang_cc1 -fsyntax-only -std=c++17 -code-completion-at=%s:%(line-1):7 %s -o - | FileCheck -check-prefix=CHECK-CC1 %s
+  // CHECK-CC1: constexpr

>From 7b4e81efe53e263e9410dd2994f126b5bdac5ef3 Mon Sep 17 00:00:00 2001
From: Letu Ren <fantasquex at gmail.com>
Date: Sat, 15 Feb 2025 18:03:38 +0800
Subject: [PATCH 3/7] rename function

---
 clang/include/clang/Sema/SemaCodeCompletion.h | 2 +-
 clang/lib/Parse/ParseStmt.cpp                 | 2 +-
 clang/lib/Sema/SemaCodeComplete.cpp           | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/clang/include/clang/Sema/SemaCodeCompletion.h b/clang/include/clang/Sema/SemaCodeCompletion.h
index af44745d5d123..c79e6ec13634b 100644
--- a/clang/include/clang/Sema/SemaCodeCompletion.h
+++ b/clang/include/clang/Sema/SemaCodeCompletion.h
@@ -152,7 +152,7 @@ class SemaCodeCompletion : public SemaBase {
   void CodeCompleteDesignator(const QualType BaseType,
                               llvm::ArrayRef<Expr *> InitExprs,
                               const Designation &D);
-  void CodeCompleteIfConstExpr(Scope *S) const;
+  void CodeCompleteIfConstexpr(Scope *S) const;
   void CodeCompleteAfterIf(Scope *S, bool IsBracedThen);
 
   void CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS, bool EnteringContext,
diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
index 3f9900dd997ad..fd7f707d87516 100644
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -1557,7 +1557,7 @@ StmtResult Parser::ParseIfStatement(SourceLocation *TrailingElseLoc) {
     if (Tok.is(tok::code_completion)) {
       if (getLangOpts().CPlusPlus17) {
         cutOffParsing();
-        Actions.CodeCompletion().CodeCompleteIfConstExpr(getCurScope());
+        Actions.CodeCompletion().CodeCompleteIfConstexpr(getCurScope());
         return StmtError();
       }
     }
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index bcc0cb18b8739..529965cb3e342 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -6749,7 +6749,7 @@ void SemaCodeCompletion::CodeCompleteInitializer(Scope *S, Decl *D) {
   CodeCompleteExpression(S, Data);
 }
 
-void SemaCodeCompletion::CodeCompleteIfConstExpr(Scope *S) const {
+void SemaCodeCompletion::CodeCompleteIfConstexpr(Scope *S) const {
   ResultBuilder Results(SemaRef, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(),
                         CodeCompletionContext::CCC_SymbolOrNewName);

>From 69856ad17c3e11db64ea2713c30d14a45d13f575 Mon Sep 17 00:00:00 2001
From: Letu Ren <fantasquex at gmail.com>
Date: Sat, 15 Feb 2025 19:10:02 +0800
Subject: [PATCH 4/7] use CCC_Other instead

---
 clang/lib/Sema/SemaCodeComplete.cpp | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 529965cb3e342..209e8da8c7611 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -6752,11 +6752,9 @@ void SemaCodeCompletion::CodeCompleteInitializer(Scope *S, Decl *D) {
 void SemaCodeCompletion::CodeCompleteIfConstexpr(Scope *S) const {
   ResultBuilder Results(SemaRef, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(),
-                        CodeCompletionContext::CCC_SymbolOrNewName);
+                        CodeCompletionContext::CCC_Other);
   Results.EnterNewScope();
-
   Results.AddResult(CodeCompletionResult("constexpr"));
-
   Results.ExitScope();
 
   HandleCodeCompleteResults(&SemaRef, CodeCompleter,

>From 2626cd4c1bf48d0a7e617a3a2f3994fed4aa0a84 Mon Sep 17 00:00:00 2001
From: Letu Ren <fantasquex at gmail.com>
Date: Mon, 17 Feb 2025 20:48:22 +0800
Subject: [PATCH 5/7] Add consteval

---
 clang/include/clang/Sema/SemaCodeCompletion.h | 2 +-
 clang/lib/Parse/ParseStmt.cpp                 | 8 +++-----
 clang/lib/Sema/SemaCodeComplete.cpp           | 9 +++++++--
 clang/test/CodeCompletion/if-const.cpp        | 6 ++++++
 clang/test/CodeCompletion/if-constexpr.cpp    | 4 ----
 5 files changed, 17 insertions(+), 12 deletions(-)
 create mode 100644 clang/test/CodeCompletion/if-const.cpp
 delete mode 100644 clang/test/CodeCompletion/if-constexpr.cpp

diff --git a/clang/include/clang/Sema/SemaCodeCompletion.h b/clang/include/clang/Sema/SemaCodeCompletion.h
index c79e6ec13634b..b930210f5f905 100644
--- a/clang/include/clang/Sema/SemaCodeCompletion.h
+++ b/clang/include/clang/Sema/SemaCodeCompletion.h
@@ -152,7 +152,7 @@ class SemaCodeCompletion : public SemaBase {
   void CodeCompleteDesignator(const QualType BaseType,
                               llvm::ArrayRef<Expr *> InitExprs,
                               const Designation &D);
-  void CodeCompleteIfConstexpr(Scope *S) const;
+  void CodeCompleteIfConst(Scope *S) const;
   void CodeCompleteAfterIf(Scope *S, bool IsBracedThen);
 
   void CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS, bool EnteringContext,
diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
index fd7f707d87516..1c83697a4f421 100644
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -1555,11 +1555,9 @@ StmtResult Parser::ParseIfStatement(SourceLocation *TrailingElseLoc) {
     }
 
     if (Tok.is(tok::code_completion)) {
-      if (getLangOpts().CPlusPlus17) {
-        cutOffParsing();
-        Actions.CodeCompletion().CodeCompleteIfConstexpr(getCurScope());
-        return StmtError();
-      }
+      cutOffParsing();
+      Actions.CodeCompletion().CodeCompleteIfConst(getCurScope());
+      return StmtError();
     }
   }
   if (!IsConsteval && (NotLocation.isValid() || Tok.isNot(tok::l_paren))) {
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 209e8da8c7611..0c7be20e6bfe4 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -6749,12 +6749,17 @@ void SemaCodeCompletion::CodeCompleteInitializer(Scope *S, Decl *D) {
   CodeCompleteExpression(S, Data);
 }
 
-void SemaCodeCompletion::CodeCompleteIfConstexpr(Scope *S) const {
+void SemaCodeCompletion::CodeCompleteIfConst(Scope *S) const {
   ResultBuilder Results(SemaRef, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(),
                         CodeCompletionContext::CCC_Other);
   Results.EnterNewScope();
-  Results.AddResult(CodeCompletionResult("constexpr"));
+  if (getLangOpts().CPlusPlus17) {
+    Results.AddResult(CodeCompletionResult("constexpr"));
+  }
+  if (getLangOpts().CPlusPlus23) {
+    Results.AddResult(CodeCompletionResult("consteval"));
+  }
   Results.ExitScope();
 
   HandleCodeCompleteResults(&SemaRef, CodeCompleter,
diff --git a/clang/test/CodeCompletion/if-const.cpp b/clang/test/CodeCompletion/if-const.cpp
new file mode 100644
index 0000000000000..3c795dcc00ab9
--- /dev/null
+++ b/clang/test/CodeCompletion/if-const.cpp
@@ -0,0 +1,6 @@
+void test() {
+  if c
+  // RUN: %clang_cc1 -fsyntax-only -std=c++17 -code-completion-at=%s:2:7 %s -o - | FileCheck -check-prefix=CHECK-CXX17 %s
+  // RUN: %clang_cc1 -fsyntax-only -std=c++23 -code-completion-at=%s:2:7 %s -o - | FileCheck -check-prefix=CHECK-CXX23 %s
+  // CHECK-CXX17: constexpr
+  // CHECK-CXX23: consteval
diff --git a/clang/test/CodeCompletion/if-constexpr.cpp b/clang/test/CodeCompletion/if-constexpr.cpp
deleted file mode 100644
index 48a89b4799cbc..0000000000000
--- a/clang/test/CodeCompletion/if-constexpr.cpp
+++ /dev/null
@@ -1,4 +0,0 @@
-void test() {
-  if c
-  // RUN: %clang_cc1 -fsyntax-only -std=c++17 -code-completion-at=%s:%(line-1):7 %s -o - | FileCheck -check-prefix=CHECK-CC1 %s
-  // CHECK-CC1: constexpr

>From 914e63cbc8ac24c808da647fe9516e1d10866c87 Mon Sep 17 00:00:00 2001
From: Letu Ren <fantasquex at gmail.com>
Date: Mon, 24 Feb 2025 01:20:45 +0800
Subject: [PATCH 6/7] support code snippet completion

---
 clang/lib/Sema/SemaCodeComplete.cpp | 31 +++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 0c7be20e6bfe4..b3351387ac804 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -6753,12 +6753,39 @@ void SemaCodeCompletion::CodeCompleteIfConst(Scope *S) const {
   ResultBuilder Results(SemaRef, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(),
                         CodeCompletionContext::CCC_Other);
+  CodeCompletionBuilder Builder(Results.getAllocator(), Results.getCodeCompletionTUInfo());
   Results.EnterNewScope();
   if (getLangOpts().CPlusPlus17) {
-    Results.AddResult(CodeCompletionResult("constexpr"));
+    if (Results.includeCodePatterns()) {
+      Builder.AddTypedTextChunk("constexpr");
+      Builder.AddChunk(CodeCompletionString::CK_HorizontalSpace);
+      Builder.AddChunk(CodeCompletionString::CK_LeftParen);
+      Builder.AddPlaceholderChunk("condition");
+      Builder.AddChunk(CodeCompletionString::CK_RightParen);
+      Builder.AddChunk(CodeCompletionString::CK_HorizontalSpace);
+      Builder.AddChunk(CodeCompletionString::CK_LeftBrace);
+      Builder.AddChunk(CodeCompletionString::CK_VerticalSpace);
+      Builder.AddPlaceholderChunk("statements");
+      Builder.AddChunk(CodeCompletionString::CK_VerticalSpace);
+      Builder.AddChunk(CodeCompletionString::CK_RightBrace);
+      Results.AddResult({Builder.TakeString()});
+    } else {
+      Results.AddResult({"constexpr"});
+    }
   }
   if (getLangOpts().CPlusPlus23) {
-    Results.AddResult(CodeCompletionResult("consteval"));
+    if (Results.includeCodePatterns()) {
+      Builder.AddTypedTextChunk("consteval");
+      Builder.AddChunk(CodeCompletionString::CK_HorizontalSpace);
+      Builder.AddChunk(CodeCompletionString::CK_LeftBrace);
+      Builder.AddChunk(CodeCompletionString::CK_VerticalSpace);
+      Builder.AddPlaceholderChunk("statements");
+      Builder.AddChunk(CodeCompletionString::CK_VerticalSpace);
+      Builder.AddChunk(CodeCompletionString::CK_RightBrace);
+      Results.AddResult({Builder.TakeString()});
+    } else {
+      Results.AddResult({"consteval"});
+    }
   }
   Results.ExitScope();
 

>From d0d3984b4b3cc92d9344bfcaebb8484906805e29 Mon Sep 17 00:00:00 2001
From: Letu Ren <fantasquex at gmail.com>
Date: Mon, 24 Feb 2025 01:25:58 +0800
Subject: [PATCH 7/7] format code

---
 clang/lib/Sema/SemaCodeComplete.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index b3351387ac804..f4f3970cb6d33 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -6753,7 +6753,8 @@ void SemaCodeCompletion::CodeCompleteIfConst(Scope *S) const {
   ResultBuilder Results(SemaRef, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(),
                         CodeCompletionContext::CCC_Other);
-  CodeCompletionBuilder Builder(Results.getAllocator(), Results.getCodeCompletionTUInfo());
+  CodeCompletionBuilder Builder(Results.getAllocator(),
+                                Results.getCodeCompletionTUInfo());
   Results.EnterNewScope();
   if (getLangOpts().CPlusPlus17) {
     if (Results.includeCodePatterns()) {



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