[clang] [Clang] Fix looking for immediate calls in default arguments. (PR #80690)

[via cfe-commits]

https://github.com/cor3ntin updated https://github.com/llvm/llvm-project/pull/80690

>From 77556982a14dc7969a5ab6dc19ce0bfc8a0a763c Mon Sep 17 00:00:00 2001
From: Corentin Jabot <corentinjabot at gmail.com>
Date: Mon, 5 Feb 2024 15:42:21 +0100
Subject: [PATCH 1/2] [Clang] Fix looking for immediate calls in default
 arguments.

Due to improper use of RecursiveASTVisitor.

Fixes #80630
---
 clang/docs/ReleaseNotes.rst                    |  2 ++
 clang/lib/Sema/SemaExpr.cpp                    |  6 +++---
 .../SemaCXX/cxx2a-consteval-default-params.cpp | 15 +++++++++++++++
 clang/test/SemaCXX/source_location.cpp         | 18 ++++++++++++++++++
 4 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 06c7d57d73ca70..184fe5dd108f96 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -265,6 +265,8 @@ Bug Fixes to C++ Support
 - No longer reject valid use of the ``_Alignas`` specifier when declaring a
   local variable, which is supported as a C11 extension in C++. Previously, it
   was only accepted at namespace scope but not at local function scope.
+- Fix evaluation of some immediate calls in default arguments.
+  Fixes (`#80630 <https://github.com/llvm/llvm-project/issues/80630>`_)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 4049ab3bf6cafb..f75ab794886444 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -6198,7 +6198,7 @@ struct ImmediateCallVisitor : public RecursiveASTVisitor<ImmediateCallVisitor> {
   bool VisitCallExpr(CallExpr *E) {
     if (const FunctionDecl *FD = E->getDirectCallee())
       HasImmediateCalls |= FD->isImmediateFunction();
-    return RecursiveASTVisitor<ImmediateCallVisitor>::VisitStmt(E);
+    return RecursiveASTVisitor<ImmediateCallVisitor>::VisitCallExpr(E);
   }
 
   // SourceLocExpr are not immediate invocations
@@ -6222,9 +6222,9 @@ struct ImmediateCallVisitor : public RecursiveASTVisitor<ImmediateCallVisitor> {
 
   // Blocks don't support default parameters, and, as for lambdas,
   // we don't consider their body a subexpression.
-  bool VisitBlockDecl(BlockDecl *B) { return false; }
+  bool VisitBlockDecl(BlockDecl *B) { return true; }
 
-  bool VisitCompoundStmt(CompoundStmt *B) { return false; }
+  bool VisitCompoundStmt(CompoundStmt *B) { return true; }
 
   bool VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) {
     return TraverseStmt(E->getExpr());
diff --git a/clang/test/SemaCXX/cxx2a-consteval-default-params.cpp b/clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
index be8f7cc788589f..e4b13725b2dacd 100644
--- a/clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
+++ b/clang/test/SemaCXX/cxx2a-consteval-default-params.cpp
@@ -82,3 +82,18 @@ namespace GH62224 {
   C<> Val; // No error since fwd is defined already.
   static_assert(Val.get() == 42);
 }
+
+namespace GH80630 {
+
+consteval const char* ce() { return "Hello"; }
+
+auto f2(const char* loc = []( char const* fn )
+    { return fn; }  ( ce() ) ) {
+    return loc;
+}
+
+auto g() {
+    return f2();
+}
+
+}
diff --git a/clang/test/SemaCXX/source_location.cpp b/clang/test/SemaCXX/source_location.cpp
index 7414fbce7828d1..b151fc45fdad62 100644
--- a/clang/test/SemaCXX/source_location.cpp
+++ b/clang/test/SemaCXX/source_location.cpp
@@ -832,3 +832,21 @@ void test() {
 }
 
 }
+
+namespace GH80630 {
+
+#define GH80630_LAMBDA \
+    []( char const* fn ) { \
+        static constexpr std::source_location loc = std::source_location::current(); \
+        return &loc; \
+    }( std::source_location::current().function() )
+
+auto f( std::source_location const* loc = GH80630_LAMBDA ) {
+    return loc;
+}
+
+auto g() {
+    return f();
+}
+
+}

>From c0fdb22a9e6484fdb037bec70aea69d0c9184f28 Mon Sep 17 00:00:00 2001
From: Corentin Jabot <corentinjabot at gmail.com>
Date: Sun, 18 Feb 2024 14:45:22 +0100
Subject: [PATCH 2/2] Address Aaron's feedback

---
 clang/lib/Sema/SemaExpr.cpp | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index f75ab794886444..0ea485cc65ce18 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -6198,7 +6198,7 @@ struct ImmediateCallVisitor : public RecursiveASTVisitor<ImmediateCallVisitor> {
   bool VisitCallExpr(CallExpr *E) {
     if (const FunctionDecl *FD = E->getDirectCallee())
       HasImmediateCalls |= FD->isImmediateFunction();
-    return RecursiveASTVisitor<ImmediateCallVisitor>::VisitCallExpr(E);
+    return RecursiveASTVisitor<ImmediateCallVisitor>::VisitStmt(E);
   }
 
   // SourceLocExpr are not immediate invocations
@@ -6220,12 +6220,6 @@ struct ImmediateCallVisitor : public RecursiveASTVisitor<ImmediateCallVisitor> {
     return VisitCXXMethodDecl(E->getCallOperator());
   }
 
-  // Blocks don't support default parameters, and, as for lambdas,
-  // we don't consider their body a subexpression.
-  bool VisitBlockDecl(BlockDecl *B) { return true; }
-
-  bool VisitCompoundStmt(CompoundStmt *B) { return true; }
-
   bool VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) {
     return TraverseStmt(E->getExpr());
   }