From caec7904bdfa9a12c7f6d4a68d1b8de946c22c7a Mon Sep 17 00:00:00 2001
From: Andreas Fertig <andy@cppinsights.io>
Date: Mon, 15 Jul 2024 21:18:57 +0200
Subject: [PATCH] Fixed object-lifetime visualization for more than one
 temporary.

---
 CodeGenerator.cpp              | 21 +++++++-----
 tests/EduLifeTimeTest12.expect |  4 +--
 tests/EduLifeTimeTest13.cpp    | 29 ++++++++++++++++
 tests/EduLifeTimeTest13.expect | 61 ++++++++++++++++++++++++++++++++++
 4 files changed, 105 insertions(+), 10 deletions(-)
 create mode 100644 tests/EduLifeTimeTest13.cpp
 create mode 100644 tests/EduLifeTimeTest13.expect

diff --git a/CodeGenerator.cpp b/CodeGenerator.cpp
index 973e238..92dd038 100644
--- a/CodeGenerator.cpp
+++ b/CodeGenerator.cpp
@@ -905,11 +905,12 @@ class BindingDeclFinder : public ConstStmtVisitor<BindingDeclFinder>
 /// \brief Find a \c DeclRefExpr belonging to a \c DecompositionDecl
 class TemporaryDeclFinder : public StmtVisitor<TemporaryDeclFinder>
 {
-    CodeGenerator& codeGenerator;
-    bool           mFound{};
-    bool           mHaveTemporary{};
-    Stmt*          mPrevStmt{};
-    std::string    mTempName{};
+    CodeGenerator&        codeGenerator;
+    bool                  mFound{};
+    bool                  mHaveTemporary{};
+    Stmt*                 mPrevStmt{};
+    std::string           mTempName{};
+    std::vector<VarDecl*> mDecls{};
 
 public:
     TemporaryDeclFinder(CodeGenerator& _codeGenerator, const Stmt* stmt, bool inspectReturn = false)
@@ -920,6 +921,10 @@ class TemporaryDeclFinder : public StmtVisitor<TemporaryDeclFinder>
 
         Visit(mPrevStmt);
 
+        for(auto d : mDecls) {
+            codeGenerator.InsertArg(d);
+        }
+
         RETURN_IF(not GetInsightsOptions().UseShow2C or mFound or not inspectReturn);
 
         if(auto* expr = dyn_cast_or_null<CXXConstructExpr>(stmt)) {
@@ -1001,7 +1006,7 @@ class TemporaryDeclFinder : public StmtVisitor<TemporaryDeclFinder>
             ReplaceNode(mPrevStmt, expr, newValue);
         }
 
-        codeGenerator.InsertArg(vd);
+        mDecls.push_back(vd);
     }
 
 #if 0
@@ -1031,14 +1036,14 @@ class TemporaryDeclFinder : public StmtVisitor<TemporaryDeclFinder>
         auto* newValue = mkDeclRefExpr(vd);
         ReplaceNode(mPrevStmt, stmt, newValue);
 
-        if(SD_FullExpression == stmt->getStorageDuration()) {
+        if(SD_FullExpression == stmt->getStorageDuration() and not mHaveTemporary) {
             codeGenerator.StartLifetimeScope();
             mHaveTemporary = true;
         } else if(const auto* extending = stmt->getExtendingDecl()) {
             codeGenerator.LifetimeAddExtended(vd, extending);
         }
 
-        codeGenerator.InsertArg(vd);
+        mDecls.push_back(vd);
     }
 
     void VisitStmt(Stmt* stmt)
diff --git a/tests/EduLifeTimeTest12.expect b/tests/EduLifeTimeTest12.expect
index 2347729..fa53368 100644
--- a/tests/EduLifeTimeTest12.expect
+++ b/tests/EduLifeTimeTest12.expect
@@ -18,15 +18,15 @@ int main()
   const std::pair<int, int> __temporary10_16 = std::pair<int, int>{__temporary10_13, __temporary10_15};
   S a = {1, __temporary10_16};
   /* __temporary10_15 // lifetime ends here */
+  /* __temporary10_13 // lifetime ends here */
   int __temporary11_21 = 2;
   int __temporary11_23 = 3;
   const std::pair<int, int> __temporary11_24 = std::pair<int, int>{__temporary11_21, __temporary11_23};
   S * p = new S{1, __temporary11_24};
   /* __temporary11_24 // lifetime ends here */
-  return 0;
   /* __temporary11_23 // lifetime ends here */
   /* __temporary11_21 // lifetime ends here */
-  /* __temporary10_13 // lifetime ends here */
+  return 0;
   /* __temporary10_16 // lifetime ends here */
   /* a // lifetime ends here */
 }
diff --git a/tests/EduLifeTimeTest13.cpp b/tests/EduLifeTimeTest13.cpp
new file mode 100644
index 0000000..32889b3
--- /dev/null
+++ b/tests/EduLifeTimeTest13.cpp
@@ -0,0 +1,29 @@
+// cmdlineinsights:-edu-show-lifetime
+
+template<class T, class U>
+struct pair {
+  T first;
+  U second;
+
+  pair(T&& t, U&& u)
+  : first{t}
+  , second{u}
+  {}
+
+  pair(const T& t, const U& u)
+  : first{t}
+  , second{u}
+  {}
+};
+
+// From: https://eel.is/c++draft/class.temporary#6.11
+struct S {
+  int                   mi;
+  const pair<int, int>& failingp;
+};
+
+int main()
+{
+  S invalids{1, {2, 3}};  // #A
+}
+
diff --git a/tests/EduLifeTimeTest13.expect b/tests/EduLifeTimeTest13.expect
new file mode 100644
index 0000000..22b89bd
--- /dev/null
+++ b/tests/EduLifeTimeTest13.expect
@@ -0,0 +1,61 @@
+/*************************************************************************************
+ * NOTE: This an educational hand-rolled transformation. Things can be incorrect or  *
+ * buggy.                                                                            *
+ *************************************************************************************/
+template<class T, class U>
+struct pair
+{
+  T first;
+  U second;
+  inline pair(T && t, U && u)
+  : first{t}
+  , second{u}
+  {
+  }
+  
+  inline pair(const T & t, const U & u)
+  : first{t}
+  , second{u}
+  {
+  }
+  
+};
+
+/* First instantiated from: EduLifeTimeTest13.cpp:27 */
+#ifdef INSIGHTS_USE_TEMPLATE
+template<>
+struct pair<int, int>
+{
+  int first;
+  int second;
+  inline pair(int && t, int && u)
+  : first{t}
+  , second{u}
+  {
+  }
+  
+  inline pair(const int & t, const int & u);
+  
+};
+
+#endif
+
+struct S
+{
+  int mi;
+  const pair<int, int> & failingp;
+};
+
+
+int main()
+{
+  int __temporary27_18 = 2;
+  int __temporary27_21 = 3;
+  const pair<int, int> __temporary27_22 = pair<int, int>{__temporary27_18, __temporary27_21};
+  S invalids = {1, __temporary27_22};
+  /* __temporary27_21 // lifetime ends here */
+  /* __temporary27_18 // lifetime ends here */
+  return 0;
+  /* __temporary27_22 // lifetime ends here */
+  /* invalids // lifetime ends here */
+}