From 9c982647f2c3deb0fbf5cf9c6d08c96ae2b0a949 Mon Sep 17 00:00:00 2001
From: Giuliano Belinassi <gbelinassi@suse.de>
Date: Fri, 19 Jul 2024 14:04:12 -0300
Subject: [PATCH] Fix nested struct being discarded if parent struct is flagged
 as partial

When clang detects that a certain struct doesn't need a full definition,
i.e. its size is not required, then the flag CompleteDefinitionRequired
is set to false.  But in the following case:
```
struct Fts3Table {
  struct Fts3Index {
    int nPrefix;
  } *aIndex;
};

int fts3PrefixParameter(
  const char *zParam,
  int *pnIndex,
  struct Fts3Index **apIndex
){
  int a = sizeof(struct Fts3Index);
  return 0;
}
```
this results in the nested struct `Fts3Index` not being output as its
parent struct `Fts3Table` is marked as CompleteDefinitionRequired as
false.  In such cases we have to force CompleteDefinitionRequired of
the parent struct as true so that its inner structs can be output.

Signed-off-by: Giuliano Belinassi <gbelinassi@suse.de>
---
 libcextract/Closure.hh            | 33 ++++++++++++++++++++-----------
 testsuite/small/record-nested-3.c | 19 ++++++++++++++++++
 2 files changed, 40 insertions(+), 12 deletions(-)
 create mode 100644 testsuite/small/record-nested-3.c

diff --git a/libcextract/Closure.hh b/libcextract/Closure.hh
index fd26d33..6e25c46 100644
--- a/libcextract/Closure.hh
+++ b/libcextract/Closure.hh
@@ -195,18 +195,14 @@ class DeclClosureVisitor : public RecursiveASTVisitor<DeclClosureVisitor>
     return VISITOR_CONTINUE
 
   /* Special Traversal functions which marks if a Decl was already analyzed.
-     This macro generates them.  */
-#define DEF_MARKING_TRAVERSE_DECL(DECL)               \
-  bool Traverse##DECL(DECL *decl)                     \
-  {                                                   \
-    DO_NOT_RUN_IF_ALREADY_ANALYZED(decl);             \
-    Mark_As_Analyzed(decl);                           \
-    return RecursiveASTVisitor::Traverse##DECL(decl); \
-  }
-
-  /* Override of TraverseDecl that marks that the given Decl was analyzed.  So
+     Override of TraverseDecl that marks that the given Decl was analyzed.  So
      far it seems we only need this function for now.  */
-  DEF_MARKING_TRAVERSE_DECL(Decl);
+  bool TraverseDecl(Decl *decl)
+  {
+    DO_NOT_RUN_IF_ALREADY_ANALYZED(decl);
+    Mark_As_Analyzed(decl);
+    return RecursiveASTVisitor::TraverseDecl(decl);
+  }
 
   /* -------- C Declarations ----------------- */
 
@@ -266,6 +262,20 @@ class DeclClosureVisitor : public RecursiveASTVisitor<DeclClosureVisitor>
         typedef struct { int a; } A;  */
       return VisitTypedefNameDecl(typedecl);
     } else {
+      /* In case this references a struct/union defined inside a struct (nested
+         struct), then we also need to analyze the parent struct.  */
+      RecordDecl *parent = dyn_cast<RecordDecl>(decl->getLexicalDeclContext());
+      if (parent) {
+        /* If the parent struct is flagged as not needing a complete definition
+           then we need to set it to true, else the nested struct won't be
+           output as of only a partial definition of the parent struct is
+           output. */
+        parent->setCompleteDefinitionRequired(true);
+
+        /* Analyze parent struct.  */
+        TRY_TO(TraverseDecl(parent));
+      }
+
       Closure.Add_Decl_And_Prevs(Maybe_Partial_Decl(decl));
     }
 
@@ -547,5 +557,4 @@ class DeclClosureVisitor : public RecursiveASTVisitor<DeclClosureVisitor>
   std::unordered_set<Decl *> AnalyzedDecls;
 #undef TRY_TO
 #undef DO_NOT_RUN_IF_ALREADY_ANALYZED
-#undef DEF_MARKING_TRAVERSE_DECL
 };
diff --git a/testsuite/small/record-nested-3.c b/testsuite/small/record-nested-3.c
new file mode 100644
index 0000000..219d520
--- /dev/null
+++ b/testsuite/small/record-nested-3.c
@@ -0,0 +1,19 @@
+/* { dg-options "-DCE_EXTRACT_FUNCTIONS=fts3PrefixParameter -DCE_NO_EXTERNALIZATION" }*/
+
+struct Fts3Table {
+  struct Fts3Index {
+    int nPrefix;
+  } *aIndex;
+};
+
+int fts3PrefixParameter(
+  const char *zParam,
+  int *pnIndex,
+  struct Fts3Index **apIndex
+){
+  int a = sizeof(struct Fts3Index);
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "struct Fts3Table *{" } } */
+/* { dg-final { scan-tree-dump "} *\*aIndex;" } } */