From d49aa60dfc1cb6c4e13b5be90bc8b707457d5dd3 Mon Sep 17 00:00:00 2001
From: Marcos Paulo de Souza <mpdesouza@suse.com>
Date: Thu, 13 Jun 2024 17:08:49 -0300
Subject: [PATCH] FunctionDepsFinder: Check for declarations inside another
 declaration

Closes: #44

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
---
 libcextract/FunctionDepsFinder.cpp | 28 ++++++++++++++++++++++++++++
 libcextract/FunctionDepsFinder.hh  | 24 ++++++++++++++++++++++++
 testsuite/linux/typedef-1.c        | 19 +++++++++++++++++++
 3 files changed, 71 insertions(+)
 create mode 100644 testsuite/linux/typedef-1.c

diff --git a/libcextract/FunctionDepsFinder.cpp b/libcextract/FunctionDepsFinder.cpp
index 90f78b0..fac6192 100644
--- a/libcextract/FunctionDepsFinder.cpp
+++ b/libcextract/FunctionDepsFinder.cpp
@@ -623,6 +623,34 @@ void FunctionDependencyFinder::Remove_Redundant_Decls(void) {
             }
           }
         }
+
+        /*
+         * Check if there wasn't any symbol that is being defined in the same
+         * interval and remove it. Otherwise we might clash the types.
+         *
+         * One example of how this can happen is then we have something like
+         *
+         * typedef struct {
+         * ...
+         * } x, y;
+         *
+         * In the process of creating the closure we might reach the following
+         * situation:
+         *
+         * typdef struct {
+         * ...
+         * } x;
+         *
+         * typedef struct {
+         *
+         * } x, y;
+         *
+         * Which then breaks the one-definition-rule. In such cases, remove the
+         * previous declaration in the same code range, since the later will
+         * contain both definitions either way.
+         */
+        if (Decl *range_decl = Closure.insideRangeOfDecl(decl))
+          Closure.Remove_Decl(range_decl);
       }
     }
     /* Handle the case where an enum is declared as:
diff --git a/libcextract/FunctionDepsFinder.hh b/libcextract/FunctionDepsFinder.hh
index 928e859..ac5c1e8 100644
--- a/libcextract/FunctionDepsFinder.hh
+++ b/libcextract/FunctionDepsFinder.hh
@@ -43,6 +43,30 @@ class ClosureSet
     Dependencies.insert(decl);
   }
 
+  /*
+   * Check if the same Decl was already added into the closure but for a
+   * different typename.
+   */
+  Decl *insideRangeOfDecl(Decl *decl)
+  {
+    SourceRange range = decl->getSourceRange();
+
+    for (auto it = Dependencies.begin(); it != Dependencies.end(); ++it) {
+      if (TypedefDecl *cur_decl = dyn_cast<TypedefDecl>(*it)) {
+        SourceRange cur_range = cur_decl->getSourceRange();
+
+        // Avoid comparing to itself
+        if (cur_range == range)
+          continue;
+
+        if (PrettyPrint::Contains_From_LineCol(range, cur_range))
+          return cur_decl;
+      }
+    }
+
+    return nullptr;
+  }
+
   inline std::unordered_set<Decl *> &Get_Set(void)
   {
     return Dependencies;
diff --git a/testsuite/linux/typedef-1.c b/testsuite/linux/typedef-1.c
new file mode 100644
index 0000000..97d7b9e
--- /dev/null
+++ b/testsuite/linux/typedef-1.c
@@ -0,0 +1,19 @@
+/* { dg-options "-DCE_EXTRACT_FUNCTIONS=f" } */
+
+typedef struct {
+	int id;
+	int val;
+} st1, st2;
+
+int f(void)
+{
+	st1 s1;
+	st2 s2;
+
+	s1.id = 10;
+	s2.val = 5;
+}
+/* { dg-final { scan-tree-dump "int f\(void\)" } } */
+/* { dg-final { scan-tree-dump "} st1, st2;" } } */
+/* { dg-final { scan-tree-dump-not "} st1;" } } */
+/* { dg-final { scan-tree-dump-not "} st2;" } } */