From fb1e177130648d2e4b1e327f28f66e38176f9f53 Mon Sep 17 00:00:00 2001
From: Victor Olin <victor.vieweg@icloud.com>
Date: Thu, 16 Feb 2023 15:22:26 +0100
Subject: [PATCH] Testing different stack pointers

---
 src/GC/Makefile         | 12 ++---------
 src/GC/lib/heap.cpp     |  5 ++++-
 src/GC/tests/stack.cpp  | 21 +++++++++++++++++++-
 src/GC/tests/stack2.cpp | 44 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 70 insertions(+), 12 deletions(-)
 create mode 100644 src/GC/tests/stack2.cpp

diff --git a/src/GC/Makefile b/src/GC/Makefile
index 64d90d6..7c0c38f 100644
--- a/src/GC/Makefile
+++ b/src/GC/Makefile
@@ -1,6 +1,6 @@
 CC = clang++
 PWD = /home/virre/dev/systemF/org/language/src/GC/include
-CFLAGS = -Wall -Wextra -v -std=gnu++20 -stdlib=libc++ -I
+CFLAGS = -Wall -Wextra -v -g -std=gnu++20 -stdlib=libc++ -I
 
 heap:
 	$(CC) $(CFLAGS)$(PWD) lib/heap.cpp
@@ -9,14 +9,6 @@ h_test:
 	rm -f tests/h_test.out
 	$(CC) $(CFLAGS)$(PWD) tests/h_test.cpp lib/heap.cpp -o tests/h_test.out
 
-h_test_vg:
-	rm -f tests/h_test.out
-	$(CC) $(CFLAGS)$(PWD) -g tests/h_test.cpp lib/heap.cpp -o tests/h_test.out
-
 linker:
 	rm -f tests/linker.out
-	$(CC) $(CFLAGS)$(PWD) tests/linker.cpp lib/heap.cpp -o tests/linker.out
-
-linker_vg:
-	rm -f tests/linker.out
-	$(CC) $(CFLAGS)$(PWD) -g tests/linker.cpp lib/heap.cpp -o tests/linker.out
\ No newline at end of file
+	$(CC) $(CFLAGS)$(PWD) tests/linker.cpp lib/heap.cpp -o tests/linker.out
\ No newline at end of file
diff --git a/src/GC/lib/heap.cpp b/src/GC/lib/heap.cpp
index 8c296b5..59f4e7d 100644
--- a/src/GC/lib/heap.cpp
+++ b/src/GC/lib/heap.cpp
@@ -65,7 +65,10 @@ namespace GC {
     // get the frame adress, whwere local variables and saved registers are located
     auto stack_start = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
     // looking at 10 stack frames back
-    const uintptr_t *stack_end = (uintptr_t *)0; //reinterpret_cast<const uintptr_t *>(__builtin_frame_address(10));
+    const uintptr_t *stack_end = (uintptr_t *)0;
+    
+    // denna segfaultar om arg för __b_f_a är > 2
+    // reinterpret_cast<const uintptr_t *>(__builtin_frame_address(10));
     auto work_list = m_allocated_chunks;
     mark(stack_start, stack_end, work_list);
 
diff --git a/src/GC/tests/stack.cpp b/src/GC/tests/stack.cpp
index 6cdf2d0..8f8382e 100644
--- a/src/GC/tests/stack.cpp
+++ b/src/GC/tests/stack.cpp
@@ -3,13 +3,32 @@
 #include <iostream>
 #include <vector>
 
+/*
+ *  Stack.cpp
+ *  - Tests stack scanning and stack pointers
+ *  
+ *  Goal:   Find the values of the following variables
+ *          and their position on the stack
+ *          - unsigned long a
+ *          - unsigned long b
+ *          - unsigned long global_1
+ *          - unsigned long global_2
+ * 
+ *  Result: Passed
+*/
+
+
+
+
 std::vector<uintptr_t *> iv;
 
 void collect() {
     std::cout << "in collect" << std::endl;
 
     uintptr_t *stack_start = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
-    // uintptr_t *stack_end = reinterpret_cast<uintptr_t *>(__builtin_frame_address(100));
+
+    // denna orsakar segfault om man ger __b_f_a ett värde större än 2
+    // uintptr_t *stack_end = reinterpret_cast<uintptr_t *>(__builtin_frame_address(100)); 
 
     std::cout << "SP1:\t" << stack_start << "\nSP2:\t" << (stack_start - 1*sizeof(int)) << std::endl;
     std::cout << "SP-:\t" << --stack_start << std::endl;
diff --git a/src/GC/tests/stack2.cpp b/src/GC/tests/stack2.cpp
new file mode 100644
index 0000000..0444e10
--- /dev/null
+++ b/src/GC/tests/stack2.cpp
@@ -0,0 +1,44 @@
+#include <cstring>
+#include <iostream>
+
+void dummy1();
+void dummy2();
+
+int main() {
+    
+    uintptr_t *prev1 = reinterpret_cast<uintptr_t *>(__builtin_frame_address(0));
+    uintptr_t *prev2 = static_cast<uintptr_t *>(__builtin_frame_address(0));
+
+    std::cout << "reinterpret:\t" << prev1 << "\nstatic:\t\t" << prev2 << std::endl;
+
+    std::cout << "Start:\t\t" << prev1 << std::endl;
+#pragma clang diagnostic ignored "-Wframe-address"
+    uintptr_t *tmp = reinterpret_cast<uintptr_t *>(__builtin_frame_address(1));
+    std::cout << "Frame 1:\t" << tmp << "\t\tDiff:\t" << std::hex << "0x"<< prev1 - tmp << std::endl;
+    prev1 = tmp;
+
+#pragma clang diagnostic ignored "-Wframe-address"
+    tmp = reinterpret_cast<uintptr_t *>(__builtin_frame_address(2));
+    std::cout << "Frame 2:\t" << tmp << "\tDiff:\t" << std::hex << "0x" << prev1 - tmp << std::endl;
+    
+    dummy1();
+
+    return 0;
+}
+
+void dummy1() {
+    std::cout << "Frame:\t\t" << __builtin_frame_address(0);
+#pragma clang diagnostic ignored "-Wframe-address"
+    std::cout << "\t\tPrev:\t" << __builtin_frame_address(1) << std::endl;
+    dummy2();
+    std::cout << "D1 RA:\t\t" << std::hex << __builtin_return_address(0) << std::endl;
+}
+
+void dummy2() {
+    std::cout << "Frame:\t\t" << __builtin_frame_address(0);
+#pragma clang diagnostic ignored "-Wframe-address"
+    std::cout << "\t\tPrev:\t" << __builtin_frame_address(1) << std::endl;
+    void *ra = __builtin_return_address(0);
+    std::cout << "D2 RA:\t\t" << std::hex << ra << std::endl;
+    std::cout << "D2 ERA:\t\t" << std::hex << __builtin_extract_return_addr(ra) << std::endl;
+}
\ No newline at end of file