From fe9ce3aca354245ff4f7596dfeed02b6332d882c Mon Sep 17 00:00:00 2001
From: Peter Evans <pevans@activecampaign.com>
Date: Sat, 2 Dec 2017 13:27:30 -0600
Subject: [PATCH] Tests for the new mos6502 functions

---
 include/mos6502.h        |  7 ++++++
 src/mos6502.c            | 31 ++++++++++++++++++++---
 tests/mos6502.c          | 53 ++++++++++++++++++++++++++++++++++++++++
 tests/mos6502.loadstor.c |  4 +++
 4 files changed, 91 insertions(+), 4 deletions(-)
 create mode 100644 tests/mos6502.loadstor.c

diff --git a/include/mos6502.h b/include/mos6502.h
index c930fe3..66805bb 100644
--- a/include/mos6502.h
+++ b/include/mos6502.h
@@ -24,6 +24,13 @@
 #define END_ADDR_MODE() \
     mos6502_free(cpu)
 
+#define START_CPU_TEST(t) \
+    t *cpu; \
+    cpu = t##_create()
+
+#define END_CPU_TEST(t) \
+    t##_free(cpu)
+
 #define DEFINE_INST(inst) \
     void mos6502_handle_##inst (mos6502 *cpu, vm_8bit oper)
 
diff --git a/src/mos6502.c b/src/mos6502.c
index faa60f5..c6b06c7 100644
--- a/src/mos6502.c
+++ b/src/mos6502.c
@@ -20,6 +20,7 @@
  *   pointers to all of that in the chip structure
  */
 
+#include <stdio.h>
 #include <stdlib.h>
 
 #include "log.h"
@@ -141,17 +142,39 @@ mos6502_modify_status(mos6502 *cpu, int statuses, vm_8bit oper)
         }
     }
 
-    if (statuses & ZERO) {
-        cpu->P &= ~ZERO;
-        if (oper == 0) {
-            cpu->P |= ZERO;
+    if (statuses & OVERFLOW) {
+        cpu->P &= ~OVERFLOW;
+        if (oper & OVERFLOW) {
+            cpu->P |= OVERFLOW;
         }
     }
 
+    // We're kind of dumb about break, decimal and interrupt. I'm
+    // probably lacking some knowledge about how these work...
+    if (statuses & BREAK) {
+        cpu->P |= BREAK;
+    }
+
+    if (statuses & DECIMAL) {
+        cpu->P |= DECIMAL;
+    }
+
+    if (statuses & INTERRUPT) {
+        cpu->P |= INTERRUPT;
+    }
+
     if (statuses & CARRY) {
         cpu->P &= ~CARRY;
         if (oper > 0) {
             cpu->P |= CARRY;
         }
     }
+
+    if (statuses & ZERO) {
+        cpu->P &= ~ZERO;
+        if (oper == 0) {
+            cpu->P |= ZERO;
+        }
+    }
+
 }
diff --git a/tests/mos6502.c b/tests/mos6502.c
index f6f60f7..3454249 100644
--- a/tests/mos6502.c
+++ b/tests/mos6502.c
@@ -35,3 +35,56 @@ Test(mos6502, next_byte) {
 
     END_ADDR_MODE();
 }
+
+Test(mos6502, push_stack)
+{
+    START_CPU_TEST(mos6502);
+
+    mos6502_push_stack(cpu, 0x1234);
+    cr_assert_eq(vm_segment_get(cpu->memory, 0x0100), 0x12);
+    cr_assert_eq(vm_segment_get(cpu->memory, 0x0101), 0x34);
+
+    END_CPU_TEST(mos6502);
+}
+
+Test(mos6502, pop_stack)
+{
+    START_CPU_TEST(mos6502);
+
+    mos6502_push_stack(cpu, 0x1234);
+    cr_assert_eq(mos6502_pop_stack(cpu), 0x1234);
+
+    END_CPU_TEST(mos6502);
+}
+
+Test(mos6502, modify_status)
+{
+    START_CPU_TEST(mos6502);
+
+    mos6502_modify_status(cpu, NEGATIVE, 130);
+    cr_assert_eq(cpu->P & NEGATIVE, NEGATIVE);
+    mos6502_modify_status(cpu, NEGATIVE, 123);
+    cr_assert_neq(cpu->P & NEGATIVE, NEGATIVE);
+
+    mos6502_modify_status(cpu, OVERFLOW, 123);
+    cr_assert_eq(cpu->P & OVERFLOW, OVERFLOW);
+    mos6502_modify_status(cpu, OVERFLOW, 44);
+    cr_assert_neq(cpu->P & OVERFLOW, OVERFLOW);
+
+    mos6502_modify_status(cpu, BREAK, 0);
+    mos6502_modify_status(cpu, INTERRUPT, 0);
+    mos6502_modify_status(cpu, DECIMAL, 0);
+    cr_assert_eq(cpu->P & BREAK & INTERRUPT & DECIMAL, BREAK & INTERRUPT & DECIMAL);
+
+    mos6502_modify_status(cpu, CARRY, 23);
+    cr_assert_eq(cpu->P & CARRY, CARRY);
+    mos6502_modify_status(cpu, CARRY, 0);
+    cr_assert_neq(cpu->P & CARRY, CARRY);
+
+    mos6502_modify_status(cpu, ZERO, 0);
+    cr_assert_eq(cpu->P & ZERO, ZERO);
+    mos6502_modify_status(cpu, ZERO, 1);
+    cr_assert_neq(cpu->P & ZERO, ZERO);
+
+    END_CPU_TEST(mos6502);
+}
diff --git a/tests/mos6502.loadstor.c b/tests/mos6502.loadstor.c
new file mode 100644
index 0000000..d6e062a
--- /dev/null
+++ b/tests/mos6502.loadstor.c
@@ -0,0 +1,4 @@
+#include <criterion/criterion.h>
+
+#include "mos6502.h"
+#include "mos6502.enums.h"