From e30fb7ae039d698dcc833ecfbc3e647a88e055df Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@alliedmods.net>
Date: Sat, 1 Jun 2024 21:21:41 -0700
Subject: [PATCH] Fix arrays not passing through varargs correctly.

Bug: sourcemod issue #2146
Test: new test case
---
 compiler/code-generator.cpp                 |  5 ++-
 tests/regressions/pass-string-as-vararg.out |  2 ++
 tests/regressions/pass-string-as-vararg.sp  | 14 ++++++++
 tests/shell.inc                             |  3 ++
 vm/shell/shell.cpp                          | 36 +++++++++++++++++++++
 5 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 tests/regressions/pass-string-as-vararg.out
 create mode 100644 tests/regressions/pass-string-as-vararg.sp

diff --git a/compiler/code-generator.cpp b/compiler/code-generator.cpp
index f152568e0..5f08dd686 100644
--- a/compiler/code-generator.cpp
+++ b/compiler/code-generator.cpp
@@ -1172,7 +1172,10 @@ void CodeGenerator::EmitCallExpr(CallExpr* call) {
         }
 
         if (arg->type_info().is_varargs) {
-            if (val.ident == iVARIABLE) {
+            if (val.type()->isArray()) {
+                if (lvalue)
+                    __ address(val.sym, sPRI);
+            } else if (val.ident == iVARIABLE) {
                 assert(val.sym);
                 assert(lvalue);
                 /* treat a "const" variable passed to a function with a non-const
diff --git a/tests/regressions/pass-string-as-vararg.out b/tests/regressions/pass-string-as-vararg.out
new file mode 100644
index 000000000..e176ae8cd
--- /dev/null
+++ b/tests/regressions/pass-string-as-vararg.out
@@ -0,0 +1,2 @@
+1: Ham
+TEST
diff --git a/tests/regressions/pass-string-as-vararg.sp b/tests/regressions/pass-string-as-vararg.sp
new file mode 100644
index 000000000..b0c1d28d9
--- /dev/null
+++ b/tests/regressions/pass-string-as-vararg.sp
@@ -0,0 +1,14 @@
+#include <shell>
+
+int TestNumber = 0;
+
+void test(const char[] title) {
+    TestNumber++;
+    printf("%d: %s\n", TestNumber, title);
+}
+
+public main() {
+    test("Ham");
+    printf("%s\n", "TEST");
+}
+
diff --git a/tests/shell.inc b/tests/shell.inc
index ec4cdd215..43db54ac6 100644
--- a/tests/shell.inc
+++ b/tests/shell.inc
@@ -13,6 +13,9 @@ native void report_error();
 native void unbound_native();
 native int donothing();
 
+// dumb version of printf(), only supports %f, %d, %s.
+native void printf(const char[] fmt, any:...);
+
 // Return arg, but through a dynamically generated native.
 native int dynamic_native(int arg);
 
diff --git a/vm/shell/shell.cpp b/vm/shell/shell.cpp
index 0936fc336..385de977b 100644
--- a/vm/shell/shell.cpp
+++ b/vm/shell/shell.cpp
@@ -125,6 +125,41 @@ static cell_t PrintNums(IPluginContext* cx, const cell_t* params)
   return 1;
 }
 
+static cell_t Printf(IPluginContext* cx, const cell_t* params) {
+  char* p;
+  cx->LocalToString(params[1], &p);
+
+  size_t index = 1;
+  while (*p) {
+    if (*p == '%') {
+      char next = *(p + 1);
+      if (next == 's' || next == 'd' || next == 'f') {
+        index++;
+        if (index > params[0])
+          return cx->ThrowNativeError("Wrong number of arguments");
+
+        cell_t* addr;
+        if (int err = cx->LocalToPhysAddr(params[index], &addr); err != SP_ERROR_NONE)
+          return cx->ThrowNativeErrorEx(err, "Could not read argument");
+
+        if (next == 's')
+          fputs(reinterpret_cast<const char*>(addr), stdout);
+        else if (next == 'f')
+          fprintf(stdout, "%f", *reinterpret_cast<float*>(addr));
+        else if (next == 'd')
+          fprintf(stdout, "%d", *addr);
+
+        p += 2;
+        continue;
+      }
+    }
+
+    fputc(*p, stdout);
+    p++;
+  }
+  return 1;
+}
+
 static cell_t DoNothing(IPluginContext* cx, const cell_t* params)
 {
   return 1;
@@ -330,6 +365,7 @@ static int Execute(const char* file)
   BindNative(rt, "copy_2d_array_to_callback", Copy2dArrayToCallback);
   BindNative(rt, "call_with_string", CallWithString);
   BindNative(rt, "assert_eq", AssertEq);
+  BindNative(rt, "printf", Printf);
 
   IPluginFunction* fun = rt->GetFunctionByName("main");
   if (!fun)