From 0bfe10c2ed0b4c17fb7d54418c439001b58229d7 Mon Sep 17 00:00:00 2001
From: Pierre Wendling <pierre.wendling.4@gmail.com>
Date: Wed, 7 Jun 2023 16:37:58 -0400
Subject: [PATCH] Add a strndup fallback implementation for Windows.

---
 src/CMakeLists.txt    | 21 ++++++++++++++++++++-
 src/dupstring.c       | 24 ++++++++++++++++++++++++
 src/dupstring.h       |  9 +++++++++
 src/elf-create-argp.c |  4 +++-
 4 files changed, 56 insertions(+), 2 deletions(-)
 create mode 100644 src/dupstring.c
 create mode 100644 src/dupstring.h

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 910b559..021c0d8 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -27,6 +27,25 @@ else()
 	set(runtime_destination lib)
 endif()
 
+# Check if strndup is available, Windows toolchains typically don't provide it
+include(CheckCSourceCompiles)
+check_c_source_compiles("
+#include <string.h>
+#include <stdlib.h>
+int main() {
+	free(strndup(\"foo\", 4));
+}"
+HAVE_STRNDUP)
+
+if(HAVE_STRNDUP)
+	set(STRNDUP_DEF "HAVE_STRNDUP=1")
+else()
+	set(STRNDUP_DEF "HAVE_STRNDUP=0")
+endif()
+
+set_source_files_properties(dupstring.c PROPERTIES
+	COMPILE_DEFINITIONS ${STRNDUP_DEF})
+
 add_library(vita-yaml yamltree.c yamltreeutil.c)
 add_library(vita-export vita-export-parse.c sha256.c)
 add_library(vita-import vita-import.c vita-import-parse.c)
@@ -53,7 +72,7 @@ target_include_directories(vita-import PUBLIC
 	$<INSTALL_INTERFACE:include>)
 
 add_executable(vita-libs-gen vita-libs-gen.c)
-add_executable(vita-elf-create vita-elf-create.c elf-create-argp.c vita-elf.c elf-defs.c sce-elf.c varray.c elf-utils.c yamlemitter.c)
+add_executable(vita-elf-create vita-elf-create.c elf-create-argp.c vita-elf.c elf-defs.c sce-elf.c varray.c elf-utils.c yamlemitter.c dupstring.c)
 add_executable(vita-mksfoex vita-mksfoex.c getopt_long.c)
 add_executable(vita-make-fself vita-make-fself.c)
 add_executable(vita-pack-vpk vita-pack-vpk.c)
diff --git a/src/dupstring.c b/src/dupstring.c
new file mode 100644
index 0000000..0145702
--- /dev/null
+++ b/src/dupstring.c
@@ -0,0 +1,24 @@
+#include "dupstring.h"
+
+#include <string.h>
+
+#if defined(HAVE_STRNDUP) && HAVE_STRNDUP
+
+char *dupstring(const char *source, size_t maxlen) {
+  return strndup(source, maxlen);
+}
+
+#else /* Fallback implementation */
+#include <stdlib.h>
+
+char *dupstring(const char *source, size_t maxlen) {
+  size_t dest_size = strnlen(source, maxlen);
+  char *dest = malloc(dest_size + 1);
+  if (dest == NULL) {
+    return NULL;
+  }
+  memcmp(dest, source, dest_size);
+  dest[dest_size] = '\0';
+  return dest;
+}
+#endif
diff --git a/src/dupstring.h b/src/dupstring.h
new file mode 100644
index 0000000..2bd5ed1
--- /dev/null
+++ b/src/dupstring.h
@@ -0,0 +1,9 @@
+#ifndef DUPSTRING_H
+#define DUPSTRING_H
+
+#include <stddef.h>
+
+/* Wrapper around strndup */
+char *dupstring(const char *source, size_t maxlen);
+
+#endif /* DUPSTRING_H */
diff --git a/src/elf-create-argp.c b/src/elf-create-argp.c
index 2c91834..e8d86c0 100644
--- a/src/elf-create-argp.c
+++ b/src/elf-create-argp.c
@@ -5,6 +5,8 @@
 #include <string.h>
 #include <unistd.h>
 
+#include "dupstring.h"
+
 int parse_arguments(int argc, char *argv[], elf_create_args *arguments)
 {
 	int c;
@@ -76,7 +78,7 @@ int parse_arguments(int argc, char *argv[], elf_create_args *arguments)
 			}
 			size_t entrypoint_length = (size_t)(entrypoint_end - entrypoint);
 			if (entrypoint_length > 0)
-				arguments->entrypoint_funcs[i] = strndup(entrypoint, entrypoint_length);
+				arguments->entrypoint_funcs[i] = dupstring(entrypoint, entrypoint_length);
 
 			i++;
 			entrypoint = entrypoint_end + 1;