Add ELF dlopen notes for SDL libraries (#536)

src/harness/platforms/elfdlopennote.h

@@ -0,0 +1,92 @@
+#ifndef DLOPENNOTE_H
+#define DLOPENNOTE_H
+
+#define ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED   "suggested"
+#define ELF_NOTE_DLOPEN_PRIORITY_RECOMMENDED "recommended"
+#define ELF_NOTE_DLOPEN_PRIORITY_REQUIRED    "required"
+
+#if !defined(__unix__) || defined(__ANDROID__)
+#ifndef DISABLE_DLOPEN_NOTES
+#define DISABLE_DLOPEN_NOTES
+#endif
+#elif defined(__GNUC__) && (__GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 1))
+/* gcc < 3.1 too old */
+#ifndef DISABLE_DLOPEN_NOTES
+#define DISABLE_DLOPEN_NOTES
+#endif
+#endif
+
+#if defined(__ELF__) && !defined(DISABLE_DLOPEN_NOTES)
+
+#define ELF_NOTE_DLOPEN_VENDOR "FDO"
+#define ELF_NOTE_DLOPEN_TYPE 0x407c0c0aU
+
+#define ELF_NOTE_INTERNAL2(json, variable_name)                 \
+    __attribute__((aligned(4), used, section(".note.dlopen")))      \
+    static const struct {                                           \
+        struct {                                                    \
+            Uint32 n_namesz;                                        \
+            Uint32 n_descsz;                                        \
+            Uint32 n_type;                                          \
+        } nhdr;                                                     \
+        char name[4];                                               \
+        __attribute__((aligned(4))) char dlopen_json[sizeof(json)]; \
+    } variable_name = {                                             \
+        {                                                           \
+             sizeof(ELF_NOTE_DLOPEN_VENDOR),                    \
+             sizeof(json),                                          \
+             ELF_NOTE_DLOPEN_TYPE                               \
+        },                                                          \
+        ELF_NOTE_DLOPEN_VENDOR,                                 \
+        json                                                        \
+    }
+
+#define ELF_NOTE_INTERNAL(json, variable_name) \
+    ELF_NOTE_INTERNAL2(json, variable_name)
+
+#define SONAME_ARRAY1(N1) "[\"" N1 "\"]"
+#define SONAME_ARRAY2(N1,N2) "[\"" N1 "\",\"" N2 "\"]"
+#define SONAME_ARRAY3(N1,N2,N3) "[\"" N1 "\",\"" N2 "\",\"" N3 "\"]"
+#define SONAME_ARRAY4(N1,N2,N3,N4) "[\"" N1 "\",\"" N2 "\",\"" N3 "\",\"" N4 "\"]"
+#define SONAME_ARRAY5(N1,N2,N3,N4,N5) "[\"" N1 "\",\"" N2 "\",\"" N3 "\",\"" N4 "\",\"" N5 "\"]"
+#define SONAME_ARRAY6(N1,N2,N3,N4,N5,N6) "[\"" N1 "\",\"" N2 "\",\"" N3 "\",\"" N4 "\",\"" N5 "\",\"" N6 "\"]"
+#define SONAME_ARRAY7(N1,N2,N3,N4,N5,N6,N7) "[\"" N1 "\",\"" N2 "\",\"" N3 "\",\"" N4 "\",\"" N5 "\",\"" N6 "\",\"" N7 "\"]"
+#define SONAME_ARRAY8(N1,N2,N3,N4,N5,N6,N7,N8) "[\"" N1 "\",\"" N2 "\",\"" N3 "\",\"" N4 "\",\"" N5 "\",\"" N6 "\",\"" N7 "\",\"" N8 "\"]"
+#define SONAME_ARRAY_GET(N1,N2,N3,N4,N5,N6,N7,N8,NAME,...) NAME
+#define SONAME_ARRAY(...) \
+    SONAME_ARRAY_GET(__VA_ARGS__, \
+         SONAME_ARRAY8, \
+         SONAME_ARRAY7, \
+         SONAME_ARRAY6, \
+         SONAME_ARRAY5, \
+         SONAME_ARRAY4, \
+         SONAME_ARRAY3, \
+         SONAME_ARRAY2, \
+         SONAME_ARRAY1 \
+    )(__VA_ARGS__)
+
+#define ELF_NOTE_JOIN2(A,B) A##B
+#define ELF_NOTE_JOIN(A,B) ELF_NOTE_JOIN2(A,B)
+#define ELF_NOTE_UNIQUE_NAME ELF_NOTE_JOIN(s_dlopen_note_, __LINE__)
+
+#define ELF_NOTE_DLOPEN(feature, description, priority, ...) \
+    ELF_NOTE_INTERNAL(                                       \
+        "[{\"feature\":\"" feature                               \
+        "\",\"description\":\"" description                      \
+        "\",\"priority\":\"" priority                            \
+        "\",\"soname\":" SONAME_ARRAY(__VA_ARGS__) "}]",     \
+        ELF_NOTE_UNIQUE_NAME)
+
+#elif defined(__GNUC__) && __GNUC__ < 3
+
+#define ELF_NOTE_DLOPEN(args...)
+
+#elif defined(_MSC_VER) && _MSC_VER < 1400
+
+#else
+
+#define ELF_NOTE_DLOPEN(...)
+
+#endif
+
+#endif /* DLOPENNOTE_H */

src/harness/platforms/sdl1.c

@@ -44,6 +44,16 @@ static const char* const possible_locations[] = {
     SDL1_LIBNAME                      /* oh well, anywhere the system can see the .dylib (/usr/local/lib or whatever) */
 };
 #else
+#include "elfdlopennote.h"
+#ifdef ELF_NOTE_DLOPEN
+ELF_NOTE_DLOPEN(
+    "SDL1",
+    "Platform-specific operations such as creating windows and handling events",
+    ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED,
+    "libSDL-1.2.so.0",
+    "libSDL-1.2.so"
+);
+#endif
 static const char* const possible_locations[] = {
     "libSDL-1.2.so.0",
     "libSDL-1.2.so",

src/harness/platforms/sdl2.c

@@ -54,6 +54,16 @@ static const char* const possible_locations[] = {
     SDL2_LIBNAME                                      /* oh well, anywhere the system can see the .dylib (/usr/local/lib or whatever) */
 };
 #else
+#include "elfdlopennote.h"
+#ifdef ELF_NOTE_DLOPEN
+ELF_NOTE_DLOPEN(
+    "SDL2",
+    "Platform-specific operations such as creating windows and handling events",
+    ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED,
+    "libSDL2-2.0.so.0",
+    "libSDL2-2.0.so"
+);
+#endif
 static const char* const possible_locations[] = {
     "libSDL2-2.0.so.0",
     "libSDL2-2.0.so",

src/harness/platforms/sdl3.c

@@ -54,6 +54,16 @@ static const char * const possible_locations[] = {
     SDL3_LIBNAME /* oh well, anywhere the system can see the .dylib (/usr/local/lib or whatever) */
 };
 #else
+#include "elfdlopennote.h"
+#ifdef ELF_NOTE_DLOPEN
+ELF_NOTE_DLOPEN(
+    "SDL3",
+    "Platform-specific operations such as creating windows and handling events",
+    ELF_NOTE_DLOPEN_PRIORITY_RECOMMENDED,
+    "libSDL3.so.0",
+    "libSDL3.so"
+);
+#endif
 static const char * const possible_locations[] = {
     "libSDL3.so.0",
     "libSDL3.so",