X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=glaze-gl.c;h=04f288ee97473791fdf40d3a1adfca230d75c9fc;hb=f5afe7a34b5f7adc8451f01db92be1de5f0830af;hp=d4ad33f77023415466f76febc3ce5c62c8437f44;hpb=fded9f20d5f5c92bd5af051117327816dda0238e;p=glaze

diff --git a/glaze-gl.c b/glaze-gl.c
index d4ad33f..04f288e 100644
--- a/glaze-gl.c
+++ b/glaze-gl.c
@@ -27,51 +27,11 @@
 #include <string.h>
 
 #include <fcntl.h>
-#include <gelf.h>
 
 void *libgl_handle;
 void *wrapper_handle;
 
-/* Is the given elf program 32 or 64 bit?
- *
- * Note: This function returns -1 if 'filename' cannot
- * be opened as a valid ELF file.
- */
-static int
-elf_bits (const char *filename)
-{
-	Elf *elf;
-	GElf_Ehdr ehdr;
-	int fd, class;
-
-	fd = open (filename, O_RDONLY, 0);
-	if (fd < 0)
-		return -1;
-
-	if (elf_version (EV_CURRENT ) == EV_NONE)
-		return -1;
-
-	elf = elf_begin (fd, ELF_C_READ, NULL);
-	if (elf == NULL)
-		return -1;
-
-	if (elf_kind (elf) != ELF_K_ELF)
-		return -1;
-
-	if (gelf_getehdr (elf, &ehdr) == NULL)
-		return -1;
-
-	class = gelf_getclass (elf);
-
-	switch (class) {
-	case ELFCLASS32:
-		return 32;
-	case ELFCLASS64:
-		return 64;
-	default:
-		return -1;
-	}
-}
+#define STRNCMP_LITERAL(str, literal) strncmp (str, literal, sizeof (literal) - 1)
 
 static void
 open_libgl_handle (void)
@@ -84,22 +44,14 @@ open_libgl_handle (void)
 	libgl_path = getenv ("GLAZE_LIBGL");
 
 	if (libgl_path == NULL) {
-		Dl_info info;
-		int bits;
 
-		if (dladdr (open_libgl_handle, &info) == 0) {
-			fprintf (stderr, "Internal error: Failed to lookup filename of glaze library with dladdr.\n");
-			exit (1);
-		}
-
-		bits = elf_bits (info.dli_fname);
+#if GLAZE_BITS == 32
+		libgl_path = getenv ("GLAZE_LIBGL_32_AUTO");
+#elif GLAZE_BITS == 64
+		libgl_path = getenv ("GLAZE_LIBGL_64_AUTO");
+#endif
 
-		if (bits == 32)
-			libgl_path = getenv ("GLAZE_LIBGL_32_AUTO");
-		if (bits == 64)
-			libgl_path = getenv ("GLAZE_LIBGL_64_AUTO");
-
-		if (libgl_path == NULL) {
+		if (libgl_path == NULL || strlen (libgl_path) == 0) {
 			fprintf (stderr,
 				 "Error: Failed to detect OpenGL library.\n"
 				 "Please set GLAZE_LIBGL to path of real libGL.so\n");
@@ -128,7 +80,7 @@ open_wrapper_handle (void)
 
 	path = getenv ("GLAZE_WRAPPER");
 	if (path == NULL) {
-		fprintf (stderr, "GLAZE_WRAPPER unset. Please set to path of real libGL.so under glaze.\n");
+		fprintf (stderr, "GLAZE_WRAPPER unset. Please set to path of Glaze-using wrapper library.\n");
 		exit (1);
 	}
 
@@ -154,8 +106,29 @@ glaze_init (void)
 static void *
 resolve (const char *name)
 {
+	static int before_first_gl_call = 1;
 	void *symbol;
 
+	if (before_first_gl_call &&
+	    STRNCMP_LITERAL (name, "gl") == 0 &&
+	    STRNCMP_LITERAL (name, "glX") != 0)
+	{
+		char *callback_name = getenv ("GLAZE_FIRST_GL_CALL_CALLBACK");
+		if (callback_name) {
+			void (*callback) (void) = dlsym (wrapper_handle,
+							 callback_name);
+			if (callback) {
+				(callback) ();
+			} else {
+				fprintf (stderr,
+					 "Error: Failed to find function %s "
+					 "in GLAZE_WRAPPER library.\n",
+					 callback_name);
+			}
+		}
+		before_first_gl_call = 0;
+	}
+
 	/* The wrapper gets first choice on all symbols. */
 	symbol = dlsym (wrapper_handle, name);
 	if (symbol)
@@ -164,6 +137,84 @@ resolve (const char *name)
 	return dlsym (libgl_handle, name);
 }
 
+void
+(*glXGetProcAddress (const unsigned char *name))(void);
+
+void
+(*glXGetProcAddress (const unsigned char *name))(void)
+{
+	static int first_call = 1;
+	static typeof (&glXGetProcAddress) wrapper_glXGetProcAddress;
+	static typeof (&glXGetProcAddress) libgl_glXGetProcAddress;
+	void *symbol;
+
+	/* On the first call, check if the wrapper provides an
+	 * implementation of this function. */
+	if (first_call) {
+		wrapper_glXGetProcAddress = dlsym (wrapper_handle,
+						   "glXGetProcAddress");
+		libgl_glXGetProcAddress = dlsym (libgl_handle,
+						 "glXGetProcAddress");
+		first_call = 0;
+	}
+
+	/* If the wrapper implements glXGetProcAddress itself, then it
+	 * had better know best what to do. Just let it. */
+	if (wrapper_glXGetProcAddress)
+		return wrapper_glXGetProcAddress (name);
+
+	/* Otherwise, we need to resolve the name.
+	 *
+	 * The wrapper gets first choice on all symbols. */
+	symbol = dlsym (wrapper_handle, (char *) name);
+	if (symbol)
+		return symbol;
+
+	/* The wrapper doesn't care, so defer to the underlying
+	 * glXGetProcAddress */
+	return libgl_glXGetProcAddress (name);
+
+}
+
+void
+(*glXGetProcAddressARB (const unsigned char *name))(void);
+
+void
+(*glXGetProcAddressARB (const unsigned char *name))(void)
+{
+	static int first_call = 1;
+	static typeof (&glXGetProcAddressARB) wrapper_glXGetProcAddressARB;
+	static typeof (&glXGetProcAddressARB) libgl_glXGetProcAddressARB;
+	void *symbol;
+
+	/* On the first call, check if the wrapper provides an
+	 * implementation of this function. */
+	if (first_call) {
+		wrapper_glXGetProcAddressARB = dlsym (wrapper_handle,
+						      "glXGetProcAddressARB");
+		libgl_glXGetProcAddressARB = dlsym (libgl_handle,
+						    "glXGetProcAddressARB");
+		first_call = 0;
+	}
+
+	/* If the wrapper implements glXGetProcAddressARB itself, then
+	 * it had better know best what to do. Just let it. */
+	if (wrapper_glXGetProcAddressARB)
+		return wrapper_glXGetProcAddressARB (name);
+
+	/* Otherwise, we need to resolve the name.
+	 *
+	 * The wrapper gets first choice on all symbols. */
+	symbol = dlsym (wrapper_handle, (char *) name);
+	if (symbol)
+		return symbol;
+
+	/* The wrapper doesn't care, so defer to the underlying
+	 * glXGetProcAddressARB */
+	return libgl_glXGetProcAddressARB (name);
+
+}
+
 #define GLAZE_API(name)							\
 void * name() __attribute__((ifunc(#name "_resolver")));		\
 static void *								\