Add GL symbol availability checking to OSX overlay.

3 files changed, 74 insertions, 13 deletions

diff --git a/macx/overlay/avail.h b/macx/overlay/avail.h
new file mode 100644
index 000000000..1f2444ae4
--- /dev/null
+++ b/macx/overlay/avail.h
@@ -0,0 +1,49 @@
+#define AVAIL_ALL_GLSYM ( \
+	AVAIL(glTexImage2D) && \
+	AVAIL(glCreateShader) && \
+	AVAIL(glLinkProgram) && \
+	AVAIL(glActiveTexture) && \
+	AVAIL(glViewport) && \
+	AVAIL(glEnableClientState) && \
+	AVAIL(glOrtho) && \
+	AVAIL(glGetIntegerv) && \
+	AVAIL(glCompileShader) && \
+	AVAIL(glGetString) && \
+	AVAIL(glPopAttrib) && \
+	AVAIL(glPushClientAttrib) && \
+	AVAIL(glAttachShader) && \
+	AVAIL(glEnd) && \
+	AVAIL(glDisableClientState) && \
+	AVAIL(glUniform1i) && \
+	AVAIL(glRenderMode) && \
+	AVAIL(glIsTexture) && \
+	AVAIL(glTexEnvi) && \
+	AVAIL(glGetTexParameterfv) && \
+	AVAIL(glPopMatrix) && \
+	AVAIL(glDisable) && \
+	AVAIL(glBindTexture) && \
+	AVAIL(glPushAttrib) && \
+	AVAIL(glUseProgram) && \
+	AVAIL(glCreateProgram) && \
+	AVAIL(glDeleteTextures) && \
+	AVAIL(glBegin) && \
+	AVAIL(glVertex2f) && \
+	AVAIL(glMatrixMode) && \
+	AVAIL(glGenTextures) && \
+	AVAIL(glGetError) && \
+	AVAIL(glBlendFunc) && \
+	AVAIL(glPopClientAttrib) && \
+	AVAIL(glBindBuffer) && \
+	AVAIL(glShaderSource) && \
+	AVAIL(glEnable) && \
+	AVAIL(glGetShaderInfoLog) && \
+	AVAIL(glPixelStorei) && \
+	AVAIL(glTexParameterfv) && \
+	AVAIL(glTexSubImage2D) && \
+	AVAIL(glTexCoord2f) && \
+	AVAIL(glGetUniformLocation) && \
+	AVAIL(glColorMaterial) && \
+	AVAIL(glPushMatrix) && \
+	AVAIL(glTexParameteri) && \
+	AVAIL(glLoadIdentity) && \
+	1)
diff --git a/macx/overlay/avail.pl b/macx/overlay/avail.pl
new file mode 100644
index 000000000..abdbac5ce
--- /dev/null
+++ b/macx/overlay/avail.pl
@@ -0,0 +1,18 @@
+#!/usr/bin/perl
+# perl avail.pl < overlay.m > avail.h
+
+%funcs = ();
+while (<STDIN>) {
+	foreach (split(/([ \t])/, $_)) {
+		@glfunc = ($_ =~ /(gl[A-Z0-9][a-zA-Z0-9]+)/);
+		foreach $func(@glfunc) {
+			$funcs{$func} = 1;
+		}
+	}
+}
+
+print "#define AVAIL_ALL_GLSYM ( \\\n";
+foreach my $key (keys %funcs) {
+	print "\tAVAIL($key) && \\\n";
+}
+print "\t1)\n";
diff --git a/macx/overlay/overlay.m b/macx/overlay/overlay.m
index bd434fe73..e4ccb9dd4 100644
--- a/macx/overlay/overlay.m
+++ b/macx/overlay/overlay.m
@@ -52,9 +52,9 @@
 #include <AGL/AGL.h>
 
 #include "mach_override.h"
-#include <objc/objc-runtime.h>
 
 #include "../../overlay/overlay.h"
+#include "avail.h"
 
 static bool bDebug = false;
 
@@ -91,6 +91,7 @@ const GLfloat fBorder[] = {0.125f, 0.250f, 0.5f, 0.75f};
 
 static Context *contexts = NULL;
 
+#define AVAIL(name) dlsym(RTLD_DEFAULT,#name)
 #define FDEF(name) static __typeof__(&name) o##name = NULL
 FDEF(CGLFlushDrawable);
 
@@ -552,25 +553,18 @@ void CGLFlushDrawableOverride(CGLContextObj ctx) {
 	oCGLFlushDrawable(ctx);
 }
 
-
 __attribute__ ((visibility("default")))
 __attribute__((constructor))
 void MumbleOverlayEntryPoint() {
-	if (getenv("MUMBLE_OVERLAY_DEBUG"))
-		bDebug = true;
-	else            
-		bDebug = false;
+	bDebug = getenv("MUMBLE_OVERLAY_DEBUG");
 
-	void *cglAvailable = dlsym(RTLD_DEFAULT, "CGLFlushDrawable");
-	if (cglAvailable) {
+	if (AVAIL(CGLFlushDrawable) && AVAIL_ALL_GLSYM) {
 		ods("Attempting to hook CGL");
 		if (mach_override("_CGLFlushDrawable", NULL, CGLFlushDrawableOverride, (void **) &oCGLFlushDrawable) != 0) {
 			ods("CGLFlushDrawable override failed.");
-		}
+		} else
+			ods("Up running.");
 	} else {
-		ods("Unable to hook CGL");
-		return;
+		ods("Required entry points not available in process. Not hooking up overlay.");
 	}
-
-	ods("Up running.");
 }