Logos語法學習

Logos語法

它是在Theos開發中容許hook代碼很是的簡單明瞭，它可以替換、修改、新增方法或者類。

塊等級

這種等級必須以%end結尾，而且也不存在函數

%group

%group Groupname
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若是爲了支持適配不一樣系統的代碼，能夠經過如下方式

%group iOS8
    %hook IOS8_SPECIFIC_CLASS
	  // your code here
    %end // end hook
    %end // end group ios8

    %group iOS9
    %hook IOS9_SPECIFIC_CLASS
    	// your code here
    %end // end hook
    %end // end group ios9

    %ctor {
    	if (kCFCoreFoundationVersionNumber >   1200) {
    		%init(iOS9);
    	} else {
    		%init(iOS8);
    	}
    }
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%hook

全部的hook都有隱藏了一個「_ungrouped」的隱式分組；它用來修飾類名

%hook Classname
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hook之間的代碼是SBApplicationController具體的函數

%hook SBApplicationController
-(void)uninstallApplication:(SBApplication *)application {
	NSLog(@"Hey, we're hooking uninstallApplication:!");
	%orig; // Call the original implementation of this method
	return;
}
%end
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%new

給hook的類添加新方法；signature是OC類型的新方法名，必須在%hook塊之間

%new  // 修飾新的方法
%new(signature)  // 修飾新的方法signature
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%hook ClassName
%new
- (id)someValue {
	return objc_getAssociatedObject(self, @selector(someValue));
}

%end
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%subclass

經過運行時建立的子類，ivars不支持；使用%new修飾新增的方法，若是須要訪問新類，必須經過%c操做符獲取，能夠在%group塊中

%subclass MyObject : NSObject

- (id)init {
	self = %orig;
	[self setSomeValue:@"value"];
	return self;
}

//the following two new methods act as `@property (nonatomic, retain) id someValue;`
%new
- (id)someValue {
	return objc_getAssociatedObject(self, @selector(someValue));
}

%new
- (void)setSomeValue:(id)value {
	objc_setAssociatedObject(self, @selector(someValue), value, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

%end

%ctor {
	MyObject *myObject = [[%c(MyObject) alloc] init];
	NSLog(@"myObject: %@", [myObject someValue]);
}
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%property

%property (nonatomic|assign|retain|copy|weak|strong|getter|setter) Type name;
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添加新的屬性在類中，必須在%hook修飾或者%subclass修飾的內部。

%end

%end
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用來修飾group/hook/subclass的塊結束

頂部等級

這部分的指令再也不group/hook/subclass的塊內部。

%config

%config(Key=Value);
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%hookf

%hookf(rtype, symbolName, args...) { … }
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// Given the function prototype
FILE *fopen(const char *path, const char *mode);
// The hook is thus made
%hookf(FILE *, fopen, const char *path, const char *mode) {
	NSLog(@"Hey, we're hooking fopen to deny relative paths!");
	if (path[0] != '/') {
		return NULL;
	}
	return %orig; // Call the original implementation of this function
}
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CFBooleanRef (*orig_MGGetBoolAnswer)(CFStringRef);
CFBooleanRef fixed_MGGetBoolAnswer(CFStringRef string)
{
	if (CFEqual(string, CFSTR("StarkCapability"))) {
		return kCFBooleanTrue;
	}
	return orig_MGGetBoolAnswer(string);
}

%hookf(CFBooleanRef, "_MGGetBoolAnswer", CFStringRef string)
{
	if (CFEqual(string, CFSTR("StarkCapability"))) {
		return kCFBooleanTrue;
	}
	return %orig;
}
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%ctor

%ctor { … }
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匿名構造方法

%dtor

%dtor { … }
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匿名銷燬構造方法

函數等級

只在函數block中

%init

%init;
%init([<class>=<expr>, …]);
%init(Group[, [+|-]<class>=<expr>, …]);
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初始化分組或默認分組

%hook SomeClass
-(id)init {
    return %orig;
}
%end

%ctor {
    %init(SomeClass=objc_getClass("class with spaces in the name"));
}
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%c

%c([+|-]Class)
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等價於實例對象，或者類名

%orig

%orig
%orig(arg1, …)
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調用原始方法，不可以在%new裏面，

%log

%log;
%log([(<type>)<expr>, …]);
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打印日誌

Logos文件擴展格式

Extension	Process order
.x	will be processed by Logos, then preprocessed and compiled as objective-c.
.xm	will be processed by Logos, then preprocessed and compiled as objective-c++.
.xi	will be preprocessed as objective-c first, then Logos will process the result, and then it will be compiled.
.xmi	will be preprocessed as objective-c++ first, then Logos will process the result, and then it will be compiled.

xi或者xmi文件能夠使用#define 宏

logify.pl

自動動幫你生成對應類的全部hook方法

$THEOS/bin/logify.pl ./SSDownloadAsset.h
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