✨add install file && my first pass

.gitignore

@@ -0,0 +1,38 @@
+llvm/
+compiler-rt/
+clang/
+build/
+# General
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+test/*.bc

README.md

@@ -1,2 +1,14 @@
 # llvm-pass-practice
 the road to write llvm pass
+
+
+## notice
+
+* path should not include Chinese character
+
+## install llvm
+`./install.sh`
+
+## practices
+
+* my first pass:show function name

install.sh

@@ -0,0 +1,26 @@
+#get LLVM
+git clone --depth=1 http://llvm.org/git/llvm.git
+
+
+#get clang
+git clone --depth=1 http://llvm.org/git/clang.git
+
+
+#get compiler-rt
+git clone --depth=1 http://llvm.org/git/compiler-rt.git
+
+
+#Set up clang, compiler-rt
+pushd llvm/tools
+ln -s ../../clang .
+popd
+
+pushd llvm/projects
+ln -s ../../compiler-rt .
+popd
+
+mkdir build
+pushd build
+cmake -G "Unix Makefiles" ../llvm
+make -j4
+popd

my first pass/FuncName/CMakeLists.txt

@@ -0,0 +1,6 @@
+add_llvm_library( LLVMFuncName MODULE
+FuncName.cpp
+
+PLUGIN_TOOL
+opt
+)

my first pass/FuncName/FuncName.cpp

@@ -0,0 +1,19 @@
+#include "llvm/Pass.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+namespace {
+    struct FuncName:public FunctionPass {
+        static char ID;
+        FuncName():FunctionPass(ID) {}
+        bool runOnFunction(Function &F) {
+            errs()<< F.getName() << "\n";
+            return false;
+        }
+    };
+}
+
+char FuncName::ID = 0;
+static RegisterPass<FuncName> X("funcName","display function name");

my first pass/README.md

@@ -0,0 +1,118 @@
+## setup env
+1. add library
+add
+    ```
+    add_llvm_library( LLVMFuncName MODULE
+    YOUR_PASS.cpp
+
+    PLUGIN_TOOL
+    opt
+    )
+    ```
+    into `PASS_DIR_PATH/CMakeLists.txt`
+
+2. add subdirectory
+    add `add_subdirectory(PASS_DIR_PATH)` into `lib/Transforms/CMakeLists.txt`
+
+## coding
+
+1. the necessary header
+    ```cpp
+    #include "llvm/Pass.h"
+    #include "llvm/IR/Function.h"
+    #include "llvm/Support/raw_ostream.h"
+    ```
+
+2. add namespace
+    ```cpp
+    using namespace llvm;
+    ```
+
+3. write your own pass in an anonymous namespace
+    ```cpp
+    namespace {
+        
+    }
+    ```
+
+## build
+
+```sh
+⇒  doublemice@DoubleMice-MBP:~/Documents/graduate/llvm-pass-practice|master⚡ pwd
+/Users/doublemice/Documents/graduate/llvm-pass-practice
+pushd llvm/lib/Transforms
+ln ../../../my\ first\ pass/FuncName .
+popd
+pushd build
+make
+popd
+```
+
+## load the pass
+
+### the output lib
+```sh
+doublemice@DoubleMice-MBP:~/Documents/graduate/llvm-pass-practice|master⚡ 
+⇒  ls build/lib/LLVMFuncName.dylib 
+build/lib/LLVMFuncName.dylib
+```
+
+as we see,the output dylib name is exact the name we define in `PASS_DIR_PATH/CMakeLists.txt`(see: setup env -> 1)
+
+### load it with opt
+1. prepare a test file in test/FuncName_test.c
+    ```cpp
+    #include <stdio.h>
+    void sayHello() {
+        printf("hello\n");
+    }
+    void sayGoodbye() {
+        printf("goodbye\n");
+    }
+    int main() {
+        sayHello();
+        sayGoodbye();
+        return 0;
+    }
+    ```
+
+2. compile it into a llvm bitcode
+    ```sh
+    $LLVM_BIN/clang -O3 -emit-llvm test/FuncName_test.c -c -o test/FuncName_test.bc
+    ```
+3. run the pass with opt
+    ```sh
+    doublemice@DoubleMice-MBP:~/Documents/graduate/llvm-pass-practice|master⚡ 
+    ⇒  $LLVM_BIN/opt -load build/lib/LLVMFuncName.dylib -funcName < test/FuncName_test.bc > /dev/null
+    sayHello
+    sayGoodbye
+    main
+    ```
+
+## a skeleton
+```cpp
+#include "llvm/Pass.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+namespace {
+    struct Example:public FunctionPass {
+        static char ID;
+        Example():FunctionPass(ID) {}
+
+        //tells llvm which other pass we need
+        void getAnalysisUsage(AnalysisUsage &AU) const {
+            ...
+        }
+        virtual bool runOnFunction(Function &F) {
+            ...
+            //true:this pass will change our program
+            //false:won't change
+            return false;
+        }
+    };
+}
+
+char Example::ID = 0;
+static RegisterPass<Example> X("PASS_NAME","PASS_DESCRIPTION")
+```

test/FuncName_test.c

@@ -0,0 +1,12 @@
+#include <stdio.h>
+void sayHello() {
+    printf("hello\n");
+}
+void sayGoodbye() {
+    printf("goodbye\n");
+}
+int main() {
+    sayHello();
+    sayGoodbye();
+    return 0;
+}