llvm-clang

问题 The man page for opt says: "It takes LLVM source files as input, runs the specified optimizations or analyses on it, and then outputs the optimized file or the analysis results". My Goal: To use the inbuilt optimisation pass -dce available in opt . This pass does Dead Code Elimination My Source file foo.c : int foo(void) { int a = 24; int b = 25; /* Assignment to dead variable -- dead code */ int c; c = a * 4; return c; } Here is what I did: 1. clang-7.0 -S -emit-llvm foo.c -o foo.ll 2. opt

问题 The man page for opt says: "It takes LLVM source files as input, runs the specified optimizations or analyses on it, and then outputs the optimized file or the analysis results". My Goal: To use the inbuilt optimisation pass -dce available in opt . This pass does Dead Code Elimination My Source file foo.c : int foo(void) { int a = 24; int b = 25; /* Assignment to dead variable -- dead code */ int c; c = a * 4; return c; } Here is what I did: 1. clang-7.0 -S -emit-llvm foo.c -o foo.ll 2. opt

问题 clang-check -ast-dump -ast-dump-filter=<function_name> main.c gives a AST (only a function declaration) of the particular code. How can we represent generated AST in JSON format? PS: I Want AST for function declaration only. 回答1: Call clang with the -ast-dump=json argument. This was implemented only recently (May 2019) so you need an up-to-date version of Clang. See https://reviews.llvm.org/D60910 for details. There's also a library to export more lower-level information available via

问题 I'm trying to link statically OpenSSL library to my Swift framework, using XCode. Most approaches mentioned online are not correct, because they suggest using Import path ( SWIFT_INCLUDE_PATHS ). As a result, the framework binary is locked to a specific location in the file system and the binary itself is not portable. While this is not end of the world, I'd still like to be able to distribute the binary via Carthage for example and following above-mentioned approach doesn't enable that. I

问题 I have a Jenkins build server running macOS 10.12. I am compiling a C++ application using the latest Clang 10 (not AppleClang) with CMake 3.17. The error I get is: The C++ compiler "/Users/XXX/llvm/bin/clang++" is not able to compile a simple test program. It fails with the following output: ld: unknown option: -platform_version clang-10: error: linker failed with exit code 1 This works fine with Clang 9 on the same server and Clang 10 works fine on macOS 10.15 with all other build tools and

问题 I'm writing a custom pass for LLVM/Clang, and recompiling tends to take a while and use a lot of memory. I've heard that the gold linker (1) takes less time and (2) uses less memory than the standard ld linker. Is there a way to pass flags into the LLVM/Clang build process and change to the gold linker? As per this answer, I've been attempting to use an override file, but I don't seem to be having a lot of success. I'll also note that I'm compiling the latest Clang/LLVM build (4.0) using

问题 Hello I am trying to implement an AST Clang visitor and this is my code. class ExampleVisitor : public RecursiveASTVisitor<ExampleVisitor> { private: ASTContext *astContext; // used for getting additional AST info public: virtual bool VisitVarDecl(VarDecl *var) { numVariables++; string varName = var->getQualifiedNameAsString(); string varType = var->getType().getAsString(); cout << "Found variable declaration: " << varName << " of type " << varType << "\n"; APIs << varType << ", "; return

问题 I am writing LLVM IR code, can I call a function in another .ll file? For example: In a.ll file, there is a function foo(); Can I use this function in b.ll, like just call foo? If so, how can I include a.ll Thanks 回答1: You need to add declaration of function foo in the ll file in which you are calling it, then as usual convert link ll files to generate executable llvm-link a.ll b.ll -o a.out example a.ll declare i32 @foo(i32) define i32 @main() { start: %0 = call i32 @foo(i32 0) ret i32 %0 }

问题 TL;DR; How to get the macro name used for size of a constant size array declaration, from a callExpr -> arg_0 -> DeclRefExpr. Detailed Problem statement: Recently I started working on a challenge which requires source to source transformation tool for modifying specific function calls with an additional argument. Reasearching about the ways i can acheive introduced me to this amazing toolset Clang. I've been learning how to use different tools provided in libtooling to acheive my goal. But

问题 I'm running into an odd quirk involving Core Data, a declared protocol, and perhaps the LLVM 1.5 compiler. Here's the situation. I have a Core Data model that among others has two classes, IPContainer and IPEvent, with IPContainer being the parent entity of IPEvent. Each entity has a custom class in the project for it, created using mogenerator. mogenerator generates an additional subclass that just contains the modeled property declarations, so the class hierarchy is actually IPEvent >