## DON'T PRINT, GO DEBUG! by Alexander Podkhalyuzin 彭俐客 ## How to print?  ## Casey Newton @CaseyNewton Here it is: p\textsubscript{lan} 1 2 3 First steps Run to cursor Don't debug. Print! ## p\textsubscript{lan} 1 2 3 4 First steps Run to cursor Don't debug. Print! Attach to process 1 2 3 4 5 ## p\textsubscript{lan} Run to cursor Don't debug. Print! Attach to process Debug Goroutines ## p\textsubscript{lan} First steps Run to cursor Don't debug. Print! Attach to process Debug Goroutines Superpower!

Dynamic Profiler • Can be used with no recompilation or code modification • APIs ## Outline • Debug Info Analysis • Type/Layout Reconstruction • Code Generation • Object Introspection as a Library Understand how to interpret data at memory offsets • Understand containers • Compiler generated debug information required • DWARF v4 (DebugFission supported) • drgn (https://github.com/osandov/drgn) [Image](/uploads/documents/f/9/2/d/f92d6739cbe6128deb047eb1259822d6/p21_1.jpg) ## Outline • Debug Info Analysis • Type/Layout Reconstruction • Code Generation • Object Introspection as a Library

JULIA_EXCLUSIVE 342 36.4 REPL formatting 342 JULIA_ERROR_COLOR 342 JULIA_WARN_COLOR 342 JULIA_INFO_COLOR 342 JULIA_INPUT_COLOR 342 JULIA_ANSWER_COLOR 342 JULIA_STACKFRAME_LINEINFO_COLOR 343 and lowering ..... 1236 105.7 Intermediate and compiled representations ..... 1237 Printing of debug information ..... 1237 06 Documentation of Julia's Internals ..... 1239 106.1 Initialization code ..... 1313 107.1 Reporting and analyzing crashes (segfaults) ..... 1313 Version/Environment info ..... 1313 Segfaults during bootstrap (sysimg.jl) ..... 1314 Segfaults when running a script

match(r"[0-9]", "aaaa1aaaa2aaaa3", 11) RegexMatch("3") You can extract the following info from a RegexMatch object: • the entire substring matched: m.match • the captured substrings as an it makes it easy to move code back and forth between a function body and the REPL when trying to debug the behavior of a function. However, it has some downsides. First, it's quite a complex behavior: It's no longer convenient to copy and paste the code from inside a function body into the REPL to debug it—you have to add global annotations and then remove them again to go back; 2. Beginners will write

mod_proxy_scgi: The default setting for PATH_INFO has changed from httpd 2.2, and some web applications will no longer operate properly with the new PATH_INFO setting. The previous setting can be restored be configured per module and per directory. New levels trace1 to trace8 have been added above the debug log level.| |Per-request configuration sections| |<If>, <ElseIf>, and <Else> sections small business logic functions. (Experimental) mod_log_debug Allows the addition of customizable debug logging at different phases of the request processing. mod_buffer Provides

"os", "arch", "compiler" ... def validate(self): if self.info.settings.os == "Macos": raise ConanInvalidConfiguration("Macos not supported") ["ANY"]} ``` ## 2.1.5 The validate() method Use always the self.info.settings instead of self.settings and self.info.options instead of self. options. Otherwise, the compatibility mechanism won't ``` Listing 10: To: ```python class Pkg(Conanfile): def validate(self): if self.info.settings.os == "Windows": raise ConanInvalidConfiguration("This package is

"os", "arch", "compiler" ... def validate(self): if self.info.settings.os == "Macos": raise ConanInvalidConfiguration("Macos not supported") {"opt": None} ``` ## 2.1.5 The validate() method Use always the self.info.settings instead of self.settings and self.info.options instead of self. options. Otherwise, the compatibility mechanism won't ``` Listing 11: To: ```python class Pkg(Conanfile): def validate(self): if self.info.settings.os == "Windows": raise ConanInvalidConfiguration("This package is

2.1.5 The validate() method Use always the self.settings instead of self.info.settings and self.options instead of self.info. options. The compatibility mechanism are not needed to verify if the configurations built. Listing 10: From: ```python class Pkg(Conanfile): def validate(self): if self.info.settings.os == "Windows": raise ConanInvalidConfiguration("This package is recipes that check for a specific self.settings.cppstd like: ```python def package_id(self): self.info.clear() def validate(self): if self.settings.get_safe("compiler.cppstd"):

2.1.5 The validate() method Use always the self.settings instead of self.info.settings and self.options instead of self.info. options. The compatibility mechanism are not needed to verify if the configurations built. Listing 10: From: ```python class Pkg(Conanfile): def validate(self): if self.info.settings.os == "Windows": raise ConanInvalidConfiguration("This package is recipes that check for a specific self.settings.cppstd like: ```python def package_id(self): self.info.clear() def validate(self): if self.settings.get_safe("compiler.cppstd"):

content of conanfile.py for a reference $ conan get Display dependency graph info for a recipe $ conan info Search Packages Search for packages in a remote $ conan search zlib generator $ conan install zlib/1.2.11@ -g deploy ## Conan Recipe Methods in Package Creation package info() From all dependency recipes exports_sources_source() generate{} build package():=] # Specify settings, e.g. build_ type=Debug # is optional: if not specified, the option/setting # applies to all dependencies (continues