--- title: Lets explore the stack | daily.dev description: An exploration of how the call stack works in C++, examining stack frames, alignment and padding of stack variables, and GCC/Clang builtins like... canonical: https://daily.dev/posts/lets-explore-the-stack-byttrvvkv twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Lets explore the stack | daily.dev og:description: An exploration of how the call stack works in C++, examining stack frames, alignment and padding of stack variables, and GCC/Clang builtins like... og:url: https://daily.dev/posts/lets-explore-the-stack-byttrvvkv og:image: https://api.daily.dev/og/posts/byttRvVKV.png og:image:alt: Lets explore the stack og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Lets explore the stack **[Meeting C\+\+](https://daily.dev/sources/meetingcpp)** · 10 min read · 2 upvotes · 0 comments ## Summary An exploration of how the call stack works in C++, examining stack frames, alignment and padding of stack variables, and GCC/Clang builtins like __builtin_frame_address and -fstack-usage for inspecting stack memory. The author builds custom code to visualize stack variable placement and padding bytes, compares results across GCC, Clang, and ARM64, and discusses how declaration order can affect stack frame size and variable access speed, while noting most of this behavior is implementation-defined and platform-specific. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How can I see the stack frame address of the current function in GCC or Clang? Use the compiler builtin __builtin_frame_address(0), which returns a void pointer to the start of the current stack frame. Passing nonzero values (1, 2...) walks up the call stack but can have unpredictable effects, including crashing the program, since it is intended for inspecting callers rather than general use. _daily.dev surfaces low-level C++ techniques like this for developers debugging stack behavior._ ### How do I measure the stack size used by a function in GCC? Compile with -fstack-usage, which generates a .su file per .cpp file listing each function name alongside its stack frame size in bytes. Compiler Explorer also has a stack viewer feature for inspecting this, though it currently only works reliably with clang. _track tooling details like this on daily.dev when profiling C++ memory footprint._ ### Does declaring variables in a certain order reduce padding in a C++ function's stack frame, similar to struct layout optimization? Yes, variables on the stack can have padding bytes between them just like struct members, and ordering them from largest to smallest can reduce total padding and shrink the stack frame size. However, the effect on performance is far smaller than for structs, since a function's size isn't defined solely by its stack variables and many variables end up in registers instead. _developers optimizing C++ memory layout follow nuances like this through daily.dev._ ## Similar posts on daily.dev - [Thoroughly Understanding C\+\+ ABI](https://daily.dev/posts/thoroughly-understanding-c-abi-31gh0fage) · Hacker News · 3 upvotes · 0 comments - [Medium](https://daily.dev/posts/medium-qywq6zdry) · Medium · 0 upvotes · 0 comments - [August 17, 2026](https://daily.dev/posts/august-17-2026-wnulmhiq0) · The Old New Thing · 0 upvotes · 0 comments --- Tags: [#c++](https://daily.dev/tags/c++) [View this post on daily.dev](https://daily.dev/posts/lets-explore-the-stack-byttrvvkv) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Lets explore the stack","url":"https://daily.dev/posts/lets-explore-the-stack-byttrvvkv","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/lets-explore-the-stack-byttrvvkv"},"datePublished":"2026-10-02T15:02:11.708Z","dateModified":"2026-10-02T15:02:36.395Z","description":"An exploration of how the call stack works in C++, examining stack frames, alignment and padding of stack variables, and GCC/Clang builtins like...","image":"https://media.daily.dev/image/upload/s--58gMhC4P--/f_auto/v1722860399/public/Placeholder%2012","thumbnailUrl":"https://media.daily.dev/image/upload/s--58gMhC4P--/f_auto/v1722860399/public/Placeholder%2012","isAccessibleForFree":true,"articleSection":"Meeting C++","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Meeting C++","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/49c7b6c7e0084e94bdd54fcf01f0ae53","url":"https://daily.dev/sources/meetingcpp"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/lets-explore-the-stack-byttrvvkv","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":2},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"c++","timeRequired":"PT10M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Meeting C++","item":"https://daily.dev/sources/meetingcpp"},{"@type":"ListItem","position":3,"name":"Lets explore the stack"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/lets-explore-the-stack-byttrvvkv#faq","mainEntity":[{"@type":"Question","name":"How can I see the stack frame address of the current function in GCC or Clang?","acceptedAnswer":{"@type":"Answer","text":"Use the compiler builtin __builtin_frame_address(0), which returns a void pointer to the start of the current stack frame. 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