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Weak Symbol

A weak symbol denotes a specially annotated symbol during linking of Executable and Linkable Format (ELF) object files.

Version
v1 · 2026-09-28 · History
Domain-specific #
12850
Domain group
Applied Sciences & Engineering
Origin domain
Computer Science & Software Engineering
Subdomains
Linkers and Loaders, Object File Formats → Computer Science & Software Engineering

Core Idea

Weak Symbol is treated here as the recurring computer science and information systems identity summarized by this source-grounded definition: A weak symbol denotes a specially annotated symbol during linking of Executable and Linkable Format (ELF) object files. A weak symbol denotes a specially annotated symbol during linking of Executable and Linkable Format (ELF) object files. By default, without any annotation, a symbol in an object file is strong. During linking, a strong symbol can override a weak symbol of the same name.

Scope of Application

  • Use cases. Weak symbols can be used as a mechanism to provide default implementations of functions that can be replaced by more specialized (e.g. optimized) ones at link-time.

  • When using constructs like. The weak function attribute is supposed to be used on function declarations.

  • Documented setting. This behavior allows an executable to override standard library functions, such as malloc(3).

  • Syntax. The GNU Compiler Collection and the Solaris Studio C compiler share the same syntax for annotating symbols as weak, namely a special #pragma, #pragma weak , and, alternatively, a function and variable.

  • Tools support. On Linux a weak function symbol is marked with "W" if a weak default definition is available, and with "w" if it is not.

Clarity

A clear use of Weak Symbol names the carrier, the operative relation, and the conditions under which the source treats the identity as present. The minimal definition is A weak symbol denotes a specially annotated symbol during linking of Executable and Linkable Format (ELF) object files. The strongest recognition evidence in the frozen account is: The difference from weak symbols is that weak symbols are interpreted by the linker.

Manages Complexity

Weak Symbol compresses multiple computer science and information systems details into a stable diagnostic relation. The source shows both the central mechanism—weak symbols can be used as a mechanism to provide default implementations of functions that can be replaced by more specialized (e.g. optimized) ones at link-time.—and the practical consequence—the error message is issued by the linker.

Abstract Reasoning

  1. Type the carrier. Identify the computer science and information systems entities to which the claim applies.
  2. State the relation. Use the source-grounded identity: A weak symbol denotes a specially annotated symbol during linking of Executable and Linkable Format (ELF) object files.
  3. Check operation and conditions. C preprocessor (CPP) conditional constructs can also be used to switch between different versions of a symbol.
  4. Demand recognition evidence. The difference from weak symbols is that weak symbols are interpreted by the linker.
  5. Test variation.

Knowledge Transfer

Within the home domain. Knowledge about Weak Symbol transfers literally when a new case preserves the same carrier type, relation, and recognition test. Weak symbols can be used as a mechanism to provide default implementations of functions that can be replaced by more specialized (e.g. optimized) ones at link-time. The weak function attribute is supposed to be used on function declarations. Beyond the home domain. No canonical parent is asserted for Weak Symbol.

Neighborhood in Abstraction Space

Weak Symbol sits in a moderately populated region (51st percentile for distinctiveness): it has near-neighbors but no dense thicket of look-alikes.

Family — Formal Notation & Symbol Conventions (5 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08