[Docs] Improve function pointer docs#26667
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kripken wants to merge 1 commit intoemscripten-core:mainfrom
Open
[Docs] Improve function pointer docs#26667kripken wants to merge 1 commit intoemscripten-core:mainfrom
kripken wants to merge 1 commit intoemscripten-core:mainfrom
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sbc100
approved these changes
Apr 10, 2026
| Function pointer casts can cause function pointer calls to fail. | ||
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| Function pointers must be called with the correct type: it is undefined behavior in C and C++ to cast a function pointer to another type and call it that way. This does work in most native platforms, however, despite it being UB, but in Wasm it can fail. In that case, you may see an ``abort(10)`` or some other number, and if assertions are on you may see a message with details that start with | ||
| Function pointers must be called with the correct type: it is undefined behavior in C and C++ to cast a function pointer to another type and call it that way. This does work in most native platforms, however, despite it being UB, but in Wasm it can fail. In that case, you may see an error like this: |
| index will call this function, which simply calls ``abort()``. | ||
| If you get | ||
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Can you combine there lines. e.g. If you get ::`?
| RuntimeError: null function or function signature mismatch | ||
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| (or, in certain build types, an ``abort()`` or an error of "incorrect function | ||
| pointer"), the problem is that a proper function pointer was not found in the |
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.. the problem is that a function of the correct type was not found in the ..
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The message mentioned was for asm.js, not wasm.
Also mention the clang flag for warnings on casts in another place.