utils: mark mesa_error with NORETURN (gcc only) #904
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This means that the function will never return to its caller. This makes life easier for the optimizer and can prevent spurious maybe-uninitialized warnings. This change was triggered by warnings in the mtx module about potentially uninitialized variables after allocation. mesa_error was used to terminate MESA if allocate would fail. Inspection of the intermediate representation of GCC showed that it considered execution to continue after mesa_error, which muddied the control flow blocks. To actually trigger a spurious warning, the variable needs to have rank > 1, be declared with pointer, and have unknown size at compile time. This is quite niche, but future changes to warnings & optimizations might change this. At least adding this attribute may make the generated assembly smaller (this was the case for a simple test function). ifort does not seem to have a similar attribute.
VincentVanlaer
requested review from
rhdtownsend and
warrickball
as code owners
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This means that the function will never return to its caller. This makes life easier for the optimizer and can prevent spurious maybe-uninitialized warnings.
This change was triggered by warnings in the mtx module about potentially uninitialized variables after allocation. mesa_error was used to terminate MESA if allocate would fail. Inspection of the intermediate representation of GCC showed that it considered execution to continue after mesa_error, which muddied the control flow blocks. To actually trigger a spurious warning, the variable needs to have rank > 1, be declared with pointer, and have unknown size at compile time. This is quite niche, but future changes to warnings & optimizations might change this. At least adding this attribute may make the generated assembly smaller (this was the case for a simple test function).
ifort does not seem to have a similar attribute.
Note: this is a retake of #708, now that the latest SDK is required. The change removes ~40 maybe uninitialized variable warnings