4c5e9870f2
gcc/ada/ * sem_util.ads: Declare a new package, Old_Attr_Util, which in turn declares two more packages, Conditional_Evaluation and Indirect_Temps. Conditional_Evaluation provides a predicate for deciding whether a given 'Old attribute reference is eligible for conditional evaluation and, in the case where it is eligible, a function that constructs the Boolean-valued condition that is to be evaluated at run time in deciding whether to evaluate the attribute prefix. Indirect_Temps provides support for declaring a temporary which is only initialized conditionally; more specifically, an access type and a variable of that type are declared (unconditionally) and then the variable is (conditionally) initialized with an allocator. The existence of the access type and the pointer variable is hidden from clients, except that a predicate, Is_Access_Type_For_Indirect_Temp, is provided for identifying such access types. This is needed because we want such an access type to be treated like a "normal" access type (specifically with respect to finalization of allocated objects). Other parts of the compiler treat access types differently if Comes_From_Source is False, or if the secondary stack storage pool is used; this predicate is used to disable this special treatment. * sem_attr.adb (Uneval_Old_Msg): Improve message text to reflect Ada202x changes. (Analyze_Attribute): A previously-illegal 'Old attribute reference is accepted in Ada2020 if it is eligible for conditional evaluation. * sem_res.adb (Valid_Conversion): Do not treat a rewritten 'Old attribute like other rewrite substitutions. This makes a difference, for example, in the case where we are generating the expansion of a membership test of the form "Saooaaat'Old in Named_Access_Type"; in this case Valid_Conversion needs to return True (otherwise the expansion will be False - see the call site in exp_ch4.adb). * exp_attr.adb (Expand_N_Attribute_Reference): When expanding a 'Old attribute reference, test for the case where the reference is eligible for conditional evaluation. In that case, use the new "indirect temporary" mechanism provided by Sem_Util. * exp_prag.adb (Expand_Attributes_In_Consequence.Expand_Attributes): If Sem_Util.Indirect_Temp_Needed indicates that there could be correctness problems associated with the old expansion scheme for dealing with 'Old attributes in contract cases consequences, then we use the new "indirect temporary" mechanism provided by Sem_Util instead. We do not want to do this unconditionally. * sem_util.adb: Provide a body for the new Old_Attr_Util package. Further work is needed in several areas for correctness: - The function Is_Repeatedly_Evaluated does not deal with container aggregates yet. - The function Is_Known_On_Entry does not deal with interactions with the Global aspect. Each area where more work is needed is indicated with a "???" comment in the code; a more detailed description can be found there. Some optimization opportunties are similarly indicated with a "???" comment. * exp_ch3.adb (Freeze_Type): In deciding whether to generate expansion for the list controller of an access type, take the predicate Is_Access_Type_For_Indirect_Temp into account. If the predicate yields True, then generate the expansion. * exp_util.adb (Build_Allocate_Deallocate_Proc): We don't normally finalize allocated objects that are allocated on the secondary stack. Add an exception to this rule if the predicate Is_Access_Type_For_Indirect_Temp yields True. As a result of this exception, we have to deal with the fact that gigi expects a different parameter profile if we are using the secondary stack pool; the Pool and Alignment parameters must be omitted in this case. |
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| contrib | ||
| fixincludes | ||
| gcc | ||
| gnattools | ||
| gotools | ||
| include | ||
| INSTALL | ||
| intl | ||
| libada | ||
| libatomic | ||
| libbacktrace | ||
| libcc1 | ||
| libcpp | ||
| libdecnumber | ||
| libffi | ||
| libgcc | ||
| libgfortran | ||
| libgo | ||
| libgomp | ||
| libhsail-rt | ||
| libiberty | ||
| libitm | ||
| libobjc | ||
| liboffloadmic | ||
| libphobos | ||
| libquadmath | ||
| libsanitizer | ||
| libssp | ||
| libstdc++-v3 | ||
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| lto-plugin | ||
| maintainer-scripts | ||
| zlib | ||
| .dir-locals.el | ||
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| ABOUT-NLS | ||
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| config.sub | ||
| configure | ||
| configure.ac | ||
| COPYING | ||
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| COPYING3.LIB | ||
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| depcomp | ||
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| ltgcc.m4 | ||
| ltmain.sh | ||
| ltoptions.m4 | ||
| ltsugar.m4 | ||
| ltversion.m4 | ||
| MAINTAINERS | ||
| Makefile.def | ||
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