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* Merge branch 'master' of https://github.com/AbsInt/CompCert into towards_3.10David Monniaux2021-09-241-0/+54
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| * Native support for bit fields (#400)Xavier Leroy2021-08-221-0/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This big PR adds support for bit fields in structs and unions to the verified part of CompCert, namely the CompCert C and Clight languages. The compilation of bit field accesses to normal integer accesses + shifts and masks is done and proved correct as part of the Cshmgen pass. The layout of bit fields in memory is done by the functions in module Ctypes. It follows the ELF ABI layout algorithm. As a bonus, basic soundness properties of the layout are shown, such as "two different bit fields do not overlap" or "a bit field and a regular field do not overlap". All this replaces the previous emulation of bit fields by source-to-source rewriting in the unverified front-end of CompCert (module cparse/Bitfield.ml). This emulation was prone to errors (see nonstandard layout instead. The core idea for the PR is that expressions in l-value position denote not just a block, a byte offset and a type, but also a bitfield designator saying whether all the bits of the type are accessed (designator Full) or only some of its bits (designator Bits). Designators of the Bits kind appear when the l-value is a bit field access; the bit width and bit offset in Bits are computed by the functions in Ctypes that implement the layout algorithm. Consequently, both in the semantics of CompCert C and Clight and in the SimplExpr, SimplLocals and Cshmgen compilation passes, pairs of a type and a bitfield designator are used in a number of places where a single type was used before. The introduction of bit fields has a big impact on static initialization (module cfrontend/Initializers.v), which had to be rewritten in large part, along with its soundness proof (cfrontend/Initializersproof.v). Both static initialization and run-time manipulation of bit fields are tested in test/abi using differential testing against GCC and randomly-generated structs. This work exposed subtle interactions between bit fields and the volatile modifier. Currently, the volatile modifier is ignored when accessing a bit field (and a warning is printed at compile-time), just like it is ignored when accessing a struct or union as a r-value. Currently, the natural alignment of bit fields and their storage units cannot be modified with the aligned attribute. _Alignas on bit fields is rejected as per C11, and the packed modifier cannot be applied to a struct containing bit fields.
| * Use the LGPL instead of the GPL for dual-licensed filesXavier Leroy2021-05-081-4/+5
| | | | | | | | | | | | The GPL makes sense for whole applications, but the dual-licensed Coq and OCaml files are more like libraries to be combined with other code, so the LGPL is more appropriate.
* | [BROKEN] Merge with v3.9 : something broken for __builtin_expect in ↵Cyril SIX2021-06-011-4/+5
| | | | | | | | cfrontend/C2C.ml
* | Oexpect in frontendDavid Monniaux2020-04-071-0/+13
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* Take the sign into account for int to ptr cast.Bernhard Schommer2020-02-121-2/+2
| | | | | | | Casting from an integer constant to pointer on 64 bit architectures did not take the signedness into account and always interpreted the integer as unsigned which causes some incompatibility with libc implementations.
* Coq 8.10 compatibility: make explicit the "core" hint databaseXavier Leroy2019-08-051-2/+2
| | | | | "Hint Resolve foo." becomes "Hint Resolve foo : core", or "Local Hint Resolve foo : core".
* Make __builtin_sel available from C source codeXavier Leroy2019-07-171-0/+21
| | | | | It is type-checked like a conditional expression then translated to a call to the known builtin function.
* Regression: handling of integer + pointer in CompCert CXavier Leroy2016-10-061-32/+46
| | | | | | During the experiments, the integer + pointer cases was removed from the semantics of the C addition operator. The idea was to turn integer + pointer into pointer + integer during elaboration, but it was not implemented. On second thoughts, we can restore the integer + pointer cases in the formal semantics of CompCert C at low cost. This is what this commit does.
* Support for 64-bit architectures: generic supportXavier Leroy2016-10-011-278/+327
| | | | | | | | | | | - Introduce Archi.ptr64 parameter. - Define module Ptrofs of integers as wide as a pointer (64 if Archi.ptr64, 32 otherwise). - Use Ptrofs.int as the offset type for Vptr values and anywhere pointer offsets are manipulated. - Modify Val operations that handle pointers (e.g. Val.add, Val.sub, Val.cmpu) so that in 64-bit pointer mode it is the "long" operation (e.g. Val.addl, Val.subl, Val.cmplu) that handles pointers. - Update the memory model accordingly. - Modify C operations that handle pointers (e.g. addition, subtraction, comparisons) accordingly. - Make it possible to turn off the splitting of 64-bit integers into pairs of 32-bit integers. - Update the compiler front-end and back-end accordingly.
* Merge pull request #90 from AbsInt/sem-castsXavier Leroy2016-03-111-50/+176
|\ | | | | Make casts of pointers to _Bool semantically well defined
| * Make casts of pointers to _Bool semantically well defined (again).Xavier Leroy2016-03-021-50/+176
| | | | | | | | | | | | In compCert 2.5 the semantics of pointer comparisons against the NULL pointer was made more accurate by making it undefined if the pointer is invalid (outside bounds). Technical difficulties prevented this change from being propagated to the semantics of casts from pointer types to the _Bool type, which involves an implicit pointer comparison against NULL. Hence, this kind of casts was temporarily given undefined semantics. This commit makes pointer-to-_Bool casts semantically defined (again), provided the pointer is valid. This reinstates the equivalence between casts to _Bool and comparisons != 0. The technical difficulties mentioned above came from the translation of assignments in a value context in the SimplExpr pass. The pass was lightly modified to work around the issue.
* | Relaxing the semantics of pointer arithmetic.Xavier Leroy2016-02-291-6/+21
|/ | | | | | Support <pointer> +/- <integer> where the pointer value is actually an integer (Vint) that has been converted to pointer type. Such arithmetic, while not defined in ISO C, appears in the wild. If present in static initializers, it used to cause a compile-time failure ("not a compile-time constant"). Hence this relaxation.
* Updated PR by removing whitespaces. Bug 17450.Bernhard Schommer2015-10-201-54/+54
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* Signedness issue in specification of subtraction between two pointers.Xavier Leroy2015-06-301-3/+5
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* Long-overdue renaming: val_inject -> Val.inject, etc, for consistency with ↵Xavier Leroy2015-04-301-26/+26
| | | | Val.lessdef, etc.
* Omission: forgot to treat pointer values in bool_of_val and sem_notbool.Xavier Leroy2015-03-291-18/+50
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* Revised semantics of comparisons between a pointer and 0.Xavier Leroy2015-03-151-3/+0
| | | | | | | | | | | It used to be that a pointer value (Vptr) always compare unequal to the null pointer (Vint Int.zero). However, this may not be true in the final machine code when pointer addition overflows and wraps around to the bit pattern 0. This patch checks the validity of the pointer being compared with 0, and makes the comparison undefined if the pointer is out of bounds. Note: only the IA32 back-end was updated, ARM and PowerPC need updating.
* Represent struct and union types by name instead of by structure.Xavier Leroy2014-12-221-42/+40
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* - Support "switch" statements over 64-bit integersxleroy2014-08-171-1/+25
| | | | | | | | | | | | | (in CompCert C to Cminor, included) - Translation of "switch" to decision trees or jumptables made generic over the sizes of integers and moved to the Cminor->CminorSel pass instead of CminorSel->RTL as before. - CminorSel: add "exitexpr" to support the above. - ValueDomain: more precise analysis of comparisons against an integer literal. E.g. "x >=u 0" is always true. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2565 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Merge of "newspilling" branch:xleroy2014-07-231-74/+200
| | | | | | | | | | | | | | | - Support single-precision floats as first-class values - Introduce chunks Many32, Many64 and types Tany32, Tany64 to support saving and restoring registers without knowing the exact types (int/single/float) of their contents, just their sizes. - Memory model: generalize the opaque encoding of pointers to apply to any value, not just pointers, if chunks Many32/Many64 are selected. - More properties of FP arithmetic proved. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2537 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Clean-up pass on C types:xleroy2014-04-231-59/+260
| | | | | | | | | | | | | - Ctypes: add useful functions on attributes; remove attrs in typeconv (because attributes are meaningless on r-values) - C2C: fixed missing or redundant Evalof - Cop: ignore attributes in ptr + int and ptr - int (meaningless on r-values); add sanity check between typeconv/classify_binarith and the C99 standard. - cparser: fixed several cases where incorrect type annotations were put on expressions. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2457 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Use "incrdecr_type ty" instead of "typeconv ty" as the intermediate typexleroy2014-04-151-0/+9
| | | | | | | for Epostincr operations. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2455 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* __builtin_absfloat can be applied to integers too.xleroy2014-03-291-17/+36
| | | | | | | | More precise classification of float results of arithmetic operations, in preparation for future work on the C/Clight static type system. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2441 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Simpler, more robust emulation of calls to variadic functions:xleroy2013-12-281-8/+8
| | | | | | | | | | | | | | - C function types and Cminor signatures annotated by calling conventions. esp. vararg / not vararg - Cshmgen: generate correct code for function call where there are more arguments than listed in the function prototype. This is still undefined behavior according to the formal semantics, but correct code is generated. - C2C, */PrintAsm.ml: remove "printf$iif" hack. - powerpc/, checklink/: don't generate stubs for variadic functions. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2386 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* - Recognize __builtin_fabs as an operator, not just a builtin,xleroy2013-11-061-1/+11
| | | | | | | | | enabling more aggressive optimizations. - Less aggressive CSE for EF_builtin builtins, causes problems for __builtin_write{16,32}_reversed. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2363 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Revised handling of int->float conversions:xleroy2013-07-081-5/+7
| | | | | | | | | | - introduce Float.floatofint{,u} and use it in the semantics of C - prove that it is equivalent to int->double conversion followed by double->float rounding, and use this fact to justify code generation in Cshmgen. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2294 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Treat casts int64 -> float32 as primitive operations instead of twoxleroy2013-07-031-5/+7
| | | | | | | | casts int64 -> float64 -> float32. The latter causes double rounding errors. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2290 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Merge of the "princeton" branch:xleroy2013-06-161-3/+3
| | | | | | | | | | | | | | - Define type "block" as "positive" instead of "Z". - Strengthen mem_unchanged_on so that the permissions are identical, instead of possibly increasing. - Move mem_unchanged_on from Events to Memory.Mem. - Define it in terms of mem_contents rather than in terms of Mem.load. - ExportClight: try to name temporaries introduced by SimplExpr - SimplExpr: avoid reusing temporaries between different functions, instead, thread a single generator through all functions. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2276 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Revised semantics and compilation of 2-argument C operators to better match xleroy2013-05-061-93/+67
| | | | | | | | "the usual binary conversions" and be more robust towards future extensions e.g. with 32-bit float values. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2239 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* driver: removed option -flonglongxleroy2013-04-221-25/+34
| | | | | | | | test/c: added SHA3 cfrontend: support casts between long long and pointers, and comparisons between them. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2213 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Big merge of the newregalloc-int64 branch. Lots of changes in two directions:xleroy2013-04-201-310/+643
| | | | | | | | | 1- new register allocator (+ live range splitting, spilling&reloading, etc) based on a posteriori validation using the Rideau-Leroy algorithm 2- support for 64-bit integer arithmetic (type "long long"). git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2200 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Pointers one pastxleroy2013-02-151-14/+15
| | | | git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2118 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Make Clight independent of CompCert C.xleroy2012-10-081-0/+822
Common parts are factored out in cfrontend/Ctypes.v and cfrontend/Cop.v git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2060 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
generated by cgit (git 2.34.1) at 2024-05-19 22:11:39 +0000