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* Native support for bit fields (#400)Xavier Leroy2021-08-221-581/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Fix evaluation order in emulation of bitfield assignmentXavier Leroy2021-05-021-2/+2
| | | | | | | | | | | | | | | | A bitfield assignment `x.b = f()` is expanded into a read-modify-write on `x.carrier`. Wrong results can occur if `x.carrier` is read before the call to `f()`, and `f` itself modifies a bitfield with the same carrier `x.carrier`. In this temporary fix, we play on the evaluation order implemented by the SimplExpr pass of CompCert (left-to-right for side-effecting subexpression) to make sure the read part of the read-modify-write sequence occurs after the evaluation of the right-hand side. More substantial fixes will be considered later. Fixes: #395
* Use Hashtbl.find_opt.Bernhard Schommer2020-06-281-2/+1
| | | | | Replace the pattern `try Some (Hashtbl.find ...) with Not_found -> None` by a call to the function Hashtbl.find_opt.
* Added warning for packed composite with bitfields.Bernhard Schommer2020-04-201-0/+2
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* Add location to transform functions.Bernhard Schommer2020-04-201-4/+4
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* Initialization of anonymous bit-fields in structsXavier Leroy2018-04-251-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | For anonymous bit-fields in structs, carrier fields may be introduced which are not initialized since no default initializer are generated earlier. This cause the translation in C2C to throw an error since too few initializers are available. Example: struct s2 { int : 10; int a; int : 10; char b; int : 10; short c; int : 10; } s2 = { 42, 'a', 43 }; To work around this issue we need to generate a default inializer for every new member that does not have a translated member. Based on P#80, with more efficient algorithms. Bug 23362
* Bitfields transformation: record the fields after transformationXavier Leroy2018-04-251-4/+20
| | | | | | | | | | | | | | For each struct or union that contains bitfields, we record the list of members after transformation, where bit fields were replaced by carrier fields. Right now we do not use this information but it will come handy to fix a problem with struct initialization. Also: clear the global hash tables on entry so that multiple runs of the Bitfields transformation don't interfere with each other. There probably was no interference before because identifiers are unique enough, but this is fragile.
* Initialization of union bit fieldsXavier Leroy2018-04-251-3/+12
| | | | | | | | | | | Bit fields in unions were initialized like normal fields, causing mismatch on the name of the field. Also: added function Bitfields.carrier_field and refactored. Patch by Bernhard Schommer. Bug 23362
* Fix mistake in Bitfield transformation (#66)Michael Schmidt2018-03-271-2/+2
| | | Unions containing multiple bit fields were transformed incorrectly.
* Refactor the handling of errors and warnings (#44)Bernhard Schommer2018-02-081-1/+1
| | | | | | | | | | | | | | | | | * Module Cerrors is now called Diagnostic and can be used in parts of CompCert other than cparser/ * Replaced eprintf error. Instead of having eprintf msg; exit 2 use the functions from the Diagnostics module. * Raise on error before calling external tools. * Added diagnostics to clightgen. * Fix error handling of AsmToJson. * Cleanup error handling of Elab and C2C. *The implementation of location printing (file & line) is simplified and correctly prints valid filenames with invalid lines.
* Revert broken change to Cutil.Bernhard Schommer2017-02-081-2/+6
| | | | | | The optional hex parameter only worked if the intconstant was also of unsigned kind. Hence it is better to have one function in Bitfields for this.
* Cleanup opens.Bernhard Schommer2017-02-061-9/+8
| | | | | | The Printf is only needed for the identifier functions. Furthermore the new intconst from Cutil is used to generate the integer constant and shadowing of the open C is removed.
* Next try for support of anonymous structs.Bernhard Schommer2016-12-071-3/+3
| | | | | | Instead of using idents the anonymous fileds get names of the for <anon>_c where c is a counter of all anonymous members. Bug 20003
* Restored original bit-field warning. Bug 18004Bernhard Schommer2016-08-311-1/+1
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* Classified all warnings and added various options.Bernhard Schommer2016-07-291-1/+1
| | | | | | | | | | Now each warning either has a name and can be turned on/off, made into an error,etc. or is a warning that always will be triggered. The message of the warnings are similar to the ones emited by gcc/clang and all fit into one line. Furthermore the diagnostics are now colored if colored output is available. Bug 18004
* Deactivate warning 27 and added back removed code.Bernhard Schommer2016-03-151-1/+1
| | | | | | The code was mostly there for documentation effort. So warning 27 is deactivated again. Bug 18349
* Code cleanup.Bernhard Schommer2016-03-101-9/+3
| | | | | | Removed some unused variables, functions etc. and resolved some problems which occur if all warnings except 3,4,9 and 29 are active. Bug 18394.
* Handle large static initializers for global arraysXavier Leroy2015-11-091-1/+1
| | | | Use tail-recursive operations to implement transformations on initializers for global arrays. This way, very large static initializers no longer cause stack overflows at compile-time.
* Updated PR by removing whitespaces. Bug 17450.Bernhard Schommer2015-10-201-6/+6
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* Merge branch 'debugscopes' into debug_locationsBernhard Schommer2015-09-211-6/+42
|\ | | | | | | | | | | Conflicts: debug/CtoDwarf.ml debug/DwarfPrinter.ml
| * Added support for bitfields in unions.Bernhard Schommer2015-09-171-6/+42
| | | | | | | | | | The transformation is the same as the one used for structs but packing always stops after each member.
* | First version with computation of dwarf info from debug info.Bernhard Schommer2015-09-171-1/+1
| | | | | | | | | | Introduced a new dwarf generation from the information collected in the DebugInformation and removed the old CtODwarf translation.
* | Move more functionality in the new interface.Bernhard Schommer2015-09-161-0/+1
|/ | | | | | Added functions to add more information to the debuging interface, like the struct layout with offsets, bitifiled layout and removed the no longer needed mapping from stamp to atom.
* Fix issue with bit fields of type _BoolXavier Leroy2015-07-081-6/+22
| | | | | | cparser/Bitfields.ml: when assigning to a bit field of type _Bool, the right-hand side must be normalized to 0 or 1 via a cast to _Bool. test/regression/bitfields{1,9}.c: add corresponding test cases.
* Bitfield improvements continued: perform bitfield expansion before ↵Xavier Leroy2015-04-281-179/+209
| | | | unblocking; improve translation of bitfield initializers and compound literals.
* Support C99 compound literals (by expansion in Unblock pass).xleroy2014-08-211-0/+2
| | | | git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2615 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Clean-up pass on C types:xleroy2014-04-231-27/+24
| | | | | | | | | | | | | - 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
* "->" can also be applied to array types, not just pointer types.xleroy2014-03-301-1/+1
| | | | git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2442 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Elab:xleroy2013-10-041-7/+7
| | | | | | | | | | | - bad error recovery on bitfield with 'long long' type - check for redefinition of function parameters Bitfields: - when assigning to a bitfield, cast the RHS to "unsigned int" (it matters if the RHS is long long). git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2339 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Support for inline assembly (asm statements).xleroy2012-12-181-2/+22
| | | | | | | cparser: add primitive support for enum types. bitfield emulation: for bitfields with enum type, choose signed/unsigned as appropriate git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2074 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* - Support for _Alignof(ty) operator from ISO C 2011xleroy2012-02-261-0/+1
| | | | | | | | | | and __alignof__(ty), __alignof__(expr) from GCC. - Resurrected __builtin_memcpy_aligned, useful for files generated by Scade KCG 6. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1827 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* cparser/*: refactoring of the expansion of read-modify-write operatorsxleroy2011-11-261-23/+1
| | | | | | | | | cparser/PackedStructs: treat r-m-w operations over byte-swapped fields cparser/PackedStructs: allow static initialization of packed structs test/regression: more packedstruct tests git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1738 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* SimplVolatile: new pass to eliminate read-modify-write ops over volatilesxleroy2011-08-181-42/+6
| | | | | | | | Elsewhere: refactoring, moving common code into Cutil and Transform (to be continued) git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1716 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Factor out bind_lvaluexleroy2011-08-171-22/+2
| | | | git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1715 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* cparser: support for attributes over struct and union.xleroy2011-05-121-3/+3
| | | | | | | | cparser: added experimental emulation of packed structs (PackedStruct.ml) git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1650 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Bitfields: MSB-to-LSB in addition to LSB-to-MSBxleroy2011-03-101-4/+11
| | | | git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1600 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Inconsistent treatment of "lone" zero-width bit fieldsxleroy2010-09-241-13/+19
| | | | | | | (i.e. not preceded by another bit field). git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1516 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Bugs with 1- empty bitfields, 2- anonymous bitfields, 3- result type of ↵xleroy2010-09-011-9/+22
| | | | | | reading a small unsigned bitfield git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1496 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Merge of branches/full-expr-4:xleroy2010-08-181-91/+182
| | | | | | | | | | | | | | | | | | | | | | - Csyntax, Csem: source C language has side-effects within expressions, performs implicit casts, and has nondeterministic reduction semantics for expressions - Cstrategy: deterministic red. sem. for the above - Clight: the previous source C language, with pure expressions. Added: temporary variables + implicit casts. - New pass SimplExpr to pull side-effects out of expressions (previously done in untrusted Caml code in cparser/) - Csharpminor: added temporary variables to match Clight. - Cminorgen: adapted, removed cast optimization (moved to back-end) - CastOptim: RTL-level optimization of casts - cparser: transformations Bitfields, StructByValue and StructAssign now work on non-simplified expressions - Added pretty-printers for several intermediate languages, and matching -dxxx command-line flags. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1467 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Bug fix: infinite loop in cparser/ on bit field of size 32 bits.xleroy2010-04-091-1/+1
| | | | | | | | Algorithmic efficiency: in cparser/, precompute sizeof and alignof of composites. Code cleanup: introduced Cutil.composite_info_{def,decl} git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1312 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Static initialization of structs with bitfieldsxleroy2010-04-071-1/+74
| | | | git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1311 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
* Switching to the new C parser/elaborator/simplifierxleroy2010-03-031-0/+323
git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1269 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
generated by cgit (git 2.34.1) at 2024-06-29 14:17:47 +0000