[Bug modula2/110125] Variables are reported as uninitialized when only set inside WITH statement

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110125

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Gaius Mulley
<gaius@gcc.gnu.org>:

https://gcc.gnu.org/g:3fd979bf568d91016b797818e6c9c940b6f389bd

commit r13-7650-g3fd979bf568d91016b797818e6c9c940b6f389bd
Author: Gaius Mulley <gaiusmod2@gmail.com>
Date:   Sun Jul 30 02:18:57 2023 +0100

    PR modula2/110125 variables reported as uninitialized when set inside WITH

    The modula-2 static analysis incorrectly identifies variables as
    uninitialized if they are initialized within a WITH statement.  This bug
    fix re-implements the variable static analysis and will detect simple
    pointer record fields being accessed before being initialized.
    The static analysis is limited to the first basic block in a procedure.
    It does not check variant records, arrays or sets.  A new option
    -Wuninit-variable-checking will turn on the new semantic checking
    (-Wall also enables the new checking).

    gcc/ChangeLog:

            PR modula2/110125
            * doc/gm2.texi (Semantic checking): Include examples using
            -Wuninit-variable-checking.

    gcc/m2/ChangeLog:

            PR modula2/110125
            * Make-lang.in (GM2-COMP-BOOT-DEFS): Add M2SymInit.def.
            (GM2-COMP-BOOT-MODS): Add M2SymInit.mod.
            * gm2-compiler/M2BasicBlock.mod: Formatting changes.
            * gm2-compiler/M2Code.mod: Remove import of VariableAnalysis from
            M2Quads.  Import VariableAnalysis from M2SymInit.mod.
            * gm2-compiler/M2GCCDeclare.mod (PrintVerboseFromList):
            Add debugging print for a component.
            (TypeConstFullyDeclared): Call RememberType for every type.
            * gm2-compiler/M2GenGCC.mod (CodeReturnValue): Add parameter to
            GetQuadOtok.
            (CodeBecomes): Add parameter to GetQuadOtok.
            (CodeXIndr): Add parameter to GetQuadOtok.
            * gm2-compiler/M2Optimize.mod (ReduceBranch): Reformat and
            preserve operand token positions when reducing the branch
            quadruples.
            (ReduceGoto): Reformat.
            (FoldMultipleGoto): Reformat.
            (KnownReachable): Reformat.
            * gm2-compiler/M2Options.def (UninitVariableChecking): New
            variable declared and exported.
            (SetUninitVariableChecking): New procedure.
            * gm2-compiler/M2Options.mod (SetWall): Set
            UninitVariableChecking.
            (SetUninitVariableChecking): New procedure.
            * gm2-compiler/M2Quads.def (PutQuadOtok): Exported and declared.
            (VariableAnalysis): Removed.
            * gm2-compiler/M2Quads.mod (PutQuadOtok): New procedure.
            (doVal): Reformatted.
            (MarkAsWrite): Reformatted.
            (MarkArrayAsWritten): Reformatted.
            (doIndrX): Use PutQuadOtok.
            (MakeRightValue): Use GenQuadOtok.
            (MakeLeftValue): Use GenQuadOtok.
            (CheckReadBeforeInitialized): Remove.
            (IsNeverAltered): Reformat.
            (DebugLocation): New procedure.
            (BuildDesignatorPointer): Use GenQuadO to preserve operand token
            position.
            (BuildRelOp): Use GenQuadOtok ditto.
            * gm2-compiler/SymbolTable.def (VarCheckReadInit): New procedure.
            (VarInitState): New procedure.
            (PutVarInitialized): New procedure.
            (PutVarFieldInitialized): New procedure function.
            (GetVarFieldInitialized): New procedure function.
            (PrintInitialized): New procedure.
            * gm2-compiler/SymbolTable.mod (VarCheckReadInit): New procedure.
            (VarInitState): New procedure.
            (PutVarInitialized): New procedure.
            (PutVarFieldInitialized): New procedure function.
            (GetVarFieldInitialized): New procedure function.
            (PrintInitialized): New procedure.
            (LRInitDesc): New type.
            (SymVar): InitState new field.
            (MakeVar): Initialize InitState.
            * gm2-gcc/m2options.h (M2Options_SetUninitVariableChecking):
            New function declaration.
            * gm2-lang.cc (gm2_langhook_handle_option): Detect
            OPT_Wuninit_variable_checking and call SetUninitVariableChecking.
            * lang.opt: Add Wuninit-variable-checking.
            * gm2-compiler/M2SymInit.def: New file.
            * gm2-compiler/M2SymInit.mod: New file.

    gcc/testsuite/ChangeLog:

            PR modula2/110125
            * gm2/switches/uninit-variable-checking/fail/testinit.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testlarge.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testlarge2.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testrecinit.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testrecinit2.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testrecinit5.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testsmallrec.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testsmallrec2.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testsmallvec.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testvarinit.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testwithnoptr.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testwithptr.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testwithptr2.mod: New
test.
            * gm2/switches/uninit-variable-checking/fail/testwithptr3.mod: New
test.
            * gm2/switches/uninit-variable-checking/pass/testrecinit3.mod: New
test.
            * gm2/switches/uninit-variable-checking/pass/testrecinit5.mod: New
test.
            * gm2/switches/uninit-variable-checking/pass/testsmallrec.mod: New
test.
            * gm2/switches/uninit-variable-checking/pass/testsmallrec2.mod: New
test.
            * gm2/switches/uninit-variable-checking/pass/testvarinit.mod: New
test.
            * gm2/switches/uninit-variable-checking/pass/testwithptr.mod: New
test.
            * gm2/switches/uninit-variable-checking/pass/testwithptr2.mod: New
test.
            * gm2/switches/uninit-variable-checking/pass/testwithptr3.mod: New
test.

    (cherry picked from commit b0762d4c7e7894845e70e839c8513ae4c9e9d42e)

    Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>