CVS commit: src/usr.bin/xlint

["Roland Illig" <rillig%netbsd.org@localhost>]

Module Name:    src
Committed By:   rillig
Date:           Wed Sep 13 20:31:58 UTC 2023

Modified Files:
        src/usr.bin/xlint/common: lint.h
        src/usr.bin/xlint/lint1: ckctype.c debug.c emit1.c lint1.h op.h oper.c
            ops.def tree.c

Log Message:
lint: prevent invalid memory access when checking an expression

In check_expr_misc, the left and right operands of an expression were
accessed even in the case of CON (constant), STRING (string literal) and
NAME (identifier), which led to invalid values in pointer variables.
These invalid values were not used though, but technically they invoked
undefined behavior.

Precede each access to the operands with a check that the expression
indeed has operands, except in those cases where the operand is known to
have operands by only looking at the code of the current function.


To generate a diff of this commit:
cvs rdiff -u -r1.43 -r1.44 src/usr.bin/xlint/common/lint.h
cvs rdiff -u -r1.6 -r1.7 src/usr.bin/xlint/lint1/ckctype.c
cvs rdiff -u -r1.61 -r1.62 src/usr.bin/xlint/lint1/debug.c
cvs rdiff -u -r1.76 -r1.77 src/usr.bin/xlint/lint1/emit1.c
cvs rdiff -u -r1.200 -r1.201 src/usr.bin/xlint/lint1/lint1.h
cvs rdiff -u -r1.21 -r1.22 src/usr.bin/xlint/lint1/op.h
cvs rdiff -u -r1.11 -r1.12 src/usr.bin/xlint/lint1/oper.c
cvs rdiff -u -r1.30 -r1.31 src/usr.bin/xlint/lint1/ops.def
cvs rdiff -u -r1.580 -r1.581 src/usr.bin/xlint/lint1/tree.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.