From 22475b5ae80b5c08115677b9abc5c62258716c08 Mon Sep 17 00:00:00 2001 From: Eliseo Martínez Date: Tue, 4 Nov 2014 15:41:48 +0100 Subject: Fix warnings: regexp.c: br_regcomp(): Np dereference: MI. Problem: Dereference of null pointer @ 1312. http://neovim.org/doc/reports/clang/report-b1d09a.html#EndPath Diagnostic: Multithreading issue. Rationale : Suggested error path contains two succesive calls to `regnext(scan)`, first of which returning nonnull, the second one returning null. This can only occur if global `reg_toolong` accesed in `regnext()` changes between the calls. Resolution: Use local variable to cache first `regnext(scan)` result. Note that this change alters function semantics, as now function only issues one call instead of two, reusing the result for the second time. This shouldn't be a problem, though, as new semantics should be in fact be better. --- src/nvim/regexp.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/src/nvim/regexp.c b/src/nvim/regexp.c index 4e5ae403d6..93fc5c62ef 100644 --- a/src/nvim/regexp.c +++ b/src/nvim/regexp.c @@ -1297,16 +1297,18 @@ static regprog_T *bt_regcomp(char_u *expr, int re_flags) r->regstart = (*mb_ptr2char)(OPERAND(scan)); else r->regstart = *OPERAND(scan); - } else if ((OP(scan) == BOW - || OP(scan) == EOW - || OP(scan) == NOTHING - || OP(scan) == MOPEN + 0 || OP(scan) == NOPEN - || OP(scan) == MCLOSE + 0 || OP(scan) == NCLOSE) - && OP(regnext(scan)) == EXACTLY) { - if (has_mbyte) - r->regstart = (*mb_ptr2char)(OPERAND(regnext(scan))); - else - r->regstart = *OPERAND(regnext(scan)); + } else if (OP(scan) == BOW + || OP(scan) == EOW + || OP(scan) == NOTHING + || OP(scan) == MOPEN + 0 || OP(scan) == NOPEN + || OP(scan) == MCLOSE + 0 || OP(scan) == NCLOSE) { + char_u *regnext_scan = regnext(scan); + if (OP(regnext_scan) == EXACTLY) { + if (has_mbyte) + r->regstart = (*mb_ptr2char)(OPERAND(regnext_scan)); + else + r->regstart = *OPERAND(regnext_scan); + } } /* -- cgit