gbranden pushed a commit to branch master
in repository groff.
commit 4c11e40e343c4a8a6e11b18e96197b082a888dd2
Author: G. Branden Robinson <[email protected]>
AuthorDate: Tue Jun 16 14:46:11 2026 -0500
[libgroff]: Further update `string` assertions.
* src/libs/libgroff/string.cpp: Manipulate assert(3)ions verifying the
invariant of `ptr`'s non-nullity to sit closer to assignments thereto.
This way the assertions can/should reliably fail prior to null pointer
dereference. Also check this invariant in more places.
(string::string, string::operator+=, string::remove_spaces): Relocate
assertions.
(string::append, string::set_length, put_string): Add assertions.
(string::clear): Uncomment assertion. Its comment was inaccurate.
---
ChangeLog | 14 ++++++++++++++
src/libs/libgroff/string.cpp | 38 ++++++++++++++++++++++++--------------
2 files changed, 38 insertions(+), 14 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index ce76b4d9b..6a08e0c6c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2026-06-16 G. Branden Robinson <[email protected]>
+
+ * src/libs/libgroff/string.cpp: Manipulate assert(3)ions
+ verifying the invariant of `ptr`'s non-nullity to sit closer to
+ assignments thereto. This way the assertions can/should
+ reliably fail prior to null pointer dereference. Also check
+ this invariant in more places.
+ (string::string, string::operator+=, string::remove_spaces):
+ Relocate assertions.
+ (string::append, string::set_length, put_string): Add
+ assertions.
+ (string::clear): Uncomment assertion. Its comment was
+ inaccurate.
+
2026-06-20 G. Branden Robinson <[email protected]>
* src/libs/libgroff/string.cpp: Document invariant.
diff --git a/src/libs/libgroff/string.cpp b/src/libs/libgroff/string.cpp
index dddcd6644..e391c9871 100644
--- a/src/libs/libgroff/string.cpp
+++ b/src/libs/libgroff/string.cpp
@@ -146,10 +146,10 @@ string::string() : len(0), sz(initial_string_buffer_size)
string::string(const char *p, size_t n) : len(n)
{
ptr = salloc(n, &sz);
+ assert(ptr != 0 /* nullptr */);
memset(ptr, 0, sz);
if (n != 0)
memcpy(ptr, p, n);
- assert(ptr != 0 /* nullptr */);
}
string::string(const char *p)
@@ -157,33 +157,34 @@ string::string(const char *p)
if (0 /* nullptr */ == p) {
len = 0;
ptr = salloc(initial_string_buffer_size, &sz);
+ assert(ptr != 0 /* nullptr */);
}
else {
len = strlen(p);
ptr = salloc(len, &sz);
+ assert(ptr != 0 /* nullptr */);
if (len < sz)
memset(ptr, 0, sz);
if (len != 0)
memcpy(ptr, p, len);
}
- assert(ptr != 0 /* nullptr */);
}
string::string(char c) : len(1)
{
ptr = salloc(1, &sz);
- *ptr = c;
assert(ptr != 0 /* nullptr */);
+ *ptr = c;
}
string::string(const string &s) : len(s.len)
{
ptr = salloc(len, &sz);
+ assert(ptr != 0 /* nullptr */);
if (sz > 0)
memset(ptr, 0, sz);
if (len != 0)
memcpy(ptr, s.ptr, len);
- assert(ptr != 0 /* nullptr */);
}
string::~string()
@@ -248,12 +249,13 @@ string &string::operator+=(const char *p)
if (p != 0 /* nullptr */) {
size_t n = strlen(p);
size_t newlen = len + n;
- if (newlen > sz)
+ if (newlen > sz) {
ptr = srealloc(ptr, sz, len, newlen, &sz);
+ assert(ptr != 0 /* nullptr */);
+ }
memcpy(ptr + len, p, n);
len = newlen;
}
- assert(ptr != 0 /* nullptr */);
return *this;
}
@@ -261,12 +263,13 @@ string &string::operator+=(const string &s)
{
if (s.len != 0) {
size_t newlen = len + s.len;
- if (newlen > sz)
+ if (newlen > sz) {
ptr = srealloc(ptr, sz, len, newlen, &sz);
+ assert(ptr != 0 /* nullptr */);
+ }
memcpy(ptr + len, s.ptr, s.len);
len = newlen;
}
- assert(ptr != 0 /* nullptr */);
return *this;
}
@@ -274,8 +277,10 @@ void string::append(const char *p, size_t n)
{
if (n > 0) {
size_t newlen = len + n;
- if (newlen > sz)
+ if (newlen > sz) {
ptr = srealloc(ptr, sz, len, newlen, &sz);
+ assert(ptr != 0 /* nullptr */);
+ }
memcpy(ptr + len, p, n);
len = newlen;
}
@@ -284,10 +289,13 @@ void string::append(const char *p, size_t n)
string::string(const char *s1, size_t n1, const char *s2, size_t n2)
{
len = n1 + n2;
- if (0 == len)
+ if (0 == len) {
ptr = salloc(initial_string_buffer_size, &sz);
+ assert(ptr != 0 /* nullptr */);
+ }
else {
ptr = salloc(len, &sz);
+ assert(ptr != 0 /* nullptr */);
if (0 == n1)
memcpy(ptr, s2, n2);
else {
@@ -296,7 +304,6 @@ string::string(const char *s1, size_t n1, const char *s2,
size_t n2)
memcpy(ptr + n1, s2, n2);
}
}
- assert(ptr != 0 /* nullptr */);
}
bool operator<=(const string &s1, const string &s2)
@@ -329,14 +336,16 @@ bool operator>(const string &s1, const string &s2)
void string::set_length(size_t i)
{
- if (i > sz)
+ if (i > sz) {
ptr = srealloc(ptr, sz, len, i, &sz);
+ assert(ptr != 0 /* nullptr */);
+ }
len = i;
}
void string::clear()
{
- //assert(ptr != 0 /* nullptr */); // XXX: TODO: held up by refer(1)
+ assert(ptr != 0 /* nullptr */);
if (ptr != 0 /* nullptr */)
memset(ptr, 0, sz);
len = 0;
@@ -484,14 +493,15 @@ void string::remove_spaces()
memcpy(tmp, p, len);
delete[] ptr;
ptr = tmp;
+ assert(ptr != 0 /* nullptr */);
}
- assert(ptr != 0 /* nullptr */);
}
void put_string(const string &s, FILE *fp)
{
size_t len = s.length();
const char *ptr = s.contents();
+ assert(ptr != 0 /* nullptr */);
for (size_t i = 0; i < len; i++)
putc(ptr[i], fp);
}
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