Closed
Description
https://godbolt.org/z/Yqr53rz4s
extern void copy(char *output, const char *input, unsigned size);
extern bool foo(const char *input);
extern void bar(char *output, unsigned count);
extern bool baz(char *output, const char *input);
void repo(const char *input, char *output) {
char temp[64];
copy(temp, input, sizeof(temp));
char result[64];
input = temp;
if (foo(temp)) {
bar(result, sizeof(result));
input = result;
}
if (!baz(output, input)) {
copy(output, input, sizeof(result));
}
}<source>:16:5: warning: Address of stack memory associated with local variable 'temp' is still referred to by the caller variable 'input' upon returning to the caller. This will be a dangling reference [clang-analyzer-core.StackAddressEscape]
7 | char temp[64];
| ~~~~~~~~~~~~~
8 | copy(temp, input, sizeof(temp));
9 |
10 | char result[64];
11 | input = temp;
12 | if (foo(temp)) {
13 | bar(result, sizeof(result));
14 | input = result;
15 | }
16 | if (!baz(output, input)) {
| ^
[<source>:12:9: note: Assuming the condition is false](javascript:;)
12 | if (foo(temp)) {
| ^~~~~~~~~
[<source>:12:5: note: Taking false branch](javascript:;)
12 | if (foo(temp)) {
| ^
[<source>:16:9: note: Assuming the condition is false](javascript:;)
16 | if (!baz(output, input)) {
| ^~~~~~~~~~~~~~~~~~~
[<source>:16:5: note: Taking false branch](javascript:;)
16 | if (!baz(output, input)) {
| ^
<source>:16:5: note: Address of stack memory associated with local variable 'temp' is still referred to by the caller variable 'input' upon returning to the caller. This will be a dangling reference
7 | char temp[64];
| ~~~~~~~~~~~~~
8 | copy(temp, input, sizeof(temp));
9 |
10 | char result[64];
11 | input = temp;
12 | if (foo(temp)) {
13 | bar(result, sizeof(result));
14 | input = result;
15 | }
16 | if (!baz(output, input)) {
| ^
1 warning generated.