0:35.60 /root/firefox-gcc-last/toolkit/components/ctypes/tests/jsctypes-test-finalizer.cpp: In function 'char* test_finalizer_acq_string_t(int)': 0:35.60 /root/firefox-gcc-last/toolkit/components/ctypes/tests/jsctypes-test-finalizer.cpp:231:1: error: '%d' directive output may be truncated writing between 1 and 11 bytes into a region of size 10 [-Werror=format-truncation=] 0:35.60 test_finalizer_acq_string_t(int i) 0:35.60 ^~~~~~~~~~~~~~~~~~~~~~~~~~~ 0:35.60 /root/firefox-gcc-last/toolkit/components/ctypes/tests/jsctypes-test-finalizer.cpp:231:1: note: using the range [1, -2147483648] for directive argument 0:35.60 /root/firefox-gcc-last/toolkit/components/ctypes/tests/jsctypes-test-finalizer.cpp:236:13: note: format output between 2 and 12 bytes into a destination of size 10 0:35.60 snprintf(buf, 10, "%d", i); 0:35.60 ~~~~~~~~^~~~~~~~~~~~~~~~~~ Because: $ echo -n "-2147483648"|wc -c 11

Comment on attachment 8831635 [details] Bug 1334979 - Fix a truncation leading to an error with gcc 7 https://reviewboard.mozilla.org/r/108184/#review110856 ::: toolkit/components/ctypes/tests/jsctypes-test-finalizer.cpp:236 (Diff revision 1) > test_finalizer_acq_string_t(int i) > { > gFinalizerTestResources[i] = 1; > if (!gFinalizerTestNames[i]) { > char* buf = new char[10]; > - snprintf(buf, 10, "%d", i); > + snprintf(buf, 11, "%d", i); 1. http://en.cppreference.com/w/c/io/fprintf says that if bufsz is the second argument, at most bufsz-1 elements are written. So to write INT32_MIN, you need 11 chars, thus bufsz should be 12. 2. The line right above needs to be changed too, to allocate 12 chars (including the leading zero character), right?

Comment on attachment 8831635 [details] Bug 1334979 - Fix a truncation leading to an error with gcc 7 https://reviewboard.mozilla.org/r/108184/#review111024 Stealing review, assuming it should have been redirected to me. Please update the reviewer in the commit message. Thanks for the patch!

Pushed by sledru@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/8be8dd1678a5 Fix a truncation leading to an error with gcc 7 r=bbouvier