https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81779
Bug ID: 81779 Summary: bool define from stdbool.h suppresses -Wdeclaration-after-statement Product: gcc Version: 8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: sirl at gcc dot gnu.org Target Milestone: --- This testcase warns only once with -Wdeclaration-after-statement since at least gcc-4.8: #include <stdbool.h> bool f2(char *pRedo) { if (!pRedo) return false; bool ret = true; return ret; } int f3(char *pRedo) { if (!pRedo) return 0; int ret = 1; return ret; } # gcc-7 -c -Wdeclaration-after-statement Wdeclaration-after-statement.c Wdeclaration-after-statement.c: In function 'f3': Wdeclaration-after-statement.c:18:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement] int ret = 1; ^~~ gcc-4.4 warned 2 for both occurences: # gcc-4.4 -c -Wdeclaration-after-statement Wdeclaration-after-statement.c Wdeclaration-after-statement.c: In function 'f2': Wdeclaration-after-statement.c:10: warning: ISO C90 forbids mixed declarations and code Wdeclaration-after-statement.c: In function 'f3': Wdeclaration-after-statement.c:17: warning: ISO C90 forbids mixed declarations and code Adding -Wsystem-headers shows 2 warnings also with newer GCC, but I don't think that this option should influence -Wdeclaration-after-statement.