diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 27c81682364e..7945eac39fb5 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2013-12-09 Joseph Myers + + PR preprocessor/55715 + * gcc.dg/cpp/expr-overflow-1.c: New test. + 2013-12-10 Tobias Burnus PR fortran/59428 diff --git a/gcc/testsuite/gcc.dg/cpp/expr-overflow-1.c b/gcc/testsuite/gcc.dg/cpp/expr-overflow-1.c new file mode 100644 index 000000000000..8a67aaa6d466 --- /dev/null +++ b/gcc/testsuite/gcc.dg/cpp/expr-overflow-1.c @@ -0,0 +1,44 @@ +/* Test overflow in preprocessor arithmetic. PR 55715. */ +/* { dg-do preprocess } */ +/* { dg-options "-std=c99" } */ + +#include + +#if -1 - INTMAX_MIN +#endif + +#if 0 - INTMAX_MIN /* { dg-warning "overflow" } */ +#endif + +#if 1 * INTMAX_MIN +#endif + +#if -1 * INTMAX_MIN /* { dg-warning "overflow" } */ +#endif + +#if 0 * INTMAX_MIN +#endif + +#if -INTMAX_MIN /* { dg-warning "overflow" } */ +#endif + +#if +INTMAX_MIN +#endif + +#if INTMAX_MIN / 1 +#endif + +#if INTMAX_MIN / -1 /* { dg-warning "overflow" } */ +#endif + +#if UINTMAX_MAX * UINTMAX_MAX +#endif + +#if UINTMAX_MAX / -1 +#endif + +#if UINTMAX_MAX + INTMAX_MAX +#endif + +#if UINTMAX_MAX - INTMAX_MIN +#endif diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog index c3391b4959d6..4a06d0c3a632 100644 --- a/libcpp/ChangeLog +++ b/libcpp/ChangeLog @@ -1,3 +1,9 @@ +2013-12-09 Joseph Myers + + PR preprocessor/55715 + * expr.c (num_binary_op): Implement subtraction directly rather + than with negation and falling through into addition case. + 2013-11-18 Bill Schmidt * lex.c (search_line_fast): Correct for little endian. diff --git a/libcpp/expr.c b/libcpp/expr.c index c0098073ab89..1e17b005deea 100644 --- a/libcpp/expr.c +++ b/libcpp/expr.c @@ -1836,7 +1836,22 @@ num_binary_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op) /* Arithmetic. */ case CPP_MINUS: - rhs = num_negate (rhs, precision); + result.low = lhs.low - rhs.low; + result.high = lhs.high - rhs.high; + if (result.low > lhs.low) + result.high--; + result.unsignedp = lhs.unsignedp || rhs.unsignedp; + result.overflow = false; + + result = num_trim (result, precision); + if (!result.unsignedp) + { + bool lhsp = num_positive (lhs, precision); + result.overflow = (lhsp != num_positive (rhs, precision) + && lhsp != num_positive (result, precision)); + } + return result; + case CPP_PLUS: result.low = lhs.low + rhs.low; result.high = lhs.high + rhs.high;