This patch fixes a bunch of ICEs related to C++14 constexprs and -fsanitize=undefined. We should ignore ubsan internal functions and ubsan builtins in constexpr functions in cxx_eval_call_expression.
Also add proper printing of internal functions into the C++ printer. Bootstrapped/regtested on ppc64-linux, ok for trunk? 2014-11-20 Marek Polacek <pola...@redhat.com> PR sanitizer/63956 * constexpr.c: Include ubsan.h. (cxx_eval_call_expression): Bail out for IFN_UBSAN_{NULL,BOUNDS} internal functions and for ubsan builtins in constexpr functions. * error.c: Include internal-fn.h. (dump_expr): Add printing of internal functions. * g++.dg/ubsan/pr63956.C: New test. diff --git gcc/cp/constexpr.c gcc/cp/constexpr.c index 2678223..684e36f 100644 --- gcc/cp/constexpr.c +++ gcc/cp/constexpr.c @@ -32,6 +32,7 @@ along with GCC; see the file COPYING3. If not see #include "gimplify.h" #include "builtins.h" #include "tree-inline.h" +#include "ubsan.h" static bool verify_constant (tree, bool, bool *, bool *); #define VERIFY_CONSTANT(X) \ @@ -1151,6 +1152,16 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, constexpr_call *entry; bool depth_ok; + if (fun == NULL_TREE) + switch (CALL_EXPR_IFN (t)) + { + case IFN_UBSAN_NULL: + case IFN_UBSAN_BOUNDS: + return void_node; + default: + break; + } + if (TREE_CODE (fun) != FUNCTION_DECL) { /* Might be a constexpr function pointer. */ @@ -1171,6 +1182,10 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, } if (DECL_CLONED_FUNCTION_P (fun)) fun = DECL_CLONED_FUNCTION (fun); + + if (!current_function_decl && is_ubsan_builtin_p (fun)) + return void_node; + if (is_builtin_fn (fun)) return cxx_eval_builtin_function_call (ctx, t, addr, non_constant_p, overflow_p); diff --git gcc/cp/error.c gcc/cp/error.c index 76f86cb..09789ad 100644 --- gcc/cp/error.c +++ gcc/cp/error.c @@ -33,6 +33,7 @@ along with GCC; see the file COPYING3. If not see #include "tree-pretty-print.h" #include "c-family/c-objc.h" #include "ubsan.h" +#include "internal-fn.h" #include <new> // For placement-new. @@ -2037,6 +2038,14 @@ dump_expr (cxx_pretty_printer *pp, tree t, int flags) tree fn = CALL_EXPR_FN (t); bool skipfirst = false; + /* Deal with internal functions. */ + if (fn == NULL_TREE) + { + pp_string (pp, internal_fn_name (CALL_EXPR_IFN (t))); + dump_call_expr_args (pp, t, flags, skipfirst); + break; + } + if (TREE_CODE (fn) == ADDR_EXPR) fn = TREE_OPERAND (fn, 0); diff --git gcc/testsuite/g++.dg/ubsan/pr63956.C gcc/testsuite/g++.dg/ubsan/pr63956.C index e69de29..7bc0b77 100644 --- gcc/testsuite/g++.dg/ubsan/pr63956.C +++ gcc/testsuite/g++.dg/ubsan/pr63956.C @@ -0,0 +1,172 @@ +// PR sanitizer/63956 +// { dg-do compile } +// { dg-options "-std=c++14 -fsanitize=undefined,float-divide-by-zero,float-cast-overflow" } + +#define SA(X) static_assert((X),#X) +#define INT_MIN (-__INT_MAX__ - 1) + +constexpr int +fn1 (int a, int b) +{ + if (b != 2) + a <<= b; + return a; +} + +constexpr int i1 = fn1 (5, 3); +constexpr int i2 = fn1 (5, -2); +constexpr int i3 = fn1 (5, sizeof (int) * __CHAR_BIT__); +constexpr int i4 = fn1 (5, 256); +constexpr int i5 = fn1 (5, 2); +constexpr int i6 = fn1 (-2, 4); +constexpr int i7 = fn1 (0, 2); + +SA (i1 == 40); +SA (i5 == 5); +SA (i7 == 0); + +constexpr int +fn2 (int a, int b) +{ + if (b != 2) + a >>= b; + return a; +} + +constexpr int j1 = fn2 (4, 1); +constexpr int j2 = fn2 (4, -1); +constexpr int j3 = fn2 (10, sizeof (int) * __CHAR_BIT__); +constexpr int j4 = fn2 (1, 256); +constexpr int j5 = fn2 (5, 2); +constexpr int j6 = fn2 (-2, 4); +constexpr int j7 = fn2 (0, 4); + +SA (j1 == 2); +SA (j5 == 5); +SA (j7 == 0); + +constexpr int +fn3 (int a, int b) +{ + if (b != 2) + a = a / b; + return a; +} + +constexpr int k1 = fn3 (8, 4); +constexpr int k2 = fn3 (7, 0); // { dg-error "is not a constant expression|constexpr call flows off" } +constexpr int k3 = fn3 (INT_MIN, -1); // { dg-error "overflow in constant expression|constexpr call flows off" } + +SA (k1 == 2); + +constexpr float +fn4 (float a, float b) +{ + if (b != 2.0) + a = a / b; + return a; +} + +constexpr float l1 = fn4 (5.0, 3.0); +constexpr float l2 = fn4 (7.0, 0.0); // { dg-error "is not a constant expression|constexpr call flows off" } + +constexpr int +fn5 (const int *a, int b) +{ + if (b != 2) + b = a[b]; + return b; +} + +constexpr int m1[4] = { 1, 2, 3, 4 }; +constexpr int m2 = fn5 (m1, 3); +constexpr int m3 = fn5 (m1, 4); // { dg-error "array subscript out of bound|constexpr call flows off" } + +constexpr int +fn6 (const int &a, int b) +{ + if (b != 2) + b = a; + return b; +} + +constexpr int +fn7 (const int *a, int b) +{ + if (b != 3) + return fn6 (*a, b); + return 7; +} + +constexpr int n1 = 7; +constexpr int n2 = fn7 (&n1, 5); +constexpr int n3 = fn7 ((const int *) 0, 8); // { dg-error "is not a constant expression|constexpr call flows off" } + +constexpr int +fn8 (int i) +{ + constexpr int g[10] = { }; + return g[i]; +} + +constexpr int o1 = fn8 (9); +constexpr int o2 = fn8 (10); // { dg-error "array subscript out of bound" } + +constexpr int +fn9 (int a, int b) +{ + if (b != 0) + return a + b; + return a; +} + +constexpr int p1 = fn9 (42, 7); +constexpr int p2 = fn9 (__INT_MAX__, 1); // { dg-error "overflow in constant expression" } +constexpr int p3 = fn9 (__INT_MAX__, -1); +constexpr int p4 = fn9 (INT_MIN, 1); +constexpr int p5 = fn9 (INT_MIN, -1); // { dg-error "overflow in constant expression" } + +SA (p1 == 49); +SA (p3 == __INT_MAX__ - 1); +SA (p4 == INT_MIN + 1); + +constexpr int +fn10 (int a, int b) +{ + if (b != 0) + return a * b; + return a; +} + +constexpr int q1 = fn10 (10, 10); +constexpr int q2 = fn10 (__INT_MAX__, 2); // { dg-error "overflow in constant expression" } +constexpr int q3 = fn10 (INT_MIN, 2); // { dg-error "overflow in constant expression" } +constexpr int q4 = fn10 (-1, -1); + +SA (q1 == 100); +SA (q4 == 1); + +constexpr int +fn11 (double d) +{ + int i = d; + if (i != 0) + return i; + return i * 2; +} + +constexpr int r1 = fn11 (3.4); +constexpr int r2 = fn11 (__builtin_inf ()); // { dg-error "overflow in constant expression|constexpr call flows off" } + +constexpr int +fn12 (int i) +{ + if (i == 42) + __builtin_unreachable (); // { dg-error "is not a constant expression" } + return i + 10; +} + +constexpr int s1 = fn12 (1); +constexpr int s2 = fn12 (42); // { dg-error "constexpr call flows off the end of the function" } + +SA (s1 == 11); Marek