about summary refs log tree commit diff
path: root/third_party/nix/src/libmain/stack.cc
diff options
context:
space:
mode:
Diffstat (limited to 'third_party/nix/src/libmain/stack.cc')
-rw-r--r--third_party/nix/src/libmain/stack.cc99
1 files changed, 46 insertions, 53 deletions
diff --git a/third_party/nix/src/libmain/stack.cc b/third_party/nix/src/libmain/stack.cc
index e6224de7d28f..621542d2198a 100644
--- a/third_party/nix/src/libmain/stack.cc
+++ b/third_party/nix/src/libmain/stack.cc
@@ -1,71 +1,64 @@
-#include "types.hh"
-
-#include <cstring>
+#include <signal.h>
+#include <unistd.h>
 #include <cstddef>
 #include <cstdlib>
-
-#include <unistd.h>
-#include <signal.h>
+#include <cstring>
+#include "types.hh"
 
 namespace nix {
 
-
-static void sigsegvHandler(int signo, siginfo_t * info, void * ctx)
-{
-    /* Detect stack overflows by comparing the faulting address with
-       the stack pointer.  Unfortunately, getting the stack pointer is
-       not portable. */
-    bool haveSP = true;
-    char * sp = 0;
+static void sigsegvHandler(int signo, siginfo_t* info, void* ctx) {
+  /* Detect stack overflows by comparing the faulting address with
+     the stack pointer.  Unfortunately, getting the stack pointer is
+     not portable. */
+  bool haveSP = true;
+  char* sp = 0;
 #if defined(__x86_64__) && defined(REG_RSP)
-    sp = (char *) ((ucontext_t *) ctx)->uc_mcontext.gregs[REG_RSP];
+  sp = (char*)((ucontext_t*)ctx)->uc_mcontext.gregs[REG_RSP];
 #elif defined(REG_ESP)
-    sp = (char *) ((ucontext_t *) ctx)->uc_mcontext.gregs[REG_ESP];
+  sp = (char*)((ucontext_t*)ctx)->uc_mcontext.gregs[REG_ESP];
 #else
-    haveSP = false;
+  haveSP = false;
 #endif
 
-    if (haveSP) {
-        ptrdiff_t diff = (char *) info->si_addr - sp;
-        if (diff < 0) diff = -diff;
-        if (diff < 4096) {
-            char msg[] = "error: stack overflow (possible infinite recursion)\n";
-            [[gnu::unused]] auto res = write(2, msg, strlen(msg));
-            _exit(1); // maybe abort instead?
-        }
+  if (haveSP) {
+    ptrdiff_t diff = (char*)info->si_addr - sp;
+    if (diff < 0) diff = -diff;
+    if (diff < 4096) {
+      char msg[] = "error: stack overflow (possible infinite recursion)\n";
+      [[gnu::unused]] auto res = write(2, msg, strlen(msg));
+      _exit(1);  // maybe abort instead?
     }
+  }
 
-    /* Restore default behaviour (i.e. segfault and dump core). */
-    struct sigaction act;
-    sigfillset(&act.sa_mask);
-    act.sa_handler = SIG_DFL;
-    act.sa_flags = 0;
-    if (sigaction(SIGSEGV, &act, 0)) abort();
+  /* Restore default behaviour (i.e. segfault and dump core). */
+  struct sigaction act;
+  sigfillset(&act.sa_mask);
+  act.sa_handler = SIG_DFL;
+  act.sa_flags = 0;
+  if (sigaction(SIGSEGV, &act, 0)) abort();
 }
 
+void detectStackOverflow() {
+#if defined(SA_SIGINFO) && defined(SA_ONSTACK)
+  /* Install a SIGSEGV handler to detect stack overflows.  This
+     requires an alternative stack, otherwise the signal cannot be
+     delivered when we're out of stack space. */
+  stack_t stack;
+  stack.ss_size = 4096 * 4 + MINSIGSTKSZ;
+  static auto stackBuf = std::make_unique<std::vector<char>>(stack.ss_size);
+  stack.ss_sp = stackBuf->data();
+  if (!stack.ss_sp) throw Error("cannot allocate alternative stack");
+  stack.ss_flags = 0;
+  if (sigaltstack(&stack, 0) == -1)
+    throw SysError("cannot set alternative stack");
 
-void detectStackOverflow()
-{
-#if defined(SA_SIGINFO) && defined (SA_ONSTACK)
-    /* Install a SIGSEGV handler to detect stack overflows.  This
-       requires an alternative stack, otherwise the signal cannot be
-       delivered when we're out of stack space. */
-    stack_t stack;
-    stack.ss_size = 4096 * 4 + MINSIGSTKSZ;
-    static auto stackBuf = std::make_unique<std::vector<char>>(stack.ss_size);
-    stack.ss_sp = stackBuf->data();
-    if (!stack.ss_sp) throw Error("cannot allocate alternative stack");
-    stack.ss_flags = 0;
-    if (sigaltstack(&stack, 0) == -1) throw SysError("cannot set alternative stack");
-
-    struct sigaction act;
-    sigfillset(&act.sa_mask);
-    act.sa_sigaction = sigsegvHandler;
-    act.sa_flags = SA_SIGINFO | SA_ONSTACK;
-    if (sigaction(SIGSEGV, &act, 0))
-        throw SysError("resetting SIGSEGV");
+  struct sigaction act;
+  sigfillset(&act.sa_mask);
+  act.sa_sigaction = sigsegvHandler;
+  act.sa_flags = SA_SIGINFO | SA_ONSTACK;
+  if (sigaction(SIGSEGV, &act, 0)) throw SysError("resetting SIGSEGV");
 #endif
 }
 
-
-}
+}  // namespace nix