Re-enable several builtins in non-gnu modes.

This is a partial revert of 183015.
By not recognizing things like _setjmp we lose (returns_twice) attribute on
them, which leads to incorrect code generation.
Fixes PR16138.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@206362 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/Builtins.def b/include/clang/Basic/Builtins.def
index 968c98b84d0512a798b5d666cd22cdb254b7260a..3a1c58f431707dbddf7469aa16c67fb3978bbc2f 100644 (file)
--- a/include/clang/Basic/Builtins.def
+++ b/include/clang/Basic/Builtins.def
@@ -740,6 +740,9 @@ LIBBUILTIN(setjmp, "iJ",          "fj",    "setjmp.h", ALL_LANGUAGES)
 LIBBUILTIN(longjmp, "vJi",        "fr",    "setjmp.h", ALL_LANGUAGES)
 
 // Non-C library functions, active in GNU mode only.
+// Functions with (returns_twice) attribute (marked as "j") are still active in
+// all languages, because losing this attribute would result in miscompilation
+// when these functions are used in non-GNU mode. PR16138.
 LIBBUILTIN(alloca, "v*z",         "f",     "stdlib.h", ALL_GNU_LANGUAGES)
 // POSIX string.h
 LIBBUILTIN(stpcpy, "c*c*cC*",     "f",     "string.h", ALL_GNU_LANGUAGES)
@@ -758,16 +761,16 @@ LIBBUILTIN(strcasecmp, "icC*cC*", "f",     "strings.h", ALL_GNU_LANGUAGES)
 LIBBUILTIN(strncasecmp, "icC*cC*z", "f",   "strings.h", ALL_GNU_LANGUAGES)
 // POSIX unistd.h
 LIBBUILTIN(_exit, "vi",           "fr",    "unistd.h", ALL_GNU_LANGUAGES)
-LIBBUILTIN(vfork, "p",            "fj",    "unistd.h", ALL_GNU_LANGUAGES)
+LIBBUILTIN(vfork, "p",            "fj",    "unistd.h", ALL_LANGUAGES)
 // POSIX setjmp.h
 
-LIBBUILTIN(_setjmp, "iJ",         "fj",   "setjmp.h", ALL_GNU_LANGUAGES)
-LIBBUILTIN(__sigsetjmp, "iSJi",   "fj",   "setjmp.h", ALL_GNU_LANGUAGES)
-LIBBUILTIN(sigsetjmp, "iSJi",     "fj",   "setjmp.h", ALL_GNU_LANGUAGES)
-LIBBUILTIN(setjmp_syscall, "iJ",  "fj",   "setjmp.h", ALL_GNU_LANGUAGES)
-LIBBUILTIN(savectx, "iJ",         "fj",   "setjmp.h", ALL_GNU_LANGUAGES)
-LIBBUILTIN(qsetjmp, "iJ",         "fj",   "setjmp.h", ALL_GNU_LANGUAGES)
-LIBBUILTIN(getcontext, "iK*",     "fj",   "setjmp.h", ALL_GNU_LANGUAGES)
+LIBBUILTIN(_setjmp, "iJ",         "fj",   "setjmp.h", ALL_LANGUAGES)
+LIBBUILTIN(__sigsetjmp, "iSJi",   "fj",   "setjmp.h", ALL_LANGUAGES)
+LIBBUILTIN(sigsetjmp, "iSJi",     "fj",   "setjmp.h", ALL_LANGUAGES)
+LIBBUILTIN(setjmp_syscall, "iJ",  "fj",   "setjmp.h", ALL_LANGUAGES)
+LIBBUILTIN(savectx, "iJ",         "fj",   "setjmp.h", ALL_LANGUAGES)
+LIBBUILTIN(qsetjmp, "iJ",         "fj",   "setjmp.h", ALL_LANGUAGES)
+LIBBUILTIN(getcontext, "iK*",     "fj",   "setjmp.h", ALL_LANGUAGES)
 
 LIBBUILTIN(_longjmp, "vJi",       "fr",    "setjmp.h", ALL_GNU_LANGUAGES)
 LIBBUILTIN(siglongjmp, "vSJi",    "fr",    "setjmp.h", ALL_GNU_LANGUAGES)

diff --git a/test/CodeGen/function-attributes.c b/test/CodeGen/function-attributes.c
index 47a0568355719d09d6f53fdd7736d658b46b5748..177ad848f74389a95f40d36da6ea02c5969bc401 100644 (file)
--- a/test/CodeGen/function-attributes.c
+++ b/test/CodeGen/function-attributes.c
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -triple i386-unknown-unknown -emit-llvm -Os -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple i386-unknown-unknown -emit-llvm -Os -std=c99 -o - %s | FileCheck %s
 // CHECK: define signext i8 @f0(i32 %x) [[NUW:#[0-9]+]]
 // CHECK: define zeroext i8 @f1(i32 %x) [[NUW]]
 // CHECK: define void @f2(i8 signext %x) [[NUW]]
@@ -117,6 +118,16 @@ void f19(void) {
   setjmp(0);
 }
 
+// CHECK-LABEL: define void @f20()
+// CHECK: {
+// CHECK: call i32 @_setjmp(i32* null)
+// CHECK: [[RT_CALL]]
+// CHECK: ret void
+int _setjmp(jmp_buf);
+void f20(void) {
+  _setjmp(0);
+}
+
 // CHECK: attributes [[NUW]] = { nounwind optsize readnone{{.*}} }
 // CHECK: attributes [[AI]] = { alwaysinline nounwind optsize readnone{{.*}} }
 // CHECK: attributes [[ALIGN]] = { nounwind optsize readnone alignstack=16{{.*}} }

diff --git a/test/Sema/builtins-gnu-mode.c b/test/Sema/builtins-gnu-mode.c
index 718803eabe2a9c6870ad9ea38a90e7a060501efe..d93b6fdef027b682f665cf1bf12b194704b383c0 100644 (file)
--- a/test/Sema/builtins-gnu-mode.c
+++ b/test/Sema/builtins-gnu-mode.c
@@ -13,14 +13,6 @@ int bzero;
 int strcasecmp;
 int strncasecmp;
 int _exit;
-int vfork;
-int _setjmp;
-int __sigsetjmp;
-int sigsetjmp;
-int setjmp_syscall;
-int savectx;
-int qsetjmp;
-int getcontext;
 int _longjmp;
 int siglongjmp;
 int strlcpy;