x86: Work around clang bugs

http://llvm.org/bugs/show_bug.cgi?21500
http://llvm.org/bugs/show_bug.cgi?21501
http://llvm.org/bugs/show_bug.cgi?21515

diff --git a/src/x86/sysv.S b/src/x86/sysv.S
index e6a8c1e..72cba6c 100644 (file)
--- a/src/x86/sysv.S
+++ b/src/x86/sysv.S
@@ -59,7 +59,12 @@
 /* This macro allows the safe creation of jump tables without an
    actual table.  The entry points into the table are all 8 bytes.
    The use of ORG asserts that we're at the correct location.  */
-#define E(X)      .align 8; .org 0b + X * 8
+/* ??? The clang assembler doesn't handle .org with symbolic expressions.  */
+#ifdef __clang__
+# define E(X)  .align 8
+#else
+# define E(X)  .align 8; .org 0b + X * 8
+#endif
 
        .text
        .align  16
@@ -194,70 +199,75 @@ ENDF(ffi_call_i386)
 
 #define closure_FS     (16 + 3*4 + 3*4 + 4)
 
-.macro FFI_CLOSURE_SAVE_REGS
-       movl    %eax, 16+R_EAX*4(%esp)
-       movl    %edx, 16+R_EDX*4(%esp)
+#define FFI_CLOSURE_SAVE_REGS          \
+       movl    %eax, 16+R_EAX*4(%esp); \
+       movl    %edx, 16+R_EDX*4(%esp); \
        movl    %ecx, 16+R_ECX*4(%esp)
-.endm
-
-.macro FFI_CLOSURE_COPY_TRAMP_DATA chain
-       movl    FFI_TRAMPOLINE_SIZE(%eax), %edx         /* copy cif */
-       movl    FFI_TRAMPOLINE_SIZE+4(%eax), %ecx       /* copy fun */
-       movl    FFI_TRAMPOLINE_SIZE+8(%eax), %eax       /* copy user_data */
-       movl    %edx, 28(%esp)
-       movl    %ecx, 32(%esp)
+
+#define FFI_CLOSURE_COPY_TRAMP_DATA                                    \
+       movl    FFI_TRAMPOLINE_SIZE(%eax), %edx;        /* copy cif */  \
+       movl    FFI_TRAMPOLINE_SIZE+4(%eax), %ecx;      /* copy fun */  \
+       movl    FFI_TRAMPOLINE_SIZE+8(%eax), %eax;      /* copy user_data */ \
+       movl    %edx, 28(%esp);                                         \
+       movl    %ecx, 32(%esp);                                         \
        movl    %eax, 36(%esp)
-.endm
 
-.macro FFI_CLOSURE_CALL_INNER
-       movl    %esp, %ecx                      /* load closure_data */
-       leal    closure_FS+4(%esp), %edx        /* load incoming stack */
-#ifdef __PIC__
-       movl    %ebx, 40(%esp)                  /* save ebx */
-       cfi_rel_offset(%ebx, 40)
-       call    __x86.get_pc_thunk.bx           /* load got register */
-       addl    $C(_GLOBAL_OFFSET_TABLE_), %ebx
-#endif
-#if defined HAVE_HIDDEN_VISIBILITY_ATTRIBUTE || !defined __PIC__
-       call    ffi_closure_inner
-#else
-       call    ffi_closure_inner@PLT
-#endif
-.endm
 
-.macro FFI_CLOSURE_MASK_AND_JUMP
-       andl    $X86_RET_TYPE_MASK, %eax
 #ifdef __PIC__
-       leal    0f@GOTOFF(%ebx, %eax, 8), %eax
-       movl    40(%esp), %ebx                  /* restore ebx */
-       cfi_restore(%ebx)
+/* We're going to always load the got register here, even if .hidden says
+   we're going to avoid the PLT call.  We'll use the got register in
+   FFI_CLOSURE_MASK_AND_JUMP.  */
+# if defined HAVE_HIDDEN_VISIBILITY_ATTRIBUTE
+#  define PLT(X) X
+# else
+#  define PLT(X) X@PLT
+# endif
+# define FFI_CLOSURE_CALL_INNER                                                \
+       movl    %esp, %ecx;                     /* load closure_data */ \
+       leal    closure_FS+4(%esp), %edx;       /* load incoming stack */ \
+       movl    %ebx, 40(%esp);                 /* save ebx */          \
+       cfi_rel_offset(%ebx, 40);                                       \
+       call    __x86.get_pc_thunk.bx;          /* load got register */ \
+       addl    $C(_GLOBAL_OFFSET_TABLE_), %ebx;                        \
+       call    PLT(ffi_closure_inner)
+#define FFI_CLOSURE_MASK_AND_JUMP                                      \
+       andl    $X86_RET_TYPE_MASK, %eax;                               \
+       leal    0f@GOTOFF(%ebx, %eax, 8), %eax;                         \
+       movl    40(%esp), %ebx;                 /* restore ebx */       \
+       cfi_restore(%ebx);                                              \
+       jmp     *%eax
 #else
-       leal    0f(, %eax, 8), %eax
-#endif
+# define FFI_CLOSURE_CALL_INNER                                                \
+       movl    %esp, %ecx;                     /* load closure_data */ \
+       leal    closure_FS+4(%esp), %edx;       /* load incoming stack */ \
+       call    ffi_closure_inner
+#define FFI_CLOSURE_MASK_AND_JUMP                                      \
+       andl    $X86_RET_TYPE_MASK, %eax;                               \
+       leal    0f(, %eax, 8), %eax;                                    \
        jmp     *%eax
-.endm
-
-.macro FFI_GO_CLOSURE suffix, chain, t1, t2
-       .align  16
-       .globl  C(ffi_go_closure_\suffix)
-       FFI_HIDDEN(C(ffi_go_closure_\suffix))
-C(ffi_go_closure_\suffix):
-       cfi_startproc
-       subl    $closure_FS, %esp
-       cfi_adjust_cfa_offset(closure_FS)
-       FFI_CLOSURE_SAVE_REGS
-       movl    4(\chain), \t1          /* copy cif */
-       movl    8(\chain), \t2          /* copy fun */
-       movl    \t1, 28(%esp)
-       movl    \t2, 32(%esp)
-       movl    \chain, 36(%esp)        /* closure is user_data */
-       jmp     88f
-       cfi_endproc
-ENDF(C(ffi_go_closure_\suffix))
-.endm
+#endif /* __PIC__ */
 
-FFI_GO_CLOSURE EAX, %eax, %edx, %ecx
-FFI_GO_CLOSURE ECX, %ecx, %edx, %eax
+#define FFI_GO_CLOSURE(suffix, chain, t1, t2)                          \
+       .align  16;                                                     \
+       .globl  C(C1(ffi_go_closure_,suffix));                          \
+       FFI_HIDDEN(C(C1(ffi_go_closure_,suffix)));                      \
+C(C1(ffi_go_closure_,suffix)):                                         \
+       cfi_startproc;                                                  \
+       subl    $closure_FS, %esp;                                      \
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */ \
+       cfi_def_cfa_offset(closure_FS + 4);                             \
+       FFI_CLOSURE_SAVE_REGS;                                          \
+       movl    4(chain), t1;           /* copy cif */                  \
+       movl    8(chain), t2;           /* copy fun */                  \
+       movl    t1, 28(%esp);                                           \
+       movl    t2, 32(%esp);                                           \
+       movl    chain, 36(%esp);        /* closure is user_data */      \
+       jmp     88f;                                                    \
+       cfi_endproc;                                                    \
+ENDF(C(C1(ffi_go_closure_,suffix)))
+
+FFI_GO_CLOSURE(EAX, %eax, %edx, %ecx)
+FFI_GO_CLOSURE(ECX, %ecx, %edx, %eax)
 
 /* The closure entry points are reached from the ffi_closure trampoline.
    On entry, %eax contains the address of the ffi_closure.  */
@@ -269,7 +279,8 @@ FFI_GO_CLOSURE ECX, %ecx, %edx, %eax
 C(ffi_closure_i386):
        cfi_startproc
        subl    $closure_FS, %esp
-       cfi_adjust_cfa_offset(closure_FS)
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */
+       cfi_def_cfa_offset(closure_FS + 4)
 
        FFI_CLOSURE_SAVE_REGS
        FFI_CLOSURE_COPY_TRAMP_DATA
@@ -337,7 +348,7 @@ E(X86_RET_UNUSED15)
        cfi_endproc
 ENDF(C(ffi_closure_i386))
 
-FFI_GO_CLOSURE STDCALL, %ecx, %edx, %eax
+FFI_GO_CLOSURE(STDCALL, %ecx, %edx, %eax)
 
 /* For REGISTER, we have no available parameter registers, and so we
    enter here having pushed the closure onto the stack.  */
@@ -350,7 +361,8 @@ C(ffi_closure_REGISTER):
        cfi_def_cfa(%esp, 8)
        cfi_offset(%eip, -8)
        subl    $closure_FS-4, %esp
-       cfi_adjust_cfa_offset(closure_FS-4)
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */
+       cfi_def_cfa_offset(closure_FS + 4)
 
        FFI_CLOSURE_SAVE_REGS
 
@@ -372,7 +384,8 @@ ENDF(C(ffi_closure_REGISTER))
 C(ffi_closure_STDCALL):
        cfi_startproc
        subl    $closure_FS, %esp
-       cfi_adjust_cfa_offset(closure_FS)
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */
+       cfi_def_cfa_offset(closure_FS + 4)
 
        FFI_CLOSURE_SAVE_REGS
 
@@ -480,7 +493,8 @@ ENDF(C(ffi_closure_STDCALL))
 C(ffi_closure_raw_SYSV):
        cfi_startproc
        subl    $raw_closure_S_FS, %esp
-       cfi_adjust_cfa_offset(raw_closure_S_FS)
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */
+       cfi_def_cfa_offset(raw_closure_S_FS + 4)
        movl    %ebx, raw_closure_S_FS-4(%esp)
        cfi_rel_offset(%ebx, raw_closure_S_FS-4)
 
@@ -575,7 +589,8 @@ C(ffi_closure_raw_THISCALL):
        /* Rearrange the stack such that %ecx is the first argument.
           This means moving the return address.  */
        popl    %edx
-       cfi_adjust_cfa_offset(-4)
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */
+       cfi_def_cfa_offset(0)
        cfi_register(%eip, %edx)
        pushl   %ecx
        cfi_adjust_cfa_offset(4)

diff --git a/src/x86/unix64.S b/src/x86/unix64.S
index 6066bbf..58cb153 100644 (file)
--- a/src/x86/unix64.S
+++ b/src/x86/unix64.S
@@ -35,9 +35,15 @@
 
        .text
 
+/* This macro allows the safe creation of jump tables without an
+   actual table.  The entry points into the table are all 8 bytes.
+   The use of ORG asserts that we're at the correct location.  */
+/* ??? The clang assembler doesn't handle .org with symbolic expressions.  */
 .macro E index
        .align  8
+#ifndef __clang__
        .org    0b + \index * 8, 0x90
+#endif
 .endm
 
 /* ffi_call_unix64 (void *args, unsigned long bytes, unsigned flags,
@@ -220,7 +226,8 @@ E UNIX64_RET_ST_RAX_RDX
 ffi_closure_unix64_sse:
        cfi_startproc
        subq    $ffi_closure_FS, %rsp
-       cfi_adjust_cfa_offset(ffi_closure_FS)
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */
+       cfi_def_cfa_offset(ffi_closure_FS + 8)
 
        movdqa  %xmm0, ffi_closure_OFS_V+0x00(%rsp)
        movdqa  %xmm1, ffi_closure_OFS_V+0x10(%rsp)
@@ -243,7 +250,8 @@ ffi_closure_unix64_sse:
 ffi_closure_unix64:
        cfi_startproc
        subq    $ffi_closure_FS, %rsp
-       cfi_adjust_cfa_offset(ffi_closure_FS)
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */
+       cfi_def_cfa_offset(ffi_closure_FS + 8)
 0:
        movq    %rdi, ffi_closure_OFS_G+0x00(%rsp)
        movq    %rsi, ffi_closure_OFS_G+0x08(%rsp)
@@ -348,7 +356,8 @@ E UNIX64_RET_ST_RAX_RDX
 ffi_go_closure_unix64_sse:
        cfi_startproc
        subq    $ffi_closure_FS, %rsp
-       cfi_adjust_cfa_offset(ffi_closure_FS)
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */
+       cfi_def_cfa_offset(ffi_closure_FS + 8)
 
        movdqa  %xmm0, ffi_closure_OFS_V+0x00(%rsp)
        movdqa  %xmm1, ffi_closure_OFS_V+0x10(%rsp)
@@ -371,7 +380,8 @@ ffi_go_closure_unix64_sse:
 ffi_go_closure_unix64:
        cfi_startproc
        subq    $ffi_closure_FS, %rsp
-       cfi_adjust_cfa_offset(ffi_closure_FS)
+       /* Note clang bug 21515: adjust_cfa_offset error across endproc.  */
+       cfi_def_cfa_offset(ffi_closure_FS + 8)
 0:
        movq    %rdi, ffi_closure_OFS_G+0x00(%rsp)
        movq    %rsi, ffi_closure_OFS_G+0x08(%rsp)