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- work-around issue with empty functions and ld64 on Darwin
This commit is contained in:
gsell
2017-01-24 15:59:34 +01:00
parent 4b02502e1f
commit 3a4fb0cc2d
2 changed files with 397 additions and 0 deletions
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394
Programming/gcc/5/PR57438_avoiding_empty_function_bodies_and_trailing_labels.patch Normal file
View File

@@ -0,0 +1,394 @@
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 9e9fe02..a60bc69 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -11866,6 +11866,9 @@ ix86_code_end (void)
current_function_decl = decl;
allocate_struct_function (decl, false);
init_function_start (decl);
+ /* We're about to hide the function body from callees of final_* by
+ emitting it directly; tell them we're a thunk, if they care. */
+ cfun->is_thunk = true;
first_function_block_is_cold = false;
/* Make sure unwind info is emitted for the thunk if needed. */
final_start_function (emit_barrier (), asm_out_file, 1);
@@ -14562,36 +14565,65 @@ ix86_output_function_epilogue (FILE *file ATTRIBUTE_UNUSED, HOST_WIDE_INT)
if (pic_offset_table_rtx
&& !ix86_use_pseudo_pic_reg ())
SET_REGNO (pic_offset_table_rtx, REAL_PIC_OFFSET_TABLE_REGNUM);
-#if TARGET_MACHO
- /* Mach-O doesn't support labels at the end of objects, so if
- it looks like we might want one, insert a NOP. */
- {
- rtx_insn *insn = get_last_insn ();
- rtx_insn *deleted_debug_label = NULL;
- while (insn
- && NOTE_P (insn)
- && NOTE_KIND (insn) != NOTE_INSN_DELETED_LABEL)
- {
- /* Don't insert a nop for NOTE_INSN_DELETED_DEBUG_LABEL
- notes only, instead set their CODE_LABEL_NUMBER to -1,
- otherwise there would be code generation differences
- in between -g and -g0. */
- if (NOTE_P (insn) && NOTE_KIND (insn) == NOTE_INSN_DELETED_DEBUG_LABEL)
- deleted_debug_label = insn;
+
+ if (TARGET_MACHO)
+ {
+ rtx_insn *insn = get_last_insn ();
+ rtx_insn *deleted_debug_label = NULL;
+
+ /* Mach-O doesn't support labels at the end of objects, so if
+ it looks like we might want one, take special action.
+ First, Collect any sequence deleted debug labels. */
+ while (insn
+ && NOTE_P (insn)
+ && NOTE_KIND (insn) != NOTE_INSN_DELETED_LABEL)
+ {
+ /* Don't insert a nop for NOTE_INSN_DELETED_DEBUG_LABEL
+ notes only, instead set their CODE_LABEL_NUMBER to -1,
+ otherwise there would be code generation differences
+ in between -g and -g0. */
+ if (NOTE_P (insn) && NOTE_KIND (insn)
+ == NOTE_INSN_DELETED_DEBUG_LABEL)
+ deleted_debug_label = insn;
+ insn = PREV_INSN (insn);
+ }
+
+ /* If we have
+ label:
+ barrier
+ That need to be guarded. */
+
+ if (insn && BARRIER_P (insn))
insn = PREV_INSN (insn);
- }
- if (insn
- && (LABEL_P (insn)
- || (NOTE_P (insn)
- && NOTE_KIND (insn) == NOTE_INSN_DELETED_LABEL)))
- fputs ("\tnop\n", file);
- else if (deleted_debug_label)
- for (insn = deleted_debug_label; insn; insn = NEXT_INSN (insn))
- if (NOTE_KIND (insn) == NOTE_INSN_DELETED_DEBUG_LABEL)
- CODE_LABEL_NUMBER (insn) = -1;
- }
-#endif
+ /* Up to now we've only seen notes or barriers. */
+ if (insn)
+ {
+ if (LABEL_P (insn)
+ || (NOTE_P (insn)
+ && NOTE_KIND (insn) == NOTE_INSN_DELETED_LABEL))
+ /* Trailing label. */
+ fputs ("\tnop\n", file);
+ else if (cfun && ! cfun->is_thunk)
+ {
+ /* See if have a completely empty function body, skipping
+ the special case of the picbase thunk emitted as asm. */
+ while (insn && ! INSN_P (insn))
+ insn = PREV_INSN (insn);
+ /* If we don't find any, we've got an empty function body; i.e.
+ completely empty - without a return or branch. GCC declares
+ that reaching __builtin_unreachable() means UB (but we want
+ finite-sized function bodies; to help the user out, let's
+ trap the case. */
+ if (insn == NULL)
+ fputs ("\tud2\n", file);
+ }
+ }
+ else if (deleted_debug_label)
+ for (insn = deleted_debug_label; insn; insn = NEXT_INSN (insn))
+ if (NOTE_KIND (insn) == NOTE_INSN_DELETED_DEBUG_LABEL)
+ CODE_LABEL_NUMBER (insn) = -1;
+ }
}
/* Return a scratch register to use in the split stack prologue. The
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index b0d2b64..326e2e9 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -30148,11 +30148,16 @@ rs6000_output_function_epilogue (FILE *file,
{
#if TARGET_MACHO
macho_branch_islands ();
- /* Mach-O doesn't support labels at the end of objects, so if
- it looks like we might want one, insert a NOP. */
+
+ if (TARGET_MACHO)
{
rtx_insn *insn = get_last_insn ();
rtx_insn *deleted_debug_label = NULL;
+
+ /* Mach-O doesn't support labels at the end of objects, so if
+ it looks like we might want one, take special action.
+
+ First, collect any sequence deleted debug labels. */
while (insn
&& NOTE_P (insn)
&& NOTE_KIND (insn) != NOTE_INSN_DELETED_LABEL)
@@ -30165,11 +30170,37 @@ rs6000_output_function_epilogue (FILE *file,
deleted_debug_label = insn;
insn = PREV_INSN (insn);
}
- if (insn
- && (LABEL_P (insn)
+
+ /* If we have:
+ label:
+ barrier
+ That need to be guarded. */
+
+ if (insn && BARRIER_P (insn))
+ insn = PREV_INSN (insn);
+
+ /* up to now we've only seen notes or barriers. */
+ if (insn)
+ {
+ if (LABEL_P (insn)
|| (NOTE_P (insn)
- && NOTE_KIND (insn) == NOTE_INSN_DELETED_LABEL)))
- fputs ("\tnop\n", file);
+ && NOTE_KIND (insn) == NOTE_INSN_DELETED_LABEL))
+ /* Trailing label: <barrier>. */
+ fputs ("\tnop\n", file);
+ else
+ {
+ /* See if have a completely empty function body. */
+ while (insn && ! INSN_P (insn))
+ insn = PREV_INSN (insn);
+ /* If we don't find any, we've got an empty function body; i.e.
+ completely empty - without a return or branch. GCC declares
+ that reaching __builtin_unreachable() means UB (but we want
+ finite-sized function bodies; to help the user out, let's trap
+ the case. */
+ if (insn == NULL)
+ fputs ("\ttrap\n", file);
+ }
+ }
else if (deleted_debug_label)
for (insn = deleted_debug_label; insn; insn = NEXT_INSN (insn))
if (NOTE_KIND (insn) == NOTE_INSN_DELETED_DEBUG_LABEL)
diff --git a/gcc/testsuite/gcc.dg/pr57438-1.c b/gcc/testsuite/gcc.dg/pr57438-1.c
new file mode 100644
index 0000000..809c96d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr57438-1.c
@@ -0,0 +1,15 @@
+/* { dg-do compile { target *-*-darwin* } } */
+/* { dg-options "-m32 -O1" } */
+
+/* This is testing that a completely empty function body results in the
+ insertion of a ud2/trap instruction to prevent a zero-sized FDE, and/or
+ the function label apparently pointing to following code. */
+
+__attribute__((noinline))
+void foo (void)
+{
+ __builtin_unreachable();
+}
+
+/* { dg-final { scan-assembler "ud2" { target { i?86-*-darwin* x86_64-*-darwin* } } } } */
+/* { dg-final { scan-assembler "trap" { target { powerpc*-*-darwin* } } } } */
diff --git a/gcc/testsuite/gcc.dg/pr57438-2.c b/gcc/testsuite/gcc.dg/pr57438-2.c
new file mode 100644
index 0000000..6d67dad
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr57438-2.c
@@ -0,0 +1,194 @@
+/* { dg-do compile { target *-*-darwin* } } */
+/* { dg-options "-m32 -O1" } */
+
+/* This is testing that a trailing local label is followed by a
+ nop where required. */
+
+extern int Error(void *, const char *);
+
+typedef enum {
+ Match_MissingFeature,
+ Match_InvalidOperand,
+ Match_InvalidSuffix,
+ Match_InvalidCondCode,
+ Match_AddSubRegExtendSmall,
+ Match_AddSubRegExtendLarge,
+ Match_AddSubSecondSource,
+ Match_LogicalSecondSource,
+ Match_InvalidMovImm32Shift,
+ Match_InvalidMovImm64Shift,
+ Match_AddSubRegShift32,
+ Match_AddSubRegShift64,
+ Match_InvalidFPImm,
+ Match_InvalidMemoryIndexedSImm9,
+ Match_InvalidMemoryIndexed4SImm7,
+ Match_InvalidMemoryIndexed8SImm7,
+ Match_InvalidMemoryIndexed16SImm7,
+ Match_InvalidMemoryWExtend8,
+ Match_InvalidMemoryWExtend16,
+ Match_InvalidMemoryWExtend32,
+ Match_InvalidMemoryWExtend64,
+ Match_InvalidMemoryWExtend128,
+ Match_InvalidMemoryXExtend8,
+ Match_InvalidMemoryXExtend16,
+ Match_InvalidMemoryXExtend32,
+ Match_InvalidMemoryXExtend64,
+ Match_InvalidMemoryXExtend128,
+ Match_InvalidMemoryIndexed1,
+ Match_InvalidMemoryIndexed2,
+ Match_InvalidMemoryIndexed4,
+ Match_InvalidMemoryIndexed8,
+ Match_InvalidMemoryIndexed16,
+ Match_InvalidImm0_1,
+ Match_InvalidImm0_7,
+ Match_InvalidImm0_15,
+ Match_InvalidImm0_31,
+ Match_InvalidImm0_63,
+ Match_InvalidImm0_127,
+ Match_InvalidImm0_65535,
+ Match_InvalidImm1_8,
+ Match_InvalidImm1_16,
+ Match_InvalidImm1_32,
+ Match_InvalidImm1_64,
+ Match_InvalidIndex1,
+ Match_InvalidIndexB,
+ Match_InvalidIndexH,
+ Match_InvalidIndexS,
+ Match_InvalidIndexD,
+ Match_InvalidLabel,
+ Match_MRS,
+ Match_MSR,
+ Match_MnemonicFail
+} ErrCode;
+
+//bool showMatchError(void *, unsigned ) __attribute__((__weak__));
+
+int showMatchError(void *Loc, unsigned ErrCode) {
+ switch (ErrCode) {
+ case Match_MissingFeature:
+ return Error(Loc,
+ "instruction requires a CPU feature not currently enabled");
+ case Match_InvalidOperand:
+ return Error(Loc, "invalid operand for instruction");
+ case Match_InvalidSuffix:
+ return Error(Loc, "invalid type suffix for instruction");
+ case Match_InvalidCondCode:
+ return Error(Loc, "expected AArch64 condition code");
+ case Match_AddSubRegExtendSmall:
+ return Error(Loc,
+ "expected '[su]xt[bhw]' or 'lsl' with optional integer in range [0, 4]");
+ case Match_AddSubRegExtendLarge:
+ return Error(Loc,
+ "expected 'sxtx' 'uxtx' or 'lsl' with optional integer in range [0, 4]");
+ case Match_AddSubSecondSource:
+ return Error(Loc,
+ "expected compatible register, symbol or integer in range [0, 4095]");
+ case Match_LogicalSecondSource:
+ return Error(Loc, "expected compatible register or logical immediate");
+ case Match_InvalidMovImm32Shift:
+ return Error(Loc, "expected 'lsl' with optional integer 0 or 16");
+ case Match_InvalidMovImm64Shift:
+ return Error(Loc, "expected 'lsl' with optional integer 0, 16, 32 or 48");
+ case Match_AddSubRegShift32:
+ return Error(Loc,
+ "expected 'lsl', 'lsr' or 'asr' with optional integer in range [0, 31]");
+ case Match_AddSubRegShift64:
+ return Error(Loc,
+ "expected 'lsl', 'lsr' or 'asr' with optional integer in range [0, 63]");
+ case Match_InvalidFPImm:
+ return Error(Loc,
+ "expected compatible register or floating-point constant");
+ case Match_InvalidMemoryIndexedSImm9:
+ return Error(Loc, "index must be an integer in range [-256, 255].");
+ case Match_InvalidMemoryIndexed4SImm7:
+ return Error(Loc, "index must be a multiple of 4 in range [-256, 252].");
+ case Match_InvalidMemoryIndexed8SImm7:
+ return Error(Loc, "index must be a multiple of 8 in range [-512, 504].");
+ case Match_InvalidMemoryIndexed16SImm7:
+ return Error(Loc, "index must be a multiple of 16 in range [-1024, 1008].");
+ case Match_InvalidMemoryWExtend8:
+ return Error(Loc,
+ "expected 'uxtw' or 'sxtw' with optional shift of #0");
+ case Match_InvalidMemoryWExtend16:
+ return Error(Loc,
+ "expected 'uxtw' or 'sxtw' with optional shift of #0 or #1");
+ case Match_InvalidMemoryWExtend32:
+ return Error(Loc,
+ "expected 'uxtw' or 'sxtw' with optional shift of #0 or #2");
+ case Match_InvalidMemoryWExtend64:
+ return Error(Loc,
+ "expected 'uxtw' or 'sxtw' with optional shift of #0 or #3");
+ case Match_InvalidMemoryWExtend128:
+ return Error(Loc,
+ "expected 'uxtw' or 'sxtw' with optional shift of #0 or #4");
+ case Match_InvalidMemoryXExtend8:
+ return Error(Loc,
+ "expected 'lsl' or 'sxtx' with optional shift of #0");
+ case Match_InvalidMemoryXExtend16:
+ return Error(Loc,
+ "expected 'lsl' or 'sxtx' with optional shift of #0 or #1");
+ case Match_InvalidMemoryXExtend32:
+ return Error(Loc,
+ "expected 'lsl' or 'sxtx' with optional shift of #0 or #2");
+ case Match_InvalidMemoryXExtend64:
+ return Error(Loc,
+ "expected 'lsl' or 'sxtx' with optional shift of #0 or #3");
+ case Match_InvalidMemoryXExtend128:
+ return Error(Loc,
+ "expected 'lsl' or 'sxtx' with optional shift of #0 or #4");
+ case Match_InvalidMemoryIndexed1:
+ return Error(Loc, "index must be an integer in range [0, 4095].");
+ case Match_InvalidMemoryIndexed2:
+ return Error(Loc, "index must be a multiple of 2 in range [0, 8190].");
+ case Match_InvalidMemoryIndexed4:
+ return Error(Loc, "index must be a multiple of 4 in range [0, 16380].");
+ case Match_InvalidMemoryIndexed8:
+ return Error(Loc, "index must be a multiple of 8 in range [0, 32760].");
+ case Match_InvalidMemoryIndexed16:
+ return Error(Loc, "index must be a multiple of 16 in range [0, 65520].");
+ case Match_InvalidImm0_1:
+ return Error(Loc, "immediate must be an integer in range [0, 1].");
+ case Match_InvalidImm0_7:
+ return Error(Loc, "immediate must be an integer in range [0, 7].");
+ case Match_InvalidImm0_15:
+ return Error(Loc, "immediate must be an integer in range [0, 15].");
+ case Match_InvalidImm0_31:
+ return Error(Loc, "immediate must be an integer in range [0, 31].");
+ case Match_InvalidImm0_63:
+ return Error(Loc, "immediate must be an integer in range [0, 63].");
+ case Match_InvalidImm0_127:
+ return Error(Loc, "immediate must be an integer in range [0, 127].");
+ case Match_InvalidImm0_65535:
+ return Error(Loc, "immediate must be an integer in range [0, 65535].");
+ case Match_InvalidImm1_8:
+ return Error(Loc, "immediate must be an integer in range [1, 8].");
+ case Match_InvalidImm1_16:
+ return Error(Loc, "immediate must be an integer in range [1, 16].");
+ case Match_InvalidImm1_32:
+ return Error(Loc, "immediate must be an integer in range [1, 32].");
+ case Match_InvalidImm1_64:
+ return Error(Loc, "immediate must be an integer in range [1, 64].");
+ case Match_InvalidIndex1:
+ return Error(Loc, "expected lane specifier '[1]'");
+ case Match_InvalidIndexB:
+ return Error(Loc, "vector lane must be an integer in range [0, 15].");
+ case Match_InvalidIndexH:
+ return Error(Loc, "vector lane must be an integer in range [0, 7].");
+ case Match_InvalidIndexS:
+ return Error(Loc, "vector lane must be an integer in range [0, 3].");
+ case Match_InvalidIndexD:
+ return Error(Loc, "vector lane must be an integer in range [0, 1].");
+ case Match_InvalidLabel:
+ return Error(Loc, "expected label or encodable integer pc offset");
+ case Match_MRS:
+ return Error(Loc, "expected readable system register");
+ case Match_MSR:
+ return Error(Loc, "expected writable system register or pstate");
+ case Match_MnemonicFail:
+ return Error(Loc, "unrecognized instruction mnemonic");
+ default:
+ __builtin_unreachable();
+ }
+}
+
+/* { dg-final { scan-assembler "nop\\nLFE.*" { target { *-*-darwin* } } } } */

3
Programming/gcc/build
View File

@@ -6,6 +6,9 @@ pbuild::patch_sources_Darwin() {
patch -p1 < "${BUILD_BLOCK_DIR}/${V_MAJOR}/non-dead-strip.patch"
patch -p1 < "${BUILD_BLOCK_DIR}/${V_MAJOR}/configure-as.patch"
fi
if (( V_MAJOR == 5 )); then
patch -p1 < "${BUILD_BLOCK_DIR}/${V_MAJOR}/PR57438_avoiding_empty_function_bodies_and_trailing_labels.patch"
fi
}
pbuild::configure() {