| author |  Andrew Kelley <andrew@ziglang.org> 2021-03-01 19:10:36-08:00 |
| committer |  GitHub <noreply@github.com> 2021-03-01 19:10:36-08:00 |
| log | f9c9b9217551b98a1d25ff6462c035b8d3a99fe1 |
| tree | b6d6c9254b8f0e3d13e95ec565f6153a8f5c3c52 |
| parent | a20169a610b693794756bbc0139f0955c1294b48 |
| parent | 448a28325c7517e6cd62ba7932a4b6c836250757 |
| signature |  Signed by PGP key 4AEE18F83AFDEB23 |
Merge pull request #7946 from koachan/sparc64-framefixes
SPARCv9: Handle various stack frame related quirks.2 files changed, 26 insertions(+), 4 deletions(-)
lib- std
- src
- stage1
lib/std/debug.zig+17-3
| ... | ... | @@ -360,14 +360,24 @@ pub const StackIterator = struct { |
| 360 | 360 | }; |
| 361 | 361 | } |
| 362 | 362 | |
| 363 | // Negative offset of the saved BP wrt the frame pointer. | |
| 363 | // Offset of the saved BP wrt the frame pointer. | |
| 364 | 364 | const fp_offset = if (builtin.arch.isRISCV()) |
| 365 | 365 | // On RISC-V the frame pointer points to the top of the saved register |
| 366 | 366 | // area, on pretty much every other architecture it points to the stack |
| 367 | 367 | // slot where the previous frame pointer is saved. |
| 368 | 368 | 2 * @sizeOf(usize) |
| 369 | else if (builtin.arch.isSPARC()) | |
| 370 | // On SPARC the previous frame pointer is stored at 14 slots past %fp+BIAS. | |
| 371 | 14 * @sizeOf(usize) | |
| 369 | 372 | else |
| 370 | 373 | 0; |
| 374 | ||
| 375 | const fp_bias = if (builtin.arch.isSPARC()) | |
| 376 | // On SPARC frame pointers are biased by a constant. | |
| 377 | 2047 | |
| 378 | else | |
| 379 | 0; | |
| 380 | ||
| 371 | 381 | // Positive offset of the saved PC wrt the frame pointer. |
| 372 | 382 | const pc_offset = if (builtin.arch == .powerpc64le) |
| 373 | 383 | 2 * @sizeOf(usize) |
| ... | ... | @@ -388,13 +398,17 @@ pub const StackIterator = struct { |
| 388 | 398 | } |
| 389 | 399 | |
| 390 | 400 | fn next_internal(self: *StackIterator) ?usize { |
| 391 | const fp = math.sub(usize, self.fp, fp_offset) catch return null; | |
| 401 | const fp = if (builtin.arch.isSPARC()) | |
| 402 | // On SPARC the offset is positive. (!) | |
| 403 | math.add(usize, self.fp, fp_offset) catch return null | |
| 404 | else | |
| 405 | math.sub(usize, self.fp, fp_offset) catch return null; | |
| 392 | 406 | |
| 393 | 407 | // Sanity check. |
| 394 | 408 | if (fp == 0 or !mem.isAligned(fp, @alignOf(usize))) |
| 395 | 409 | return null; |
| 396 | 410 | |
| 397 | const new_fp = @intToPtr(*const usize, fp).*; | |
| 411 | const new_fp = math.add(usize, @intToPtr(*const usize, fp).*, fp_bias) catch return null; | |
| 398 | 412 | |
| 399 | 413 | // Sanity check: the stack grows down thus all the parent frames must be |
| 400 | 414 | // be at addresses that are greater (or equal) than the previous one. |
src/stage1/codegen.cpp+9-1
| ... | ... | @@ -4153,7 +4153,15 @@ static LLVMValueRef gen_frame_size(CodeGen *g, LLVMValueRef fn_val) { |
| 4153 | 4153 | LLVMValueRef casted_fn_val = LLVMBuildBitCast(g->builder, fn_val, ptr_usize_llvm_type, ""); |
| 4154 | 4154 | LLVMValueRef negative_one = LLVMConstInt(LLVMInt32Type(), -1, true); |
| 4155 | 4155 | LLVMValueRef prefix_ptr = LLVMBuildInBoundsGEP(g->builder, casted_fn_val, &negative_one, 1, ""); |
| 4156 | return LLVMBuildLoad(g->builder, prefix_ptr, ""); | |
| 4156 | LLVMValueRef load_inst = LLVMBuildLoad(g->builder, prefix_ptr, ""); | |
| 4157 | ||
| 4158 | // Some architectures (e.g SPARCv9) has different alignment requirements between a | |
| 4159 | // function/usize pointer and also require all loads to be aligned. | |
| 4160 | // On those architectures, not explicitly setting the alignment will lead into @frameSize | |
| 4161 | // generating usize-aligned load instruction that could crash if the function pointer | |
| 4162 | // happens to be not usize-aligned. | |
| 4163 | LLVMSetAlignment(load_inst, 1); | |
| 4164 | return load_inst; | |
| 4157 | 4165 | } |
| 4158 | 4166 | |
| 4159 | 4167 | static void gen_init_stack_trace(CodeGen *g, LLVMValueRef trace_field_ptr, LLVMValueRef addrs_field_ptr) { |