From de18d960d51810d71b5f2fa812c21a991924f00c Mon Sep 17 00:00:00 2001 From: Alon Zakai Date: Fri, 24 Jan 2020 16:06:13 -0800 Subject: DWARF: Properly emit signed 32 bit values for advance_line (#2625) The LLVM SData field is 64-bit (to support 64-bit addresses I suppose) so when we assigned to it we actually led it to emit an LEB for a signed 64-bit value that is an unsigned 32-bit one. This worked in LLVM (where I guess it forces the value to 32-bit anyhow?) but failed in gimli (where I guess it doesn't?). --- src/wasm/wasm-debug.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'src/wasm/wasm-debug.cpp') diff --git a/src/wasm/wasm-debug.cpp b/src/wasm/wasm-debug.cpp index c4d403e64..73e473f9a 100644 --- a/src/wasm/wasm-debug.cpp +++ b/src/wasm/wasm-debug.cpp @@ -261,7 +261,10 @@ struct LineState { } if (line != old.line && !useSpecial) { auto item = makeItem(llvm::dwarf::DW_LNS_advance_line); - item.SData = line - old.line; + // In wasm32 we have 32-bit addresses, and the delta here might be + // negative (note that SData is 64-bit, as LLVM supports 64-bit + // addresses too). + item.SData = int32_t(line - old.line); newOpcodes.push_back(item); } if (col != old.col) { -- cgit v1.2.3