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Open Watcom V2.0 - Source code repository, Wiki, Latest Binary build, Archived builds including all installers for download.
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WASM crash in TASM compatibility mode, uninitialized pointer dereference in PROC argument handling code #767

Open nxd51 opened 2 years ago

nxd51 commented 2 years ago

Open Watcom assembler supports several TASM ideal mode features, including procedures. However, at least the 32-bit Windows version of the assembler very often crashes if the assembly code contains procedures with arguments. I have attached a simple test case (renamed to .TXT) that uses the syntax causing a crash. It should be assembled using the following switches: -0 -mm -zcm=tasm .

I did some investigation, and I think I have found the cause of the bug: function proc_exam (in direct.c) does not initialize the "sym" field of the "paranode" structure , yet this pointer is later dereferenced in function WritePrologue. According to my tests, this bug was already present in Open Watcom 1.9. wa_crash.txt

jmalak commented 2 years ago

Handling of symbols in WASM need rework. There are multiple problem with de-refferencing symbol. This is one of them.