Found while trying to compile Adam D. Ruppe's terminal-emulator, reduced with dustmite and some manual work % cat terminalemulator.d void foo() { new OVERLAPPED; } union OVERLAPPED { uint OffsetHigh; uint Pointer; } % gdb dmd < ... blah blah ... > (gdb) r terminalemulator.d -dip1000 < ... blah blah ... > DMD v2.079.0-283-g2e21d0713-dirty DEBUG Program received signal SIGSEGV, Segmentation fault. 0x000000000059f2bd in dmd.escape.escapeByValue(dmd.expression.Expression, dmd.escape.EscapeByResults*) (er=0x7ffffffeca60, e=0x0) at dmd/escape.d:1293 1293 e.accept(v); (gdb) bt #0 0x000000000059f2bd in dmd.escape.escapeByValue(dmd.expression.Expression, dmd.escape.EscapeByResults*) (er=0x7ffffffeca60, e=0x0) at dmd/escape.d:1293 #1 0x000000000059e4a9 in dmd.escape.checkNewEscape(dmd.dscope.Scope*, dmd.expression.Expression, bool) (gag=false, e=0x0, sc=0x7ffffe274120) at dmd/escape.d:592 #2 0x00000000005b8342 in ExpressionSemanticVisitor::visit(NewExp*) (this=0x7ffffffecf08, exp=0x7fffff6b53b0) at dmd/expressionsem.d:2363 #3 0x00000000005a9ba6 in NewExp::accept(Visitor*) (this=0x7fffff6b53b0, v=0x7ffffffecf08) at dmd/expression.d:4155 #4 0x00000000005cc5ef in expressionSemantic(Expression*, Scope*) (e=0x7fffff6b53b0, sc=0x7ffffe274120) at dmd/expressionsem.d:9367 #5 0x000000000064f0cc in StatementSemanticVisitor::visit(ExpStatement*) (this=0x7ffffffecfd8, s=0x7fffff6b5420) at dmd/statementsem.d:177 #6 0x0000000000631a0e in ExpStatement::accept(Visitor*) (this=0x7fffff6b5420, v=0x7ffffffecfd8) at dmd/statement.d:715 #7 0x000000000064efa7 in statementSemantic(Statement*, Scope*) (s=0x7fffff6b5420, sc=0x7ffffe274120) at dmd/statementsem.d:126 #8 0x000000000064f38a in StatementSemanticVisitor::visit(CompoundStatement*) (this=0x7ffffffed2d8, cs=0x7fffff6b5440) at dmd/statementsem.d:235 #9 0x0000000000632206 in CompoundStatement::accept(Visitor*) (this=0x7fffff6b5440, v=0x7ffffffed2d8) at dmd/statement.d:908 #10 0x000000000064efa7 in statementSemantic(Statement*, Scope*) (s=0x7fffff6b5440, sc=0x7ffffe274120) at dmd/statementsem.d:126 #11 0x0000000000663aae in Semantic3Visitor::visit(FuncDeclaration*) (this=0x7ffffffedb80, funcdecl=0x7fffff6b5060) at dmd/semantic3.d:581 #12 0x00000000005d35e6 in FuncDeclaration::accept(Visitor*) (this=0x7fffff6b5060, v=0x7ffffffedb80) at dmd/func.d:2277 #13 0x00000000006623c5 in semantic3(Dsymbol*, Scope*) (dsym=0x7fffff6b5060, sc=0x7ffffe273e30) at dmd/semantic3.d:82 #14 0x00000000006627c6 in Semantic3Visitor::visit(Module*) (this=0x7ffffffedc30, mod=0x7fffff6b4c00) at dmd/semantic3.d:193 #15 0x000000000055838e in Module::accept(Visitor*) (this=0x7fffff6b4c00, v=0x7ffffffedc30) at dmd/dmodule.d:1322 #16 0x00000000006623c5 in semantic3(Dsymbol*, Scope*) (dsym=0x7fffff6b4c00, sc=0x0) at dmd/semantic3.d:82 #17 0x00000000005fd1f7 in dmd.mars.tryMain(ulong, const(char)**) (argv=0x7ffffffee958, argc=3) at dmd/mars.d:836 #18 0x00000000005fe17b in D main () at dmd/mars.d:1098
This is an ICE; upping priority.
Unable to reproduce problem on git master. Perhaps it has since been fixed?
P.S. Tested on git commit 2e21d0713babf760e4428d6404d733282ef85e8a, just to be clear.
I can reproduce the segfault on master, the easy fix is to add a `arg !is null` before calling `escapeByValue` to take into account the union types but I'm not sure if the change is sound wrt the escape analysis.
PR : https://github.com/dlang/dmd/pull/8094
Closed the former one to retarget stable : https://github.com/dlang/dmd/pull/8095
Fixed in stable : https://github.com/dlang/dmd/pull/8095
Commits pushed to master at https://github.com/dlang/dmd https://github.com/dlang/dmd/commit/7bf608bdbca8c147c413614f3ca7a2062a0c1909 Fix Issue 18670 - compiler segfault if new on a union type with dip1000 https://github.com/dlang/dmd/commit/15213da2465922c7a33fe8037941122926325f6c Merge pull request #8095 from RazvanN7/Issue_18670v2 Fix Issue 18670 - compiler segfault if new on a union type with dip1000