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authorqmuntal <quimmuntal@gmail.com>2023-01-17 08:15:33 +0100
committerQuim Muntal <quimmuntal@gmail.com>2023-05-02 07:42:50 +0000
commit14cf82aa37ec33012ca48febd83fb16e1178beee (patch)
tree0d8b39e6bf1a7919029951aa229a996d990ee967 /src/cmd/link/internal/loader
parent53279a6af372e3708afe8eaf618d56ee98edf045 (diff)
downloadgo-14cf82aa37ec33012ca48febd83fb16e1178beee.tar.xz
cmd/link: generate .pdata PE section
This CL adds a .pdata section to the PE file generated by the Go linker. The .pdata section is a standard section [1] that contains an array of function table entries that are used for stack unwinding. The table entries layout is taken from [2]. This CL just generates the table entries without any unwinding information, which is enough to start doing some E2E tests between the Go linker and the Win32 APIs. The goal of the .pdata table is to allow Windows retrieve unwind information for a function at a given PC. It does so by doing a binary search on the table, looking for an entry that meets BeginAddress >= PC < EndAddress. Each table entry takes 12 bytes and only non-leaf functions with frame pointer needs an entry on the .pdata table. The result is that PE binaries will be ~0.7% bigger due to the unwind information, a reasonable amount considering the benefits in debuggability. Updates #57302 [1] https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#the-pdata-section [2] https://learn.microsoft.com/en-us/cpp/build/exception-handling-x64#struct-runtime_function Change-Id: If675d10c64452946dbab76709da20569651e3e9f Reviewed-on: https://go-review.googlesource.com/c/go/+/461738 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com> Reviewed-by: Than McIntosh <thanm@google.com> Run-TryBot: Quim Muntal <quimmuntal@gmail.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
Diffstat (limited to 'src/cmd/link/internal/loader')
-rw-r--r--src/cmd/link/internal/loader/loader.go10
1 files changed, 10 insertions, 0 deletions
diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go
index a989d14362..5fcbf160e0 100644
--- a/src/cmd/link/internal/loader/loader.go
+++ b/src/cmd/link/internal/loader/loader.go
@@ -1646,6 +1646,16 @@ func (l *Loader) WasmImportSym(fnSymIdx Sym) (Sym, bool) {
return 0, false
}
+// SEHUnwindSym returns the auxiliary SEH unwind symbol associated with
+// a given function symbol.
+func (l *Loader) SEHUnwindSym(fnSymIdx Sym) Sym {
+ if l.SymType(fnSymIdx) != sym.STEXT {
+ log.Fatalf("error: non-function sym %d/%s t=%s passed to SEHUnwindSym", fnSymIdx, l.SymName(fnSymIdx), l.SymType(fnSymIdx).String())
+ }
+
+ return l.aux1(fnSymIdx, goobj.AuxSehUnwindInfo)
+}
+
// GetFuncDwarfAuxSyms collects and returns the auxiliary DWARF
// symbols associated with a given function symbol. Prior to the
// introduction of the loader, this was done purely using name