Various fixes and improvements to printpcs

Search for an addr2line that supports elf32-i386. Don't print the path of addr2line as a side-effect of which. Don't uselessly pipe "grep '^ '" to addr2line's stdin. Enable as many pretty-printing and otherwise helpful options as possible (this makes the output *much* more pleasant on modern addr2lines).

Various fixes and improvements to printpcs
951b77f7 · Austin Clements · 020acb4f · 951b77f7
--- a/printpcs
+++ b/printpcs
 #!/bin/sh
-# Decode the symbols from a panic stack trace on stdin
+# Decode the symbols from a panic EIP list
-if which addr2line
+# Find a working addr2line
-then
+for p in i386-jos-elf-addr2line addr2line; do
-    p="addr2line"
+    if which $p 2>&1 >/dev/null && \
-else
+       $p -h 2>&1 | grep -q '\belf32-i386\b'; then
-    p="i386-jos-elf-addr2line"
+        break
-fi
+    fi
-echo grep '^ ' | $p -e kernel $*
+done
+# Enable as much pretty-printing as this addr2line can do
+$p $($p -h | grep ' -[aipsf] ' | awk '{print $1}') -e kernel "$@"