[arm] Improve error checking in parsecpu.awk

This patch adds a bit more error checking to parsecpu.awk to ensure
that statements are not missing arguments or have excess arguments
beyond those permitted.  It also slightly improves the handling of
errors so that we terminate properly if parsing fails and be as
helpful as we can while in the parsing phase.

2017-09-22  Richard Earnshaw  <richard.earnshaw@arm.com>

	* config/arm/parsecpu.awk (fatal): Note that we've encountered an
	error.  Only quit immediately if parsing is complete.
	(BEGIN): Initialize fatal_err and parse_done.
	(begin fpu, end fpu): Check number of arguments.
	(begin arch, end arch): Likewise.
	(begin cpu, end cpu): Likewise.
	(cname, tune for, tune flags, architecture, fpu, option): Likewise.
	(optalias): Likewise.

From-SVN: r253098

gcc/ChangeLog

 2017-09-22  Richard Earnshaw  <richard.earnshaw@arm.com>
 
+	* config/arm/parsecpu.awk (fatal): Note that we've encountered an
+	error.  Only quit immediately if parsing is complete.
+	(BEGIN): Initialize fatal_err and parse_done.
+	(begin fpu, end fpu): Check number of arguments.
+	(begin arch, end arch): Likewise.
+	(begin cpu, end cpu): Likewise.
+	(cname, tune for, tune flags, architecture, fpu, option): Likewise.
+	(optalias): Likewise.
+
+2017-09-22  Richard Earnshaw  <richard.earnshaw@arm.com>
+
 	* config.gcc (arm*-*-*): Don't add arm-isa.h to tm_p_file.
 	* config/arm/arm-isa.h: Delete.  Move definitions to ...
 	* arm-cpus.in: ... here.  Use new feature and fgroup values.

gcc/config/arm/parsecpu.awk

@@ -32,7 +32,8 @@
 
 function fatal (m) {
     print "error ("lineno"): " m > "/dev/stderr"
-    exit 1
+    fatal_err = 1
+    if (parse_done) exit 1
 }
 
 function toplevel () {
@@ -502,14 +503,18 @@ BEGIN {
     arch_name = ""
     fpu_name = ""
     lineno = 0
+    fatal_err = 0
+    parse_done = 0
     if (cmd == "") fatal("Usage parsecpu.awk -v cmd=<xyz>")
 }
 
+# New line.  Reset parse status and increment line count for error messages
 // {
     lineno++
     parse_ok = 0
 }
 
+# Comments must be on a line on their own.
 /^#/ {
     parse_ok = 1
 }
@@ -552,12 +557,14 @@ BEGIN {
 }
 
 /^begin fpu / {
+    if (NF != 3) fatal("syntax: begin fpu <name>")
     toplevel()
     fpu_name = $3
     parse_ok = 1
 }
 
 /^end fpu / {
+    if (NF != 3) fatal("syntax: end fpu <name>")
     if (fpu_name != $3) fatal("mimatched end fpu")
     if (! (fpu_name in fpu_isa)) {
 	fatal("fpu definition \"" fpu_name "\" lacks an \"isa\" statement")
@@ -570,24 +577,28 @@ BEGIN {
 }
 
 /^begin arch / {
+    if (NF != 3) fatal("syntax: begin arch <name>")
     toplevel()
     arch_name = $3
     parse_ok = 1
 }
 
 /^[ 	]*base / {
+    if (NF != 2) fatal("syntax: base <architecture-base-name>")
     if (arch_name == "") fatal("\"base\" statement outside of arch block")
     arch_base[arch_name] = $2
     parse_ok = 1
 }
 
 /^[ 	]*profile / {
+    if (NF != 2) fatal("syntax: profile <profile-name>")
     if (arch_name == "") fatal("\"profile\" statement outside of arch block")
     arch_prof[arch_name] = $2
     parse_ok = 1
 }
 
 /^end arch / {
+    if (NF != 3) fatal("syntax: end arch <name>")
     if (arch_name != $3) fatal("mimatched end arch")
     if (! arch_name in arch_tune_for) {
 	fatal("arch definition lacks a \"tune for\" statement")
@@ -603,18 +614,21 @@ BEGIN {
 }
 
 /^begin cpu / {
+    if (NF != 3) fatal("syntax: begin cpu <name>")
     toplevel()
     cpu_name = $3
     parse_ok = 1
 }
 
 /^[ 	]*cname / {
+    if (NF != 2) fatal("syntax: cname <identifier>")
     if (cpu_name == "") fatal("\"cname\" outside of cpu block")
     cpu_cnames[cpu_name] = $2
     parse_ok = 1
 }
 
 /^[ 	]*tune for / {
+    if (NF != 3) fatal("syntax: tune for <cpu-name>")
     if (cpu_name != "") {
 	cpu_tune_for[cpu_name] = $3
     } else if (arch_name != "") {
@@ -624,6 +638,7 @@ BEGIN {
 }
 
 /^[ 	]*tune flags / {
+    if (NF < 3) fatal("syntax: tune flags <flag> [<flag>]*")
     flags=""
     flag_count = NF
     for (n = 3; n <= flag_count; n++) {
@@ -640,18 +655,21 @@ BEGIN {
 }
 
 /^[ 	]*architecture / {
+    if (NF != 2) fatal("syntax: architecture <arch-name>")
     if (cpu_name == "") fatal("\"architecture\" outside of cpu block")
     cpu_arch[cpu_name] = $2
     parse_ok = 1
 }
 
 /^[ 	]*fpu / {
+    if (NF != 2) fatal("syntax: fpu <fpu-name>")
     if (cpu_name == "") fatal("\"fpu\" outside of cpu block")
     cpu_fpu[cpu_name] = $2
     parse_ok = 1
 }
 
 /^[ 	]*isa / {
+    if (NF < 2) fatal("syntax: isa <feature-or-fgroup> [<feature-or-fgroup>]*")
     flags=""
     flag_count = NF
     for (n = 2; n <= flag_count; n++) {
@@ -670,6 +688,7 @@ BEGIN {
 }
 
 /^[ 	]*option / {
+    if (NF < 4) fatal("syntax: option <name> add|remove <feature-or-fgroup>+")
     name=$2
     if ($3 == "add") {
 	remove = "false"
@@ -696,6 +715,7 @@ BEGIN {
 }
 
 /^[ 	]*optalias / {
+    if (NF != 3) fatal("syntax: optalias <name> <option-name>")
     name=$2
     alias=$3
     if (cpu_name != "") {
@@ -709,12 +729,14 @@ BEGIN {
 }
 
 /^[ 	]*costs / {
+    if (NF != 2) fatal("syntax: costs <identifier>")
     if (cpu_name == "") fatal("\"costs\" outside of cpu block")
     cpu_cost[cpu_name] = $2
     parse_ok = 1
 }
 
 /^end cpu / {
+    if (NF != 3) fatal("syntax: end cpu <name>")
     if (cpu_name != $3) fatal("mimatched end cpu")
     if (! (cpu_name in cpu_cnames)) {
 	cpu_cnames[cpu_name] = cpu_name
@@ -731,6 +753,8 @@ BEGIN {
 }
 
 END {
+    parse_done = 1
+    if (fatal_err) exit 1
     toplevel()
     if (cmd == "data") {
 	gen_data()