Generate error data at build time.

This avoids cluttering up the diff and making merge conflicts a pain.  It does,
however, mean we need to generate err_data.c ahead of time in Chromium and
likely other downstream builds. It also adds a build dependency on Go.

Change-Id: I6e0513ed9f50cfb030f7a523ea28519590977104
Reviewed-on: https://boringssl-review.googlesource.com/3790
Reviewed-by: Adam Langley <agl@google.com>

BUILDING

@@ -19,7 +19,8 @@ Build Prerequisites:
     with Platform SDK 8.1 or later are supported. Recent versions of GCC and
     Clang should work on non-Windows platforms, and maybe on Windows too.
 
-  * Go[5] is required for running tests, but not for building.
+  * Go[5] is required. If not found by CMake, the go executable may be
+    configured explicitly by setting GO_EXECUTABLE.
 
 Using Ninja (note the 'N' is capitalized in the cmake invocation):
 

CMakeLists.txt

@@ -4,6 +4,11 @@ project (BoringSSL)
 
 find_package(Perl REQUIRED)
 
+find_program(GO_EXECUTABLE go)
+if (NOT GO_EXECUTABLE)
+  message(FATAL_ERROR "Could not find Go")
+endif()
+
 if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -ggdb -fvisibility=hidden")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Werror -ggdb -std=c++0x -fvisibility=hidden")

crypto/err/CMakeLists.txt

@@ -1,11 +1,43 @@
 include_directories(. .. ../../include)
 
+add_custom_command(
+  OUTPUT err_data.c
+  COMMAND ${GO_EXECUTABLE} run err_data_generate.go > ${CMAKE_CURRENT_BINARY_DIR}/err_data.c
+  DEPENDS
+  err_data_generate.go
+  asn1.errordata
+  bio.errordata
+  bn.errordata
+  buf.errordata
+  cipher.errordata
+  conf.errordata
+  crypto.errordata
+  dh.errordata
+  digest.errordata
+  dsa.errordata
+  ecdh.errordata
+  ecdsa.errordata
+  ec.errordata
+  engine.errordata
+  evp.errordata
+  hkdf.errordata
+  obj.errordata
+  pem.errordata
+  pkcs8.errordata
+  rsa.errordata
+  ssl.errordata
+  x509.errordata
+  x509v3.errordata
+  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+)
+
 add_library(
   err
 
   OBJECT
 
   err.c
+  err_data.c
   err_impl.c
 )
 

crypto/err/err.c

@@ -126,6 +126,14 @@
 #include <openssl/thread.h>
 
 
+extern const uint32_t kOpenSSLFunctionValues[];
+extern const size_t kOpenSSLFunctionValuesLen;
+extern const char kOpenSSLFunctionStringData[];
+
+extern const uint32_t kOpenSSLReasonValues[];
+extern const size_t kOpenSSLReasonValuesLen;
+extern const char kOpenSSLReasonStringData[];
+
 /* err_fns contains a pointer to the current error implementation. */
 static const struct ERR_FNS_st *err_fns = NULL;
 extern const struct ERR_FNS_st openssl_err_default_impl;
@@ -423,8 +431,6 @@ void ERR_error_string_n(uint32_t packed_error, char *buf, size_t len) {
   }
 }
 
-#include "err_data.h"
-
 // err_string_cmp is a compare function for searching error values with
 // |bsearch| in |err_string_lookup|.
 static int err_string_cmp(const void *a, const void *b) {
@@ -545,9 +551,9 @@ const char *ERR_func_error_string(uint32_t packed_error) {
   }
 
   return err_string_lookup(ERR_GET_LIB(packed_error),
-                           ERR_GET_FUNC(packed_error), kFunctionValues,
-                           sizeof(kFunctionValues) / sizeof(kFunctionValues[0]),
-                           kFunctionStringData);
+                           ERR_GET_FUNC(packed_error), kOpenSSLFunctionValues,
+                           kOpenSSLFunctionValuesLen,
+                           kOpenSSLFunctionStringData);
 }
 
 const char *ERR_reason_error_string(uint32_t packed_error) {
@@ -582,9 +588,8 @@ const char *ERR_reason_error_string(uint32_t packed_error) {
     }
   }
 
-  return err_string_lookup(lib, reason, kReasonValues,
-                           sizeof(kReasonValues) / sizeof(kReasonValues[0]),
-                           kReasonStringData);
+  return err_string_lookup(lib, reason, kOpenSSLReasonValues,
+                           kOpenSSLReasonValuesLen, kOpenSSLReasonStringData);
 }
 
 void ERR_print_errors_cb(ERR_print_errors_callback_t callback, void *ctx) {

crypto/err/err_data_generate.go

@@ -140,13 +140,16 @@ func (st *stringList) WriteTo(out stringWriter, name string) {
 	list := st.buildList()
 	fmt.Fprintf(os.Stderr, "%s: %d bytes of list and %d bytes of string data.\n", name, 4*len(list), len(st.stringData))
 
-	out.WriteString("static const uint32_t k" + name + "Values[] = {\n")
+	values := "kOpenSSL" + name + "Values"
+	out.WriteString("const uint32_t " + values + "[] = {\n")
 	for _, v := range list {
 		fmt.Fprintf(out, "    0x%x,\n", v)
 	}
 	out.WriteString("};\n\n")
+	out.WriteString("const size_t " + values + "Len = sizeof(" + values + ") / sizeof(" + values + "[0]);\n\n");
 
-	out.WriteString("static const char k" + name + "StringData[] =\n    \"")
+	stringData := "kOpenSSL" + name + "StringData"
+	out.WriteString("const char " + stringData + "[] =\n    \"")
 	for i, c := range st.stringData {
 		if c == 0 {
 			out.WriteString("\\0\"\n    \"")
@@ -267,6 +270,7 @@ func main() {
  /* This file was generated by err_data_generate.go. */
 
 #include <openssl/base.h>
+#include <openssl/err.h>
 #include <openssl/type_check.h>
 
 

util/make_errors.go

@@ -21,7 +21,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"sort"
 	"strconv"
@@ -132,25 +131,6 @@ func makeErrors(reset bool) error {
 	outputStrings(dataFile, lib, typeReasons, reasons)
 	dataFile.Close()
 
-	generateCmd := exec.Command("go", "run", "err_data_generate.go")
-	generateCmd.Dir = errDir
-
-	errDataH, err := os.OpenFile(filepath.Join(errDir, "err_data.h"), os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
-	if err != nil {
-		return err
-	}
-	defer errDataH.Close()
-
-	generateCmd.Stdout = errDataH
-	generateCmd.Stderr = os.Stderr
-
-	if err := generateCmd.Start(); err != nil {
-		return err
-	}
-	if err := generateCmd.Wait(); err != nil {
-		return err
-	}
-
 	return nil
 }