Config file: Treat section names as target triple regexps (#2718)

appveyor.yml

@@ -232,7 +232,7 @@ after_test:
             ren lib lib32
             (cat etc\ldc2.conf).replace('%%ldcbinarypath%%/../lib', '%%ldcbinarypath%%/../lib64') | Set-Content etc\ldc2.conf
             $conf32 = cat ..\ldc2-x86\etc\ldc2.conf -Raw
-            $conf32 = "`r`ni686-pc-windows-msvc:" + $conf32.Substring($conf32.IndexOf("`r`ndefault:") + 10)
+            $conf32 = "`r`n""i[3-6]86-.*-windows-msvc"":" + $conf32.Substring($conf32.IndexOf("`r`ndefault:") + 10)
             $conf32 = $conf32.Replace('%%ldcbinarypath%%/../lib', '%%ldcbinarypath%%/../lib32')
             Add-Content etc\ldc2.conf $conf32
             cd ..

driver/config.d

@@ -136,7 +136,7 @@ EBNF grammar.
 It is a subset of the libconfig grammar (http://www.hyperrealm.com/libconfig).
 
 config  =   { ows , setting } , ows ;
-setting =   name , (":" | "=") , value , [";" | ","] ;
+setting =   (name | string) , (":" | "=") , value , [";" | ","] ;
 name    =   alpha , { alpha | digit | "_" | "-" } ;
 value   =   string | array | group ;
 array   =   "[" , ows ,
@@ -445,14 +445,20 @@ struct Parser
 
     Setting parseSetting()
     {
-        immutable name = accept(Token.name);
+        string name;
+        auto t = getTok(name);
+        if (t != Token.name && t != Token.str)
+        {
+            unexpectedTokenError(t, Token.name, name);
+            assert(false);
+        }
 
         accept(Token.assign);
 
         Setting res = parseValue(name);
 
         string s;
-        immutable t = getTok(s);
+        t = getTok(s);
         if (t != Token.semicolon && t != Token.comma)
         {
             ungetTok(t, s);
@@ -567,25 +573,25 @@ unittest
 `// comment
 
 // comment
-group-1: {};
+group-1_2: {};
 // comment
-Group-2:
+"86(_64)?-.*linux\\.?":
 {
     // comment
     scalar = "abc";
     // comment
-    Array_1 = [ "a" ];
+    Array_1-2 = [ "a" ];
 };
 `;
 
     auto settings = Parser(input).parseConfig();
     assert(settings.length == 2);
 
-    assert(settings[0].name == "group-1");
+    assert(settings[0].name == "group-1_2");
     assert(settings[0].type == Setting.Type.group);
     assert((cast(GroupSetting) settings[0]).children == []);
 
-    assert(settings[1].name == "Group-2");
+    assert(settings[1].name == "86(_64)?-.*linux\\.?");
     assert(settings[1].type == Setting.Type.group);
     auto group2 = cast(GroupSetting) settings[1];
     assert(group2.children.length == 2);
@@ -594,7 +600,7 @@ Group-2:
     assert(group2.children[0].type == Setting.Type.scalar);
     assert((cast(ScalarSetting) group2.children[0]).val == "abc");
 
-    assert(group2.children[1].name == "Array_1");
+    assert(group2.children[1].name == "Array_1-2");
     assert(group2.children[1].type == Setting.Type.array);
     assert((cast(ArraySetting) group2.children[1]).vals == [ "a" ]);
 }

driver/configfile.cpp

@@ -13,6 +13,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/Regex.h"
 #include <cassert>
 #include <cstring>
 #include <iostream>
@@ -172,7 +173,7 @@ bool ConfigFile::locate(std::string &pathstr) {
   return false;
 }
 
-bool ConfigFile::read(const char *explicitConfFile, const char *section) {
+bool ConfigFile::read(const char *explicitConfFile, const char *triple) {
   std::string pathstr;
   // explicitly provided by user in command line?
   if (explicitConfFile) {
@@ -201,7 +202,7 @@ bool ConfigFile::read(const char *explicitConfFile, const char *section) {
   pathcstr = strdup(pathstr.c_str());
   auto binpath = exe_path::getBinDir();
 
-  return readConfig(pathcstr, section, binpath.c_str());
+  return readConfig(pathcstr, triple, binpath.c_str());
 }
 
 void ConfigFile::extendCommandLine(llvm::SmallVectorImpl<const char *> &args) {
@@ -219,3 +220,7 @@ void ConfigFile::extendCommandLine(llvm::SmallVectorImpl<const char *> &args) {
   args.insert(runIndex == 0 ? args.end() : args.begin() + runIndex,
               postSwitches.begin(), postSwitches.end());
 }
+
+bool ConfigFile::sectionMatches(const char *section, const char *triple) {
+  return llvm::Regex(section).match(triple);
+}

driver/configfile.d

@@ -29,27 +29,28 @@ string prepareBinDir(const(char)* binDir)
     return cast(string)res; // assumeUnique
 }
 
-
-ArraySetting findArraySetting(GroupSetting section, string name)
+T findSetting(T)(GroupSetting[] sections, Setting.Type type, string name)
+{
+    // lexically later sections dominate earlier ones
+    foreach_reverse (section; sections)
     {
-    if (!section) return null;
         foreach (c; section.children)
         {
-        if (c.type == Setting.Type.array && c.name == name)
-            return cast(ArraySetting) c;
+            if (c.type == type && c.name == name)
+                return cast(T) c;
+        }
     }
     return null;
 }
 
-ScalarSetting findScalarSetting(GroupSetting section, string name)
+ArraySetting findArraySetting(GroupSetting[] sections, string name)
 {
-    if (!section) return null;
-    foreach (c; section.children)
-    {
-        if (c.type == Setting.Type.scalar && c.name == name)
-            return cast(ScalarSetting) c;
+    return findSetting!ArraySetting(sections, Setting.Type.array, name);
 }
-    return null;
+
+ScalarSetting findScalarSetting(GroupSetting[] sections, string name)
+{
+    return findSetting!ScalarSetting(sections, Setting.Type.scalar, name);
 }
 
 string replace(string str, string pattern, string replacement)
@@ -107,47 +108,37 @@ private:
     Array!(const(char)*) postSwitches;
     const(char)* rpathcstr;
 
-    bool readConfig(const(char)* cfPath, const(char)* sectionName, const(char)* binDir)
+    static bool sectionMatches(const(char)* section, const(char)* triple);
+
+    bool readConfig(const(char)* cfPath, const(char)* triple, const(char)* binDir)
     {
         switches.setDim(0);
         postSwitches.setDim(0);
 
         immutable dBinDir = prepareBinDir(binDir);
-        const dSec = sectionName[0 .. strlen(sectionName)];
 
         try
         {
-            GroupSetting section, defaultSection;
+            GroupSetting[] sections; // in lexical order
             foreach (s; parseConfigFile(cfPath))
             {
-                if (s.type != Setting.Type.group)
-                    continue;
-                if (s.name == dSec)
-                    section = cast(GroupSetting) s;
-                else if (s.name == "default")
-                    defaultSection = cast(GroupSetting) s;
+                if (s.type == Setting.Type.group &&
+                    (s.name == "default" || sectionMatches((s.name ~ '\0').ptr, triple)))
+                {
+                    sections ~= cast(GroupSetting) s;
+                }
             }
 
-            if (!section && !defaultSection)
+            if (sections.length == 0)
             {
+                const dTriple = triple[0 .. strlen(triple)];
                 const dCfPath = cfPath[0 .. strlen(cfPath)];
-                if (sectionName)
-                    throw new Exception("Could not look up section '" ~ cast(string) dSec
-                                        ~ "' nor the 'default' section in " ~ cast(string) dCfPath);
-                else
-                    throw new Exception("Could not look up 'default' section in " ~ cast(string) dCfPath);
+                throw new Exception("No matching section for triple '" ~ cast(string) dTriple
+                                    ~ "' in " ~ cast(string) dCfPath);
             }
 
-            ArraySetting findArray(string name)
-            {
-                auto r = findArraySetting(section, name);
-                if (!r)
-                    r = findArraySetting(defaultSection, name);
-                return r;
-            }
-
-            auto switches = findArray("switches");
-            auto postSwitches = findArray("post-switches");
+            auto switches = findArraySetting(sections, "switches");
+            auto postSwitches = findArraySetting(sections, "post-switches");
             if (!switches && !postSwitches)
             {
                 const dCfPath = cfPath[0 .. strlen(cfPath)];
@@ -170,16 +161,7 @@ private:
             applyArray(this.switches, switches);
             applyArray(this.postSwitches, postSwitches);
 
-            ScalarSetting findScalar(string name)
-            {
-                auto r = findScalarSetting(section, name);
-                if (!r)
-                    r = findScalarSetting(defaultSection, name);
-                return r;
-            }
-
-            auto rpath = findScalar("rpath");
-            if (rpath)
+            if (auto rpath = findScalarSetting(sections, "rpath"))
                 this.rpathcstr = (rpath.val.replace("%%ldcbinarypath%%", dBinDir) ~ '\0').ptr;
 
             return true;
@@ -191,3 +173,10 @@ private:
         }
     }
 }
+
+unittest
+{
+    assert(ConfigFile.sectionMatches("i[3-6]86-.*-windows-msvc", "i686-pc-windows-msvc"));
+    assert(ConfigFile.sectionMatches("86(_64)?-.*-linux", "x86_64--linux-gnu"));
+    assert(!ConfigFile.sectionMatches("^linux", "x86_64--linux-gnu"));
+}

driver/configfile.h

@@ -24,7 +24,7 @@ class ConfigFile {
 public:
   static ConfigFile instance;
 
-  bool read(const char *explicitConfFile, const char *section);
+  bool read(const char *explicitConfFile, const char *triple);
 
   llvm::StringRef path() {
     return pathcstr ? llvm::StringRef(pathcstr) : llvm::StringRef();
@@ -38,9 +38,10 @@ public:
 
 private:
   bool locate(std::string &pathstr);
+  static bool sectionMatches(const char *section, const char *triple);
 
   // implemented in D
-  bool readConfig(const char *cfPath, const char *section, const char *binDir);
+  bool readConfig(const char *cfPath, const char *triple, const char *binDir);
 
   const char *pathcstr = nullptr;
   Array<const char *> switches;

ldc2.conf.in

@@ -1,7 +1,19 @@
 // See comments in driver/config.d in ldc source tree for grammar description of
 // this config file.
 
-// The default group is required
+// For cross-compilation, you can add sections for specific target triples by
+// naming the sections as (quoted) regex patterns. See LDC's `-v` output
+// (`config` line) to figure out your normalized triple, depending on the used
+// `-mtriple`, `-m32` etc. E.g.:
+//
+//     "^arm.*-linux-gnueabihf$": { … };
+//     "86(_64)?-.*-linux": { … };
+//     "i[3-6]86-.*-windows-msvc": { … };
+//
+// Later sections take precedence and override settings from previous matching
+// sections while inheriting unspecified settings from previous sections.
+// A `default` section always matches (treated as ".*") and is therefore usually
+// the first section.
 default:
 {
     // default switches injected before all explicit command-line switches

ldc2_install.conf.in

@@ -1,7 +1,19 @@
 // See comments in driver/config.d in ldc source tree for grammar description of
 // this config file.
 
-// The default group is required
+// For cross-compilation, you can add sections for specific target triples by
+// naming the sections as (quoted) regex patterns. See LDC's `-v` output
+// (`config` line) to figure out your normalized triple, depending on the used
+// `-mtriple`, `-m32` etc. E.g.:
+//
+//     "^arm.*-linux-gnueabihf$": { … };
+//     "86(_64)?-.*-linux": { … };
+//     "i[3-6]86-.*-windows-msvc": { … };
+//
+// Later sections take precedence and override settings from previous matching
+// sections while inheriting unspecified settings from previous sections.
+// A `default` section always matches (treated as ".*") and is therefore usually
+// the first section.
 default:
 {
     // default switches injected before all explicit command-line switches

ldc2_phobos.conf.in

@@ -1,7 +1,19 @@
 // See comments in driver/config.d in ldc source tree for grammar description of
 // this config file.
 
-// The default group is required
+// For cross-compilation, you can add sections for specific target triples by
+// naming the sections as (quoted) regex patterns. See LDC's `-v` output
+// (`config` line) to figure out your normalized triple, depending on the used
+// `-mtriple`, `-m32` etc. E.g.:
+//
+//     "^arm.*-linux-gnueabihf$": { … };
+//     "86(_64)?-.*-linux": { … };
+//     "i[3-6]86-.*-windows-msvc": { … };
+//
+// Later sections take precedence and override settings from previous matching
+// sections while inheriting unspecified settings from previous sections.
+// A `default` section always matches (treated as ".*") and is therefore usually
+// the first section.
 default:
 {
     // default switches injected before all explicit command-line switches

tests/driver/config_diag.d

@@ -2,7 +2,7 @@
 // NOSWITCHES: Could not look up switches in {{.*}}noswitches.conf
 
 // RUN: not %ldc -conf=%S/inputs/section_aaa.conf %s 2>&1 | FileCheck %s --check-prefix=NO_SEC
-// NO_SEC: Could not look up section '{{.*}}' nor the 'default' section in {{.*}}section_aaa.conf
+// NO_SEC: No matching section for triple '{{.*}}' in {{.*}}section_aaa.conf
 
 
 void foo()

tests/driver/inputs/override_default.conf

@@ -1,9 +1,9 @@
-x86-apple-windows-msvc:
-{
-    switches = [ "-version" ];
-};
-
 default:
 {
     switches = [ "" ];
 };
+
+x86-apple-windows-msvc:
+{
+    switches = [ "-version" ];
+};