TypeInfo_Struct: Switch to stored mangled name & demangle lazily (with per-thread cache)

.cirrus.yml

@@ -1,13 +1,31 @@
 common_steps_template: &COMMON_STEPS_TEMPLATE
+  set_repo_branch_env_var_script: |
+    set -uexo pipefail
+    if [ -z ${CIRRUS_PR+x} ]; then
+      # not a PR
+      REPO_BRANCH="$CIRRUS_BRANCH"
+    elif [[ ! "$CIRRUS_BRANCH" =~ ^pull/ ]]; then
+      # PR originating from the official dlang repo
+      REPO_BRANCH="$CIRRUS_BRANCH"
+    else
+      # PR from a fork
+      REPO_BRANCH="$CIRRUS_BASE_BRANCH"
+    fi
+    echo "REPO_BRANCH=$REPO_BRANCH" >> $CIRRUS_ENV
   clone_dmd_script: |
     set -uexo pipefail
-    git clone --branch "${CIRRUS_BASE_BRANCH:-$CIRRUS_BRANCH}" --depth 1 https://github.com/dlang/dmd.git ../dmd
+    DMD_BRANCH="$REPO_BRANCH"
+    if [ "$DMD_BRANCH" != master ] && [ "$DMD_BRANCH" != stable ] &&
+       ! git ls-remote --exit-code --heads "https://github.com/dlang/dmd.git" "$DMD_BRANCH" > /dev/null; then
+      DMD_BRANCH="master"
+    fi
+    git clone --branch "$DMD_BRANCH" --depth 1 https://github.com/dlang/dmd.git ../dmd
   install_prerequisites_script: cd ../dmd && ./cirrusci.sh
   install_host_compiler_script: cd ../dmd && ./ci.sh install_host_compiler
   setup_repos_script: |
     set -uexo pipefail
     ln -s $CIRRUS_WORKING_DIR ../druntime
-    cd ../dmd && ./ci.sh setup_repos "${CIRRUS_BASE_BRANCH:-$CIRRUS_BRANCH}"
+    cd ../dmd && ./ci.sh setup_repos "$REPO_BRANCH"
   build_script: cd ../dmd && ./ci.sh build
   test_dmd_script: cd ../dmd && ./ci.sh test_dmd
   test_druntime_script: cd ../dmd && ./ci.sh test_druntime

azure-pipelines.yml

@@ -1,7 +1,6 @@
 # Learn more: https://aka.ms/yaml
 
 variables:
-  DMD_BRANCH: $[ coalesce(variables['System.PullRequest.TargetBranch'], variables['Build.SourceBranchName'], 'master') ]
   VSINSTALLDIR: C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\
 
 jobs:
@@ -34,7 +33,23 @@ jobs:
           sourceFolder: '$(Build.SourcesDirectory)'
           contents: '**/*'
           TargetFolder: '$(Build.SourcesDirectory)/../druntime'
-      - script: git clone --branch $(DMD_BRANCH) --depth 1 https://github.com/dlang/dmd.git ../dmd
+      - bash: |
+          set -ex
+          if [ -z ${SYSTEM_PULLREQUEST_TARGETBRANCH+x} ]; then
+              # no PR
+              DMD_BRANCH="$BUILD_SOURCEBRANCHNAME"
+          elif [ $SYSTEM_PULLREQUEST_ISFORK == False ]; then
+              # PR originating from the official dlang repo
+              DMD_BRANCH="$SYSTEM_PULLREQUEST_SOURCEBRANCH"
+          else
+              # PR from a fork
+              DMD_BRANCH="$SYSTEM_PULLREQUEST_TARGETBRANCH"
+          fi
+          if [ "$DMD_BRANCH" != master ] && [ "$DMD_BRANCH" != stable ] &&
+             ! git ls-remote --exit-code --heads "https://github.com/dlang/dmd.git" "$DMD_BRANCH" > /dev/null; then
+            DMD_BRANCH="master"
+          fi
+          git clone --branch "$DMD_BRANCH" --depth 1 https://github.com/dlang/dmd.git ../dmd
         displayName: Clone DMD repo
       - script: |
           call "%VSINSTALLDIR%\VC\Auxiliary\Build\vcvarsall.bat" %ARCH%
@@ -72,7 +87,23 @@ jobs:
           sourceFolder: '$(Build.SourcesDirectory)'
           contents: '**/*'
           TargetFolder: '$(Build.SourcesDirectory)/../druntime'
-      - script: git clone --branch $(DMD_BRANCH) --depth 1 https://github.com/dlang/dmd.git ../dmd
+      - bash: |
+          set -ex
+          if [ -z ${SYSTEM_PULLREQUEST_TARGETBRANCH+x} ]; then
+              # no PR
+              DMD_BRANCH="$BUILD_SOURCEBRANCHNAME"
+          elif [ $SYSTEM_PULLREQUEST_ISFORK == False ]; then
+              # PR originating from the official dlang repo
+              DMD_BRANCH="$SYSTEM_PULLREQUEST_SOURCEBRANCH"
+          else
+              # PR from a fork
+              DMD_BRANCH="$SYSTEM_PULLREQUEST_TARGETBRANCH"
+          fi
+          if [ "$DMD_BRANCH" != master ] && [ "$DMD_BRANCH" != stable ] &&
+             ! git ls-remote --exit-code --heads "https://github.com/dlang/dmd.git" "$DMD_BRANCH" > /dev/null; then
+            DMD_BRANCH="master"
+          fi
+          git clone --branch "$DMD_BRANCH" --depth 1 https://github.com/dlang/dmd.git ../dmd
         displayName: Clone DMD repo
       - script: cd ../dmd && sh --login .azure-pipelines/windows-visual-studio.sh
         displayName: Download required binaries

changelog/UniqueTypeInfoNames.md

@@ -0,0 +1,14 @@
+TypeInfo names for aggregates are fully qualified and hence unique now
+
+Previously, template arguments weren't fully qualified; they now are,
+implying longer names in that case.
+
+`TypeInfo_Struct` instances now store the (potentially significantly shorter)
+mangled name only and demangle it lazily on the first `name` or `toString()`
+call (with a per-thread cache). So if you only need a unique string per
+struct TypeInfo, prefer `mangledName` over computed `name` (non-`@nogc` and
+non-`pure`).
+
+**Related breaking change**: `TypeInfo.toString()` isn't `pure` anymore to
+account for the `TypeInfo_Struct` demangled name cache.
+`TypeInfo_Class.toString()` and others are still `pure`.

src/core/internal/gc/impl/conservative/gc.d

@@ -4058,7 +4058,7 @@ string debugTypeName(const(TypeInfo) ti) nothrow
     else if (auto ci = cast(TypeInfo_Class)ti)
         name = ci.name;
     else if (auto si = cast(TypeInfo_Struct)ti)
-        name = si.name;
+        name = si.mangledName; // .name() might GC-allocate, avoid deadlock
     else if (auto ci = cast(TypeInfo_Const)ti)
         static if (__traits(compiles,ci.base)) // different whether compiled with object.di or object.d
             return debugTypeName(ci.base);

src/object.d

@@ -418,7 +418,7 @@ struct OffsetTypeInfo
  */
 class TypeInfo
 {
-    override string toString() const pure @safe nothrow
+    override string toString() const @safe nothrow
     {
         return typeid(this).name;
     }
@@ -665,7 +665,7 @@ class TypeInfo
 
 class TypeInfo_Enum : TypeInfo
 {
-    override string toString() const { return name; }
+    override string toString() const pure { return name; }
 
     override bool opEquals(Object o)
     {
@@ -977,7 +977,9 @@ class TypeInfo_StaticArray : TypeInfo
         import core.internal.string : unsignedToTempString;
 
         char[20] tmpBuff = void;
-        return value.toString() ~ "[" ~ unsignedToTempString(len, tmpBuff) ~ "]";
+        const lenString = unsignedToTempString(len, tmpBuff);
+
+        return (() @trusted => cast(string) (value.toString() ~ "[" ~ lenString ~ "]"))();
     }
 
     override bool opEquals(Object o)
@@ -1202,7 +1204,7 @@ class TypeInfo_Vector : TypeInfo
 
 class TypeInfo_Function : TypeInfo
 {
-    override string toString() const @trusted
+    override string toString() const pure @trusted
     {
         import core.demangle : demangleType;
 
@@ -1279,7 +1281,7 @@ class TypeInfo_Function : TypeInfo
 
 class TypeInfo_Delegate : TypeInfo
 {
-    override string toString() const @trusted
+    override string toString() const pure @trusted
     {
         import core.demangle : demangleType;
 
@@ -1399,7 +1401,7 @@ private extern (C) int _d_isbaseof(scope TypeInfo_Class child,
  */
 class TypeInfo_Class : TypeInfo
 {
-    override string toString() const { return info.name; }
+    override string toString() const pure { return info.name; }
 
     override bool opEquals(Object o)
     {
@@ -1584,7 +1586,7 @@ alias ClassInfo = TypeInfo_Class;
 
 class TypeInfo_Interface : TypeInfo
 {
-    override string toString() const { return info.name; }
+    override string toString() const pure { return info.name; }
 
     override bool opEquals(Object o)
     {
@@ -1703,13 +1705,17 @@ class TypeInfo_Struct : TypeInfo
 {
     override string toString() const { return name; }
 
+    override size_t toHash() const
+    {
+        return hashOf(this.mangledName);
+    }
+
     override bool opEquals(Object o)
     {
         if (this is o)
             return true;
         auto s = cast(const TypeInfo_Struct)o;
-        return s && this.name == s.name &&
-                    this.initializer().length == s.initializer().length;
+        return s && this.mangledName == s.mangledName;
     }
 
     override size_t getHash(scope const void* p) @trusted pure nothrow const
@@ -1794,7 +1800,29 @@ class TypeInfo_Struct : TypeInfo
             (*xpostblit)(p);
     }
 
-    string name;
+    string mangledName;
+
+    final @property string name() nothrow const @trusted
+    {
+        import core.demangle : demangleType;
+
+        if (mangledName is null) // e.g., opaque structs
+            return null;
+
+        const key = cast(const void*) this; // faster lookup than TypeInfo_Struct, at the cost of potential duplicates per binary
+        static string[typeof(key)] demangledNamesCache; // per thread
+
+        // not nothrow:
+        //return demangledNamesCache.require(key, cast(string) demangleType(mangledName));
+
+        if (auto pDemangled = key in demangledNamesCache)
+            return *pDemangled;
+
+        const demangled = cast(string) demangleType(mangledName);
+        demangledNamesCache[key] = demangled;
+        return demangled;
+    }
+
     void[] m_init;      // initializer; m_init.ptr == null if 0 initialize
 
     @safe pure nothrow

src/rt/aaA.d

@@ -294,8 +294,8 @@ TypeInfo_Struct fakeEntryTI(ref Impl aa, const TypeInfo keyti, const TypeInfo va
     extra[0] = cast() kti;
     extra[1] = cast() vti;
 
-    static immutable tiName = __MODULE__ ~ ".Entry!(...)";
-    ti.name = tiName;
+    static immutable tiMangledName = "S2rt3aaA__T5EntryZ";
+    ti.mangledName = tiMangledName;
 
     ti.m_RTInfo = rtisize > 0 ? rtinfoEntry(aa, keyinfo, valinfo, cast(size_t*)(extra + 2), rtisize) : rtinfo;
     ti.m_flags = ti.m_RTInfo is rtinfoNoPointers ? cast(TypeInfo_Struct.StructFlags)0 : TypeInfo_Struct.StructFlags.hasPointers;

src/rt/util/typeinfo.d

@@ -464,12 +464,12 @@ class TypeInfo_v : TypeInfoGeneric!ubyte
     {
         return 1;
     }
+}
 
-    unittest
-    {
-        assert(typeid(void).toString == "void");
-        assert(typeid(void).flags == 1);
-    }
+unittest
+{
+    assert(typeid(void).toString == "void");
+    assert(typeid(void).flags == 1);
 }
 
 // All integrals.