Fix various XCode and PVS-Studio static analyzer warnings (#2309)

imgui.cpp

@@ -4039,7 +4039,8 @@ int ImGui::CalcTypematicPressedRepeatAmount(float t, float t_prev, float repeat_
 int ImGui::GetKeyPressedAmount(int key_index, float repeat_delay, float repeat_rate)
 {
     ImGuiContext& g = *GImGui;
-    if (key_index < 0) return false;
+    if (key_index < 0) 
+        return 0;
     IM_ASSERT(key_index >= 0 && key_index < IM_ARRAYSIZE(g.IO.KeysDown));
     const float t = g.IO.KeysDownDuration[key_index];
     return CalcTypematicPressedRepeatAmount(t, t - g.IO.DeltaTime, repeat_delay, repeat_rate);
@@ -4048,7 +4049,8 @@ int ImGui::GetKeyPressedAmount(int key_index, float repeat_delay, float repeat_r
 bool ImGui::IsKeyPressed(int user_key_index, bool repeat)
 {
     ImGuiContext& g = *GImGui;
-    if (user_key_index < 0) return false;
+    if (user_key_index < 0) 
+        return false;
     IM_ASSERT(user_key_index >= 0 && user_key_index < IM_ARRAYSIZE(g.IO.KeysDown));
     const float t = g.IO.KeysDownDuration[user_key_index];
     if (t == 0.0f)
@@ -4139,13 +4141,12 @@ ImVec2 ImGui::GetMousePosOnOpeningCurrentPopup()
     return g.IO.MousePos;
 }
 
-// We typically use ImVec2(-FLT_MAX,-FLT_MAX) to denote an invalid mouse position
+// We typically use ImVec2(-FLT_MAX,-FLT_MAX) to denote an invalid mouse position.
 bool ImGui::IsMousePosValid(const ImVec2* mouse_pos)
 {
-    if (mouse_pos == NULL)
-        mouse_pos = &GImGui->IO.MousePos;
     const float MOUSE_INVALID = -256000.0f;
-    return mouse_pos->x >= MOUSE_INVALID && mouse_pos->y >= MOUSE_INVALID;
+    ImVec2 p = mouse_pos ? *mouse_pos : GImGui->IO.MousePos;
+    return p.x >= MOUSE_INVALID && p.y >= MOUSE_INVALID;
 }
 
 // Return the delta from the initial clicking position.
@@ -4819,7 +4820,10 @@ void ImGui::UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags
     if (parent_window && !(flags & ImGuiWindowFlags_Modal) && (flags & (ImGuiWindowFlags_ChildWindow | ImGuiWindowFlags_Popup)))
         window->RootWindowForTitleBarHighlight = parent_window->RootWindowForTitleBarHighlight;
     while (window->RootWindowForNav->Flags & ImGuiWindowFlags_NavFlattened)
+    {
+        IM_ASSERT(window->RootWindowForNav->ParentWindow != NULL);
         window->RootWindowForNav = window->RootWindowForNav->ParentWindow;
+    }
 }
 
 // Push a new ImGui window to add widgets to.
@@ -5082,7 +5086,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // Position child window
         if (flags & ImGuiWindowFlags_ChildWindow)
         {
-            IM_ASSERT(parent_window->Active);
+            IM_ASSERT(parent_window && parent_window->Active);
             window->BeginOrderWithinParent = (short)parent_window->DC.ChildWindows.Size;
             parent_window->DC.ChildWindows.push_back(window);
             if (!(flags & ImGuiWindowFlags_Popup) && !window_pos_set_by_api && !window_is_child_tooltip)
@@ -9283,7 +9287,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                         {
                             ImDrawVert& v = draw_list->VtxBuffer[idx_buffer ? idx_buffer[vtx_i] : vtx_i];
                             triangles_pos[n] = v.pos;
-                            buf_p += ImFormatString(buf_p, (int)(buf_end - buf_p), "%s %04d: pos (%8.2f,%8.2f), uv (%.6f,%.6f), col %08X\n", (n == 0) ? "vtx" : "   ", vtx_i, v.pos.x, v.pos.y, v.uv.x, v.uv.y, v.col);
+                            buf_p += ImFormatString(buf_p, buf_end - buf_p, "%s %04d: pos (%8.2f,%8.2f), uv (%.6f,%.6f), col %08X\n", (n == 0) ? "vtx" : "   ", vtx_i, v.pos.x, v.pos.y, v.uv.x, v.uv.y, v.col);
                         }
                         ImGui::Selectable(buf, false);
                         if (ImGui::IsItemHovered())
@@ -9352,12 +9356,11 @@ void ImGui::ShowMetricsWindow(bool* p_open)
 
         static void NodeTabBar(ImGuiTabBar* tab_bar)
         {
-            // Standalone tab bars (not associated to docking/windows functionality) currently hold no discernable strings.
+            // Standalone tab bars (not associated to docking/windows functionality) currently hold no discernible strings.
             char buf[256];
             char* p = buf;
             const char* buf_end = buf + IM_ARRAYSIZE(buf);
-            p += ImFormatString(p, buf_end - p, "TabBar (%d tabs)%s",
-                tab_bar->Tabs.Size, (tab_bar->PrevFrameVisible < ImGui::GetFrameCount() - 2) ? " *Inactive*" : "");
+            ImFormatString(p, buf_end - p, "TabBar (%d tabs)%s", tab_bar->Tabs.Size, (tab_bar->PrevFrameVisible < ImGui::GetFrameCount() - 2) ? " *Inactive*" : "");
             if (ImGui::TreeNode(tab_bar, "%s", buf))
             {
                 for (int tab_n = 0; tab_n < tab_bar->Tabs.Size; tab_n++)

imgui.h

@@ -1945,7 +1945,7 @@ struct ImFontGlyphRangesBuilder
 {
     ImVector<int> UsedChars;            // Store 1-bit per Unicode code point (0=unused, 1=used)
 
-    ImFontGlyphRangesBuilder()          { UsedChars.resize(0x10000 / 32); memset(UsedChars.Data, 0, 0x10000 / 32); }
+    ImFontGlyphRangesBuilder()          { UsedChars.resize(0x10000 / sizeof(int)); memset(UsedChars.Data, 0, 0x10000 / sizeof(int)); }
     bool           GetBit(int n) const  { int off = (n >> 5); int mask = 1 << (n & 31); return (UsedChars[off] & mask) != 0; } // Get bit n in the array
     void           SetBit(int n)        { int off = (n >> 5); int mask = 1 << (n & 31); UsedChars[off] |= mask; }              // Set bit n in the array
     void           AddChar(ImWchar c)   { SetBit(c); }                          // Add character

imgui_demo.cpp

@@ -879,12 +879,13 @@ static void ShowDemoWindowWidgets()
                 ImGui::PushID(i);
                 if (ImGui::Selectable("Sailor", &selected[i], 0, ImVec2(50,50)))
                 {
+                    // Note: We _unnecessarily_ test for both x/y and i here only to silence some static analyzer. The second part of each test is unnecessary.
                     int x = i % 4;
                     int y = i / 4;
-                    if (x > 0) { selected[i - 1] ^= 1; }
-                    if (x < 3) { selected[i + 1] ^= 1; }
-                    if (y > 0) { selected[i - 4] ^= 1; }
-                    if (y < 3) { selected[i + 4] ^= 1; }
+                    if (x > 0 && i > 0)  { selected[i - 1] ^= 1; }
+                    if (x < 3 && i < 15) { selected[i + 1] ^= 1; }
+                    if (y > 0 && i > 3)  { selected[i - 4] ^= 1; }
+                    if (y < 3 && i < 12) { selected[i + 4] ^= 1; }
                 }
                 if ((i % 4) < 3) ImGui::SameLine();
                 ImGui::PopID();
@@ -3093,7 +3094,7 @@ struct ExampleAppConsole
     // Portable helpers
     static int   Stricmp(const char* str1, const char* str2)         { int d; while ((d = toupper(*str2) - toupper(*str1)) == 0 && *str1) { str1++; str2++; } return d; }
     static int   Strnicmp(const char* str1, const char* str2, int n) { int d = 0; while (n > 0 && (d = toupper(*str2) - toupper(*str1)) == 0 && *str1) { str1++; str2++; n--; } return d; }
-    static char* Strdup(const char *str)                             { size_t len = strlen(str) + 1; void* buff = malloc(len); return (char*)memcpy(buff, (const void*)str, len); }
+    static char* Strdup(const char *str)                             { size_t len = strlen(str) + 1; void* buf = malloc(len); IM_ASSERT(buf); return (char*)memcpy(buf, (const void*)str, len); }
     static void  Strtrim(char* str)                                  { char* str_end = str + strlen(str); while (str_end > str && str_end[-1] == ' ') str_end--; *str_end = 0; }
 
     void    ClearLog()

imgui_draw.cpp

@@ -2063,6 +2063,7 @@ void ImFontAtlasBuildSetupFont(ImFontAtlas* atlas, ImFont* font, ImFontConfig* f
 void ImFontAtlasBuildPackCustomRects(ImFontAtlas* atlas, void* stbrp_context_opaque)
 {
     stbrp_context* pack_context = (stbrp_context*)stbrp_context_opaque;
+    IM_ASSERT(pack_context != NULL);
 
     ImVector<ImFontAtlas::CustomRect>& user_rects = atlas->CustomRects;
     IM_ASSERT(user_rects.Size >= 1); // We expect at least the default custom rects to be registered, else something went wrong.

imgui_internal.h

@@ -183,7 +183,7 @@ IMGUI_API int           ImFormatString(char* buf, size_t buf_size, const char* f
 IMGUI_API int           ImFormatStringV(char* buf, size_t buf_size, const char* fmt, va_list args) IM_FMTLIST(3);
 IMGUI_API const char*   ImParseFormatFindStart(const char* format);
 IMGUI_API const char*   ImParseFormatFindEnd(const char* format);
-IMGUI_API const char*   ImParseFormatTrimDecorations(const char* format, char* buf, int buf_size);
+IMGUI_API const char*   ImParseFormatTrimDecorations(const char* format, char* buf, size_t buf_size);
 IMGUI_API int           ImParseFormatPrecision(const char* format, int default_value);
 
 // Helpers: ImVec2/ImVec4 operators

imgui_widgets.cpp

@@ -2577,7 +2577,7 @@ const char* ImParseFormatFindEnd(const char* fmt)
 //  fmt = "%.3f"       -> return fmt
 //  fmt = "hello %.3f" -> return fmt + 6
 //  fmt = "%.3f hello" -> return buf written with "%.3f"
-const char* ImParseFormatTrimDecorations(const char* fmt, char* buf, int buf_size)
+const char* ImParseFormatTrimDecorations(const char* fmt, char* buf, size_t buf_size)
 {
     const char* fmt_start = ImParseFormatFindStart(fmt);
     if (fmt_start[0] != '%')
@@ -2585,7 +2585,7 @@ const char* ImParseFormatTrimDecorations(const char* fmt, char* buf, int buf_siz
     const char* fmt_end = ImParseFormatFindEnd(fmt_start);
     if (fmt_end[0] == 0) // If we only have leading decoration, we don't need to copy the data.
         return fmt_start;
-    ImStrncpy(buf, fmt_start, ImMin((int)(fmt_end + 1 - fmt_start), buf_size));
+    ImStrncpy(buf, fmt_start, ImMin((size_t)(fmt_end - fmt_start) + 1, buf_size));
     return buf;
 }
 
@@ -6427,7 +6427,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
     // Render tab label, process close button
     const ImGuiID close_button_id = p_open ? window->GetID((void*)((intptr_t)id + 1)) : 0;
     bool just_closed = TabItemLabelAndCloseButton(display_draw_list, bb, flags, label, id, close_button_id);
-    if (just_closed)
+    if (just_closed && p_open != NULL)
     {
         *p_open = false;
         TabBarCloseTab(tab_bar, tab);

imstb_textedit.h

@@ -563,7 +563,6 @@ static void stb_textedit_find_charpos(StbFindState *find, STB_TEXTEDIT_STRING *s
 
    // now scan to find xpos
    find->x = r.x0;
-   i = 0;
    for (i=0; first+i < n; ++i)
       find->x += STB_TEXTEDIT_GETWIDTH(str, first, i);
 }

imstb_truetype.h

@@ -1,3 +1,6 @@
+// [ImGui] this is a slightly modified version of stb_truetype.h 1.19. Those changes would need to be pushed into nothings/stb
+// grep for [ImGui] to find the changes.
+
 // stb_truetype.h - v1.19 - public domain
 // authored from 2009-2016 by Sean Barrett / RAD Game Tools
 //
@@ -2368,7 +2371,8 @@ static stbtt_int32  stbtt__GetGlyphClass(stbtt_uint8 *classDefTable, int glyph)
             if (glyph >= startGlyphID && glyph < startGlyphID + glyphCount)
                 return (stbtt_int32)ttUSHORT(classDef1ValueArray + 2 * (glyph - startGlyphID));
 
-            classDefTable = classDef1ValueArray + 2 * glyphCount;
+            // [ImGui: commented to fix static analyzer warning]
+            //classDefTable = classDef1ValueArray + 2 * glyphCount;
         } break;
 
         case 2: {
@@ -2392,7 +2396,8 @@ static stbtt_int32  stbtt__GetGlyphClass(stbtt_uint8 *classDefTable, int glyph)
                     return (stbtt_int32)ttUSHORT(classRangeRecord + 4);
             }
 
-            classDefTable = classRangeRecords + 6 * classRangeCount;
+            // [ImGui: commented to fix static analyzer warning]
+            //classDefTable = classRangeRecords + 6 * classRangeCount;
         } break;
 
         default: {
@@ -3024,6 +3029,7 @@ static void stbtt__fill_active_edges_new(float *scanline, float *scanline_fill,
                   dx = -dx;
                   dy = -dy;
                   t = x0, x0 = xb, xb = t;
+                  (void)dx; // [ImGui: fix static analyzer warning]
                }
 
                x1 = (int) x_top;
@@ -4253,7 +4259,7 @@ static int stbtt__compute_crossings_x(float x, float y, int nverts, stbtt_vertex
    int winding = 0;
 
    orig[0] = x;
-   orig[1] = y;
+   //orig[1] = y; // [ImGui] commmented double assignment without reading
 
    // make sure y never passes through a vertex of the shape
    y_frac = (float) STBTT_fmod(y, 1.0f);